Journal of Critical Care

2011 in Review

Philip D. Lumb — 2012-04-01

The Journal of Critical Care (JCC) Editorial Board reviewed the Journal's 2011 activities at its meeting on February 5, 2012, at the Society of Critical Care Medicine (SCCM) Annual Congress in Houston, Texas; the results are interesting and provide information about how the Journal is perceived by authors and readers alike. In summary, the number of submissions has increased (up 36% from the previous year), manuscript processing times have improved, the Journal's international presence continues to expand (with manuscripts submitted from 58 different countries in 2011), and electronic access (especially institutional access) has increased significantly.

Effects of intracellular acidosis on endothelial function: An overview

2011-07-28

Abstract: The endothelium represents the largest functional organ in the human body playing an active role in vasoregulation, coagulation, inflammation, and microvascular permeability. Endothelium contributes to maintain vascular integrity, intravascular volume, and tissue oxygenation promoting inflammatory network response for local defense and repair. Acid-basis homeostasis is an important physiologic parameter that controls cell function, and changes in pH can influence vascular tone by regulating endothelium and vascular smooth muscle cells. This review presents a current perspective of the effects of intracellular acidosis on the function and the basic regulatory mechanisms of endothelial cells.

Blood glucose amplitude variability as predictor for mortality in surgical and medical intensive care unit patients: a multicenter cohort study

2012-01-09

Abstract: Purpose: The aim of this study was to test the hypothesis that blood glucose amplitude variability (BGAV) is associated with mortality in critically ill patients.Method: A prospectively collected multicenter data set including all glucose measurements during intensive care unit (ICU) treatment and outcome was analyzed. We used logistic regression to assess the association between hospital mortality and standard deviation (SD), mean amplitude of glycemic excursions (MAGE), mean absolute glucose change per hour (MAG), and glycemic lability index (GLI). The analysis was adjusted for ICU, Acute Physiology And Chronic Health Evaluation IV–expected mortality, the presence of severe hypoglycemia, mean glucose, mean glucose measurement interval, and interaction between the latter 2.Results: There were 855 032 glucose measurements included of 20 375 patients admitted to 37 Dutch ICUs in 2008 and 2009. Median Acute Physiology And Chronic Health Evaluation IV–predicted mortality was 14%, and median glucose was 7.3 mmol/L. In all patients combined, adjusted hospital mortality was associated with SD and MAGE, but not with MAG and GLI. In surgical patients, adjusted hospital mortality was associated with SD, MAGE, and MAG, but not GLI. In medical patients, adjusted mortality was associated with SD but not with other BGAV measures.Conclusion: Not all BGAV measures were associated with mortality. Blood glucose amplitude variability as quantified by SD was consistently independently associated with hospital mortality.

Glucose variability negatively impacts long-term functional outcome in patients with traumatic brain injury

2011-10-28

Abstract: Purpose: Significant glycemic excursions (so-called glucose variability) affect the outcome of generic critically ill patients but has not been well studied in patients with traumatic brain injury (TBI). The purpose of this study was to evaluate the impact of glucose variability on long-term functional outcome of patients with TBI.Material and Methods: A noncomputerized tight glucose control protocol was used in our intensivist model surgical intensive care unit. The relationship between the glucose variability and long-term (a median of 6 months after injury) functional outcome defined by extended Glasgow Outcome Scale (GOSE) was analyzed using ordinal logistic regression models. Glucose variability was defined by SD and percentage of excursion (POE) from the preset range glucose level.Results: A total of 109 patients with TBI under tight glucose control had long-term GOSE evaluated. In univariable analysis, there was a significant association between lower GOSE score and higher mean glucose, higher SD, POE more than 60, POE 80 to 150, and single episode of glucose less than 60 mg/dL but not POE 80 to 110. After adjusting for possible confounding variables in multivariable ordinal logistic regression models, higher SD, POE more than 60, POE 80 to 150, and single episode of glucose less than 60 mg/dL were significantly associated with lower GOSE score.Conclusions: Glucose variability was significantly associated with poorer long-term functional outcome in patients with TBI as measured by the GOSE score. Well-designed protocols to minimize glucose variability may be key in improving long-term functional outcome.

