Higher Intensive Care Unit Mortality Research Articles

Acute kidney injury in critical ill patients affected by influenza A (H1N1) virus infection

IntroductionLittle information exists about the impact of acute kidney injury (AKI) in critically ill patients with the pandemic 2009 influenza A (H1N1) virus infection.MethodsWe conducted a prospective, observational, multicenter study in 148 Spanish intensive care units (ICUs). Patients with chronic renal failure were excluded. AKI was defined according to Acute Kidney Injury Network (AKIN) criteria.ResultsA total of 661 patients were analyzed. One hundred eighteen (17.7%) patients developed AKI; of these, 37 (31.4%) of the patients with AKI were classified as AKI I, 15 (12.7%) were classified as AKI II and 66 (55.9%) were classified as AKI III, among the latter of whom 50 (75.7%) required continuous renal replacement therapy. Patients with AKI had a higher Acute Physiology and Chronic Health Evaluation II score (19.2 ± 8.3 versus 12.6 ± 5.9; P < 0.001), a higher Sequential Organ Failure Assessment score (8.7 ± 4.2 versus 4.8 ± 2.9; P < 0.001), more need for mechanical ventilation (MV) (87.3% versus 56.2%; P < 0.01, odds ratio (OR) 5.3, 95% confidence interval (CI) 3.0 to 9.4), a greater incidence of shock (75.4% versus 38.3%; P < 0.01, OR 4.9, 95% CI, 3.1 to 7.7), a greater incidence of multiorgan dysfunction syndrome (92.4% versus 54.7%; P < 0.01, OR 10.0, 95% CI, 4.9 to 20.21) and a greater incidence of coinfection (23.7% versus 14.4%; P < 0.01, OR 1.8, 95% CI, 1.1 to 3.0). In survivors, patients with AKI remained on MV longer and ICU and hospital length of stay were longer than in patients without AKI. The overall mortality was 18.8% and was significantly higher for AKI patients (44.1% versus 13.3%; P < 0.01, OR 5.1, 95% CI, 3.3 to 7.9). Logistic regression analysis was performed with AKIN criteria, and it demonstrated that among patients with AKI, only AKI III was independently associated with higher ICU mortality (P < 0.001, OR 4.81, 95% CI 2.17 to 10.62).ConclusionsIn our cohort of patients with H1N1 virus infection, only those cases in the AKI III category were independently associated with mortality.

Intensive care-acquired hypernatremia after major cardiothoracic surgery is associated with increased mortality

Hypernatremia is common in the medical Intensive Care Unit (ICU) and has been described as an independent risk factor for mortality. Hypernatremia has not yet been studied in a collection of ICU patients after cardiothoracic surgery. Therefore, we wanted to determine the incidence of hypernatremia in a surgical ICU and its association with outcomes of critically ill surgical patients. In this retrospective cohort study performed at a surgical ICU of a university hospital in Vienna, patients were admitted to the ICU after major cardiothoracic surgery between May 1999 and October 2007. Data on serum sodium in the ICU, ICU mortality, hospital mortality, and length of ICU stay were collected prospectively. 2,699 patients underwent surgery during the study period, and 2,314 patients were included in the study. Two hundred twenty-one (10%) patients acquired hypernatremia during their ICU stay. Median onset of hypernatremia was on day 4 (2-7). Patients with ICU-acquired hypernatremia had a higher ICU mortality (19%) compared to patients without hypernatremia (8%; p < 0.01). Length of ICU stay was increased in patients with hypernatremia (17 vs. 3 days; p < 0.01). In a multivariate Cox regression, ICU-acquired hypernatremia was an independent risk factor for ICU mortality within 28 days. Hypernatremia is a common event early in the course of critical illness after major cardiothoracic surgery and is independently associated with ICU mortality within 28 days. Future research should focus on the impact of hypernatremia on physiological functions as well as adequate and safe treatment of the electrolyte disorder.

Who is at increased risk for acute kidney injury following noncardiac surgery?

