Journal of Critical Care - Articles in Press

African American race, obesity, and blood product transfusion are risk factors for acute kidney injury in critically ill trauma patients - Corrected Proof

2012-05-17

Abstract: Purpose: Acute kidney injury (AKI) is a common source of morbidity after trauma. We sought to determine novel risk factors for AKI, by Acute Kidney Injury Network (AKIN) criteria, in critically ill trauma patients.Materials and Methods: A prospective cohort of 400 patients admitted to the intensive care unit of a level 1 trauma center was followed for the development of AKI over 5 days.Results: Acute kidney injury developed in 147 (36.8%) of 400 patients. In multivariable regression analysis, independent risk factors for AKI included African American race (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.08-3.18; P = .024), body mass index of 30 kg/m2 or greater (OR, 4.72 versus normal body mass index; 95% CI, 2.59-8.61; P < .001), diabetes mellitus (OR, 3.26; 95% CI, 1.30-8.20; P = .012), abdominal Abbreviated Injury Scale score of 4 or more (OR, 3.78; 95% CI, 1.79-7.96; P < .001), and unmatched packed red blood cells administered during resuscitation (OR, 1.13 per unit; 95% CI, 1.04-1.23; P = .004). Acute Kidney Injury Network stages 1, 2, and 3 were associated with hospital mortality rates of 9.8%, 13.7%, and 30.4%, respectively, compared with 3.8% for those without AKI (P < .001).Conclusions: Acute kidney injury in critically ill trauma patients is associated with substantial mortality. The findings of African American race, obesity, and blood product administration as independent risk factors for AKI deserve further study to elucidate underlying mechanisms.

Discordance between microcirculatory alterations and arterial pressure in patients with hemodynamic instability - Corrected Proof

2012-05-17

Abstract: Purpose: Recent studies reported that microcirculatory blood flow alterations occur in patients with circulatory shock independent of arterial pressure but typically lack baseline microcirculatory data before the insult and after recovery. We selected cardiopulmonary bypass (CPB) patients with expected and rapidly reversible hemodynamic instability to test the hypothesis that microcirculatory alterations can occur independent of mean arterial pressure (MAP).Methods: Prospective observational study using sidestream darkfield videomicroscopy to measure sublingual microcirculatory flow preoperative (PRE), postoperatively after CPB (POST), and after recovery (REC). We determined the microcirculatory flow index (MFI) at each time point, blinded to all clinical data and compared change in MFI and MAP across time points using analysis of variance adjusted for multiple comparisons.Results: We enrolled 20 subjects, 17 of 20 required inotrope/vasopressor agents at CPB discontinuation, 7 of 20 were on inotrope/vasopressor agents at the time of imaging, 20 of 20 were receiving continuous nitroglycerin. We observed an increase in post-CPB MFI (PRE, 2.16 ± 0.29; POST, 2.45 ± 0.62; REC, 2.26 ± 0.25; P < .01) without a concomitant increase in MAP.Conclusion: In this cohort of patients with hemodynamic instability, we observed discordance between microcirculatory blood flow and arterial pressure. These data support the concept that microcirculatory blood flow indices can yield physiologic information distinct from macrocirculatory hemodynamic parameters.

Extracorporeal membrane oxygenation–assisted primary percutaneous coronary intervention may improve survival of patients with acute myocardial infarction complicated by profound cardiogenic shock - Corrected Proof

2012-05-17

Abstract: Purpose: The aim of this study was to evaluate the impact of extracorporeal membrane oxygenation (ECMO) assistance on the clinical outcome of patients with acute myocardial infarction (AMI) that is complicated by profound cardiogenic shock (CS) who received primary percutaneous coronary intervention (PCI).Materials and Methods: We collected patients from January 2004 through December 2006 (stage 1); 25 patients who presented with AMI and received primary PCI and had profound CS were enrolled in the study. Intra-aortic balloon counter-pulsation (IABP) was the only modality for extracorporeal support in our hospital. From January 2007 through December 2009 (stage 2), 33 patients who presented with AMI and received primary PCI and had profound CS were enrolled; for this stage; both intra-aortic balloon counter-pulsation and ECMO support were available in our facility.Results: A Kaplan-Meier survival analysis displayed significantly improved survival for patients in stage 2 (P = .001; 1-year survival in stage 1 vs 2; 24% vs 63.64%). Patients presenting with either STEMI (ST segment elevation myocardial infarction) or NSTEMI (Non-ST segment elevation myocardial infarction) benefited from ECMO-assisted PCI (P < .05). In stage 1, patients with refractory ventricular tachycardia/ventricular fibrillation had a very low survival rate; however, in stage 2, the survival rate of patients with and without refractory ventricular tachycardia/ventricular fibrillation was similar (P = .316).Conclusion: Extracorporeal membrane oxygenation–assisted PCI for patients with AMI that is complicated by profound CS may improve the 30-day and 1-year survival rates.

Hypophosphatemia and its clinical implications in critically ill children: A retrospective study - Corrected Proof

Omer Kilic, Demet Demirkol, Raif Ucsel, Agop Citak, Metin Karabocuoglu — 2012-05-17

Abstract: Purpose: The aims of this study were to determine the prevalence of hypophosphatemia and to discuss the clinical implications of hypophosphatemia in critically ill children.Materials and Methods: A retrospective review of the medical records of children admitted to the pediatric intensive care unit from December 2006 to December 2007 was conducted.Results: In 60.2% (n = 71) of the patients, any serum phosphorous level at admission and at the third day or seventh day after admission to pediatric intensive care unit was in hypophosphatemic range. Sepsis was present in 22.9% (n = 27) of the children studied and was associated with hypophosphatemia (P = .02). Hypophosphatemia was also associated with use of furosemide (P = .04), use of steroid (P = .04), use of β2 agonist (P = .026), and use of an H2 blocker (P = .004). There was a significant association between hypophosphatemia and the rate to attain target caloric requirements by enteral route (P = .007). The median time to attain target caloric requirements by enteral route was 2.9 ± 1.9 (0.2-10) days in the normophosphatemic group and 4.4 ± 2.8 (0.3-12) days in the hypophosphatemic group. In the multiple regression model, solely the rate to attain the target caloric requirements by enteral route demonstrated independent association with hypophosphatemia (P = .006; β = .27; 95% confidence interval, 0.02-0.09). Significant association was found between hypophosphatemia and the duration of mechanical ventilation and between hypophosphatemia and pediatric intensive care unit length of stay (P = .02 and P = .001, respectively).Conclusions: Critically ill pediatric patients are prone to hypophosphatemia, especially if they cannot be fed early by enteral route. Hypophosphatemia is associated with an increased duration of mechanical ventilation and increased length of stay in the pediatric intensive care unit, suggesting that active repletion might improve these parameters.

Prognostic models based on administrative data alone inadequately predict the survival outcomes for critically ill patients at 180 days post–hospital discharge - Corrected Proof

2012-05-17

Abstract: There is interest in evaluating the quality of critical care by auditing patient outcomes after hospital discharge. Risk adjustment using acuity of illness scores, such as Acute Physiology and Chronic Health Evaluation (APACHE III) scores, derived from clinical databases is commonly performed for in-hospital mortality outcome measures. However, these clinical databases do not routinely track patient outcomes after hospital discharge. Linkage of clinical databases to administrative data sets that maintain records on patient survival after discharge can allow for the measurement of survival outcomes of critical care patients after hospital discharge while using validated risk adjustment methods.Objective: The aim of this study was to compare the ability of 4 methods of risk adjustment to predict survival of critically ill patients at 180 days after hospital discharge: one using only variables from an administrative data set, one using only variables from a clinical database, a model using a full range of administrative and clinical variables, and a model using administrative variables plus APACHE III scores.Design: This was a population-based cohort study.Patients: The study sample consisted of adult (>15 years of age) residents of Victoria, Australia, admitted to a public hospital intensive care unit between 1 January 2001 and 31 December 2006 (n = 47,312 linked cases). Logistic regression analyses were used to develop the models.Results: The administrative-only model was the poorest predictor of mortality at 180 days after hospital discharge (C = 0.73). The clinical model had substantially better predictive capabilities (C = 0.82), whereas the full-linked model achieved similar performance (C = 0.83). Adding APACHE III scores to the administrative model also had reasonable predictive capabilities (C = 0.83).Conclusions: The addition of APACHE III scores to administrative data substantially improved model performance to the level of the clinical model. Although linking data systems requires some investment, having the ability to evaluate case ascertainment and accurately risk adjust outcomes of intensive care patients after discharge will add valuable insights into clinical audit and decision-making processes.