Prevalence and significance of lactic acidosis in diabetic ketoacidosis

2011-10-28

Abstract: Purpose: The prevalence and clinical significance of lactic acidosis in diabetic ketoacidosis (DKA) are understudied. The objective of this study was to determine the prevalence of lactic acidosis in DKA and its association with intensive care unit (ICU) length of stay (LOS) and mortality.Methods: Retrospective, observational study of patients with DKA presenting to the emergency department of an urban tertiary care hospital between January 2004 and June 2008.Results: Sixty-eight patients with DKA who presented to the emergency department were included in the analysis. Of 68 patients, 46 (68%) had lactic acidosis (lactate, >2.5 mmol/L), and 27 (40%) of 68 had a high lactate (>4 mmol/L). The median lactate was 3.5 mmol/L (interquartile range, 3.32-4.12). There was no association between lactate and ICU LOS in a multivariable model controlling for Acute Physiology and Chronic Health Evaluation II, glucose, and creatinine. Lactate correlated negatively with blood pressure (r = −0.44; P < .001) and positively with glucose (r = 0.34; P = .004).Conclusions: Lactic acidosis is more common in DKA than traditionally appreciated and is not associated with increased ICU LOS or mortality. The positive correlation of lactate with glucose raises the possibility that lactic acidosis in DKA may be due not only to hypoperfusion but also to altered glucose metabolism.

Plasma-Lyte 148 vs 0.9% saline for fluid resuscitation in diabetic ketoacidosis

2012-04-01

Abstract: Purpose: The purpose of the study was to determine the effects of Plasma-Lyte 148 (PL) vs 0.9% saline (NS) fluid resuscitation in diabetic ketoacidosis (DKA).Methods: A multicenter retrospective analysis of adults admitted for DKA to the intensive care unit, who received almost exclusively PL or NS infusion up until 12 hours, was performed.Results: Nine patients with PL and 14 patients with NS were studied. Median serum bicarbonate correction was higher in the PL vs NS groups at 4 to 6 hours (8.4 vs 1.7 mEq/L) and 6 to 12 hours (12.8 vs 6.2 mEq/L) from baseline (P < .05). Median standard base excess improved by 10.5 vs 4.2 mEq/L at 4 to 6 hours and by 16.0 vs 9.1 mEq/L at 6 to 12 hours in the PL and NS groups, respectively (P < .05). Chloride levels increased significantly in the NS vs PL groups over 24 hours. Potassium levels were lower at 6 to 12 hours in the PL group. Mean arterial blood pressure was higher at 2 to 4 hours in the PL group, whereas cumulative urine output was lower at 4 to 6 hours in the NS group. There were no differences in glycemic control or duration of intensive care unit stay.Conclusion: Patients with DKA resuscitated with PL instead of NS had faster initial resolution of metabolic acidosis and less hyperchloremia, with a transiently improved blood pressure profile and urine output.

The association of mean glucose level and glucose variability with intensive care unit mortality in patients with severe acute pancreatitis

Yan-yan Zuo, Yan Kang, Wan-hong Yin, Bo Wang, Yao Chen — 2012-04-01

Abstract: Purpose: The objective of this study was to retrospectively analyze the association of mean glucose level (MGL) and glycemic lability index (GLI; as a measure of glucose variability) with intensive care unit (ICU) mortality in patients with severe acute pancreatitis (SAP).Materials and Methods: Paper-based medical records of patients with SAP who were admitted to the ICU of West China Hospital between July 1, 2005, and July 1, 2010, were analyzed. Glucose measurements, demographic characteristics, clinical features, data on the first and second 24-hour Acute Physiology and Chronic Health Evaluation (APACHE) II scores, and outcomes were obtained. Time-weighted glucose parameters were used. We statistically analyzed the relationship between these variables and both ICU and hospital mortality.Results: A total of 294 patients with 34 796 glucose measurements were included in the final analysis. The time-weighted MGL was 9.31 ± 1.91 mmol/L, and the median of GLI was 55.27 (mmol/L)2 h−1 wk−1. Intensive care unit mortality was 43.5% and increased progressively as GLI increased, reaching 62.5% of patients with GLI above 115.89 (mmol/L)2 h−1 wk−1. The highest odds ratio for ICU death was found in patients with the highest quartile of GLI: odds ratio, 3.47 (95% confidence interval, 1.76-6.86; P < .000). No such relationship could be found with MGL. Glycemic lability index was better able to predict ICU death than was MGL (the area under the curves were 0.642 vs 0.561, respectively; z test was 2.677; P = .0074). The logistic regression analysis showed that GLI, the second 24-hour APACHE II score, and the number of organ failures upon ICU admission contributed independently to the risk of mortality.Conclusions: We observed that GLI was a better predictor of ICU and hospital mortality than was MGL. Together with the second 24-hour APACHE II score and the number of organ failures upon ICU admission, GLI is an independent predictor of mortality in patients with SAP.