Abelha and colleagues evaluated the incidence and determinants of postoperative acute kidney injury (AKI) after major noncardiac surgery in patients with previously normal renal function. In this retrospective study of 1,166 patients with no previous renal insufficiency, who were admitted to a postsurgical intensive care unit (ICU) over a 2-year period, the incidence of AKI was 7.5%. Multivariate analysis identified American Society of Anesthesiologists physical status, Revised Cardiac Risk Index, high-risk surgery and congestive heart disease as preoperative AKI risk factors. AKI was an independent risk factor for hospital mortality (odds ratio = 3.12, 95% confidence interval = 1.41 to 6.93; P = 0.005), and was associated with higher severity of illness scores (Simplified Acute Physiology Score II and Acute Physiology and Chronic Health Evaluation II), longer ICU length of stay, higher ICU mortality, increased hospital mortality and higher mortality at 6-month follow up. Although the study design excluded 121 patients with significant preoperative renal insufficiency by design, the relatively crude serum creatinine cut-offs used certainly permitted inclusion of numerous patients with preoperative renal impairment. Accordingly, the study design failed to quantify the impact of preoperative renal impairment on risk and outcomes of perioperative AKI in noncardiac surgery, and this should be a goal of such studies in the future. Nonetheless, the study is an important addition to the literature in an under-studied population of patients at high risk for AKI.

The acquisition and outcome of ICU-acquired Clostridium difficile infection in a single centre in the UK

The clinical course and outcome of Clostridium difficile infection (CDI) in the intensive care unit (ICU) setting have been reported in a small number of studies in the US and Canada. However, no such study has been reported in the UK. Therefore, we aimed to study the acquisition rate and outcome of ICU-acquired CDIs in our unit. Patient admissions to the ICU and nosocomial infection databases from April 2004 to April 2007 were reviewed to identify study groups, followed by retrospective case note review. Patients who acquired CDI prior to ICU admission were excluded. Sixty-two patients (31 males) who acquired CDI during their ICU stays were included in our study. The acquisition rate of CDI ranged from 1.52 to 4.78% per year. The median APACHE II score was 18, and the median interval between ICU admission and acquisition of CDI was 7 days. The median ICU stay was 16 days. Of the 62 patients, 13 (20.97%) died in the ICU. Of the 49 patients who were discharged, 41 were discharged ultimately from the hospital. Thus, the overall mortality attributable to CDI acquired in the ICU was 33.87%, compared to the average baseline mortality of 29% in our unit. Univariate analysis showed that increasing age (p = 0.004), APACHE II score (p=0.007), and male gender (p = 0.05) were significantly associated with ICU mortality in patients who acquired CDI in the ICU. Multivariate analysis showed that only increasing age (p = 0.031; OR 1.141, CI 1.013-1.287) was significantly associated with higher ICU mortality. Patients admitted to the ICU have a moderate risk of acquiring CDI. There is a small increase in mortality observed in patients who acquired CDI in the ICU. Increasing age is an independent predictor associated with mortality.

Impact of energy deficit calculated by a predictive method on outcome in medical patients requiring prolonged acute mechanical ventilation

To assess energy balance in very sick medical patients requiring prolonged acute mechanical ventilation and its possible impact on outcome, we conducted an observational study of the first 14 d of intensive care unit (ICU) stay in thirty-eight consecutive adult patients intubated at least 7 d. Exclusive enteral nutrition (EN) was started within 24 h of ICU admission and progressively increased, in absence of gastrointestinal intolerance, to the recommended energy of 125.5 kJ/kg per d. Calculated energy balance was defined as energy delivered - resting energy expenditure estimated by a predictive method based on static and dynamic biometric parameters. Mean energy balance was - 5439 (sem 222) kJ per d. EN was interrupted 23 % of the time and situations limiting feeding administration reached 64 % of survey time. ICU mortality was 72 %. Non-survivors had higher mean energy deficit than ICU survivors (P = 0.004). Multivariate analysis identified mean energy deficit as independently associated with ICU death (P = 0.02). Higher ICU mortality was observed with higher energy deficit (P = 0.003 comparing quartiles). Using receiver operating characteristic curve analysis, the best deficit threshold for predicting ICU mortality was 5021 kJ per d. Kaplan-Meier analysis showed that patients with mean energy deficit > or =5021 kJ per d had a higher ICU mortality rate than patients with lower mean energy deficit after the 14th ICU day (P = 0.01). The study suggests that large negative energy balance seems to be an independent determinant of ICU mortality in a very sick medical population requiring prolonged acute mechanical ventilation, especially when energy deficit exceeds 5021 kJ per d.