Extravascular lung water indexed or not to predicted body weight is a predictor of mortality in septic shock patients - Corrected Proof

2012-05-17

Abstract: Purpose: The purpose was to investigate whether extravascular lung water (EVLW) indexed to actual body weight (EVLWa) is an independent predictor of mortality in patients with septic shock, to determine the relationship between EVLWa and other markers of lung injury, and to test if indexing EVLW with predicted body weight (EVLWp) strengthens its predictive power.Methods: Extravascular lung water, pulmonary vascular permeability index, and other markers of lung injury were measured prospectively in 55 patients with septic shock for 3 days.Results: At day 1, EVLWa, EVLWp, and pulmonary vascular permeability index were not significantly different between survivors and nonsurvivors. However, in parallel to the course of septic shock, these variables decreased only in the survivors and remained elevated in the nonsurvivors, reaching intergroup difference by day 3. In multiple logistic regression analysis, both EVLWa and EVLWp (at day 3) were predictors of mortality with an odds ratio of 2 (95% confidence interval, 1.12-3.7) and 1.7 (95% confidence interval, 1.1-2.5) per SD increase, respectively. The receiver operating characteristic curve analysis showed that EVLWp did not improve the discriminative power of EVLW to predict mortality. Extravascular lung water indexed to actual body weight correlated with lung injury score and with the ratio of arterial oxygen partial pressure to inspired oxygen fraction but not with static respiratory compliance. Indexing EVLW to predicted body weight did not ameliorate these correlations.Conclusions: Extravascular lung water indexed or not to predicted body weight is an independent predictor of mortality in patients with septic shock. Repeated measurements of EVLW indexes over time, rather than a too-early measurement, seem to be more appropriate for predicting outcome.

Influence of full-time intensivist and the nurse-to-patient ratio on the implementation of severe sepsis bundles in Korean intensive care units - Corrected Proof

2012-05-17

Abstract: Purpose: The reported actual compliance for severe sepsis bundles was very low, suggesting the presence of barriers to their implementation. The purpose of this study was to assess the influence of full-time intensivist and nurse-to-patient ratio in Korean intensive care units (ICUs) on the implementation of the severe sepsis bundles and clinical outcome.Materials and Methods: A total of 251 patients with severe sepsis were enrolled from 28 adult ICUs during the July, 2009. We recorded the organizational characteristics of ICUs, patients' characteristics and clinical outcomes, and the compliance for severe sepsis bundles.Results: Complete compliance with the resuscitation bundle and totally complete compliance with all element targets for resuscitation and management bundles were significantly higher in the ICU with full-time intensivist and a nurse-to-patient ratio of 1:2 (P < .05). The hazard ratio (HR) for hospital mortality was independently reduced by the presence of full-time intensivist (HR, 0.456; 95% confidence interval, 0.223-0.932), and a nurse-to-patient ratio of 1:2 was independently associated with a lower 28-day mortality (HR, 0.459; 95% confidence interval, 0.211-0.998).Conclusions: The full-time intensivist and the nurse-to-patient ratio had a substantial influence on the implementation of severe sepsis bundles and the mortalities of patients with severe sepsis.

Chronic heart failure modifies the response to positive end-expiratory pressure in patients with chronic obstructive pulmonary disease - Corrected Proof

Shailesh Bihari, Andrew D. Bersten — 2012-05-17

Abstract: Introduction: Potentially beneficial effects of positive end-expiratory pressure (PEEP) in patients with chronic obstructive pulmonary disease (COPD) must be balanced against further overinflation and increased alveolar dead space. Concurrent chronic heart failure (CHF) is common and can lead to changes in lung that can reduce the detrimental effects of PEEP.Objective: The aim of this study was to compare the effect of PEEP on volumetric capnography, blood gases, pulmonary mechanics, and vital signs in subjects with either COPD (n = 13) or COPD + CHF (n = 7) during pressure support ventilation.Methods: Positive end-expiratory pressure was administered at 0, 5, 10, 15, and 0 cm H2O for 15 minutes with pressure support maintained at 10 cm H2O. Data are expressed as mean ± SD, and the effect of PEEP and differences between COPD alone and COPD + CHF were tested with repeated-measures analysis of variance.Results: Subjects were elderly (72.5 ± 13.3 years) with severe COPD (force expired volume in 1 second, 1.3 ± 0.6L; force expired volume in 1 second/force vital capacity, 40% ± 15%). With increasing PEEP in COPD subjects, dead space ratio increased (P < .001), minute alveolar ventilation decreased (P = .001), and Paco2 increased (P = .013), with no change in COPD + CHF subjects. Subjects with COPD + CHF had improvement in Pao2 and lower mean arterial pressure, whereas both were unchanged in subjects with COPD alone.Conclusion: In subjects with severe COPD alone, caution must be used when administering PEEP 10 cm H2O or greater. Subjects with COPD + CHF may benefit from higher levels of PEEP.

A method for estimation of plasma albumin concentration from the buffering properties of whole blood - Corrected Proof

Stephen E. Rees, Tue Diemer, Søren Risom Kristensen — 2012-04-20

Abstract: Purpose: Hypoalbuminemia is strongly associated with poor clinical outcome. Albumin is usually measured at the central laboratory rather than point of care, but in principle, information exists in the buffering properties of whole blood to estimate plasma albumin concentration from point of care measurements of acid-base and oxygenation status. This article presents and evaluates a new method for doing so.Materials and Methods: The mathematical method for estimating plasma albumin concentration is described. To evaluate the method at numerous albumin concentrations, blood from 19 healthy subjects was diluted at 3 different levels giving 57 data sets. Calculated and measured plasma albumin concentrations were compared using correlation coefficient (r2), regression line, and Bland-Altman bias and limits of agreement.Results: Albumin levels covered the clinically interesting range from 8.8 to 53.3 g/L. Calculated and measured plasma albumin concentrations compared well with r2 = 0.9, a regression line of albumin-calculated = 1.05 × albumin-measured – 2.25, a small average bias between measured and calculated values of 0.7 g/L, and Bland-Altman limits of agreement of 10 g/L.Conclusions: This new method may be a valuable tool in screening and monitoring plasma albumin concentration in acutely ill patients, from measurements taken at the point of care.

Pharmacokinetic changes in patients receiving extracorporeal membrane oxygenation - Corrected Proof

Kiran Shekar, John F. Fraser, Maree T. Smith, Jason A. Roberts — 2012-04-20

Abstract: Extracorporeal membrane oxygenation (ECMO) is a form of prolonged cardiopulmonary bypass used to temporarily sustain cardiac and/or respiratory function in critically ill patients. Extracorporeal membrane oxygenation further complicates the management of critically ill patients who already have profound physiologic derangements with consequent altered pharmacokinetics. The purpose of this study is to identify and critically review the published literature describing pharmacokinetics in the presence of ECMO. This review revealed a dearth of data describing pharmacokinetics during ECMO in critically ill adults, with most of the available data originating in neonates. Of concern, the present data indicate substantial variability and a lack of predictability in drug behavior in the presence of ECMO. The most common mechanisms by which ECMO affects pharmacokinetics are sequestration in the circuit, increased volume of distribution, and decreased drug elimination. While lipophilic drugs and highly protein-bound drugs (eg, voriconazole and fentanyl) are significantly sequestered in the circuit, hydrophilic drugs (eg, β-lactam antibiotics, glycopeptides) are significantly affected by hemodilution and other pathophysiologic changes that occur during ECMO. Although the published literature is insufficient to make any meaningful recommendations for adjusting therapy for drug dosing, this review systematically describes the available data enabling clinicians to make conclusions based on available data. Furthermore, this review serves to highlight the need for well-designed and conducted clinical and laboratory-based studies to provide the data from which robust dosing guidance can be developed to improve clinical outcomes in this most unwell cohort of patients.

Use of an abnormal laboratory value–drug combination alert to detect drug-induced thrombocytopenia in critically Ill patients - Corrected Proof

2012-04-20

Abstract: Purpose: The aim of this study was to assess the performance of a commercially available clinical decision support system (CDSS) drug-laboratory result alert in detecting drug-induced thrombocytopenia in critically ill patients.Materials and Methods: Adult patients admitted to the medical and cardiac intensive care unit during an 8-week period and identified by 1 of 3 signals in the CDSS, TheraDoc, were eligible. Alerts were generated when the patient had a low platelet count and was ordered a potentially causal drug. Patients were evaluated in real time for the occurrence of an adverse drug reaction using 3 causality instruments. Positive predictive values were calculated for the alert.Results: Sixty-four patients with a mean age of 54 years met the inclusion criteria, generating 350 alerts. Positive predictive values were 0.36, 0.83, and 0.40 for signals 1, 2, and 3, respectively. Overall, there were 137 adverse drug reactions identified in the 350 alerts, with heparin, vancomycin, and famotidine as the 3 most common potential causes.Conclusions: A commercial CDSS drug-laboratory alert is effective at identifying drug-induced thrombocytopenia in the intensive care unit and may improve patient safety. Compared with previous studies, the combination alert performs better than alerts based exclusively on laboratory values and should be considered to reduce alert fatigue.

Predicting the need for mechanical ventilation in acute exacerbations of chronic obstructive pulmonary disease: Comparing the CURB-65 and BAP-65 scores - Corrected Proof

Andrew F. Shorr, Xiaowu Sun, Richard S. Johannes, Karen G. Derby, Ying P. Tabak — 2012-04-20

Abstract: Purpose: Clinicians lack a validated tool for risk stratification for need for mechanical ventilation (MV) in acute exacerbations of chronic obstructive pulmonary disease (AECOPD). We sought to compare 2 risk scores, BAP-65 and CURB-65, at predicting a need for MV in AECOPDs.Materials and Methods: We analyzed 34 478 AECOPD admissions to 195 US hospitals (2007). We compared the rates of MV at admission and at any point during hospitalization based on the respective BAP-65 and CURB-65 scores. We compared the accuracy of the 2 scores via the area under the receiver operating characteristic curves.Results: The overall MV rate at admission was 7.9%, and the rate of MV any time equaled 9.3%. Use of MV increased with escalating BAP-65 and CURB-65 scores. The area under the receiver operating characteristic curve for BAP-65 was higher than that for CURB-65 for both early MV, 0.81 (95% confidence interval [CI], 0.80-0.82) vs 0.76 (95% CI, 0.75-0.77), P < .0001, and MV any time, 0.78 (95% CI, 0.77-0.79) vs 0.74 (95% CI, 0.73-0.75), P < .0001.Conclusions: BAP-65 identifies patients with AECOPD at high risk for need of MV more accurately than does CURB-65. BAP-65 may represent a useful tool for initial MV risk stratification in AECOPD.