Stress hyperglycemia may not be harmful in critically ill patients with sepsis

2011-08-22

Abstract: Background: Stress hyperglycemia (SH) is commonly seen in critically ill patients. It has been shown to be associated with adverse outcomes in some groups of patients. The effects of SH on critically ill patients with sepsis have not been well studied. We aimed to evaluate the effects of SH in critically ill patients with sepsis.Methods: In this retrospective study, patients with sepsis admitted to intensive care unit (ICU) over a 5-year period were included.Results: Of 297 patients, 204 (68.7%) had SH during the study period. The mean blood glucose level in patients with SH was 8.7 mmol/L compared with 5.9 mmol/L in those without SH (P < .05). There were no statistically significant differences in age; sex; sepsis severity; cardiovascular, respiratory, and renal comorbidities; requirement of mechanical ventilation; inotropes; and Acute Physiology, Age, and Chronic Health Evaluation III and Simplified Acute Physiology 2 scores on ICU admission. Intensive care unit mortality was significantly lower in patients who had SH. The median duration of ICU and hospital length of stay was longer in patients with SH. On logistic regression analysis, the presence of SH was associated with reduced ICU mortality. Subgroup analysis revealed SH to be protective in patients with septic shock.Conclusion: Stress hyperglycemia may not be harmful in critically ill patients with sepsis. Patients with SH had lower ICU mortality.

Incidence and risk factors for sepsis in surgical patients: A cohort study

2011-12-15

Abstract: Purpose: The aim of the study was to evaluate risk factors for infection and sepsis in surgical patients admitted to the intensive care unit (ICU).Materials and Methods: Data were prospectively collected from a cohort of surgical patients from January 2005 to December 2007. We analyzed the incidence of infection and sepsis and certain other variables from the pre-, intra-, and postoperative periods as risk factors for infection and sepsis.Results: We studied 625 surgical patients. The mortality rate was 18.2%, and the mean age of the subjects was 53.1 ± 18.8 years. The incidences of severe sepsis and septic shock were 5% and 11.5%, respectively. A multivariate analysis showed that the following variables were associated with sepsis in the postoperative period: urgent surgery (odds ratio, 2.63; 95% confidence interval [CI], 1.50-4.63), fluid resuscitation (odds ratio, 1.90; 95% CI, 1.18-3.05), vasoactive drugs (odds ratio, 2.58; 95% CI, 1.61-4.14), and mechanical ventilation (odds ratio, 5.51; 95% CI, 3.07-9.89). A Sequential Organ Failure Assessment was associated with infection or sepsis upon ICU admission (area under the curve, 0.737 ± 0.019; 95% CI, 0.748-0.825).Conclusions: This study showed that sepsis has high incidence and mortality in surgical patients admitted to the ICU. Urgent surgeries, mechanical ventilation, fluid resuscitation, and vasoactive drugs in the postoperative period and Sequential Organ Failure Assessment at ICU admission were risk factors for sepsis.

Relationship between the timing of administration of IgM and IgA enriched immunoglobulins in patients with severe sepsis and septic shock and the outcome: A retrospective analysis

2011-07-07

Abstract: Purpose: Because the use of IgM and IgA enriched polyclonal intravenous immunoglobulins (eIg) is a standard of care in critically ill patients admitted to our intensive care unit (ICU) with the diagnosis of severe sepsis or septic shock, we investigated if the delay from the onset of severe sepsis and septic shock and their administration could influence the outcome.Materials and Methods: The medical records of all patients with severe sepsis or septic shock admitted to our ICU from July 2004 through October 2009 and treated with eIg (Pentaglobin®; Biotest, Dreieich, Germany) were retrospectively examined.Results: A total of 129 adult patients with severe sepsis or septic shock were considered eligible. Thirty-two percent of patients died during the ICU stay. Survivors were given eIg significantly earlier than nonsurvivors (23 vs 63 hours, P < .05). The delay in the administration of eIg and the Simplified Acute Physiology Score II were the only variables that entered stepwise a propensity score-adjusted logistic model. The delay in the administration of eIg was a significant predictor of the odds of dying during the ICU stay (odds ratio for 1 hour of delay, 1.007; P < .01; 99% confidence interval from 1.001 to 1.010) and proved to be independent from the Simplified Acute Physiology Score II and other variables.Conclusions: The efficacy of eIg, being maximal in early phases of severe sepsis and/or septic shock, is probably time dependent.

