Predicting the risk of documented ventilator-associated pneumonia for benchmarking: construction and validation of a score.

OBJECTIVES: : To build and validate a ventilator-associated pneumonia risk score for benchmarking. The rate of ventilator-associated pneumonia varies widely with case-mix, a fact that has limited its use for measuring intensive care unit performance. METHODS: : We studied 1856 patients in the OUTCOMEREA database treated at intensive care unit admission by endotracheal intubation followed by mechanical ventilation for >48 hrs; they were allocated randomly to a training data set (n = 1233) or a validation data set (n = 623). Multivariate logistic regression was used. Calibration of the final model was assessed in both data sets, using the Hosmer-Lemeshow chi-square test and receiver operating characteristic curves. MEASUREMENTS AND MAIN RESULTS: : Independent risk factors for ventilator-associated pneumonia were male gender (odds ratio = 1.97, 95% confidence interval = 1.32-2.95); SOFA at intensive care unit admission (<3 [reference value], 3-4 [2.57, 1.39-4.77], 5-8 [7.37, 4.24-12.81], >8 [5.81 (3.2-10.52)], no use within 48 hrs after intensive care unit admission of parenteral nutrition (2.29, 1.52-3.45), no broad-spectrum antimicrobials (2.11, 1.46-3.06); and mechanical ventilation duration (<5 days (); 5-7 days (17.55, 4.01-76.85); 7-15 days (53.01, 12.74-220.56); >15 days (225.6, 54.3-936.7). Tests in the training set showed good calibration and good discrimination (area under the curve-receiver operating characteristic curve = 0.881), and both criteria remained good in the validation set (area under the curve-receiver operating characteristic curve = 0.848) and good calibration (Hosmer-Lemeshow chi-square = 9.98, p = .5). Observed ventilator-associated pneumonia rates varied across intensive care units from 9.7 to 26.1 of 1000 mechanical ventilation days but the ratio of observed over theoretical ventilator-associated pneumonia rates was >1 in only two intensive care units. CONCLUSIONS: : The ventilator-associated pneumonia rate may be useful for benchmarking provided the ratio of observed over theoretical rates is used. External validation of our prediction score is needed.

Diagnostic bronchoscopy in hematology and oncology patients with acute respiratory failure: prospective multicenter data.

OBJECTIVE: To describe the diagnostic yields of test strategies with and without fiberoptic bronchoscopy and bronchoalveolar lavage (FO-BAL), as well as outcomes, in cancer patients with acute respiratory failure (ARF). DESIGN: Prospective observational study. SETTING: Fifteen intensive care units in France. PATIENTS: In all, 148 cancer patients, including 45 bone marrow transplant recipients (27 allogeneic, 18 autologous) with hypoxemic ARF. INTERVENTION: None. RESULTS: Overall, 146 causes of ARF were identified in 128 patients (97 [66.4%] pulmonary infections). The cause of ARF was identified in 50.5% of the 101 patients who underwent FO-BAL and in 66.7% of the other patients. FO-BAL was the only conclusive test in 34 (33.7%) of the 101 investigated patients. Respiratory status deterioration after FO-BAL occurred in 22 of 45 (48.9%) nonintubated patients, including 16 (35.5%) patients who required ventilatory support. Hospital mortality was 55.4% (82 deaths) overall and was not significantly different in the groups with and without FO-BAL. By multivariate analysis, mortality was affected by characteristics of the malignancy (remission, allogeneic bone marrow transplantation), cause of ARF (ARF during neutropenia recovery, cause not identified), and need for life-sustaining treatments (mechanical ventilation and vasopressors). CONCLUSION: In critically ill cancer patients with ARF, a diagnostic strategy that does not include FO-BAL may be as effective as FO-BAL without exposing the patients to respiratory status deterioration.

Platelet count decline: an early prognostic marker in critically ill patients with prolonged ICU stays.