Changes in heart rate, mean arterial pressure, and oxygen saturation after open and closed endotracheal suctioning: A prospective observational study - Corrected Proof

2012-04-20

Abstract: Purpose: It is widely assumed that closed suction systems (CSSs), as compared with open suction systems (OSSs), better guarantee optimal oxygenation with less disturbance of physiologic parameters in mechanically ventilated intensive care patients. We, therefore, quantified changes in heart rate (HR), mean arterial pressure (MAP), and peripheral oxygen saturation (Spo2) in patients undergoing endotracheal suctioning (ES) with CSS and OSS.Materials and Methods: We performed a prospective observational study nested within a crossover trial in 4 intensive care units between January 2007 and February 2008. Per unit, 50 ES procedures were selected at random, and HR, MAP, and Spo2 were measured before and after ES.Results: In total, 197 complete ES procedures (103 OSS and 94 CSS) were monitored. Mean HR, MAP, and Spo2 changed directly after ES and returned to baseline after 5 minutes. Changes in HR and MAP were comparable after using CSS and OSS, whereas in Spo2, slightly better values were monitored 3 and 5 minutes after OSS, these differences being rather small (0.3%-0.7%) and clinically not relevant.Conclusions: Changes in HR, MAP, and Spo2 were comparable and mild during and after CSS and OSS. Both systems can be considered equally safe.

The American Rare Donor Program - Corrected Proof

Geralyn M. Meny, Cynthia Flickinger, Catherine Marcucci — 2012-04-20

Abstract: The American Rare Donor Program (ARDP), headquartered in Philadelphia, Pennsylvania, maintains a comprehensive database of donors with “rare blood types.” The ARDP secures blood and blood products for difficult-to-transfuse patients. Remarkably, a significant number of physicians, both in the United States and abroad, remain unaware of the unique and critical services that the ARDP provides to critical care specialists and their patients.

Fractional excretion of urea as a diagnostic index in acute kidney injury in intensive care patients - Corrected Proof

2012-04-20

Abstract: Purpose: Acute kidney injury (AKI) is a dynamic process that evolves from an early reversible condition to an established disease. Value of urine indices in the event of AKI is uncertain in critically ill patients. The aim of this study was to evaluate the performance of fractional excretion of urea (FeU) for differentiating persistent from transient AKI in patients admitted to the intensive care unit.Methods: This was an observational study. Forty-seven patients with AKI according to the RIFLE classification were included. Transient AKI was defined as AKI resolved within 3 days after inclusion. Persistent AKI was defined as persistent serum creatinine elevation or oliguria.Results: Fractional excretion of urea was lower in case of transient, 33% (25-39), than persistent AKI, 47% (36-61) (P = .001). Areas under the receiver operating characteristic curve for FeU in case of transient AKI were better than those for other urinary indexes, 0.78 (95% confidence interval, 0.63-0.92). Optimal cutoff point according to the receiver operating characteristic curve was 40%. In patients treated with diuretics, FeU was the only predictive index of transient AKI. Fractional excretion of urea gradually increased from days 1 to 7 in transient AKI, whereas plasma creatinine decreased.Conclusions: Fractional excretion of urea less than 40% was found to be a sensitive and specific index in differentiating transient from persistent AKI in intensive care unit patients especially if diuretics had been administered.

Muscle strength assessment in critically ill patients with handheld dynamometry: An investigation of reliability, minimal detectable change, and time to peak force generation - Corrected Proof

Claire E. Baldwin, Jennifer D. Paratz, Andrew D. Bersten — 2012-04-20

Abstract: Purpose: Dynamometry is an objective tool for volitional strength evaluation that may overcome the limited sensitivity of the Medical Research Council scale for manual muscle tests, particularly at grades 4 and 5. The primary aims of this study were to investigate the reliability, minimal detectable change, and time to peak muscle force, measured with portable dynamometry, in critically ill patients.Materials and methods: Isometric hand grip, elbow flexion, and knee extension were measured with portable dynamometry.Results: Interrater consistency (intraclass correlation coefficient [95% confidence interval]) (0.782 [0.321-0.930] to 0.946 [0.840-0.982]) and test-retest agreement (0.819 [0.390-0.943] to 0.918 [0.779-0.970]) were acceptable for all dynamometry forces, with the exception of left elbow flexion. Despite generally good reliability, a mean change (upper 95% confidence interval) of 2.8 (7.8) kg, 1.9 (5.2) kg, and 2.6(7.1) kg may be required from a patient's baseline force measurement of right grip, elbow flexion, and knee extension to reflect real force changes. There was also a delay in the time for critically ill patients to generate peak muscle forces, compared with healthy controls (P ≤ .001).Conclusions: Dynamometry can provide reliable measurements in alert critically ill patients, but moderate changes in strength may be required to overcome measurement error, during the acute recovery period. Deficits in force timing may reflect impaired neuromuscular control.

Response to a bolus of conivaptan in patients with acute hyponatremia after brain injury - Corrected Proof

Theresa Human, Adaeze Onuoha, Michael Diringer, Rajat Dhar — 2012-04-20

Abstract: Purpose: The aim of the study was to analyze the response to the vasopressin-receptor antagonist conivaptan in a large cohort of brain-injured patients with acute hyponatremia.Materials and Methods: The natremic response (rise in serum sodium) to an initial bolus of conivaptan was retrospectively evaluated in 124 patients over a 3-year period in our neurosciences intensive care unit. Variables associated with this response were identified using linear regression.Results: Median pretreatment sodium was 132 mEq/L, and duration of hyponatremia before dose was 1 day. Median natremic response was +4 mEq/L (interquartile range, 2-7 mEq/L), measured a median of 9 hours (interquartile range, 6-12 hours) after conivaptan administration. This was associated with significant urine output (median, 2.6 L over 12 hours), with degree of aquaresis associated with natremic response (regression coefficient, B = 1.8 change in sodium per liter; 95% confidence interval, 1.3-2.4; P < .001). Seventy-four patients (60%) responded with a rise of at least 4 mEq/L. Response was predicted by higher baseline urine output (B = 0.018 per mL; 0.004-0.032; P = .01) and lack of oral fluid intake (B = 2.06; 0.44-3.68; P = .01) but not tonicity of intravenous fluids or creatinine clearance.Conclusions: Conivaptan given as a bolus can effectively treat acute hyponatremia in brain-injured patients.

Integrating lung ultrasound in the hemodynamic evaluation of acute circulatory failure (the fluid administration limited by lung sonography protocol) - Corrected Proof

Daniel Lichtenstein, Dimitrios Karakitsos — 2012-04-20

Abstract: In circulatory failure, fluid administration limited by lung sonography protocol uses lung ultrasound artifacts and makes sequential diagnosis of obstructive, cardiogenic, hypovolemic, and septic shock. Lung ultrasound is used along with simple cardiac and vena cava analysis. Whenever echocardiography cannot be performed, fluid administration limited by lung sonography protocol is favored because of its simplicity and could prove contributive. It is based on the presence (B profile) or the absence (A profile) of interstitial pulmonary edema. However, the latter does not represent actual alveolar edema, and transthoracic echocardiography is still used by intensivists as a pivotal hemodynamic measure. Tissue Doppler imaging facilitates the estimation of left ventricular filling pressures, whereas assessing right ventricular function is of prognostic value in states of shock due to massive pulmonary embolism and acute respiratory distress syndrome. In mechanically ventilated patients, poor acoustic windows are evident and performing transesophageal echocardiography may be necessary. Whenever noninvasive hemodynamic measures are inconclusive, in a deteriorating patient, a pulmonary artery catheter may be placed. Ultrasound is not a therapy but a guide for treatment, and physicians should aim to treat underlying pathologies. Despite its limitations, general chest ultrasound (lung and cardiac ultrasound) is a powerful diagnostic and monitoring tool reflecting an era of genuine “visual” medicine.