Detecting myocardial infarction in critical illness using screening troponin measurements and ECG recordings

IntroductionTo use screening cardiac troponin (cTn) measurements and electrocardiograms (ECGs) to determine the incidence of elevated cTn and of myocardial infarction (MI) in patients admitted to the intensive care unit (ICU), and to assess whether these findings influence prognosis. This is a prospective screening study.Materials and methodsWe enrolled consecutive patients admitted to a general medical-surgical ICU over two months. All patients underwent systematic screening with cTn measurements and ECGs on ICU admission, then daily for the first week in ICU, alternate days for up to one month and weekly thereafter until ICU death or discharge, for a maximum of two months. Patients without these investigations ordered during routine clinical care underwent screening for study purposes but these results were unavailable to the ICU team. After the study, all ECGs were interpreted independently in duplicate for ischaemic changes meeting ESC/ACC criteria supporting a diagnosis of MI. Patients were classified as having MI (elevated cTn and ECG evidence supporting diagnosis of MI), elevated cTn only (no ECG evidence supporting diagnosis of MI), or no cTn elevation.ResultsOne hundred and three patients were admitted to the ICU on 112 occasions. Overall, 37 patients (35.9 per cent) had an MI, 15 patients (14.6 per cent) had an elevated cTn only and 51 patients (49.5 per cent) had no cTn elevation. Patients with MI had longer duration of mechanical ventilation (p < 0.0001), longer ICU stay (p = 0.001), higher ICU mortality (p < 0.0001) and higher hospital mortality (p < 0.0001) compared with those with no cTn elevation. Patients with elevated cTn had higher hospital mortality (p = 0.001) than patients without cTn elevation. Elevated cTn was associated with increased hospital mortality (odds ratio 27.3, 95 per cent CI 1.7 – 449.4), after adjusting for APACHE II score, MI and advanced life support. The ICU team diagnosed 18 patients (17.5 per cent) as having MI on clinical grounds; four of these patients did not have MI by adjudication. Thus, screening detected an additional 23 MIs not diagnosed in practice, reflecting 62.2 per cent of MIs ultimately diagnosed. Patients with MI diagnosed by the ICU team had similar outcomes to patients with MI detected by screening alone.ConclusionSystematic screening detected elevated cTn measurements and MI in more patients than were found in routine practice. Elevated cTn was an independent predictor of hospital mortality. Further research is needed to evaluate whether screening and subsequent treatment of these patients reduces mortality.

Long-term outcome of elderly patients requiring intensive care admission for abdominal pathologies: survival and quality of life

Medical developments have allowed the management of patients aged over 70 years with severe abdominal pathologies requiring intensive care unit (ICU) admission. These patients require enhanced life support and present a high ICU mortality. We investigated the outcome and quality of life (QOL) of elderly patients 2 years after their ICU stay for abdominal pathologies. Patients aged 70 years or over with abdominal pathologies, admitted to our ICU over a period of 2 years, were included. Two years following their ICU stay, a letter informed the patients about the present study. Consent to participate was obtained by telephone. QOL was assessed by the Euro-QOL and Short Form-36 questionnaires. Other patient-centered outcomes were evaluated. Overall, 2780 patients were admitted to the ICU during the study period; 141 (5%) patients were eligible; 112 of the 141 (79%) survived their ICU stay, 95 (67%) survived their hospital stay and 52 (37%) were alive 2 years after their ICU stay; 36 of the 52 survivors (69%) answered the questionnaire. Their QOL 2 years after their ICU stay was decreased in comparison with an age-matched population. Eighty-one per cent of patients lived at home and 57% were totally independent. They perceived their ICU stay as positive and 75% stated that they would agree to go through intensive care again. Factors associated with 2-year survival were the absence of co-morbidity, absence of malignancy and a lower Simplified Acute Physiology II score on ICU admission. A high mortality rate and a decrease in QOL were observed in elderly patients with severe abdominal pathologies. Nonetheless, these patients were able to adapt well to their physical disabilities.