High-frequency oscillatory ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease

2011-06-29

Abstract: Purpose: High-frequency oscillatory ventilation (HFOV) is usually considered not indicated for treatment of patients with chronic obstructive pulmonary disease (COPD) because of the theoretical risk of air trapping and hyperinflation. The aim of our study was to establish whether HFOV can be safely applied in patients with acute exacerbation of COPD and hypercapnic respiratory failure.Methods: Ten patients (age, 63-83 years) requiring intensive care treatment who failed on noninvasive ventilation were studied. After initial conventional mechanical ventilation (CMV) of less than 72 hours, all patients were transferred to HFOV for 24 hours and then back to CMV. Arterial blood gases, spirometry, and hemodynamic parameters were repeatedly obtained in all phases of CMV and HFOV at different settings. Regional lung aeration and ventilation were assessed by electrical impedance tomography.Results: High-frequency oscillatory ventilation was tolerated well; no adverse effects or severe hyperinflation and hemodynamic compromise were observed. Effective CO2 elimination and oxygenation were achieved. Ventilation was more homogeneously distributed during HFOV than during initial CMV. Higher respiratory system compliance and tidal volume were found during CMV after 24 hours of HFOV.Conclusions: Our study indicates that short-term HFOV, using lower mean airway pressures than recommended for acute respiratory distress syndrome, appears safe in patients with COPD while securing adequate pulmonary gas exchange.

High-frequency oscillatory ventilation with and without arteriovenous extracorporeal lung assist in patients with severe respiratory failure

2011-10-28

Abstract: Purpose: Elimination of carbon dioxide by an arteriovenous extracorporeal lung assist (av-ECLA) can facilitate the lung protective capabilities of high-frequency oscillatory ventilation (HFOV). This case series describes patients treated with HFOV because of severe respiratory failure with and without additional av-ECLA.Methods: A retrospective analysis of 31 patients regarding patient characteristics, gas exchange, respirator settings, hemodynamics, and outcome. In 18 patients, av-ECLA was started before, together with, or during HFOV.Results: The initial arterial carbon dioxide tension before HFOV and av-ECLA was higher in patients who received av-ECLA compared with patients without (P = .043): 65 (48-84) mm Hg and 50 (44-60) mmHg (median and interquartile range). The initial arterial oxygen tension (Pao2)/inspiratory oxygen fraction (Fio2) index in patients who received av-ECLA was 79 (63-133) mm Hg. The Pao2/Fio2 index immediately before HFOV was 84 (65-124) mm Hg (av-ECLA) and 121 (68-150) mmHg (no av-ECLA) and improved to 149 (89-231) mm Hg and 200 (117-233) mmHg during HFOV. Similarly, the oxygenation index improved. No statistically significant differences among groups were detected for Pao2/Fio2 index, oxygenation index, and arterial carbon dioxide tension immediately before and during HFOV. The hospital mortality was 39% (av-ECLA) and 69% (no av-ECLA).Conclusions: High-frequency oscillatory ventilation improved the oxygenation in patients with severe respiratory failure. Additional av-ECLA may facilitate using lung protective HFOV settings in more severe lung injury and hypercapnia.

Effectiveness of extracorporeal membrane oxygenation when conventional ventilation fails: Valuable option or vague remedy?

Ravindranath Tiruvoipati, John Botha, Giles Peek — 2011-06-24

Abstract: The mortality and morbidity of patients with severe acute respiratory distress syndrome (ARDS) remains high despite the advances in intensive care practice. The low-tidal-volume ventilation strategy (ARDS net protocol) has been shown to be effective in improving survival. Unfortunately, however, some patients have such severe ARDS that they cannot be managed with the ARDS net strategy. In these patients, rescue therapies such as high-frequency ventilation, prone ventilation, nitric oxide, and extracorporeal membrane oxygenation (ECMO) are considered. The CESAR trial has shown that an ECMO-based protocol improved survival without severe disability as compared with conventional ventilation. The recent increased incidence of severe respiratory failure due to H1N1 influenza pandemic has led to an increased use of ECMO. Although several reports showed ECMO use to be encouraging, some scepticism remains. In this article, we reviewed the usefulness of ECMO in patients with severe ARDS in the light of current evidence.

