Single-drug versus combination antimicrobial therapy in critically ill patients with hospital-acquired pneumonia and ventilator-associated pneumonia due to Gram-negative pathogens: a multicenter retrospective cohort study

KEY MESSAGES

In this study including 391 critically ill patients with nosocomial pneumonia due to Gram-negative pathogens, combination therapy was not associated with a reduced hazard of death at Day 28 or a greater likelihood of clinical cure at Day 14. No over-risk of AKI was observed in patients receiving combination therapy.

BACKGROUND

The benefits and harms of combination antimicrobial therapy remain controversial in critically ill patients with hospital-acquired pneumonia (HAP), ventilated HAP (vHAP) or ventilator-associated pneumonia (VAP) involving Gram-negative bacteria.

METHODS

We included all patients in the prospective multicenter OutcomeRea database with a first HAP, vHAP or VAP due to a single Gram-negative bacterium and treated with initial adequate single-drug or combination therapy. The primary endpoint was Day-28 all-cause mortality. Secondary endpoints were clinical cure rate at Day 14 and a composite outcome of death or treatment-emergent acute kidney injury (AKI) at Day 7. The average effects of combination therapy on the study endpoints were investigated through inverse probability of treatment-weighted regression and multivariable regression models. Subgroups analyses were performed according to the resistance phenotype of the causative pathogens (multidrug-resistant or not), the pivotal (carbapenems or others) and companion (aminoglycosides/polymyxins or others) drug classes, the duration of combination therapy (< 3 or ≥ 3 days), the SOFA score value at pneumonia onset (< 7 or ≥ 7 points), and in patients with pneumonia due to non-fermenting Gram-negative bacteria, pneumonia-related bloodstream infection, or septic shock.

RESULTS

Among the 391 included patients, 151 (38.6%) received single-drug therapy and 240 (61.4%) received combination therapy. VAP (overall, 67.3%), vHAP (16.4%) and HAP (16.4%) were equally distributed in the two groups. All-cause mortality rates at Day 28 (overall, 31.2%), clinical cure rate at Day 14 (43.7%) and the rate of death or AKI at Day 7 (41.2%) did not significantly differ between the groups. In inverse probability of treatment-weighted analyses, combination therapy was not independently associated with the likelihood of all-cause death at Day 28 (adjusted odd ratio [aOR], 1.14; 95% confidence interval [CI] 0.73-1.77; P = 0.56), clinical cure at Day 14 (aOR, 0.79; 95% CI 0.53-1.20; P = 0.27) or death or AKI at Day 7 (aOR, 1.07; 95% CI 0.71-1.63; P = 0.73). Multivariable regression models and subgroup analyses provided similar results.

CONCLUSIONS

Initial combination therapy exerts no independent impact on Day-28 mortality, clinical cure rate at Day 14, and the hazard of death or AKI at Day 7 in critically ill patients with mono-bacterial HAP, vHAP or VAP due to Gram-negative bacteria.

Non-ventilator-associated ICU-acquired pneumonia (NV-ICU-AP) in patients with acute exacerbation of COPD: From the French OUTCOMEREA cohort

BACKGROUND

Non-ventilator-associated ICU-acquired pneumonia (NV-ICU-AP), a nosocomial pneumonia that is not related to invasive mechanical ventilation (IMV), has been less studied than ventilator-associated pneumonia, and never in the context of patients in an ICU for severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD), a common cause of ICU admission. This study aimed to determine the factors associated with NV-ICU-AP occurrence and assess the association between NV-ICU-AP and the outcomes of these patients.

METHODS

Data were extracted from the French ICU database, OutcomeRea™. Using survival analyses with competing risk management, we sought the factors associated with the occurrence of NV-ICU-AP. Then we assessed the association between NV-ICU-AP and mortality, intubation rates, and length of stay in the ICU.