BACKGROUND: Thrombocytopenia is common in ICU patients. The objective of this study was to evaluate possible links between declining platelet counts early in the ICU stay and survival. METHODS: All patients who were admitted to the ICU for at least 5 days and had no thrombocytopenia at the time of admission were included in the study. A multivariable logistic regression model, with hospital mortality as the outcome variable, was built. RESULTS: We included 1,077 patients in the study. At ICU admission, the median platelet count was not significantly different in survivors (256 x 10(9) cells/L; interquartile range [IQR], 206 to 330 x 10(9) cells/L) and nonsurvivors (262 x 10(9) cells/L; 211 to 351 x 10(9) cells/L). Median simplified acute physiology scores II (SAPS II) at ICU admission was worse in nonsurvivors than in survivors (50 [IQR, 37 to 63] vs 37 [IQR, 27 to 48], respectively; p < 0.0001), as was the mean (+/- SD) sequential organ failure assessment (SOFA) score on day 3 (6.3 +/- 3.24 vs 4 +/- 2.8, respectively; p < 0.0001). Absolute platelet counts were lowest on day 4, but differed significantly between survivors and nonsurvivors only on day 7. Conversely, any percentage decline in platelet counts from 10 to 60% on day 4 was significantly associated with mortality. By multivariable analysis, a 30% decline in platelet count independently predicted death (odds ratio, 1.54; 95% confidence interval, 1.12 to 2.14; p = 0.008), in addition to increasing or stable SOFA scores from ICU admission to day 4, older age, male gender, ICU admission for coma, worse SAPS II score at ICU admission, transfer from another ward, and comorbidity. CONCLUSION: In patients who spend > 5 days in the ICU and have normal platelet counts at ICU admission, a decline in platelet counts provides prognostic information. This parameter deserves to be included in new scoring systems.

Tracheostomy does not improve the outcome of patients requiring prolonged mechanical ventilation: a propensity analysis.

OBJECTIVE: To examine the association between the performance of a tracheostomy and intensive care unit and postintensive care unit mortality, controlling for treatment selection bias and confounding variables. DESIGN: Prospective, observational, cohort study. SETTING: Twelve French medical or surgical intensive care units. PATIENTS: Unselected patients requiring mechanical ventilation for > or =48 hrs enrolled between 1997 and 2004. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Two models of propensity scores for tracheostomy were built using multivariate logistic regression. After matching on these propensity scores, the association of tracheostomy with outcomes was assessed using multivariate conditional logistic regression. Results obtained with the two models were compared. Of the 2,186 patients included, 177 (8.1%) received a tracheostomy. Both models led to similar results. Tracheostomy did not improve intensive care unit survival (model 1: odds ratio, 0.94; 95% confidence interval, 0.63-1.39; p = .74; model 2: odds ratio, 1.12; 95% confidence interval, 0.75-1.67; p = .59). There was no difference whether tracheostomy was performed early (within 7 days of ventilation) or late (after 7 days of ventilation). In patients discharged free from mechanical ventilation, tracheostomy was associated with increased postintensive care unit mortality when the tracheostomy tube was left in place (model 1: odds ratio, 3.73; 95% confidence interval, 1.41-9.83; p = .008; model 2: odds ratio, 4.63; 95% confidence interval, 1.68-12.72, p = .003). CONCLUSIONS: Tracheostomy does not seem to reduce intensive care unit mortality when performed in unselected patients but may represent a burden after intensive care unit discharge.

Excess risk of death from intensive care unit-acquired nosocomial bloodstream infections: a reappraisal.

BACKGROUND: Overall rates of bloodstream infection (BSI) are often used as quality indicators in intensive care units (ICUs). We investigated whether ICU-acquired BSI increased mortality (by > or = 10%) after adjustment for severity of infection at ICU admission and during the pre-BSI stay. METHODS: We conducted a matched, risk-adjusted (1:n), exposed-unexposed study of patients with stays longer than 72 h in 12 ICUs randomly selected from the Outcomerea database. RESULTS: Patients with BSI after the third ICU day (exposed group) were matched on the basis of risk-exposure time and mortality predicted at admission using the Three-Day Recalibrated ICU Outcome (TRIO) score to patients without BSI (unexposed group). Severity was assessed daily using the Logistic Organ Dysfunction (LOD) score. Of 3247 patients with ICU stays of >3 days, 232 experienced BSI by day 30 (incidence, 6.8 cases per 100 admissions); among them, 226 patients were matched to 1023 unexposed patients. Crude hospital mortality was 61.5% among exposed and 36.7% among unexposed patients (P<.0001). Attributable mortality was 24.8%. The only variable associated with both BSI and hospital mortality was the LOD score determined 4 days before onset of BSI (odds ratio [OR], 1.10; 95% confidence interval [CI], 1.03-1.16; P = .0025). The adjusted OR for hospital mortality among exposed patients (OR, 3.20; 95% CI, 2.30-4.43) decreased when the LOD score determined 4 days before onset of BSI was taken into account (OR, 3.02; 95% CI, 2.17-4.22; P<.0001). The estimated risk of death from BSI varied considerably according to the source and resistance of organisms, time to onset, and appropriateness of treatment. CONCLUSIONS: When adjusted for risk-exposure time and severity at admission and during the ICU stay, BSI was associated with a 3-fold increase in mortality, but considerable variation occurred across BSI subgroups. Focusing on BSI subgroups may be valuable for assessing quality of care in ICUs.