Emotional consequences of intensive care unit delirium and delusional memories after intensive care unit admission: A systematic review

2011-09-29

Abstract: Purpose: The aim of this study was to review literature exploring the emotional consequences of delirium and delusional memories in intensive care unit patients.Methods: A systematic review was performed using PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, and PsychINFO.Results: Fourteen articles were eligible for this review. Five of them assessed delirium during intensive care unit admission, and the remainder assessed delusional memories during or after admission. No association was found for delirium and adverse emotional outcome. Data regarding delusional memories and emotional outcome were heterogenic. Some studies presented worse scores on posttraumatic stress disorder screening tools in patients with delusional memories, whereas other studies found better scores in patients with delirium or delusional memories.Conclusions: Based on current literature, no relationship could be shown for delirium and emotional outcome. Regarding delusional memories and adverse emotional outcome, results were in contradiction.

Comparison of CAM-ICU and ICDSC for the detection of delirium in critically ill patients focusing on relevant clinical outcomes

2011-07-07

Abstract: Purpose: Delirium is a frequent and serious problem in the intensive care unit (ICU) that is associated with increased mortality, prolonged mechanical ventilation, and prolonged hospital length of stay (LOS). The main objective of the present study was to compare and assess the agreement between the diagnosis of delirium obtained by the Confusion Assessment Method for the ICU (CAM-ICU) and Intensive Care Delirium Screening Checklist (ICDSC) in patients admitted to the ICU and their association with outcomes.Methods: Adult patients admitted to the ICU for more than 24 hours between May and November 2008 were included. Patients with a Richmond Agitation-Sedation Scale score of −4 to −5 for more than 3 days were excluded. Delirium was evaluated twice a day by the ICDSC and CAM-ICU. Patients were followed-up until ICU discharge or for a maximum of 28 days.Results: During the study period, 383 patients were admitted to the ICU and 162 (42%) were evaluated; delirium was identified in 26.5% of patients by CAM-ICU and in 34.6% by ICDSC. There was agreement in diagnosing delirium diagnosis between the 2 methods in 42 (27.8%) patients and in excluding delirium in 105 (64.8%) patients. The ICDSC was positive in 14 (8.6%) patients in whom CAM-ICU was negative. Delirium, diagnosed either by ICDSC or CAM-ICU assessments, was associated with both significantly increased hospital LOS (14.8 ± 8.3 vs 9.8 ± 6.4, P < .001; 15.3 ± 8.7 vs 10.5 ± 7.1, P < .001, respectively), mortality in the ICU (11.1% vs 5.8%, P < .001; 12.5% vs 2.5%, P = .022), and in the hospital (10.7% vs 5.6%, P < .001; 23.2% vs 10.9%, P = .047). In addition, patients with positive ICDSC presenting with negative CAM-ICU had similar outcomes as compared with those without delirium.Conclusion: The findings of our study suggest that the CAM-ICU is better predictor of outcome when compared with ICDSC.

Implementation challenges in the intensive care unit: The why, who, and how of daily interruption of sedation

Melissa A. Miller, Emily A. Bosk, Theodore J. Iwashyna, Sarah L. Krein — 2012-01-09

Abstract: Purpose: Despite strong medical evidence and policy initiatives supporting the use of daily interruption of sedation in mechanically ventilated patients, compliance remains suboptimal. We sought to identify new barriers to daily interruption of sedation.Materials and Methods: We conducted 5 focus groups of intensive care unit physicians, nurses, and respiratory therapists during a 2-month period to identify attitudes, barriers, and motivations to perform a daily interruption of sedation. Each focus group was audiotaped, and the transcripts were analyzed using qualitative methods to identify recurrent themes.Results: There was wide consensus on the importance of daily interruptions of sedation; however, practitioners usually performed sedation interruption for 1 of 5 distinct reasons: minimizing the dose of sedation, performing a neurologic examination, facilitating ventilator weaning, reducing intensive care unit length of stay, and assessing patient pain. Participants rarely espoused more than 1 main reason, and there was no shared understanding of why one might do a daily interruption of sedation. This lack of shared understanding led to different patients being selected and diverse approaches to carrying out the DIS.Conclusions: Despite apparent consensus, lack of shared understanding of the rationale for an intervention may lead to divergent practice patterns and failure to implement standardized, evidence-based practice.