RESULTS

Of the 844 COPD exacerbations managed in ICUs without immediate IMV, NV-ICU-AP occurred in 42 patients (5%) with an incidence density of 10.8 per 1,000 patient-days. In multivariate analysis, prescription of antibiotics at ICU admission (sHR, 0.45 [0.23; 0.86], p = 0.02) and no decrease in consciousness (sHR, 0.35 [0.16; 0.76]; p < 0.01) were associated with a lower risk of NV-ICU-AP. After adjusting for confounders, NV-ICU-AP was associated with increased 28-day mortality (HR = 3.03 [1.36; 6.73]; p < 0.01), an increased risk of intubation (csHR, 5.00 [2.54; 9.85]; p < 0.01) and with a 10-day increase in ICU length of stay (p < 0.01).

CONCLUSION

We found that NV-ICU-AP incidence reached 10.8/1000 patient-days and was associated with increased risks of intubation, 28-day mortality, and longer stay for patients admitted with AECOPD.

Outcomes in critically Ill HIV-infected patients between 1997 and 2020: analysis of the OUTCOMEREA multicenter cohort

PURPOSE

Despite antiviral therapy (ART), 800,000 deaths still occur yearly and globally due to HIV infection. In parallel with the good virological control and the aging of this population, multiple comorbidities [HIV-associated-non-AIDS (HANA) conditions] may now be observed.

METHODS

HIV adult patients hospitalized in intensive care unit (ICU) from all the French region from university and non-university hospital who participate to the OutcomeRea™ database on a voluntary basis over a 24-year period.

RESULTS

Of the 24,298 stays registered, 630 (2.6%) were a first ICU stay for HIV patients. Over time, the mean age and number of comorbidities (diabetes, renal and respiratory history, solid neoplasia) of patients increased. The proportion of HIV diagnosed on ICU admission decreased significantly, while the median duration of HIV disease as well as the percentage of ART-treated patients increased. The distribution of main reasons for admission remained stable over time (acute respiratory distress > shock > coma). We observed a significant drop in the rate of active opportunistic infection on admission, while the rate of active hemopathy (newly diagnosed or relapsed within the last 6 months prior to admission to ICU) qualifying for AIDS increased-nonsignificantly-with a significant increase in the anticancer chemotherapy administration in ICU. Admissions for HANA or non-HIV reasons were stable over time. In multivariate analysis, predictors of 60-day mortality were advanced age, chronic liver disease, past chemotherapy, sepsis-related organ failure assessment score > 4 at admission, hospitalization duration before ICU admission > 24 h, AIDS status, but not the period of admission.

CONCLUSION

Whereas the profile of ICU-admitted HIV patients has evolved over time (HIV better controlled but more associated comorbidities), mortality risk factors remain stable, including AIDS status.

Corticosteroids for severe acute exacerbations of chronic obstructive pulmonary disease in intensive care: From the French OUTCOMEREA cohort

INTRODUCTION

Acute exacerbation of chronic obstructive pulmonary disease (COPD) is a frequent cause of intensive care unit (ICU) admission. However, data are scarce and conflicting regarding the impact of systemic corticosteroid treatment in critically ill patients with acute exacerbation of COPD. The aim of the study was to assess the impact of systemic corticosteroids on the occurrence of death or need for continuous invasive mechanical ventilation at day 28 after ICU admission.

METHODS

In the OutcomeReaTM prospective French national ICU database, we assessed the impact of corticosteroids at admission (daily dose ≥ 0.5 mg/kg of prednisone or equivalent during the first 24 hours ICU stay) on a composite outcome (death or invasive mechanical ventilation) using an inverse probability treatment weighting.

RESULTS

Between January 1, 1997 and December 31, 2018, 391 out of 1,247 patients with acute exacerbations of COPDs received corticosteroids at ICU admission. Corticosteroids improved the main composite endpoint (OR = 0.70 [0.49; 0.99], p = 0.044. However, for the subgroup of most severe COPD patients, this did not occur (OR = 1.12 [0.53; 2.36], p = 0. 770). There was no significant impact of corticosteroids on rates of non-invasive ventilation failure, length of ICU or hospital stay, mortality or on the duration of mechanical ventilation. Patients on corticosteroids had the same prevalence of nosocomial infections as those without corticosteroids, but more glycaemic disorders.