Evaluation of a strategy of screening multiple anatomical sites for methicillin-resistant Staphylococcus aureus at admission to a teaching hospital.

We compared the sensitivity of screening with nasal culture alone with that of a multiple-site screening method for the identification of carriers of methicillin-resistant Staphylococcus aureus at hospital admission. If nasal cultures alone had been used during the 1-year study, 27.0% of carriers of methicillin-resistant S. aureus would have been missed, which corresponds to 560 theoretical isolation days. If rectal screening had not been used, 431 theoretical isolation days would have been missed, and, if axillary screening had not been used, 99 theoretical isolation days would have been missed.

Pneumothorax in the intensive care unit: incidence, risk factors, and outcome.

BACKGROUND: The risk factors and outcomes of critically ill patients with iatrogenic pneumothorax (IP) have not been studied in a large unselected intensive care unit (ICU) population. METHODS: The authors studied a prospective cohort of adults admitted for more than 24 h. Data were collected at ICU admission and daily by senior physicians until ICU discharge. Risk factors for IP were identified in the entire cohort. A matched nested case-control study was used to evaluate the excess risk of IP in decedents. RESULTS: Of the 3,499 patients, 69 with pneumothorax before ICU admission were excluded. Of the remaining 3,430 patients, 94 experienced IP within 30 days (42 due to barotrauma and 52 due to invasive procedures). The cumulative incidence of IP was 1.4% (95% confidence interval [CI], 1.0-1.8) on day 5 and 3.0% (95% CI, 2.4-3.6) on day 30. Risk factors for IP (hazard ratio [95% CI]) were body weight less than 80 kg (2.4 [1.3-4.2]), history of adult immunodeficiency syndrome (2.8 [1.2-6.4]), diagnosis of acute respiratory distress syndrome (5.3 [2.6-11]) or cardiogenic pulmonary edema at admission (2.0 [1.1-3.6]), central vein or pulmonary artery catheter insertion (1.7 [1.0-2.7]), and use of inotropic agents during the first 24 h (2.1 [1.3-3.4]). Excess risk of IP in decedents was 2.6 (95% CI, 1.3-4.9; P = 0.004). CONCLUSION: Iatrogenic pneumothorax is a life-threatening complication seen in 3% of ICU patients. Incorporating risk factors for IP into preventive strategies should reduce the occurrence of IP.

Candida colonization of the respiratory tract and subsequent pseudomonas ventilator-associated pneumonia.

BACKGROUND: Recovery of Candida from the respiratory tract of a critically ill patient receiving mechanical ventilation (MV) usually indicates colonization rather than infection of the respiratory tract. However, interactions between Candida and bacteria, particularly Pseudomonas, have been reported. Thus, Candida colonization of the respiratory tract may predispose to bacterial ventilator-associated pneumonia (VAP). METHODS: In a multicenter study of immunocompetent critically ill patients receiving MV for > 2 days, we compared the incidence of pneumonia in patients with and without (exposed/unexposed) respiratory-tract Candida colonization, matched on study center, admission year, and MV duration. RESULTS: Over the 4-year study period, of the 803 patients meeting study inclusion criteria in the six study centers, 214 patients (26.6%) had respiratory tract Candida colonization. Candida albicans was the most common species (68.7%), followed by Candida glabrata (20.1%) and Candida tropicalis (13.1%). Extrapulmonary Candida colonization was more common in exposed patients (39.7% vs 8.3%, p = 0.01). Exposed patients had longer ICU and hospital stays but similar mortality to unexposed patients. The matched exposed/unexposed nested cohort study identified bronchial Candida colonization as an independent risk factor for pneumonia (24.1% vs 17.6%; adjusted odds ratio [OR], 1.58; 95% confidence interval [CI], 0.94 to 2.68; p = 0.0860); the risk increase was greatest for Pseudomonas pneumonia (9% vs 4.8%; adjusted OR, 2.22; 95% CI, 1.00 to 4.92; p = 0.049). CONCLUSIONS: Candida colonization of the respiratory tract is common in patients receiving MV for > 2 days and is associated with prolonged ICU and hospital stays, and with an increased risk of Pseudomonas VAP.