Incidence, risk factors and consequences of ICU delirium

Delirium in the critically ill is reported in 11-80% of patients. We estimated the incidence of delirium using a validated scale in a large cohort of ICU patients and determined the associated risk factors and outcomes. Prospective study in a 16-bed medical-surgical intensive care unit (ICU). 820 consecutive patients admitted to ICU for more than 24 h. Tools used were: the Intensive Care Delirium Screening Checklist for delirium, Richmond Agitation and Sedation Scale for sedation, and Numerical Rating Scale for pain. Risk factors were evaluated with univariate and multivariate analysis, and factors influencing mortality were determined using Cox regression. Delirium occurred in 31.8% of 764 patients. Risk of delirium was independently associated with a history of hypertension (OR 1.88, 95% CI 1.3-2.6), alcoholism (2.03, 1.2-3.2), and severity of illness (1.25, 1.03-1.07 per 5-point increment in APACHE II score) but not with age or corticosteroid use. Sedatives and analgesics increased the risk of delirium when used to induce coma (OR 3.2, 95% CI 1.5-6.8), and not otherwise. Delirium was linked to longer ICU stay (11.5+/-11.5 vs. 4.4+/-3.9 days), longer hospital stay (18.2+/-15.7 vs. 13.2+/-19.4 days), higher ICU mortality (19.7% vs. 10.3%), and higher hospital mortality (26.7% vs. 21.4%). Delirium is associated with a history of hypertension and alcoholism, higher APACHE II score, and with clinical effects of sedative and analgesic drugs.

Elevated serum levels of S-100β protein and neuron-specific enolase are associated with brain injury in patients with severe sepsis and septic shock*

We investigated whether serum levels of neuron-specific enolase (NSE) and S-100beta protein could be used to evaluate cerebral injury and to predict outcome in severe sepsis and severe septic shock. Prospective study. University hospital. In 170 consecutively enrolled patients with severe sepsis and septic shock, serum S-100beta and NSE were measured daily during four consecutive days after intensive care unit admission. Admission Glasgow Coma Scale before sedation and daily Sequential Organ Failure Assessment scores were recorded in all patients. Acute encephalopathy was defined as either a state of agitation, confusion, irritability, and convulsions (type A) or characterized by somnolence, stupor, and coma (type B) and persistently observed during 72 hrs after withdrawing sedation. When clinically indicated, contrast computed tomography or magnetic resonance imaging were performed to evaluate brain injury. S-100beta and NSE increased in, respectively, 72 (42%) and 90 (53%) patients. High biomarker levels were associated with the maximum Sequential Organ Failure Assessment scores (p = .001), and the highest values were found in patients who died early, within 4 days of inclusion (p = .005). Low consciousness encephalopathy type B was more frequently observed in patients with elevated S-100beta (p = .004). S-100beta levels of >or=4 microg/L were associated with severe brain ischemia or hemorrhage, and values of <2 microg/L were found in patients with diffuse cerebral embolic infarction lesions. High S-100beta levels were associated with higher intensive care unit mortality (p = .04) and represented the strongest independent predictor of intensive care unit survival, whereas NSE and the Glasgow Coma Scale failed to predict fatal outcome. S-100beta and NSE are frequently increased and associated with brain injury in patients with severe sepsis and septic shock. S-100beta levels more closely reflected severe encephalopathy and type of brain lesions than NSE and the Glasgow Coma Scale.