CONCLUSION

Using systemic corticosteroids for acute exacerbation of COPD at ICU admission had a positive effect on a composite outcome defined by death or need for invasive mechanical ventilation at day 28.

One-year survival in acute stroke patients requiring mechanical ventilation: a multicenter cohort study

Background

Most prognostic studies in acute stroke patients requiring invasive mechanical ventilation are outdated and have limitations such as single-center retrospective designs. We aimed to study the association of ICU admission factors, including the reason for intubation, with 1-year survival of acute stroke patients requiring mechanical ventilation.

Methods

We conducted a secondary data use analysis of a prospective multicenter database (14 ICUs) between 1997 and 2016 on consecutive ICU stroke patients requiring mechanical ventilation at admission. We excluded patients with stroke of traumatic origin, subdural hematoma or cerebral venous thrombosis. The primary outcome was survival 1 year after ICU admission. Factors associated with the primary outcome were identified using a multivariable Cox model stratified on inclusion center.

Results

We identified 419 patients (age 68 [58–76] years, males 60%) with a Glasgow coma score (GCS) of 4 [3–8] at admission. Stroke subtypes were acute ischemic stroke (AIS, 46%), intracranial hemorrhage (ICH, 42%) and subarachnoid hemorrhage (SAH, 12%). At 1 year, 96 (23%) patients were alive. Factors independently associated with decreased 1-year survival were ICH and SAH stroke subtypes, a lower GCS score at admission, a higher non-neurological SOFA score. Conversely, patients receiving acute-phase therapy had improved 1-year survival. Intubation for acute respiratory failure or coma was associated with comparable survival hazard ratios, whereas intubation for seizure was not associated with a worse prognosis than for elective procedure. Survival did not improve over the study period, but patients included in the most recent period had more comorbidities and presented higher severity scores at admission.

Conclusions

In acute stroke patients requiring mechanical ventilation, the reason for intubation and the opportunity to receive acute-phase stroke therapy were independently associated with 1-year survival. These variables could assist in the decision process regarding the initiation of mechanical ventilation in acute stroke patients.

ICU survival and need of renal replacement therapy with respect to AKI duration in critically ill patients

BACKGROUND

Transient and persistent acute kidney injury (AKI) could share similar physiopathological mechanisms. The objective of our study was to assess prognostic impact of AKI duration on ICU mortality.

DESIGN

Retrospective analysis of a prospective database via cause-specific model, with 28-day ICU mortality as primary end point, considering discharge alive as a competing event and taking into account time-dependent nature of renal recovery. Renal recovery was defined as a decrease of at least one KDIGO class compared to the previous day.

SETTING

23 French ICUs.

PATIENTS

Patients of a French multicentric observational cohort were included if they suffered from AKI at ICU admission between 1996 and 2015.

INTERVENTION

None.

RESULTS

A total of 5242 patients were included. Initial severity according to KDIGO creatinine definition was AKI stage 1 for 2458 patients (46.89%), AKI stage 2 for 1181 (22.53%) and AKI stage 3 for 1603 (30.58%). Crude 28-day ICU mortality according to AKI severity was 22.74% (n = 559), 27.69% (n = 327) and 26.26% (n = 421), respectively. Renal recovery was experienced by 3085 patients (58.85%), and its rate was significantly different between AKI severity stages (P < 0.01). Twenty-eight-day ICU mortality was independently lower in patients experiencing renal recovery [CSHR 0.54 (95% CI 0.46-0.63), P < 0.01]. Lastly, RRT requirement was strongly associated with persistent AKI whichever threshold was chosen between day 2 and 7 to delineate transient from persistent AKI.

CONCLUSIONS

Short-term renal recovery, according to several definitions, was independently associated with higher mortality and RRT requirement. Moreover, distinction between transient and persistent AKI is consequently a clinically relevant surrogate outcome variable for diagnostic testing in critically ill patients.