Control and outcome of a large outbreak of colonization and infection with glycopeptide-intermediate Staphylococcus aureus in an intensive care unit.

BACKGROUND: Glycopeptide-intermediate Staphylococcus aureus (GISA) is emerging as a cause of nosocomial infection and outbreaks of infection and colonization in intensive care units (ICUs). We describe an outbreak of GISA colonization/infection and the ensuing control measures in an ICU and investigate outcomes of the affected patients. METHODS: We describe an outbreak of GISA colonization and infection that affected 21 patients in a medical ICU at a tertiary care teaching hospital, as well as the measures taken to eradicate the GISA strain. RESULT: Recognition of the outbreak was difficult. Infections, all of which were severe, were diagnosed in 11 of 21 patients. Patient isolation and barrier precautions failed when used alone. Addition of a stringent policy of restricted admissions, twice daily environmental cleaning, and implementation of hand decontamination with a hydroalcoholic solution led to outbreak termination. This was associated with increases in workload, despite a marked decrease in the number of admissions. CONCLUSION: This first description of a large outbreak of GISA colonization and infection underlines the importance of routine GISA-strain detection when methicillin-resistant S. aureus is isolated. Outbreak control may be difficult to achieve.

Is methicillin resistance associated with a worse prognosis in Staphylococcus aureus ventilator-associated pneumonia?

BACKGROUND: Excess mortality associated with methicillin resistance in patients with Staphylococcus aureus ventilator-associated pneumonia (SA-VAP), taking into account such confounders as treatment adequacy and time in the intensive care unit (ICU), have not been adequately estimated. METHODS: One hundred thirty-four episodes of SA-VAP entered in the Outcomerea database were studied. Patients from whom methicillin-resistant S. aureus (MRSA) was recovered were compared with those from whom methicillin-susceptible S. aureus (MSSA) was recovered, stratified for duration of stay in the ICU at the time of VAP diagnosis and adjusted for confounders (severity at admission, characteristics at VAP diagnosis, and treatment adequacy). RESULTS: Treatment was adequate within 24 h after VAP diagnosis for 86% of the 65 MSSA-infected patients and 77% of the 69 MRSA-infected patients (P = .2). Polymicrobial VAP was more commonly associated with MSSA than with MRSA (49.2% vs. 25.7%; P = .01). MRSA infection was associated with a lower prevalence of coma at hospital admission and a higher rate of use of central venous lines and fluoroquinolones during the first 48 h of the ICU stay. The rates of shock, recurrence, and superinfection were similar in both groups. The crude hospital mortality rate was higher for MRSA-infected patients than for MSSA-infected patients (59.4% vs. 40%; P = .024). This difference disappeared after controlling for time in the ICU before VAP and parameters imbalanced at ICU admission (odds ratio [OR], 1.23; 95% confidence interval [CI], 0.49-3.12; P = .7) and remained unchanged after further adjustments for initial treatment adequacy and polymicrobial VAP (OR, 0.98; 95% CI, 0.36-2.66). CONCLUSIONS: Differences in patient characteristics, initial ICU treatment, and time in the ICU confounded estimates of excess death due to MRSA VAP. After careful adjustment, methicillin resistance did not affect ICU or hospital mortality rates.

Epidemiology and economic evaluation of severe sepsis in France: age, severity, infection site, and place of acquisition (community, hospital, or intensive care unit) as determinants of workload and cost.