Epidemiology and prognostic factors of critically ill patients treated with hemodiafiltration

Purpose The objective of this study is to study the epidemiology, outcome, and prognostic factors of critically ill patients treated with continuous venovenous hemodiafiltration (CVVHDF). Materials and Methods Observational cohort was done in a French 16-bed intensive care unit (ICU) from a university-affiliated urban hospital. All patients requiring, in the opinion of the treating physician, the initiation of CVVHDF were included in the study. Results One hundred ninety-seven patients with acute renal failure (ARF) treated with CVVHDF were studied. The incidence of ARF treated with CVVHDF was 5.9% in the ICU with a mortality rate of 71.6%. A multivariate analysis identified 3 independent factors associated with fatal outcome: mechanical ventilation, sepsis, and septic shock requiring vasoactive drug. In contrast, 2 independent factors predicted a favorable outcome: nonoliguric ARF and serum creatinine concentration higher than 34 mg/L at CVVHDF initiation. A flowchart determined by the χ 2 Automatic Interaction and Detection statistical method allowed for the identification of patients' subgroups with different mortality rates ranging from 25% to 100%. Conclusions In our series, ARF treated with CVVHDF was associated with a high overall ICU mortality rate (71.6%). However, our prognostic flowchart identified patients with low mortality rates for which renal replacement therapy must be initiated with no discussion as soon as required.

Red blood cell 2,3-diphosphoglycerate concentration and in vivo P50 during early critical illness*

To measure red blood cell 2,3-diphosphoglycerate (RBC 2,3-DPG) concentrations in early critical illness; to investigate factors associated with high or low RBC 2,3-DPG levels; to calculate in vivo P50 in patients with early critical illness; and to explore the relationship between RBC 2,3-DPG and intensive care mortality. Prospective cohort study. General medical-surgical intensive care unit (ICU) of a major Scottish teaching hospital. One-hundred eleven critically ill patients during the first 24 hrs in the ICU with no history of chronic hematologic disorders or RBC transfusion within 24 hrs and 34 age- and sex-matched healthy reference subjects. None. We measured RBC 2,3-DPG concentration, plasma biochemistry values, and arterial blood gas parameters. On average, RBC 2,3-DPG was lower among critically ill patients than controls (mean [sd], 14.1 [6.3] vs. 16.7 [3.7] mumol/g hemoglobin; p = .004) and had a wider range of values (patients, 3.2-32.5 mumol/g hemoglobin; reference group, 9.1-24.3). Regression analysis indicated a strong independent association between plasma pH and RBC 2,3-DPG (B, 32.15 [95% confidence interval, 19.07-46.22], p < .001) and a weak association with plasma chloride (B, -0.196 [95% confidence interval, -0.39 to -0.01], p = .044) but not with hemoglobin or other measured biochemical parameters. The mean calculated in vivo P50 level was normal (3.8 kPa) but varied widely among patients (range, 2.0-5.5 kPa). RBC 2,3-DPG concentration was similar for ICU survivors and nonsurvivors. RBC 2,3-DPG concentrations vary widely among critically ill patients. Acidosis is associated with lower RBC 2,3-DPG concentrations, but anemia is not associated with a compensatory increase in RBC 2,3-DPG early in critical illness. Lower RBC 2,3-DPG concentrations during the first 24 hrs of intensive care are not associated with higher ICU mortality.

VENTILATOR-ASSOCIATED PNEUMONIA IN A TERTIARY CARE ICU: ANALYSIS OF RISK FACTORS FOR ACQUISITION AND MORTALITY

Objective: To investigate the incidence, risk factors and mortality of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients.Design: Prospective, observational, population-based study.Setting: The medical (14-bed) and surgical ICU (26-bed) of the Ghent University Hospital.Methods: All 1295 patients admitted to the ICU during 4 three-month periods between 1996 and 1998 were included. A set of demographic and clinical variables were collected at the day of admission and during the ICU course.Results: The incidence of VAP among ICU patients ventilated at least 48 hours was 23.1%. The mean time to the development of VAP was 9.6 days with a median of 6 days. In the population of patients ventilated for at least 48 hours, a comparison was made between patients with (n=89) and without VAP (n=296). Patients with VAP had a significant longer ICU stay, with a longer ventilation dependency. Logistic regression analysis identified admission diagnosis other than trauma (OR: 0.51, 95% CI: 0.29-0.89; p=0.02) and the length of ICU stay (OR: 1.05, 95% CI: 1.03-1.07; p<0.001) to be independently associated with the acquisiton of VAP. In comparison with the total study population, patients with VAP had a higher ICU mortality (20.2% vs. 12.0%; p=0.04), but not in the cohort group of patients at risk for VAP (ventilated >48 hours) (20.2% vs. 31.3%; p=0.03). The factors independently associated with death were higher SAPS II scores (OR 1.02, 95% CI: 1.003-1.032; p=0.02), an admission diagnosis other than trauma (OR 0.36, 95% CI: 0.17-0.75; p=0.006) and length of ICU stay (OR 0.97, 95% CI: 0.946-0.995; p=0.02). This model did not recognize VAP as an independent predictor of death (OR 0.79, 95% CI: 0.41-1.53; p=0.492).Conclusions: The incidence of VAP in our ICU is 23.1%. Length of ICU stay and an admission diagnosis other than trauma are major risk factors for the development of this nosocomial infection. VAP is associated with a high fatality rate. However, after adjustment for disease severity and length of ICU stay, VAP was not identified as an independent predictor of death.