Impact of transfusion on patients with sepsis admitted in intensive care unit: a systematic review and meta-analysis

Red blood cell transfusion (RBCT) threshold in patients with sepsis remains a matter of controversy. A threshold of 7 g/dL for stabilized patients with sepsis is commonly proposed, although debated. The aim of the study was to compare the benefit and harm of restrictive versus liberal RBCT strategies in order to guide physicians on RBCT strategies in patients with severe sepsis or septic shock. Four outcomes were assessed: death, nosocomial infection (NI), acute lung injury (ALI) and acute kidney injury (AKI). Studies assessing RBCT strategies or RBCT impact on outcome and including intensive care unit (ICU) patients with sepsis were assessed. Two systematic reviews were achieved: first for the randomized controlled studies (RCTs) and second for the observational studies. MEDLINE, EMBASE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Clinical Trials.gov were analyzed up to March 01, 2015. Der Simonian and Laird random-effects models were used to report pooled odds ratios (ORs). Subgroup analyses and meta-regressions were performed to explore studies heterogeneity. One RCT was finally included. The restrictive RBCT strategy was not associated with harm or benefit compared to liberal strategy. Twelve cohort studies were included, of which nine focused on mortality rate. RBCT was not associated with increased mortality rate (overall pooled OR was 1.10 [0.75, 1.60]; I 2 = 57%, p = 0.03), but was associated with the occurrence of NI (2 studies: pooled OR 1.25 [1.04-1.50]; I 2 = 0%, p = 0.97), the occurrence of ALI (1 study: OR 2.75 [1.22-6.37]; p = 0.016) and the occurrence of AKI (1 study: OR 5.22 [2.1-15.8]; p = 0.001). Because there was only one RCT, the final meta-analyses were only based on the cohort studies. As a result, the safety of a RBCT restrictive strategy was confirmed, although only one study specifically focused on ICU patients with sepsis. Then, RBCT was not associated with increased mortality rate, but was associated with increased in occurrence of NI, ALI and AKI. Nevertheless, the data on RBCT in patients with sepsis are sparse and the high heterogeneity between studies prevents from drawing any definitive conclusions.

Respective impact of implementation of prevention strategies, colonization with multiresistant bacteria and antimicrobial use on the risk of early- and late-onset VAP: An analysis of the OUTCOMEREA network

Rationale

The impact of prevention strategies and risk factors for early-onset (EOP) versus late-onset (LOP) ventilator-associated pneumonia (VAP) are still debated.

Objectives

To evaluate, in a multicenter cohort, the risk factors for EOP and LOP, as the evolution of prevention strategies.

Methods

7,784 patients with mechanical ventilation (MV) for at least 48 hours were selected into the multicenter prospective OUTCOMEREA database (1997–2016). VAP occurring between the 3^rd and 6^th day of MV defined EOP, while those occurring after defined LOPs. We used a Fine and Gray subdistribution model to take the successful extubation into account as a competing event.

Measurements and main results

Overall, 1,234 included patients developed VAP (EOP: 445 (36%); LOP: 789 (64%)). Male gender was a risk factor for both EOP and LOP. Factors specifically associated with EOP were admission for respiratory distress, previous colonization with multidrug-resistant Pseudomonas aeruginosa, chest tube and enteral feeding within the first 2 days of MV. Antimicrobials administrated within the first 2 days of MV were all protective of EOP. ICU admission for COPD exacerbation or pneumonia were early risk factors for LOP, while imidazole and vancomycin use within the first 2 days of MV were protective factors. Late risk factors (between the 3^rd and the 6^th day of MV) were the intra-hospital transport, PAO2-FIO2<200 mmHg, vasopressor use, and known colonization with methicillin-resistant Staphylococcus aureus. Among the antimicrobials administered between the 3^rd and the 6^th day, fluoroquinolones were the solely protective one.Contrarily to LOP, the risk of EOP decreased across the study time periods, concomitantly with an increase in the compliance with bundle of prevention measures.