Impact of pattern of admission on outcomes after aneurysmal subarachnoid hemorrhage - Corrected Proof

2012-04-20

Abstract: Objective: Patients with aneurysmal subarachnoid hemorrhage (aSAH) require management in centers with neurosurgical expertise necessitating emergent interhospital transfer (IHT). Our objective was to compare outcomes in aSAH IHTs to our institution with aSAH admissions from our institutional emergency department (ED).Methods: Data for consecutive patients with aSAH admitted to Johns Hopkins Medical Institutions between 1991 and 2009 were analyzed from a prospectively obtained database. We compared in-hospital mortality and functional outcomes at first clinical appointment post-aSAH (30-120 days) using dichotomized Glasgow Outcome Scale (good outcome: Glasgow Outcome Scale 4-5) in ED admissions with IHTs.Results: A total of 1134 consecutive patients with aSAH were included in analysis (ED 40.1%, IHT 59.9%). Direct ED admissions had a higher incidence of poor Hunt and Hess grade (4/5) and major medical comorbidities, with no significant differences between the 2 groups in age, intraventricular hemorrhage, and hydrocephalus. In-hospital mortality for ED admissions (14.9%) was significantly lower than that for IHTs (20.5%), with 1.8 times greater adjusted odds of survival after multivariate analysis (P = .001). Emergency department admissions had nearly 2-fold greater odds of good outcomes (odds ratio, 1.89; P < .001) after multivariate analysis.Conclusions: Our institutional ED SAH admissions had significantly better outcomes than did IHTs, suggesting that delays in optimizing care before transfer could deleteriously impact outcomes.

What is the best method for estimating the burden of severe sepsis in the United States? - Corrected Proof

2012-04-19

Abstract: Purpose: The aim of the study was to compare estimates of hospitalizations, outcomes, and costs produced by 2 approaches for defining severe sepsis.Methods: We used the Nationwide Inpatient Sample to study adults hospitalized in the United States in 2007. We defined severe sepsis using 2 previously published algorithms: (1) the presence of a principal or secondary diagnosis of septicemia combined with organ dysfunction or (2) the presence of a principal or secondary diagnosis of septicemia or another infection (eg, pneumonia) combined with organ dysfunction. For each approach, we calculated the weighted frequency of hospitalizations, population-based mortality rates, and geometric mean costs.Results: A total of 711 736 (SD, 16 412) hospitalizations had a diagnosis of septicemia and a diagnosis of organ dysfunction. A total of 2.5 million hospitalizations were recorded, with a diagnosis code for either septicemia or infection combined with a diagnosis code for organ dysfunction. Hospitalizations without a diagnosis code for septicemia had lower rates of respiratory failure (33% vs 47%, P < .001) or shock (20% vs 46%, P < .001), lower in-hospital mortality (8% vs 29%, P < .001), and lower mean costs.Conclusions: An approach that requires a diagnosis code for septicemia and a diagnosis code for organ dysfunction yields estimates of disease burden and outcomes that are more consistent with chart-based studies.

Exposure keratopathy in sedated and ventilated patients - Corrected Proof

2012-04-19

Abstract: Purpose: The purpose of this study is to determine the frequency of exposure keratopathy in sedated/mechanically ventilated patients in the intensive care unit and its risk factors.Materials and Methods: This is a prospective cohort study including all patients admitted to an adult intensive care unit department between March and October 2010 who were sedated and mechanically ventilated. Patients were examined by an ophthalmologist 1 to 5 days after commencing ventilation and subsequently every day. Examination included assessment of lid position, conjunctival edema (chemosis), and corneal changes.Results: Of the 74 patients included in the study, 57% had exposure keratopathy. Fifty-four percent of patients developed chemosis, and 31% of patients developed lagophthalmos. Frequency of exposure keratopathy differed significantly according to degree of chemosis and lagophthalmos (P < .0001); lagophthalmos was also significantly related to chemosis (P < .0001). For lagophthalmos score of 3, the odds ratio of association with higher exposure keratopathy score was 136 (95% confidence interval [CI], 14.97-1242.6); for lagophthalmos score of 2, it was 14.4 (95% CI, 2.67-77.2). For any edema, the odds ratio of association with exposure keratopathy was 5.50 (95% CI, 2.02-15.00).Conclusion: The frequency of exposure keratopathy in sedated/mechanically ventilated patients is high with lagophthalmos and chemosis as the main risk factors.

A risk, injury, failure, loss, and end-stage renal failure score–based trigger for renal replacement therapy and survival after cardiac surgery - Corrected Proof

2012-04-05

Abstract: Purpose: It is controversial whether all critically ill patients with risk, injury, failure, loss, and end-stage renal failure (RIFLE) F class acute kidney injury (AKI) should receive renal replacement therapy (RRT). We reviewed the outcome of open heart surgery patients with severe RIFLE-F AKI who did not receive RRT.Materials and Methods: We identified all patients with AKI after cardiac surgery over 4 years and obtained baseline characteristics, intraoperative details, and in-hospital outcomes. We analyzed physiologic and biochemical features at RRT initiation or at peak creatinine if no RRT was provided.Results: We reviewed 1504 patients. Of these, 137 (9.1%) developed postoperative AKI with 71 meeting RIFLE-F criteria and 23 (32.4% of RIFLE-F cases) not receiving RRT. Compared with RRT-treated RIFLE-F patients, “no-RRT” patients had lower Acute Physiology and Chronic Health Evaluation III scores, less intra-aortic balloon pump requirements, shorter intensive care stay, and a trend toward lower mortality. At peak RIFLE score, their urinary output, arterial pH, and Pao2/fraction of inspired oxygen ratio were all significantly higher. Their serum creatinine was also higher (304 vs 262 μmol/L; P = .02). Only 3 RIFLE-F no-RRT patients died in-hospital. Detailed review of cause and mode of death was consistent with non–RRT-preventable deaths. In contrast, 27 patients with RIFLE-R or RIFLE-I class received RRT. Compared with RRT-treated RIFLE-F patients, such RIFLE-R or RIFLE-I treated patients had a more severe presentation and higher mortality (51.8% vs 29.2%; P = .02).Conclusions: After cardiac surgery, RRT was typically applied to patients with the most severe clinical presentation irrespective of creatinine levels. A RIFLE score–based trigger for RRT is unlikely to improve patient survival.

Comparison of 3 modes of automated weaning from mechanical ventilation: A bench study - Corrected Proof

José B. Morato, Mayara T.A. Sakuma, Juliana C. Ferreira, Pedro Caruso — 2012-03-29

Abstract: Purpose: Automated weaning modes are available in some mechanical ventilators, but no studies compared them hitherto. We compared the performance of 3 automated modes under standard and challenging situations.Methods: We used a lung simulator to compare 3 automated modes, adaptive support ventilation (ASV), mandatory rate ventilation (MRV), and Smartcare, in 6 situations, weaning success, weaning failure, weaning success with extreme anxiety, weaning success with Cheyne-Stokes, weaning success with irregular breathing, and weaning failure with ineffective efforts.Results: The 3 modes correctly recognized the situations of weaning success and failure, even when anxiety or irregular breathing were present but incorrectly recognized weaning success with Cheyne-Stokes. MRV incorrectly recognized weaning failure with ineffective efforts. Time to pressure support (PS) stabilization was shorter for ASV (1-2 minutes for all situations) and MRV (1-7 minutes) than for Smartcare (8-78 minutes). ASV had higher rates of PS oscillations per 5 minutes (4-15), compared with Smartcare (0-1) and MRV (0-12), except when extreme anxiety was present.Conclusions: Smartcare, ASV, and MRV were equally able to recognize weaning success and failure, despite the presence of anxiety or irregular breathing but performed incorrectly in the presence of Cheyne-Stokes. PS behavior over the time differs among modes, with ASV showing larger and more frequent PS oscillations over the time. Clinical studies are needed to confirm our results.

Mechanical ventilation in the emergency department for 24 hours or longer is associated with delayed weaning - Corrected Proof

2012-03-29

Abstract: Purpose: We examined various aspects of critical care to identify factors in the emergency department (ED) that affected the overall duration of mechanical ventilation (MV). We specifically focused on whether 24 hours of ED MV affected the weaning success and the duration of MV.Materials and Methods: Mechanical ventilation cases that started in the ED because of purely respiratory problems were enrolled in the retrospective cohort. We recorded demographic data, duration of MV in ED, various severity scores, previously known factors of prolonged MV, and achievement of ventilator weaning. All the significant factors in univariate survival analyses were included in a multivariate analysis.Results: The estimated median of the entire duration of MV was longer in patients who received 24 hours or more of MV in ED compared with that of patients who received MV for less than 24 hours (33.0 vs 15.4 days, P = .003). Mechanical ventilation for longer than 24 hours in the ED remained a significant factor that prolonged the entire MV duration in the multivariate analysis (hazard ratio, 0.577; P = .019). Hypoalbuminemia and abbreviated mortality in ED sepsis (MEDS) score were also independently correlated (P ≤ .001 for both).Conclusions: Mechanical ventilation in the ED for 24 hours or longer is associated with delayed ventilator weaning.

Continuous intravenous administration of vancomycin in medical intensive care unit patients - Corrected Proof

2012-03-29

Abstract: Purpose: The aim of this study was to evaluate continuous vancomycin infusion (contV) in intensive care unit patients.Materials and Methods: A retrospective study in 164 patients treated with contV was conducted. They were compared with 75 patients treated with intermittent vancomycin infusion.Results: The median duration of vancomycin therapy in the contV group was 6 (5%-95% percentile range, 2-21) days. The median daily vancomycin dose in the contV group was 960 (526-1723) mg, resulting in a median serum vancomycin plateau concentration of 19.8 (9.8-29.4) mg/L (target: 15-25 mg/L). The contV administration regime was sufficient regarding achievement of the target serum vancomycin concentration. However, in the contV group, serum vancomycin levels were frequently in a subtherapeutic range on treatment days 1 (44%), 2 (29%), and 3 (23%). In the contV group, serum vancomycin concentration determinations per treatment day were performed significantly less often compared with the intermittent vancomycin infusion group (0.38 [0.15-0.75] vs 0.43 [0.22-1.00], P = .041).Conclusions: In medical intensive care unit patients, contV is sufficient to achieve target serum vancomycin concentrations. Because contV frequently resulted in subtherapeutic drug levels on the first days of therapy, a higher loading or starting dose might be necessary.