Cystatin C as a Marker of Residual Renal Function during Continuous Hemodiafiltration

Background: The level of residual renal function (RRF) has an important impact on follow-up in critically ill patients with renal failure. There is currently no clear marker of RRF. Methods: Cystatin C (cysC) concentrations were measured before and during the first 48 h of CVVHDF in 33 mechanically ventilated patients suffering from renal failure. Samples were drawn both from the ports proximal and distal to the filter. Each of the two control groups consisted of 10 patients. Results: The levels of cysC were significantly higher in the group where diuresis (Vu) remained low or decreased after 48 h of treatment (n = 21, Vu median 380 (80–935) ml/24 h, cysC range 4.44–3.42 mg/l) than in the group where Vu increased to the level of 1.5 ml·kg^–1·h^–1 or higher after 48 h of treatment (n = 12, Vu 4,570 (4,000–5,130) ml/24 h, cysC 3.17–2.46 mg/l, p < 0.01). Creatinine clearance taken before treatment was not different between the groups. Significant correlation between cysC levels and Vu was found (r = –0.44, p < 0.0001). CysC levels were significantly higher in non-survivors than in survivors (3.54 ± 1.38 vs. 3.07 ± 1.24, p < 0.03). Conclusion: The levels of cysC are inversely related to Vu. High levels of cysC are associated with low residual diuresis, longer duration of CVVHDF and higher intensive care unit mortality in patients treated with CVVHDF.

Timing of tracheostomy as a determinant of weaning success in critically ill patients: a retrospective study

IntroductionTracheostomy is frequently performed in critically ill patients for prolonged intubation. However, the optimal timing of tracheostomy, and its impact on weaning from mechanical ventilation and outcomes in critically ill patients who require mechanical ventilation remain controversial.MethodsThe medical records of patients who underwent tracheostomy in the medical intensive care unit (ICU) of a tertiary medical centre from July 1998 to June 2001 were reviewed. Clinical characteristics, length of stay in the ICU, rates of post-tracheostomy pneumonia, weaning from mechanical ventilation and mortality rates were analyzed.ResultsA total of 163 patients (93 men and 70 women) were included; their mean age was 70 years. Patients were classified into two groups: successful weaning (n = 78) and failure to wean (n = 85). Shorter intubation periods (P = 0.02), length of ICU stay (P = 0.001) and post-tracheostomy ICU stay (P = 0.005) were noted in patients in the successful weaning group. Patients who underwent tracheostomy more than 3 weeks after intubation had higher ICU mortality rates and rates of weaning failure. The length of intubation correlated with the length of ICU stay in the successful weaning group (r = 0.70; P < 0.001). Multivariate analysis revealed that tracheostomy after 3 weeks of intubation, poor oxygenation before tracheostomy (arterial oxygen tension/fractional inspired oxygen ratio <250) and occurrence of nosocomial pneumonia after tracheostomy were independent predictors of weaning failure.ConclusionThe study suggests that tracheostomy after 21 days of intubation is associated with a higher rate of failure to wean from mechanical ventilation, longer ICU stay and higher ICU mortality.