PURPOSE: Severe sepsis is a leading cause of death in critically ill patients. We evaluated cost and workload according to infection site, place and time of acquisition, and severity. MATERIAL AND METHOD: We used a prospective 3-year database from 6 intensive care units (ICUs) including 1698 patients. RESULTS: Of the 1698 patients, 713 (42%) had severe sepsis at admission and 339 during the ICU stay (211 had both). Mortality was twice as high in patients with than those without ICU-acquired infection, independent of the presence of severe sepsis at admission. The mean (SD; median) cost of severe sepsis was 22 800 (21 400 ; 15 800 ). Among patients with severe sepsis at admission, workload and cost were higher for pneumonia, peritonitis, and multiple-site infections and for hospital-acquired (17,400 [14,700; 17,400]) vs community-acquired infection (12,600 [12,100 ; 8900 ]). Intensive care unit-acquired severe sepsis was associated with greater than 3-fold increases in workload and costs. By multiple linear regression, older age, emergency surgery, septic shock, Acute Physiological and Chronic Health Evaluation II score, and hospital or ICU-acquired severe sepsis were independently associated with higher costs. CONCLUSIONS: The wide variations in cost and workload invite efforts to identify patient subgroups most likely to benefit from high-cost treatments and from prevention, particularly targeting severe nosocomial infections.

Efficacy of adequate early antibiotic therapy in ventilator-associated pneumonia: influence of disease severity.

OBJECTIVE: To test the hypothesis that the outcome of patients with ventilator-associated pneumonia (VAP) depends on both their baseline severity at VAP onset and the adequacy of empirical antibiotic therapy. DESIGN AND SETTING: Prospective clinical study in six intensive care units in Paris, France. PATIENTS: One hundred and forty-two patients with VAP after >/= 48 h of mechanical ventilation. MEASUREMENTS AND RESULTS: Patients were compared according to whether adequate antibiotics were started when VAP was first suspected (D0). At day 0, the rate of adequate antibiotic therapy was 44.4% and rose to 92% at day 2. Outcomes were recorded at the ICU and hospital discharge. Overall, no significant mortality difference was found with and without adequate early antibiotics. When patients were also classified based on the initial Logistic Organ Dysfunction score (LOD), mortality was significantly higher with inadequate early antibiotic therapy in the groups with LOD

Practices in non-neutropenic ICU patients with Candida-positive airway specimens.

OBJECTIVE: To examine practices of French intensivists regarding the management of mechanically ventilated patients with Candida-positive airway specimens but no major risk factors for immunodepression. Design : Closed-item questionnaire with a clinical vignette. SETTING: 564 French intensive care units (ICUs). PARTICIPANTS: 198 intensivists who have a special interest in infectious diseases and who answered the questionnaire (response rate, 35.1%). INTERVENTION: None. MEASUREMENTS AND RESULTS: The respondents recommended bronchoalveolar lavage (62.6% of respondents), protected distal sampling and protected specimen brush (59.1%), transbronchial biopsy (38.9%), and tracheal aspiration (12.1%) for the diagnosis of candidal pneumonia. A positive airway specimen was felt by most respondents (83.3%) to indicate colonisation; 66.7% of respondents recommended tests for systemic candidiasis in this situation, and 56.5% serial sampling to compute the colonisation index. Azole derivatives were the preferred antifungal medications. The clinical vignette described a patient with chronic obstructive lung disease who required mechanical ventilation for an acute exacerbation and who had a tracheal aspirate positive for Candida. Responses varied widely, with 37.8% of respondents diagnosing clinically insignificant colonisation but 24.2% recommending antifungal treatment and 61.6% serial testing to assess the Candida colonisation index. Intensivists with greater experience with severely immunocompromised patients were more aggressive in their diagnostic management. CONCLUSIONS: Wide variations occur among practices of French intensivists regarding Candida-positive airway specimens in patients without major risk factors for immunodepression. Additional studies are needed to improve our understanding of the links between Candida colonisation and infection and to determine the indications for pre-emptive antifungal treatment in non-neutropenic critically ill patients.

Accuracy of delayed (24 hours) processing of bronchoalveolar lavage for diagnosing bacterial pneumonia.