Feasibility of continuous multiorgan variability analysis in the intensive care unit

Beverly Bradley, Geoffrey C. Green, Izmail Batkin, Andrew J.E. Seely — 2011-12-15

Abstract: Purpose: The aim of the study was to evaluate the feasibility of continuous heart and respiratory rate variability (HRV and RRV, respectively) monitoring in critically ill patients derived from electrocardiogram (ECG) and end-tidal capnography (etCO2) waveforms.Methods: Thirty-four patients (age, 56.5 ± 15.9 years; Acute Physiology and Chronic Health Evaluation II score, 22.8 ± 6.7) underwent continuous recording of ECG and etCO2 waveforms from intensive care unit admission and intubation to discharge or maximum of 14 days. Overlapping 5-minute windows were analyzed with a wide range of variability measures (time, frequency, entropy, and scale-invariant and nonlinear domains). Waveform data quality, presence of disconnections and arrhythmias, quality of beat and breath detection, and subsequent variability computations were evaluated.Results: Patients were enrolled for 11.0 ± 3.6 days. The proportion of missing waveform data among all patients was (median [interquartile range, maximum]) 2.9% (1.3%-9.7%, 36.4%) for ECG and 3.1% (1.1%-11.4%, 84.5%) for etCO2. Heart rate variability data loss (ie, proportion of windows removed) was 1.3% (1.0%-2.1%, 5.9%) due to disconnection, 0.6% (0.1%-3.9%, 39.5%) due to atrial fibrillation, and 6.6% (1.4%-17.9%, 89.0%) due to data cleaning. Respiratory rate variability data loss was 7.3% (2.9%-11.6%, 47.7%) due to disconnection (or apnea) and 5.5% (2.9%-8.4%, 56.4%) due to cleaning. Continuous individualized multiorgan variability analysis processing resulted in HRV and RRV computations for 81.2% ± 25.0% and 87.5% ± 11.9% of available ECG and etCO2 waveform data, respectively.Conclusions: The quality of continuously recorded ECG and etCO2 waveforms in critically ill patients is adequate for subsequent continuous variability monitoring in this pilot study. The clinical utility of continuous variability analysis merits further investigation.

Feasibility and observed safety of interactive video games for physical rehabilitation in the intensive care unit: a case series

Michelle E. Kho, Abdulla Damluji, Jennifer M. Zanni, Dale M. Needham — 2011-09-26

Abstract: Background: Early rehabilitation in the intensive care unit (ICU) improves patients' physical function. Despite reports of using commercially available interactive video game systems for rehabilitation, there are few data evaluating feasibility and safety as part of routine in-patient rehabilitation, particularly in the ICU.Methods: We conducted an observational study from September 1, 2009, to August 31, 2010, of adults admitted to a 16-bed medical ICU receiving video games as part of routine physical therapy (PT), evaluating use and indications and occurrence of 14 prospectively monitored safety events.Results: Of 410 patients receiving PT in the medical ICU, 22 (5% of all patients; male, 64%; median age, 52 years) had 42 PT treatments with video games (median [interquartile range] per patient, 1.0 [1.0-2.0]). Main indications for video game therapy included balance (52%) and endurance (45%), and the most common activities included boxing (38%), bowling (24%), and balance board (21%). Of 42 treatments, 69% occurred while standing and 45% while mechanically ventilated. During 35 hours of PT treatment, 0 safety events occurred (95% upper confidence limit for safety event rate, 8.4%).Conclusions: Novel use of interactive video games as part of routine PT in critically ill patients is feasible and appears safe in our case series. Video game therapy may complement existing rehabilitation techniques for ICU patients.

Use of simulation-based education to improve resident learning and patient care in the medical intensive care unit: A randomized trial

2011-10-28

Abstract: Purpose: The purpose of this study is to determine the effect of simulation-based education on the knowledge and skills of internal medicine residents in the medical intensive care unit (MICU).Methods and Materials: From January 2009 to January 2010, 60 first-year residents at a tertiary care teaching hospital were randomized by month of rotation to an intervention group (simulator-trained, n = 26) and a control group (traditionally trained, n = 34). Simulator-trained residents completed 4 hours of simulation-based education before their medical intensive care unit (MICU) rotation. Topics included circulatory shock, respiratory failure, and mechanical ventilation. After their rotation, residents completed a standardized bedside skills assessment using a 14-item checklist regarding respiratory mechanics, ventilator settings, and circulatory parameters. Performance of simulator-trained and traditionally trained residents was compared using a 2-tailed independent-samples t test.Results: Simulator-trained residents scored significantly higher on the bedside skills assessment compared with traditionally trained residents (82.5% ± 10.6% vs 74.8% ± 14.1%, P = .027). Simulator-trained residents were highly satisfied with the simulation curriculum.Conclusions: Simulation-based education significantly improved resident knowledge and skill in the MICU. Knowledge acquired in the simulated environment was transferred to improved bedside skills caring for MICU patients. Simulation-based education is a valuable adjunct to standard clinical training for residents in the MICU.