The impact of delirium on the survival of mechanically ventilated patients*

To revalidate a means of assessing delirium in intensive care unit patients and to investigate the independent effect of delirium on the mortality of mechanically ventilated patients. A prospective cohort study. A 37-bed medical intensive care unit of a tertiary care hospital. Subjects were 102 of 131 consecutive mechanically ventilated patients. All the enrolled patients were assessed for delirium using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Mortality rate were compared between patients with or without delirium, and the predictors of death were investigated. The two CAM-ICU assessors' sensitivities in diagnosing delirium compared with reference standard were 91% and 95%, whereas their specificities were both 98%. They also demonstrated high interrater reliability with kappa statistics of 0.91. Delirium was present in 22 of 102 (22%) patients in the first 5 days. The delirious patients had higher intensive care unit mortality rate than nondelirious patients (63.6% vs. 32.5%, respectively), with a hazard ratio of 2.57 (95% confidence interval, 1.56-8.15). In multivariate analysis, delirium (odds ratio, 13.0; 95% confidence interval, 2.69-62.91), shock (odds ratio, 12.91; 95% confidence interval, 2.93-56.92), and illness severity (odds ratio, 9.61; 95% confidence interval, 2.24-41.18) were independent predictors of mortality. This study confirms previous work showing that delirium is an independent predictor for increased mortality among mechanically ventilated patients.

Cardiac troponin I levels are a risk factor for mortality and multiple organ failure in noncardiac critically ill patients and have an additive effect to the APACHE II score in outcome prediction.

Cardiac troponin I (cTnI) is a specific marker of myocardial damage used in the diagnosis of acute coronary syndrome (ACS). Recent studies have shown that cTnI levels can also be elevated in patients without ACS, such as in sepsis and trauma patients, and that this is associated with an adverse prognosis. We have evaluated the clinical implications and prognostic significance of serum cTnI levels in noncardiac critically ill patients in a prospective observational study in a general medical intensive care unit at a tertiary-level hospital. A total of 108 consecutive patients without ACS or other cardiac disease was enrolled. Serum cTnI levels were measured on admission using enzyme-linked immunoabsorbant assay kits. Clinical laboratory parameters and outcome were compared between patients with elevated and normal cTnI levels. The prognostic significance of cTnI levels and the Acute Physiology And Chronic Health Evaluation (APACHE) II score was also analyzed. Forty-nine patients (45%) had elevated cTnI levels and 59 (55%) had normal levels. Compared with patients with normal cTnI levels, patients with elevated levels had a higher incidence of new failure of two or more organs, had a lower left ventricular ejection fraction during admission, were more likely to be associated with bacteremia, and had a higher intensive care unit mortality; they also had a significantly shorter survival over a 180-day follow up, before and after stratification by the APACHE II score. Multiple organ failure was the leading cause of mortality in patients with elevated cTnI levels. By multivariate analysis, elevated cTnI levels, a high APACHE II score, and underlying cancer were the three most important independent predictors for a shorter survival. Combination analysis showed a shorter survival in patients with a high APACHE II score plus elevated cTnI levels than in patients with a high APACHE II score or elevated cTnI levels alone. In conclusion, elevated serum cTnI levels is a risk factor for multiple organ failure and mortality in noncardiac critically ill patients, and the cTnI levels and APACHE II score have an additive effect in outcome prediction.

Extubation failure: an outcome to be avoided

Extubation failure is an outcome of increasing importance but nearly all studies have been conducted in academic settings. The article by Seymour and colleagues demonstrates that extubation failure is an outcome to be avoided in the community hospital setting as well. Patients failing extubation experience longer lengths of stay, experience higher intensive care unit mortality, and incur greater hospital costs. Investigators have identified tools for predicting extubated patients at highest risk for reintubation. The predictors focus on detecting upper airway obstruction, inadequate cough, excess respiratory secretions, and abnormal mental status. Systematic application of these predictors has the potential to improve outcome.

Blood component use in critically ill patients.