OBJECTIVE: Pneumonia in the intensive care unit is associated with a high mortality rate. Diagnostic accuracy is mandatory to improve prognosis. However, in many hospitals, samples from the respiratory tract cannot be immediately processed bacteriologically around the clock. This may complicate therapeutic choice based on invasive diagnostic procedures. We evaluated the effect of storing bronchoalveolar lavage fluid at 4 degrees C for 24 hrs on direct examination and culturing for diagnosing pneumonia. DESIGN: Prospective, paired comparison study. SETTING: Intensive care unit in a university hospital. PATIENTS: A total of 93 bronchoalveolar lavages were performed on 66 intensive care unit patients who were suspected to have bacterial pneumonia. INTERVENTION: Each sample was divided into two; one half was processed immediately (H0), and the other was processed after refrigeration at 4 degrees C for 24 hrs (H24). MEASUREMENTS AND MAIN RESULTS: All negative H0 culture samples (n = 31) were also negative for pathogens in H24 samples. Sixty two bronchoalveolar lavage cultures yielded one or more microorganisms, giving a total of 113 microorganisms in one or both samples. The results of positive cultures at H0 and H24 for the culturing diagnostic threshold of 10 colony forming units/mL agreed well (Kappa coefficient, 0.84); agreement was even better (Kappa coefficient, 0.85) when possible contaminants were excluded. The bias calculated as the mean difference between paired culture results was 0.195 +/- 1.31 (Delta log). When considering the accepted threshold of 10 colony forming units/mL, specificity at H24 compared to H0 was excellent (100%), but sensitivity was slightly lower (80%). CONCLUSION: Delayed processing of bronchoalveolar lavage sampling is an acceptable alternative when immediate culturing cannot be performed because it enables antibiotic administration.

Body mass index. An additional prognostic factor in ICU patients.

OBJECTIVE: To examine the association between body mass index (BMI) and mortality in adult intensive care unit (ICU) patients. DESIGN. A prospective multi-center study. INTERVENTIONS: None. METHODS: A cohort study (yielding the OUTCOMEREA database) was conducted over 2 years in 6 medical-surgical ICUs. In each participating ICU, the following were collected daily: demographic information, admission height and weight, comorbidities, severity scores (SAPS II, LOD, and SOFA), ICU and hospital lengths of stay, and ICU and hospital mortality rates. RESULTS: A total of 1,698 patients were examined and divided into 4 groups based on BMI: <18.5, 18.5-24.9, 25-29.9, and >30 kg/m(2). These groups differed significantly for age, gender, admission category (medical, scheduled surgery, unscheduled surgery), ICU and hospital lengths of stay, and comorbidities. Severity at admission and within the first 2 days was similar in the 4 groups, except for the SOFA score. Overall hospital mortality was 31.3% (532 out of 1,698 patients). By multivariate analysis, a BMI below 18.5 kg/m(2) was independently associated with increased mortality (odds ratio 1.63; 95% confidence intervals 1.11-2.39). None of the other BMI categories were associated with higher mortality and even a BMI>30 kg/m(2) was protective of mortality (odds ratio 0.60, 95% confidence intervals 0.40-0.88). CONCLUSIONS: A low BMI was independently associated with higher mortality and a high BMI with lower mortality in this large cohort of critically ill patients. Since BMI is absent from currently available scoring systems, further studies are needed to determine whether adding BMI would improve the effectiveness of scores in predicting mortality.

Decisions to forgo life-sustaining therapy in ICU patients independently predict hospital death.

OBJECTIVE: More than one-half the deaths of patients admitted to intensive care units (ICUs) occur after a decision to forgo life-sustaining therapy (DFLST). Although DFLSTs typically occur in patients with severe comorbidities and intractable acute medical disorders, other factors may influence the likelihood of DFLSTs. The objectives of this study were to describe the factors and mortality associated with DFLSTs and to evaluate the potential independent impact of DFLSTs on hospital mortality. DESIGN AND SETTING: Prospective multicenter 2-year study in six ICUs in France. PATIENTS: The 1,698 patients admitted to the participating ICUs during the study period, including 295 (17.4%) with DFLSTs. MEASUREMENTS AND RESULTS: The impact of DFLSTs on hospital mortality was evaluated using a model that incorporates changes in daily logistic organ dysfunction scores during the first ICU week. Univariate predictors of death included demographic factors (age, gender), comorbidities, reasons for ICU admission, severity scores at ICU admission, and DFLSTs. In a stepwise Cox model five variables independently predicted mortality: good chronic health status (hazard ratio, 0.479), SAPS II score higher than 39 (2.05), chronic liver disease (1.463), daily logistic organ dysfunction score (1.357 per point), and DFLSTs (1.887). CONCLUSIONS: DFLSTs remain independently associated with death after adjusting on comorbidities and severity at ICU admission and within the first ICU week. This highlights the need for further clarifying the many determinants of DFLSTs and for routinely collecting DFLSTs in studies with survival as the outcome variable of interest.