Noninvasive ventilation with helium-oxygen in children

Federico Martinón-Torres — 2011-09-29

Abstract: Most existing literature on noninvasive ventilation (NIV) in combination with helium-oxygen (HELIOX) mixtures focuses on its use in adults, basically for treatment of acute exacerbations of chronic obstructive pulmonary disease. This article reviews and summarizes the theoretical basis, existing clinical evidence, and practical aspects of the use of NIV with HELIOX in children. There is only a small body of literature on HELIOX in pediatric NIV but with positive results. The reported experience focuses on treatment for patients with severe acute bronchiolitis who cannot be treated with standard therapies. The inert nature of helium adds no biological risk to NIV performance. Noninvasive ventilation with HELIOX is a promising therapeutic option for children with various respiratory pathologies who do not respond to conventional treatment. Further controlled studies should be warranted.

Procalcitonin level as an aid for the diagnosis of bacterial infections following pediatric cardiac surgery

2011-09-29

Abstract: Purpose: The aim of the present study was to determine if blood procalcitonin can serve as an aid to differentiate between bacterial and nonbacterial cause of fever in children after cardiac surgery.Materials and Methods: A nested case-control study of children who underwent open cardiac surgery in critical care units of fourth-level pediatric hospital was performed. Blood samples for procalcitonin level were collected 1 day before operation; 1 hour postoperation; on postoperative days 1, 2, and 5; and on the day of fever, when it occurred.Results: Of 665 children who underwent cardiac bypass surgery, 126 had a febrile episode postoperatively, 47 children with a proven bacterial infection and 79 without bacterial infection. Among the 68 children in whom fever developed within the first 5 postoperative days, procalcitonin level at fever day was significantly higher in those with bacterial infection (n = 16) than in those without infection (n = 52). Similarly, among the 58 children in whom fever developed after day 5 postoperation, a significant difference was found in procalcitonin level at fever day between those with (n = 31) and without (n = 27) bacterial infection.Conclusion: During the critical early and late periods after cardiac surgery in children, procalcitonin level may help to differentiate patients with bacterial infection from patients in whom the fever is secondary to nonbacterial infectious causes.

Weaning predictors do not predict extubation failure in simple-to-wean patients

2011-09-29

Abstract: Background: Predictor indexes are often included in weaning protocols and may help the intensive care unit (ICU) staff to reach expected weaning outcome in patients on mechanical ventilation.Objective: The objective of this study is to evaluate the potential of weaning predictors during extubation.Design: This is a prospective clinical study.Settings: The study was conducted in 3 medical-surgical ICUs.Patients: Five hundred consecutive unselected patients ventilated for more than 48 hours were included.Methods and Measurements: All patients were extubated after 30 minutes of successful spontaneous breathing trial and followed up for 48 hours. The protocol evaluated hemodynamics, ventilation parameters, arterial blood gases, and the weaning indexes frequency to tidal volume ratio; compliance, respiratory rate, oxygenation, and pressure; maximal inspiratory pressure; maximal expiratory pressure; Pao2/fraction of inspired oxygen; respiratory frequency; and tidal volume during mechanical ventilation and in the 1st and 30th minute of spontaneous breathing trial.Results: Reintubation rate was 22.8%, and intensive care mortality was higher in the reintubation group (10% vs 31%; P < .0001). The areas under the receiver operating characteristic curve showed that tests did not discriminate which patients could tolerate extubation.Conclusion: Usual weaning indexes are poor predictors for extubation outcome in the overall ICU population.