Antibiotic resistance patterns in medical and surgical patients in a combined medical-surgical intensive care unit - Corrected Proof

Jason A. Akulian, Mark L. Metersky — 2012-03-29

Abstract: Purpose: Studies have found different rates of antimicrobial resistance among patients in medical and surgical intensive care units (ICUs). We studied whether these differences were a function of geography or differences in the patient populations, by comparing resistance rates among bacteria isolated from a combined medical/surgical ICU.Materials and Methods: We retrospectively evaluated the results of bacterial cultures of each patient admitted to the ICU between February 2005 and September 2006. Data collection included patient demographics and culture and sensitivity results. Intensive care unit populations were compared using the Fisher exact test and the Student t test.Results: One hundred seventy-one medical and 94 surgical patients with positive cultures were studied. Organisms were grouped into 4 classes: Staphylococcus aureus, nonlactose fermenting gram-negative bacilli, Enterococcus species, and gram-negative enteric bacteria. In the 4 classes, no significant difference in antibiotic resistance was found between medical and surgical patients.Conclusion: Reported differences in resistance patterns among bacteria cultured from medical and surgical patients may be due to geographic separation of the ICUs as opposed to differences in the patient characteristics. This study suggests that ICU-specific antibiograms remain a useful tool to guide the choice of antimicrobial therapy, even in medical/surgical ICUs.

The effect of body position changes on stroke volume variation in 66 mechanically ventilated patients with sepsis - Corrected Proof

Yu Daihua, Chai Wei, Sun Xude, Yao Linong, Gao Changjun, Zhao Hui — 2012-03-29

Abstract: Purpose: The aim of the study was to investigate the effect of body position changes on the stroke volume (SI) variation (SVV) in ventilated patients with sepsis.Methods: Sixty patients with sepsis were studied during mechanical ventilation. All patients were randomly placed in the supine, 30° head-up, 30° left or right recumbent, or prone position. In addition to standard hemodynamic monitoring, SVV, central venous pressure, cardiac index (CI), SV index (SVI), global end-diastolic volume index (GEDVI), and global ejection fraction (GEF) were recorded at each position after stabilization.Results: Stroke volume variation had strong negative correlation with CI, SVI, GEF, and GEDVI (P < .0001). After the change to the 30° head-up or the prone position, SVV increased significantly, whereas CI, SVI, GEF, and GEDVI decreased dramatically. Stroke volume variation in the supine position did not correlate with 30° head-up– or prone-induced changes in CI (P < .05). All variables did not differ between 30° left or right recumbent and supine positions.Conclusions: Body position changes may affect the correlation of SVV with hemodynamic variables. The 30° head-up and prone positions increased SVV because of the associated decreased SV. The 30° left or right recumbent position does not affect SVV and SV.

Prevalence and characteristics of nonlactate and lactate expressors in septic shock - Corrected Proof

2012-03-22

Abstract: Purpose: The study's objective was to determine the proportion and patient characteristics of patients in vasopressor-dependent septic shock who presented without lactatemia.Methods: A retrospective review of patients presenting to an urban tertiary-care emergency department between December 2007 and September 2008 was conducted. Patients with a final diagnosis of septic shock requiring vasopressors were divided, based on initial lactate, to nonlactate expressors (0-2.4 mmol/L), intermediate (2.5-3.9 mmol/L), and high (>4.0 mmol/L) lactate groups.Results: Among 123 patients with vasopressor-dependent septic shock, 55 (45%) were nonlactate expressors (lactate ≤2.4 mmol/L). Acute liver injury, history of liver disease, and presence of bacteremia were associated with elevated lactate.Conclusion: Almost one-half of patients with vasopressor-dependent septic shock did not express lactate on presentation, although a high mortality rate remains in this population. We found a significant association between lactate expressors and liver disease and between lactate expressors and positive blood cultures. The use of lactatemia as the sole indicator of need for additional intravenous fluid or an end point of resuscitation in septic shock may be inadequate.

Prediction of extubation failure in medical intensive care unit patients - Corrected Proof

2012-03-22

Abstract: Purpose: The purpose of this study was to evaluate prediction factors for extubation failure (need for reintubation within 48 hours) in medical intensive care unit patients.Materials and Methods: Sixty-one patients extubated after mechanical ventilation for more than 48 hours were included in the study. A retrospective analysis of medical records and a prospectively maintained database on respiratory parameters was conducted.Results: Low serum anion gap (P = .001), low serum anion gap corrected for serum albumin (P = .010), and low arterial partial pressure of oxygen (Pao2)/fraction of inspired oxygen (Fio2) ratio (P = .032) were significantly associated with extubation failure. Binary logistic regression analysis revealed low uncorrected and corrected serum anion gap (P = .006 and P = .025, respectively; odds ratio, 0.59 for both) and low Pao2/Fio2 ratio (P = .038; odds ratio, 0.99) as risk factors for extubation failure. Regarding extubation failure, receiver operating characteristic curve (ROC) analysis demonstrated good predictive capabilities of serum anion gap (ROC area under the curve, 0.835; P = .004; cutoff, 7.7 mEq/L; sensitivity, 70.4%; specificity, 85.7%) and corrected serum anion gap (ROC area under the curve, 0.808; P = .009; cutoff, 8.8 mEq/L; sensitivity, 87.5%; specificity, 71.4%). A significantly higher risk for extubation failure was observed in patients with serum anion gap 5.2 mEq/L or less (relative risk, 8.8; 95% confidence interval, 2.4-32.4; P = .004) and corrected serum anion gap 8.6 mEq/L or less (relative risk, 10.0; 95% confidence interval, 2.2-44.9; P = .004).Conclusions: Low preextubation serum anion gap values and low preextubation Pao2/Fio2 ratio might help to predict extubation failure in medical intensive care unit patients.

A comparison of predictive equations of energy expenditure and measured energy expenditure in critically ill patients - Corrected Proof

Erin K. Kross, Matthew Sena, Karyn Schmidt, Renee D. Stapleton — 2012-03-15

Abstract: Purpose: Multiple equations exist for predicting resting energy expenditure (REE). The accuracy of these for estimating energy requirements of critically ill patients is not clear, especially for obese patients. We sought to compare REE, calculated with published formulas, with measured REE in a cohort of mechanically ventilated subjects.Materials and Methods: We retrospectively identified all mechanically ventilated patients with measured body mass index who underwent indirect calorimetry in the intensive care unit. Limits of agreement and Pitman's test of difference in variance were performed to compare REE by equations with REE measured by indirect calorimetry.Results: A total of 927 patients were identified, including 401 obese patients. There were bias and poor agreement between measured REE and REE predicted by the Harris-Benedict, Owen, American College of Chest Physicians, and Mifflin equations (P > .05). There was poor agreement between measured and predicted REE by the Ireton-Jones equation, stratifying by sex. Ireton-Jones was the only equation that was unbiased for men and those in weight categories 1 and 2. In all cases except Ireton-Jones, predictive equations underestimated measured REE.Conclusion: None of these equations accurately estimated measured REE in this group of mechanically ventilated patients, most underestimating energy needs. Development of improved predictive equations for adequate assessment of energy needs is needed.

Perceived benefit of a telemedicine consultative service in a highly staffed intensive care unit - Corrected Proof

Mark C. Romig, Asad Latif, Randeep S. Gill, Peter J. Pronovost, Adam Sapirstein — 2012-03-14

Abstract: Purpose: The aim of this study was to evaluate whether a nocturnal telemedicine service improves culture, staff satisfaction, and perceptions of quality of care in a highly staffed university critical care system.Methods: We conducted an experiment to determine the effect of telemedicine on nursing-staff satisfaction and perceptions of the quality of care in an intensive care unit (ICU). We surveyed ICU nurses using a modified version of a previously validated tool before deployment and after a 2-month experimental program of tele-ICU. Nurses in another, similar ICU within the same hospital academic medical center served as concurrent controls for the survey responses.Results: Survey responses were measured using a 5-point Likert scale, and results were analyzed using paired t testing. Survey responses of the nurses in the intervention ICU (n = 27) improved significantly after implementation of the tele-ICU program in the relations and communication subscale (2.99 ± 1.13 pre vs 3.27 ±1.27 post, P < .01), the psychological working conditions and burnout subscale (3.10 ± 1.10 pre vs 3.23 ± 1.11 post, P < .02), and the education subscale (3.52 ± 0.84 pre vs 3.76± 0.78 post, P < .03). In contrast, responses in the control ICU (n = 11) declined in the patient care and perceived effectiveness (3.94 ± 0.80 pre vs 3.48 ± 0.86 post, P < .01) and the education (3.95 ± 0.39 pre vs 3.50 ± 0.80 post, P < .05) subscales.Conclusion: Telemedicine has the potential to improve staff satisfaction and communication in highly staffed ICUs.