Heat and moisture exchangers in mechanically ventilated intensive care unit patients: a plea for an independent assessment of their performance.

OBJECTIVE: To determine whether use of a hygroscopic and hydrophobic heat and moisture exchanger (HME) for 7 days without change affects its efficiency in long-term, mechanically ventilated, chronic obstructive pulmonary disease (COPD) patients. DESIGN: Prospective, randomized, controlled clinical study comparing two combined HMEs. SETTING: Medical intensive care unit at a university teaching hospital. PATIENTS: Long-term, mechanically ventilated, COPD patients compared with non-COPD patients. INTERVENTIONS: In the first part of the study, COPD patients were studied with the Hygroster HME changed once a week. For the second part, the Hygroster was assessed in non-COPD patients and compared with the Hygrobac HME used in COPD and non-COPD patients for 1 wk without change. Devices could be changed if hygrometric measurements indicated insufficient humidity delivery. MEASUREMENTS AND MAIN RESULTS: Daily measurements were recorded for inspired gas temperature and relative and absolute humidity. Ventilatory variables, clinical indicators of efficient humidification, were also recorded. No tracheal tube occlusion occurred. However, contrary to the manufacturer advertisement, the Hygroster experienced surprisingly low values for absolute humidity in both COPD and non-COPD patients. Such events did not occur with the Hygrobac. Absolute humidity with the Hygroster was constantly and significantly lower during the 7-day study period than with the Hygrobac. Absolute humidity measured in COPD patients was identical to that measured in the rest of the study population with both HMEs. CONCLUSIONS: Manufacturer specifications and bedside measurements of absolute humidity differed considerably for the Hygroster, which in certain instances did not achieve efficient humidification in both COPD and non-COPD patients. This did not occur with the Hygrobac, which performed well throughout the 7-day period in both COPD and non-COPD patients. Our results speak for independent and evaluation of HMEs.

Long-term mechanical ventilation with hygroscopic heat and moisture exchangers used for 48 hours: a prospective clinical, hygrometric, and bacteriologic study.

OBJECTIVE: To determine whether use of a hygroscopic heat and moisture exchanger (HME) for 48 hrs without change affects its efficiency and the level of bacterial colonization in long-term mechanically ventilated medical intensive care unit patients. DESIGN: Prospective, randomized clinical study evaluating two hygroscopic HMEs. SETTING: Medical intensive care unit at a university teaching hospital. PATIENTS: Long-term mechanically ventilated medical intensive care unit patients, including chronic obstructive pulmonary disease patients. INTERVENTIONS: Patients were randomly allocated to one of the two HMEs studied (Hygrolife and EdithFlex) and changed every 48 hrs. Devices in both groups could be changed if hygrometric measurements indicated insufficient humidity delivery. MEASUREMENTS AND MAIN RESULTS: Daily measurements of inspired gas temperature and relative and absolute humidity. In addition, cultures of tracheal aspirations and both patient and ventilator sides of the device were performed after 48 hrs of use. Ventilatory variables and clinical indicators of efficient humidification were also recorded. Prolonged use of both HMEs was safe and efficient (no tracheal tube occlusion occurred). Mean duration of mechanical ventilation was 20 days. Both clinical indicators and hygrometric measurements showed that both devices performed well during 48 hrs. Absolute humidity with EdithFlex was significantly higher on day 0 and day 1 than with Hygrolife. Absolute humidity measured in chronic obstructive pulmonary disease patients was identical to that measured in the rest of the study population. Tracheal colonization and HME colonization were similar with both HMEs. Bacterial contamination of the ventilator side of both devices was markedly low. CONCLUSIONS: These two purely hygroscopic HMEs provided safe and efficient humidification during a 48-hr period of use in long-term mechanically ventilated medical intensive care unit patients, including chronic obstructive pulmonary disease patients. In addition, they maintained ventilatory circuits clean, despite the absence of filtering media. The cost of mechanical ventilation is consequently reduced.

Determinants of postintensive care unit mortality: a prospective multicenter study.