Conclusion

VAP risk factors are mostly different according to the pneumonia time of onset, which should lead to differentiated prevention strategies.

Treatment of severe hospital-acquired and ventilator-associated pneumonia: a systematic review of inclusion and judgment criteria used in randomized controlled trials

BACKGROUND

Hospital-acquired and ventilator-associated pneumonia (HAP/VAP) are often selected for randomized clinical trials (RCTs) aiming at new drug approval. Guidelines for the design of such RCTs have been repeatedly updated by regulatory agencies. We hypothesized that large variability in the enrolled populations, the endpoints assessed and the HAP/VAP definition criteria may impact the results of these studies, and addressed this through a systematic review of HAP/VAP RCTs.

METHODS

A search (Pubmed-Embase-ICAAC-ECCMID) of all RCTs published between 1994 and 2016 comparing antimicrobial treatment for HAP/VAP in the intensive care unit was conducted. The populations enrolled, inclusion/exclusion criteria, statistical design and endpoints assessed were recorded. All unpublished RCTs recorded on the ClinicalTrials.gov registry were also screened.

RESULTS

From the 93 abstracts reviewed, 39 potentially relevant studies were inspected, leading to 27 studies being included. As expected, illness severity or the proportion with VAP (27-100%) differed greatly among the enrolled populations. The HAP/VAP definition used various clinical and biological criteria, and only 55% of studies required a microbiological sample. The mandatory duration of prior hospital stay was variable; the mechanical ventilation duration was an inclusion criterion in only 41% of VAP studies. Nine studies had non-inferiority design, but nine studies (33%) did not have a pre-specified statistical hypothesis. Clinical cure was the primary endpoint in 24 studies, but was recorded in several populations or as the co-primary endpoint in 13 studies. The definition of clinical cure and the timing of its assessment greatly differed. This variability slightly improved over time but remained significant in the 13 registered but currently unpublished RCTs that we screened.

CONCLUSION

Our study provides a description of populations and endpoints of RCTs evaluating antimicrobials for treatment of HAP/VAP in the ICU. There was significant heterogeneity in enrollment criteria, endpoints and statistical design, which may influence the ability of studies to demonstrate differences between studied drugs.

Persistent lymphopenia is a risk factor for ICU-acquired infections and for death in ICU patients with sustained hypotension at admission

Background

Severely ill patients might develop an alteration of their immune system called post-aggressive immunosuppression. We sought to assess the risk of ICU-acquired infection and of mortality according to the absolute lymphocyte count at ICU admission and its changes over 3 days.

Methods

Adults in ICU for at least 3 days with a shock or persistent low blood pressure were extracted from a French ICU database and included. We evaluated the impact of the absolute lymphocyte count at baseline and its change at day 3 on the incidence of ICU-acquired infection and on the 28-day mortality rate. We categorized lymphocytes in 4 groups: above 1.5 × 10³ cells/µL; between 1 and 1.5 × 10³ cells/µL; between 0.5 and 1 × 10³ cells/µL; and below 0.5 × 10³ cells/µL.

Results

A total of 753 patients were included. The median lymphocyte count was 0.8 × 10³ cells/µL [0.51–1.29]. A total of 174 (23%) patients developed infections; the 28-day mortality rate was 21% (161/753). Lymphopenia at admission was associated with ICU-acquired infection (p < 0.001) but not with 28-day mortality. Independently of baseline lymphocyte count, the absence of lymphocyte count increase at day 3 was associated with ICU-acquired infection (sub-distribution hazard ratio sHR: 1.37 [1.12–1.67], p = 0.002) and with 28-day mortality (sHR: 1.67 [1.37–2.03], p < 0.0001).

Conclusion

Lymphopenia at ICU admission and its persistence at day 3 were associated with an increased risk of ICU-acquired infection, while only persisting lymphopenia predicted increased 28-day mortality. The lymphocyte count at ICU admission and at day 3 could be used as a simple and reproductive marker of post-aggressive immunosuppression.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0242-0) contains supplementary material, which is available to authorized users.