Staff satisfaction between 2 models of care for the chronically critically ill - Corrected Proof

Marie-José Roulin, Marie-France Boul'ch, Paolo Merlani — 2012-03-14

Abstract: Introduction: Chronically critically ill (CCI) patients are a growing population in intensive care units (ICUs), and evidence suggests that this patient group is perceived as demanding by healthcare professionals. However, information is scarce regarding organizational factors that affect staff satisfaction during the care of CCI patients.Purpose: The purpose of this study was to evaluate staff satisfaction between 2 models of care for the CCI. In the first model, a patient-centered program of care in a traditional ICU was evaluated. In the second model, care of patients hospitalized in a multidisciplinary ICU ward dedicated to the CCI was further evaluated. Indicators of staff satisfaction with respect to the care of the CCI were also identified.Methods: A before and after study was used to evaluate the 2 models of care. After implementation of the first model in 2006, an initial evaluation was performed using a questionnaire given to ICU health-care personnel. In 2009, after implementing the second model (a separate ward for the CCI), a second evaluation took place.Results: A total of 147 participants answered the questionnaire in both phases. Participants described CCI as a burden, and grouping these patients into 1 ward only increased this perception. Overall, the staff was more satisfied with the first model of care. In this model, the indicators of increased satisfaction were perceived access to professional development and the availability of information.Conclusions: Results from this study provide information about health-care professionals' perceived burden of care when treating CCI patients. Strategies promoting professional development have a potential to increase staff satisfaction when it comes to the care of this patient group.

Exploring the capacity to ambulate after a period of prolonged mechanical ventilation - Corrected Proof

Shane M. Patman, Diane M. Dennis, Kylie Hill — 2012-03-14

Abstract: Purpose: The purposes were to assess the functional recovery of those who survived a prolonged intensive care unit (ICU) stay by reporting the proportion who were able to ambulate independently at hospital discharge and also to examine if the time duration between admission and when the patient first stood impacted on their capacity to ambulate at discharge.Materials and Methods: A retrospective review was conducted of medical records of ICU patients in 2007 to 2008, who were mechanically ventilated for 168 hours or more, and survived their acute care stay. Main outcome measures were (1) ambulation status before admission and at time of hospital discharge and (2) time between admission to the ICU and when the patient first stood.Results: A total of 190 patients were included. Before admission, 189 (99%; 95% confidence interval [CI], 98%-100%) were ambulating independently, of whom 180 (95%) did not require a gait aid. On discharge from acute care, 89 (47%; 95% CI, 40%-54%) were ambulating independently, of whom 54 (61%) did not require a gait aid. Compared with those who stood within 30 days of ICU admission, a delay in standing of between 30 and 60 days increased the odds 5-fold (95% CI, 2-11) of being unable to ambulate independently at the time of discharge.Conclusions: After a prolonged ICU admission, more than 50% of patients were unable to ambulate independently by hospital discharge, with the time between admission and first stand, being an important predictor of this outcome.

The association between vital signs and major hemorrhagic injury is significantly improved after controlling for sources of measurement variability - Corrected Proof

Andrew T. Reisner, Liangyou Chen, Jaques Reifman — 2012-03-14

Abstract: Purpose: Measurement error and transient variability affect vital signs. These issues are inconsistently considered in published reports and clinical practice. We investigated the association between major hemorrhagic injury and vital signs, successively applying analytic techniques that excluded unreliable measurements, reduced transient variation, and then controlled for ambiguity in individual vital signs through multivariate analysis.Methods: Vital sign data from 671 adult prehospital trauma patients were analyzed retrospectively. Computer algorithms were used to identify and exclude unreliable data and to apply time averaging. An ensemble classifier was developed and tested by cross-validation. Primary outcome was hemorrhagic injury plus red cell transfusion. Areas under receiver operating characteristic curves (ROC AUCs) were compared by the test of DeLong et al.Results: Of initial vital signs, systolic blood pressure (BP) had the highest ROC AUC of 0.71 (95% confidence interval, 0.64-0.78). The ROC AUCs improved after excluding unreliable data, significantly for heart rate and respiratory rate but not significantly for BP. Time averaging to reduce temporal variability further increased AUCs, significantly for BP and not significantly for heart rate and respiratory rate. The ensemble classifier yielded a final ROC AUC of 0.84 (95% confidence interval, 0.80-0.89) in cross-validation.Conclusions: Techniques to reduce variability in vital sign data can lead to significantly improved diagnostic performance. Failure to consider such variability could significantly reduce clinical effectiveness or confound research investigations.

Usefulness of cardiac biomarkers to predict cardiac recovery in patients on extracorporeal membrane oxygenation support for refractory cardiogenic shock - Corrected Proof

2012-03-05

Abstract: Background: No prognostic markers of myocardial recovery in patients with refractory cardiogenic shock requiring circulatory support are known, but early identification of patients who will not recover might provide an opportunity to change the treatment strategy to improve outcome. Because N-terminal fragment of the B-type natriuretic peptide, troponin Ic, midregional fragment of the proatrial natriuretic peptide, proadrenomedullin, and copeptin are prognostic markers in patients with cardiac failure, we hypothesized that, among patients with refractory cardiogenic shock of potentially reversible cause supported with extracorporeal membrane oxygenation (ECMO), the kinetics of these markers might help identify patients who would recover.Methods: This was a prospective, observational, single-center study in a medical-surgical intensive care unit. Among 41 consecutive patients with refractory cardiogenic shock of potentially reversible cause receiving ECMO support, 18 recovered and were successfully weaned off the machine. Blood N-terminal fragment of the B-type natriuretic peptide, troponin Ic, midregional fragment of the proatrial natriuretic peptide, proadrenomedullin, and copeptin concentrations were determined on days 1, 3, and 7 post-ECMO.Results: Neither the absolute values of those biomarkers at days 1, 3, or 7 nor their kinetics during the first week differed between patients weaned or not. Areas under the receiver operating characteristic curves (95% confidence interval) of the day 1-to-day 3 biomarker changes for predicting cardiac recovery were 0.54 (0.36-0.71), 0.61 (0.43-0.78), 0.61 (0.42-0.77), 0.56 (0.38-0.73), and 0.61 (0.43-0.78), respectively.Conclusion: In patients with refractory cardiogenic shock of potentially reversible cause receiving ECMO support, early measurements of cardiac biomarkers are not useful for identifying those who would recover.

Impact of a multidimensional approach on ventilator-associated pneumonia rates in a hospital of Shanghai: Findings of the International Nosocomial Infection Control Consortium - Corrected Proof

2012-03-02

Abstract: Purpose: The aim of this study was to analyze the impact of a multidimensional infection control approach on the reduction of ventilator-associated pneumonia (VAP) in intensive care units (ICUs) patients of one hospital in China.Materials and Methods: We conducted a before-after study from January 2005 to July 2009, which was divided into baseline (phase 1) and intervention (phase 2) periods. During phase 1, active prospective outcome surveillance of VAP was performed by applying the definitions of the Centers for Disease Control and Prevention/National Health Safety Network, and the methodology of the International Nosocomial Infection Control Consortium. During phase 2, the multidimensional approach was implemented. Ventilator-associated pneumonia rates obtained in phases 1 and 2 were compared in yearly periods.Results: We recorded data from 16 429 patients hospitalized in 3 ICUs, for a total of 74 116 ICU bed days. The VAP baseline rate was 24.1 per 1000 ventilator-days. During phase 2, the VAP rate significantly decreased to 5.7 per 1000 ventilator-days in 2009 (2009 vs 2005: relative risk, 0.31; 95% confidence interval, 0.16-0.36; P = .0001), amounting to a 79% cumulative VAP rate reduction.Conclusions: Implementing a multidimensional infection control intervention for VAP was associated with a significant cumulative reduction in the VAP rate in our ICUs.

Impact of red blood cells transfusion on ICU-acquired bloodstream infections: A case-control study - Corrected Proof

2012-03-02

Abstract: Our study investigated the impact of packed red blood cell (pRBC) transfusion on the occurrence of bloodstream infections (BSIs) in patients admitted in a multidisciplinary intensive care unit (ICU), further assessing potential associations with particular BSI types. A nested matched (1:1) case-control design was implemented. Sex, age, admission category, Acute Physiology and Chronic Health Evaluation score II (plus Injury Severity Score in trauma patients) were used for matching. Controls were selected to have an ICU length of stay at least equal to the time to first BSI episode of the corresponding cases. Propensity scores for receiving pRBC transfusion were calculated in the entire prospective cohort. Of 582consecutive ICU patients, 165 matched case-control pairs were formed. In multivariable analysis, pRBC transfusion was independently associated with 2-fold probability for BSI (adjusting for matching variables and propensity score). There was a significant dose-dependent association of BSI risk with regard to the number of pRBC units transfused (odds ratios [OR], 1.73, 2.09, 2.34 for 1-3, 4-6, and more than 6 pRBC units transfused, respectively, compared with nontransfused patients, P values .116, .018, and .015, respectively). In subgroup analysis, catheter-related BSIs displayed the strongest association with pRBC transfusion (OR = 5.01, P = .014).