Physiologic determinants of prolonged mechanical ventilation in patients after major surgery

2011-10-28

Abstract: Purpose: The aim of the study was to evaluate the physiologic determinants of ventilator dependency in patients who underwent major surgery.Materials and Methods: In this observational study, 43 stable tracheostomized patients undergoing prolonged ventilation (>14 days) were evaluated. Diaphragmatic muscle function was assessed invasively by the tension-time index of the diaphragm (TTdi), an indicator of diaphragm endurance time. The TTdi was calculated as transdiaphragmatic pressure/maximum transdiaphragmatic pressure × inspiratory time/total respiratory time and was recorded either when weaning from mechanical ventilation had finally been successful (n = 28 patients) or at the end of the fifth week in those patients in whom weaning failed (FW) (n = 15). Furthermore, the characteristics of survivors (n = 33) were compared with those of nonsurvivors (n = 10).Results: Successfully weaned patients had a lower breathing frequency/tidal volume or rapid shallow breathing index compared with FW patients (93.9 ± 45.5 vs 142.4 ± 60.3, respectively; P < .005). The TTdi was significantly higher in FW than in successfully weaned patients (0.107 ± 0.050 vs 0.148 ± 0.059; P < .023) and in nonsurvivors than in survivors (0.106 ± 0.046 vs 0.174 ± 0.058, P < .0001, respectively). A transdiaphragmatic pressure/maximum transdiaphragmatic pressure ratio of more than 40% was an independent predictor of mortality, whereas an increased frequency/tidal volume ratio and TTdi were independent predictors of weaning failure.Conclusions: Difficult-to-wean patients after major surgery have overall a limited diaphragm endurance time, in particular, FW breathe very close to the fatigue threshold, and they adopt a rapid shallow breathing respiratory pattern to avoid crossing this threshold.

The evaluation of the effect of body positioning on intra-abdominal pressure measurement and the effect of intra-abdominal pressure at different body positioning on organ function and prognosis in critically ill patients

Min Yi, Yuxin Leng, Yu Bai, Gaiqi Yao, Xi Zhu — 2011-10-28

Abstract: Purpose: Current literatures confirmed the widespread and frequent development of both intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) among the critically ill with a significant associated risk of organ failure and increased mortality. The 2004 International ACS Consensus Conference committee proposed that intra-abdominal pressure (IAP) be measured in complete supine position; however, the supine position of intensive care unit (ICU) patients (<30° of bed increase) presented a significant risk for ventilator-associated pneumonia. Therefore, the potential contribution of head of bed (HOB) position in elevating IAP should be considered. The purpose of this study was to evaluate the effect of body positioning on IAP measurement and the effect of IAP at different body positions on organ function and prognosis in critically ill patients.Materials and Methods: A prospective cohort study to investigate the effect of different patient positioning on IAP, organ function, and prognosis was conducted on 88 patients admitted to a medical-surgical ICU. On admission, patients' epidemiological data and risk factors for IAH were studied; daily mean IAPs, abdominal perfusion pressure, filtration gradient, Acute Physiology and Chronic Health Evaluation II score, sequential organ failure assessment score, and multiple organ dysfunction scores were registered; next, conventional hemodynamic variables, intrathoracic blood volume index, global end-diastolic volume index and extravascular lung water using the pulse contour cardiac output system were recorded. Intra-abdominal pressures were recorded through a bladder catheter every 4 hours on the first day. Intra-abdominal pressure was measured with the patient HOB increases from 0° to 45°. Mean arterial pressure was recorded simultaneously, whereas abdominal perfusion pressure and filtration gradient (FG) were also calculated simultaneously.Results: The main results of this study were the incidence of IAH (28.4%) and ACS (2.3%) in ICU patients; the significant and independent relationship between IAP and HOB increases. Considering the absolute numbers of IAP, the HOB of 10° and 20° showed slight differences, whereas that of 30° and 45° showed clinically significant differences; HOB elevation was associated with clinically significant decreases in abdominal perfusion pressure and FG; patients with IAH were prone to the development of shock and multiple organ dysfunction syndrome and exhibited significantly lower intrathoracic blood volume index and global end-diastolic volume index and higher extravascular lung water.Conclusions: There is a significant and independent relationship between IAP and HOB positioning in critically ill patients, with the HOB of 30° and 45° showing significant difference. Abdominal perfusion pressure and FG are significantly decreased when the patient's HOB is elevated. The potential contribution of body position in elevating IAP should be considered in critically ill patients with the risk of IAH and ACS.

2012-04-01

Editorial Board

2012-04-01

Journal of Critical Care

2011 in Review

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The evaluation of the effect of body positioning on intra-abdominal pressure measurement and the effect of intra-abdominal pressure at different body positioning on organ function and prognosis in critically ill patients

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