Attributable mortality of ICU-acquired bloodstream infections: Impact of the source, causative micro-organism, resistance profile and antimicrobial therapy

OBJECTIVES

ICU-acquired bloodstream infection (ICUBSI) in Intensive Care unit (ICU) is still associated with a high mortality rate. The increase of antimicrobial drug resistance makes its treatment increasingly challenging.

METHODS

We analyzed 571 ICU-BSI occurring amongst 10,734 patients who were prospectively included in the Outcomerea Database and who stayed at least 4 days in ICU. The hazard ratio of death associated with ICU-BSI was estimated using a multivariate Cox model adjusted on case mix, patient severity and daily SOFA.

RESULTS

ICU-BSI was associated with increased mortality (HR, 1.40; 95% CI, 1.16-1.69; p = 0.0004). The relative increase in the risk of death was 130% (HR, 2.3; 95% CI, 1.8-3.0) when initial antimicrobial agents within a day of ICU-BSI onset were not adequate, versus only 20% (HR, 1.2; 95% CI, 0.9-1.5) when an adequate therapy was started within a day. The adjusted hazard ratio of death was significant overall, and even higher when the ICU-BSI source was pneumonia or unknown origin. When treated with appropriate antimicrobial agents, the death risk increase was similar for ICU-BSI due to multidrug resistant pathogens or susceptible ones. Interestingly, combination therapy with a fluoroquinolone was associated with more favorable outcome than monotherapy, whereas combination with aminoglycoside was associated with similar mortality than monotherapy.

CONCLUSIONS

ICU-BSI was associated with a 40% increase in the risk of 30-day mortality, particularly if the early antimicrobial therapy was not adequate. Adequacy of antimicrobial therapy, but not pathogen resistance pattern, impacted attributable mortality.

Endotoxin tolerance: is there a clinical relevance?

Beeson (1946) first defined endotoxin tolerance as a reduced endotoxin-induced fever following repeated injections of typhoid vaccine. Freudenberg and Galanos (1988) demonstrated that endotoxin tolerance that can protect against a lethal challenge of lipopolysaccharide (LPS) involves the participation of macrophages. Evans and Zuckerman (1991) reported a role for glucocorticoids in endotoxin tolerance. Prostaglandins, interleukin-(IL-)10, and transforming growth factor-β are other players of in vivo endotoxin tolerance. Dramatic reduction of plasma tumor necrosis factor (TNF) (Mathison et al. 1990) and other cytokines in response to LPS parallels endotoxin tolerance. The reduced capacity to produce TNF and other cytokines can be mimicked in vitro by pretreatment of monocytes or macrophages with LPS. It is not a specific phenomenon and can be induced by other agents or events. Cross-tolerance between LPS, TLR2 specific ligands, IL-1 and TNF has been regularly reported. A similar loss of LPS-reactivity has been repeatedly reported in leukocytes of septic patients and in patients with non-infectious systemic inflammation response syndrome (SIRS; e.g . surgery, trauma, cardiac arrest and resuscitation, etc.). Studies on cellular signaling within leukocytes from septic and SIRS patients reveal numerous alterations of the activation pathways reminiscent of those observed in endotoxin-tolerant cells. While endotoxin tolerance prevents severity of infections and ischemia-reperfusion damage, it has been suggested that the immune dysregulation observed in SIRS patients was associated with an enhanced sensitivity to nosocomial infections. In conclusion, in vitro and in vivo endotoxin tolerance, either experimental or due to clinical status, are similar but not identical.

Continuous renal replacement therapy versus intermittent hemodialysis in intensive care patients: impact on mortality and renal recovery

PURPOSE

The best renal replacement therapy (RRT) modality remains controversial. We compared mortality and short- and long-term renal recovery between patients treated with continuous RRT and intermittent hemodialysis.

METHODS

Patients of the prospective observational multicenter cohort database OUTCOMEREA™ were included if they underwent at least one RRT session between 2004 and 2014. Differences in patients' baseline and daily characteristics between treatment groups were taken into account by using a marginal structural Cox model, allowing one to substantially reduce the bias resulting from confounding factors in observational longitudinal data analysis. The composite primary endpoint was 30-day mortality and dialysis dependency.