This prospective observational study was conducted to assess the current transfusion practice in critically ill patients. One thousand two hundred and forty-seven consecutive critically ill patients admitted between February 1999 and October 1999 were included in the study. Overall 666 (53%) patients were administered red cells. Transfused patients had significantly higher intensive care unit mortality but also had higher Acute Physiology and Chronic Health Evaluation II scores and longer durations of stay. The average pretransfusion haemoglobin concentration was < 9 g.dl(-1) in 75% of transfusion episodes. The common indications for transfusion were low haemoglobin (72%) and haemorrhage (25%). Overall, 202 (16%) and 281 (22%) of the patients were transfused platelets and fresh frozen plasma, respectively. The indications for transfusion were haemorrhage, low platelet counts, prolonged prothrombin time or to provide cover for invasive interventions. Most platelet transfusions were given at values in the order of 50-100 x 10(9).l(-1). The pretransfusion platelet count varied according to the indications for transfusion. This study showed that transfusion practice is consistent and that in general there does not seem to be an excessive use of blood components in critically ill patients.

Abstracts of the literature

Preintubation shock index (SI) and modified shock index (MSI) have demonstrated predictive capability for postintubation hypotension in emergency department. The primary aim was to explore this relationship in the critical care environment. The secondary aims were to evaluate the relationship of shock indices with other short-term outcomes like mortality and length of stay in intensive care unit.This is a nonconcurrent cohort study, conducted in eligible 140 adult intensive care unit (ICU) patients of a tertiary care medical center. Eligibility criterion was emergent endotracheal intubation in apparently hemodynamically stable patients.Preintubation SI ≥ 0.90 had a significant association with postintubation hypotension as defined by systolic blood pressure < 90 mm Hg in the univariate (P = .03; odds ratio [OR], 2.13; 95% confidence interval [CI], 1.07-4.35) and multivariate analyses (P = .01; OR, 3.17; 95% CI, 1.36-7.73) after adjusting for confounders. It was also associated with higher ICU mortality in both the univariate (P = .01; OR, 4.00; 95% CI, 1.26-12.67) and multivariate analyses (P = .01; OR, 5.75; 95% CI, 1.58-26.48). There was no association of preintubation MSI with postintubation hemodynamic instability and ICU mortality. No association was found between preintubation SI and MSI, with ICU length of stay and 30-day mortality.Our findings indicate that preintubation SI greater than or equal to 0.90 is a predictor of postintubation hypotension (systolic blood pressure <90 mm Hg) and ICU mortality in emergently intubated adult patients in intensive care units.

Predictors of failure of noninvasive positive pressure ventilation in patients with acute hypoxemic respiratory failure: a multi-center study.

In patients with hypoxemic acute respiratory failure (ARF), randomized studies have shown noninvasive positive pressure ventilation (NPPV) to be associated with lower rates of endotracheal intubation. In these patients, predictors of NPPV failure are not well characterized. To investigate variables predictive of NPPV failure in patients with hypoxemic ARF. Prospective, multicenter cohort study. Eight Intensive Care Units (ICU) in Europe and USA. Of 5,847 patients admitted between October 1996 and December 1998, 2,770 met criteria for hypoxemic ARF. Of these, 2,416 were already intubated and 354 were eligible for the study. NPPV failed in 30% (108/354) of patients. The highest intubation rate was observed in patients with ARDS (51%) or community-acquired pneumonia (50%). The lowest intubation rate was observed in patients with cardiogenic pulmonary edema (10%) and pulmonary contusion (18%). Multivariate analysis identified age > 40 years (OR 1.72, 95% CI 0.92-3.23), a simplified acute physiologic score (SAPS II) > or = 35 (OR 1.81, 95% CI 1.07-3.06), the presence of ARDS or community-acquired pneumonia (OR 3.75, 95% CI 2.25-6.24), and a PaO2:FiO2 < or = 146 after 1 h of NPPV (OR 2.51, 95% CI 1.45-4.35) as factors independently associated with failure of NPPV. Patients requiring intubation had a longer duration of ICU stay ( P < 0.001), higher rates of ventilator-associated pneumonia and septic complications ( P < 0.001), and a higher ICU mortality ( P < 0.001). In hypoxemic ARF, NPPV can be successful in selected populations. When patients have a higher severity score, an older age, ARDS or pneumonia, or fail to improve after 1 h of treatment, the risk of failure is higher.