Decreased plasma gelsolin is associated with 1-year outcome in patients with traumatic brain injury - Corrected Proof

Yong Jin, Bo-You Li, Ling-Li Qiu, Yuan-Ren Ling, Zhi-Qiang Bai — 2012-03-02

Abstract: Purpose: Decreased plasma gelsolin level has been associated with 1-month mortality after traumatic brain injury (TBI). Thus, we investigated the ability of gelsolin to predict 1-year mortality and functional outcome in these patients.Methods: One hundred fourteen healthy controls and 114 patients with acute severe TBI were included in this study. Plasma gelsolin concentration on admission was measured by ELISA.Results: Fifty-five patients (48.2%) had unfavorable outcome (Glasgow Outcome Scale score of 1-3) and 38 patients (33.3%) died in 1 year after TBI. Upon admission, plasma gelsolin level in patients was substantially lower than that in healthy controls. A multivariate analysis selected plasma gelsolin level as an independent predictor for 1-year unfavorable outcome and mortality of patients. A receiver operating characteristic curve analysis showed plasma gelsolin level predicted 1-year unfavorable outcome and mortality statistically significantly. The predictive value of the gelsolin concentration was thus similar to that of Glasgow Coma Scale (GCS) score. In a combined logistic-regression model, gelsolin did not statistically significantly improve the area under curve of GCS score.Conclusions: Plasma gelsolin level is a useful, complementary tool to predict functional outcome and mortality 1 year after TBI.

Usefulness of heart-type fatty acid–binding protein in patients with severe sepsis - Corrected Proof

Zhao-cai Zhang, Hai-wen Dai, Yi-hua Yu, Ji-dong Yang, Cai-bao Hu — 2012-03-02

Abstract: Purpose: The purpose of the study was to evaluate the value of heart-type fatty acid–binding protein (hFABP) as a novel clinical biomarker in patients with severe sepsis.Methods: Serum concentrations of hFABP and traditional cardiac biomarkers including cardiac troponin I, creatine kinase–MB, and B-type natriuretic peptides levels were measured within 6 hours after admission in 93 severe septic patients. The value of hFABP for the diagnosis of sepsis-related myocardial dysfunction (SRMD) and for the prediction of 28-day mortality was evaluated by receiver operating characteristics curve analysis. The prognostic value of elevated hFABP was subsequently confirmed by multivariate Cox proportional hazards analysis and Kaplan-Meier survival analysis.Results: Heart-type fatty acid–binding protein was elevated (≥4.5 ng/mL) in 58 (62.4%) patients; patients with elevated hFABP appeared more likely to have SRMD (84.5% vs 31.4%, P < .001) and have higher prevalence of 28-day death (37.9% vs 8.6%, P = .002). Heart-type fatty acid–binding protein offered superior value over conventional biomarkers in both diagnosis of SRMD (area under the curve, 0.767; P < .001) and prediction of 28-day death (area under the curve, 0.805; P < .001).Conclusions: Serum hFABP is frequently elevated among patients with severe sepsis and appears to be associated with SRMD. Elevated hFABP independently predicts 28-day mortality in severe sepsis.

Portable miniaturized extracorporeal membrane oxygenation systems for H1N1-related severe acute respiratory distress syndrome: A case series - Corrected Proof

2012-03-02

Abstract: Background: Technological advances improved the practice of “modern” extracorporeal membrane oxygenation (ECMO). In the present report, we describe the experience of a referral ECMO center using portable miniaturized ECMO systems for H1N1-related severe acute respiratory distress syndrome (ARDS).Methods: An observational study of all patients with H1N1-associated ARDS treated with ECMO in Hospital S. João (Porto, Portugal) between November 2009 and April 2011 was performed. Extracorporeal membrane oxygenation support was established using either ELS or Cardiohelp systems (Maquet-Cardiopulmonary-AG, Hirrlingen, Germany).Results: Ten adult patients with severe ARDS secondary to H1N1 infection (Pao2/fraction of inspired oxygen, 69 mm Hg [56-84]; Murray score, 3.5 [3.5-3.8]) were included, and 60% survived to hospital discharge. Five patients were uneventfully transferred on ECMO from referring hospitals to our center by ambulance. Six patients were treated during the first postpandemic influenza season. All patients were treated with oseltamivir, and 1 received in addition zanamivir. Four patients received corticosteroids. Nosocomial infection was the most common complication (40%). Of the 4 deaths, 2 were caused by hemorrhagic shock; 1, by irreversible multiple organ failure; and 1, by refractory septic shock.Conclusion: In our experience, ECMO support was a valuable therapeutic option for H1N1-related severe ARDS. The use of portable miniaturized systems allowed urgent rescue of patients from referring hospitals and safe interhospital and intrahospital transport during ECMO support.

A new parameter for the diagnosis of hemorrhagic shock: Jugular index - Corrected Proof

Nazire Belgin Akilli, Basar Cander, Zerrin Defne Dundar, Ramazan Koylu — 2012-03-02

Abstract: Purpose: The purpose of this study is to investigate whether there are any significant changes in the diameter and the area of the internal jugular vein (IJV) during the hemorrhagic shock.Materials and Methods: Healthy volunteers donating blood were included in the study. Arterial blood pressure, pulse rate, anteroposterior (AP) and transverse diameter, and area measurements of the IJV during inspiration and expiration were performed on the volunteers before and after 450 mL of blood donation.Results: A total of 35 volunteers were enrolled in the study. The IJV prehemorrhagic AP diameters during inspiration and expiration were 4.9 ± 2.2 and 7.9 ± 3.1 mm, and the posthemorrhagic values were 2.7 ± 1.6 and 6.6 ± 3.1 mm (respectively, P < .001 and P = .007). The jugular index–AP was 36% ± 15% before hemorrhage and 58% ± 17% after hemorrhage (P < .001). The IJV areas during inspiration and expiration were 0.40 ± 0.28 and 0.81 ± 0.51 cm2 before hemorrhage and were 0.14 ± 0.15 and 0.61 ± 0.47 cm2 after hemorrhage (for both, P < .001). The jugular index–area was found as 47% ± 18% before hemorrhage and as 73% ± 18% after hemorrhage (P < .001).Conclusions: We believe that measurement of the IJV and the jugular index is a reliable indicator of class 1 hemorrhagic shock. It may be used as a part of focused abdominal sonography for trauma in clinical practice.

Hypothermia attenuates the severity of oxidative stress development in asphyxiated newborns - Corrected Proof

2012-02-23

Abstract: Purpose: This retrospective case-control study aimed to examine the development of oxidative stress in asphyxiated infants delivered at more than 37 weeks of gestation.Material and Methods: Thirty-seven neonates were stratified into 3 groups: the first group experienced hypothermia (n = 6); the second received hypothermia cooling cup treatment for 3 days, normothermia (n = 16); and the third was the control group (n = 15).Serum total hydroperoxide (TH), biological antioxidant potential, and oxidative stress index (OSI) (calculated as TH/biological antioxidant potential) were measured within 3 hours after birth.Results: Serum TH and OSI levels gradually increased after birth in hypothermia and normothermia cases. At all time points, serum TH and OSI levels were higher in hypothermia and normothermia cases than in control cases. Serum TH and OSI levels were higher in normothermia cases than in hypothermia cases at days 3, 5, and 7.Conclusion: This study demonstrated that hypothermia attenuated the development of systemic oxidative stress in asphyxiated newborns.

Comparison of physician prediction with 2 prognostic scoring systems in predicting 2-year mortality after intensive care admission: A linked-data cohort study - Corrected Proof

Edward Litton, Kwok M. Ho, Steven A.R. Webb — 2012-02-16

Abstract: Purpose: Patients who survive an episode of critical illness continue to experience significant mortality after hospital discharge. This study assessed the accuracy of physician prediction of 2-year mortality and compared it with 2 objective prognostic models.Methods: Sensitivity (probability of a prediction of death in patients who died within 2 years) and specificity (probability of a prediction of survival in patients who survived at least 2 years) of physicians' 2-year prediction were compared with those from 2 objective prognostic models, Acute Physiology and Chronic Health Evaluation (APACHE) II and Predicted Risk Existing Disease Intensive Care Therapy (PREDICT).Results: Physician prediction of 2-year mortality was available for 2497 (94.8%) intensive care unit admissions. Specificity was high (85.2%; 95% confidence interval [CI], 83.7-86.4), but sensitivity (65.0%; 95% CI, 61.1-68.8) and positive predictive value (57.4%; 95% CI, 53.6-61.2) were relatively low, suggesting overpessimistic prediction of 2-year mortality. Age, Charlson comorbidity index, and APACHE score were independent risk factors for an inaccurate physician prediction. The diagnostic odds ratio for the physician predictions was at least comparable with the APACHE and PREDICT models, which both had very good discrimination of mortality at 2-year follow-up.Conclusions: Physicians tended to overpredict the risk of 2-year mortality of critically ill patients, but accuracy was comparable with 2 objective prognostic models.