OBJECTIVE: Six to 25 percent of patients discharged alive from the intensive care unit (ICU) die before hospital discharge. Although this post-ICU mortality may indicate premature discharge from a full ICU or suboptimal management in the ICU or ward, another factor may be discharge from the ICU as part of a decision to limit treatment of hopelessly ill patients. We investigated determinants of post-ICU mortality, with special attention to this factor. DESIGN: Prospective, multicenter, database study. SETTING: Seven ICUs in or near Paris, France. PATIENTS: A total of 1,385 patients who were discharged alive from an ICU after a stay of > or = 48 hrs; 150 (10.8%) died before hospital discharge. Decisions to withhold or withdraw life-sustaining treatments were implemented in the ICUs in 80 patients, including 47 (58.7%) who died before hospital discharge. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In the univariate analysis, post-ICU mortality was associated with advanced age, poor chronic health status, severe comorbidities, severity and organ failure scores (Simplified Acute Physiology Score II, sepsis-related organ failure assessment, and Logistic Organ Dysfunction at admission and at ICU discharge), decisions to withhold or withdraw life-sustaining treatments, and Omega score (reflecting ICU resource utilization and length of ICU stay). Multivariate stepwise logistic regression identified five independent determinants of post-ICU mortality: McCabe class 1 (odds ratio, 0.388 [95% confidence interval, 0.26-0.58]), transfer from a ward (odds ratio, 1.89 [95% confidence interval, 1.27-2.80]), Simplified Acute Physiology Score II score at admission >36 (odds ratio, 1.57 [95% confidence interval, 1.6-2.33]), decisions to withhold or withdraw life-sustaining treatments (odds ratio, 9.64 [95% confidence interval, 5.75-16.6]), and worse sepsis-related organ failure assessment score at discharge (odds ratio, 1.11 [95% confidence interval, 1.03-1.18] per point). CONCLUSIONS: More than 10% of ICU survivors died before hospital discharge. Determinants of post-ICU mortality included variables reflecting patient status before and during the ICU stay. However, the most powerful predictor of post-ICU mortality was the decision to withhold or withdraw life-sustaining treatments in the ICU, suggesting that the decision has been made not to use the unique services of the ICU for these patients.

Calibration and discrimination by daily Logistic Organ Dysfunction scoring comparatively with daily Sequential Organ Failure Assessment scoring for predicting hospital mortality in critically ill patients.

OBJECTIVE: The Logistic Organ Dysfunction (LOD) score has been proved effective in evaluating severity during the first day in an intensive care unit but has not been evaluated later. To evaluate attributable mortality related to nosocomial events, organ dysfunction scores that remain accurate throughout the intensive care unit stay are needed. The objective of this study was to evaluate how accurately daily LOD scoring predicts mortality comparatively with daily Sequential Organ Failure Assessment (SOFA) scoring. DESIGN: Prospective multicenter study. SETTING: Six intensive care units in France. PATIENTS: A total of 1685 patients with intensive care unit stays longer than 48 hrs were included in this study (511 hospital deaths). Median age was 66 yrs, and median Simplified Acute Physiology Score II at admission was 38. For each patient, a senior physician recorded the variables needed to compute organ dysfunction scores daily throughout the intensive care unit stay. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: SOFA and LOD scores were computed daily during the first 7 days. Calibration was evaluated based on goodness-of-fit by the Hosmer-Lemeshow chi-square statistic (lower chi-square values and higher values indicate better fit) and discrimination based on the receiver operating characteristics (ROC) area under the curve (AUC; a ROC-AUC of 1 indicates faultless discrimination and a ROC-AUC of 0.5 indicates the effects of chance alone). Because calibration of both scores was poor at all time points ( p<.001), customization was performed using the total score (model 1) or separate introduction of each dysfunction (model 2). The performance of customized LOD and SOFA scores on a given day in predicting mortality was assessed in those patients who spent at least one more calendar day in the intensive care unit. The original LOD and SOFA scores had satisfactory ROC-AUC values (0.720 to 0.766). Internal consistency of both scores was acceptable ( p< 10(-4) for each organ dysfunction). After customization, the original scores calibrated well between days 1 and 7. Discrimination by both scores was better with model 2 (AUC-ROC, 0.729-0.784). CONCLUSION: Daily LOD and SOFA scores showed good accuracy and internal consistency, and they could be used to adjust severity for events occurring in the intensive care unit.