US practitioner opinions and prescribing practices regarding corticosteroid therapy for severe sepsis and septic shock - Corrected Proof

2012-02-16

Abstract: Purpose: The aim of this study was to examine opinions and practices of US critical care practitioners (USCCPs) toward corticosteroid therapy in adult patients with severe sepsis or septic shock.Materials and Methods: A multicenter, electronic survey of USCCP members of the Society of Critical Care Medicine was conducted between March 18 and July 31, 2009.Results: A total of 542 USCCPs responded to the survey. The majority (83%) do not commonly use corticosteroids in adult patients with severe sepsis; however, up to 81% report use of corticosteroids for septic shock. Twenty-eight percent believe that corticosteroids reduce mortality in septic shock, whereas 27% do not and 45% are unsure. The decision to initiate therapy is based, more often, on a patient's clinical status (65%) vs serum cortisol analysis (35%). Hydrocortisone is the most common corticosteroid prescribed (93%), with a median dosage of 200 mg/d and administration via intermittent intravenous injection. The Corticosteroid Therapy of Septic Shock trial had a large impact on survey respondents, with 62% reporting a practice change. Among the 19% of practitioners who do not prescribe corticosteroids, the most common reason was lack of proven survival benefit.Conclusions: Corticosteroids are commonly used by USCCPs in adult patients with septic shock; however, criteria used to initiate therapy and opinions regarding their impact vary.

Adrenal insufficiency in cardiothoracic patients: An evaluation of the corticotrophin stimulation test and other diagnostic methods - Corrected Proof

2012-02-16

Abstract: Purpose: The purposes of the study were to determine the incidence of adrenal insufficiency (AI) using several published techniques, compare the response rates using a low-dose (LD) corticotropin (ACTH) stimulation test vs a standard dose (SD), and identify the technique that is most closely related to vasopressor use.Materials and Methods: Consecutive adult patients who were undergoing open heart surgery for CAD or valvular disease were prospectively enrolled. Exclusion criteria included history of steroid use, operative steroid, or etomidate administration. Postoperatively, each patient underwent ACTH stimulation with 1 μg (LD) and 249 μg (SD), 60 minutes apart. Agreement among the tests was evaluated, and vasopressor use was compared between groups.Results: There were 40 patients evaluated. The incidence of AI based on operative change, postoperative values, and LD-ACTH and SD-ACTH tests was 53%, 38%, 60%, and 38%, respectively. Agreement between the LD- and SD-ACTH tests was 73% (κ = 0.476, P = .001). There was a significant difference in the need for (93% vs 52%, P = .013) and duration (18.9 [0-180.6] vs 0.6 [0-73.2] hours, P = .003) of vasopressor therapy in patients with and without AI but only using the SD-ACTH definition.Conclusion: The incidence of AI will vary greatly based on technique used for diagnosis. The SD-ACTH stimulation test should be used to determine AI in open heart patients postoperatively because of the close association with vasopressor usage.

Central line placement in patients with and without prophylactic plasma - Corrected Proof

Gerardo P. Carino, Arseniy V. Tsapenko, Joseph D. Sweeney — 2012-02-16

Abstract: Central line placement (CLP) is a common life-saving intervention in critically ill patients, and patients with coagulation abnormalities as identified by an abnormal international normalized ratio (INR) may receive prophylactic plasma transfusion before the procedure despite previously published data that such a practice is not efficacious. Over a 14-month period, 287 CLPs were performed in the intensive care unit. The use of plasma preprocedure in patients with an elevated INR was generally discouraged but left to the discretion of the operator. A total of 100 lines were placed in patients with a preprocedure INR greater than 1.5, 27 of whom received prophylactic fresh frozen plasma. Only 1 case of bleeding was observed in a patient with an INR of 3.9, who received fresh frozen plasma preprocedure (0/73 vs 1/27; P = .6). The occurrence of bleeding was very low overall with CLP (0.3%; 95% confidence interval, 0%-2%), and no benefit of prophylactic plasma was observed.

Estimation of fluid status changes in critically ill patients: Fluid balance chart or electronic bed weight? - Corrected Proof

Antoine G. Schneider, Ian Baldwin, Elke Freitag, Neil Glassford, Rinaldo Bellomo — 2012-02-16

Abstract: Purpose: Monitoring of fluid balance (FB) can be achieved by subtracting recorded fluid output from input or by measuring changes in body weight (BW). The latter approach is difficult in the critically ill. Recently, hospital beds have become available with the ability to directly weigh patients in the intensive care unit (ICU) patients directly. We sought to compare FB estimates obtained by these 2 methods in a cohort of critically ill patients.Materials and Methods: Between November 2010 and May 2011, all patients admitted in our ICU for more than 2 consecutive days and nursed on a Hill-Rom (Batesville, Ind) Total Care bed were weighed daily at midnight hours. Fluids charting was done by electronic spreadsheet with automated 24 hours calculation. Differences in BW and FB between 2 consecutive days were compared using correlation and Bland-Altman analysis. Corrections for unmeasured fluids losses were performed using a predetermined formula based on peak temperature and intubation status.Results: We obtained complete data in 160 (31%) of 504 admissions exceeding 2 days (153 patients) resulting in 435 data points. The change in BW over 24 hours and FB for the same period was only weakly correlated before (r = 0.34; P < .001; Fig. 1) or after correction for insensible fluid losses (r = 0.34; P < .001). On Bland-Altman plot, the mean bias was small (0.07 kg), but the 95% limits of agreement, very large (−5.8 and 6.0 kg). The lack of agreement increased with the magnitude of the changes.Conclusion: Obtaining daily weights in ICU patients proved difficult. Compliance was poor. The correlation between changes in BWs and FB was weak. Further studies are required to establish if accurate and reproducible daily weighing of ICU patients is feasible.

Identification of deteriorating patients on general wards; measurement of vital parameters and potential effectiveness of the Modified Early Warning Score - Corrected Proof

Jeroen Ludikhuize, Susanne M. Smorenburg, Sophia E. de Rooij, Evert de Jonge — 2012-02-16

Abstract: Background and Purpose: Clear and detectable signs of deterioration have been shown to be present in many patients multiple hours before undergoing a serious life-threatening event. To date, few studies are available describing normal practice and the possible effectiveness of structured tools regarding recognition of deteriorating patients. The aim of this study was to describe the current practice in measurement and documentation of vital signs and the possible usefulness of the Modified Early Warning Score (MEWS) to identify deteriorating patients on hospital wards.Methods: A retrospective observational study of medical and surgical patients from 2007 with a severe adverse event including cardiopulmonary arrest, unplanned intensive care unit admission, emergency surgery, or unexpected death was performed. We studied all vital parameters that were collected and documented in the 48 hours before these events, and the MEWS was retrospectively calculated.Results: Two hundred four patients were included. In the 48 hours before the event, a total of 2688 measurements of one or more vital signs were taken. Overall, 81% of the patients had an MEWS value of 3 or more at least once during the 48 hours before their event. Recordings of vital signs were mostly incomplete. Even when the MEWS was 3 or more, respiratory rate, diuresis, and oxygen saturation were documented in only 30% to 66% of assessments.

Comparative study of pressure- and volume-controlled ventilation on stroke volume variation as a predictor of fluid responsiveness in patients undergoing major abdominal surgery - Corrected Proof

Ji Yeon Lee, Hee Yeon Park, Wol Seon Jung, Youn Yi Jo, Hyun Jeong Kwak — 2012-02-10

Abstract: Purpose: We hypothesized that the 2 ventilation modes might have a different influence on the stroke volume variation (SVV). This study investigated the effect of the ventilation modes on SVV as a predictor of fluid responsiveness during major abdominal surgery.Materials and Methods: Sixty patients were randomly allocated to volume-controlled ventilation (VCV, n = 30) or pressure-controlled ventilation (PCV, n = 30) modes. After the induction of anesthesia, hemodynamic variables and SVV were measured before and after volume expansion (VE) with colloid solution of 10 mL/kg. The ability of SVV to predict the fluid responsiveness was tested by calculation of the area under a receiver operating characteristic curve for an increase in stroke volume index of at least 15% after VE.Results: There were 10 and 16 responders in the VCV and PCV groups, respectively. The area under a receiver operating characteristic curve (95% confidence interval) for SVV before VE was 0.723 (0.538-0.907) and 0.799 (0.625-0.973) in the VCV and PCV groups, respectively. The optimal threshold value of SVV was 11% and 14% in the VCV and PCV groups, respectively.Conclusions: Stroke volume variation can predict fluid responsiveness during both VCV and PCV modes. However, the optimal threshold values of SVV may differ according to the ventilation modes.

Use of wireless motility capsule to determine gastric emptying and small intestinal transit times in critically ill trauma patients - Corrected Proof

2012-02-10

Abstract: Purpose: The purpose of this study is to use a novel wireless motility capsule to compare gastric emptying and small bowel transit times in critically ill trauma patients and healthy volunteers.Materials and Methods: We evaluated gastric emptying, small bowel transit time, and total intestinal transit time in 8 critically ill trauma patients. These data were compared with those obtained in 87 healthy volunteers from a separate trial. Data were obtained with a motility capsule that wirelessly transmitted pH, pressure, and temperature to a recorder attached to each subject's abdomen.Results: The gastric emptying time was significantly longer in critically ill patients (median, 13.9; interquartile range [IQR], 6.6-48.3 hours) than in healthy volunteers (median, 3.0; IQR, 2.5-3.9 hours), P < .001. The small bowel transit time in critically ill patients was significantly longer than in healthy volunteers (median, 6.7 hours; IQR, 4.4-8.5 hours vs median, 3.8 hours; IQR, 3.1-4.7 hours), P = .01. Furthermore, the capsules passed after 10 (IQR, 8.5-13) days in the critical care group and 1.2 (IQR, 0.9-1.9) days in healthy volunteers (P < .001).Conclusions: Both gastric emptying and small bowel transit were delayed in critically ill trauma patients.