RESULTS

Among 1360 included patients with RRT, 544 (40.0 %) and 816 (60.0 %) were initially treated by continuous RRT and intermittent hemodialysis, respectively. At day 30, 39.6 % patients were dead. Among survivors, 23.8 % still required RRT. There was no difference between groups for the primary endpoint in global population (HR 1.00, 95 % CI 0.77-1.29; p = 0.97). In patients with higher weight gain at RRT initiation, mortality and dialysis dependency were significantly lower with continuous RRT (HR 0.54, 95 % CI 0.29-0.99; p = 0.05). Conversely, this technique appeared to be deleterious in patients without shock (HR 2.24, 95 % CI 1.24-4.04; p = 0.01). Six-month mortality and persistent renal dysfunction were not influenced by the RRT modality in patients with dialysis dependence at ICU discharge.

CONCLUSION

Continuous RRT did not appear to improve 30-day and 6-month patient outcomes. It seems beneficial for patients with fluid overload, but might be deleterious in the absence of hemodynamic failure.

Very high volume hemofiltration with the Cascade system in septic shock patients

PURPOSE

We compared hemodynamic and biological effects of the Cascade system, which uses very high volume hemofiltration (HVHF) (120 mL kg(-1) h(-1)), with those of usual care in patients with septic shock.

METHODS

Multicenter, prospective, randomized, open-label trial in three intensive care units (ICU). Adults with septic shock with administration of epinephrine/norepinephrine were eligible. Patients were randomized to usual care plus HVHF (Cascade group), or usual care alone (control group). Primary end point was the number of catecholamine-free days up to 28 days after randomization. Secondary end points were number of days free of mechanical ventilation, renal replacement therapy (RRT) or ICU up to 90 days, and 7-, 28-, and 90-day mortality.

RESULTS

We included 60 patients (29 Cascade, 31 usual care). Baseline characteristics were comparable. Median number of catecholamine-free days was 22 [IQR 11-23] vs 20 [0-25] for Cascade vs control; there was no significant difference even after adjustment. There was no significant difference in number of mechanical ventilation-free days or ICU requirement. Median number of RRT-free days was 85 [46-90] vs 74 [0-90] for Cascade vs control groups, p = 0.42. By multivariate analysis, the number of RRT-free days was significantly higher in the Cascade group (up to 25 days higher after adjustment). There was no difference in mortality at 7, 28, or 90 days.

CONCLUSION

Very HVHF using the Cascade system can safely be used in patients presenting with septic shock, but it was not associated with a reduction in the need for catecholamines during the first 28 days.

Decreased Risk of Ventilator-Associated Pneumonia in Sepsis Due to Intra-Abdominal Infection

RATIONALE

Experimental studies suggest that intra-abdominal infection (IAI) induces biological alterations that may affect the risk of lung infection.

OBJECTIVES

To investigate the potential effect of IAI at ICU admission on the subsequent occurrence of ventilator-associated pneumonia (VAP).

METHODS

We used data entered into the French prospective multicenter Outcomerea database in 1997-2011. Consecutive patients who had severe sepsis and/or septic shock at ICU admission and required mechanical ventilation for more than 3 days were included. Patients with acute pancreatitis were not included.

MEASUREMENTS AND MAIN RESULTS

Of 2623 database patients meeting the inclusion criteria, 290 (11.1%) had IAI and 2333 (88.9%) had other infections. The IAI group had fewer patients with VAP (56 [19.3%] vs. 806 [34.5%], P<0.01) and longer time to VAP (5.0 vs.10.5 days; P<0.01). After adjustment on independent risk factors for VAP and previous antimicrobial use, IAI was associated with a decreased risk of VAP (hazard ratio, 0.62; 95% confidence interval, 0.46-0.83; P<0.0017). The pathogens responsible for VAP were not different between the groups with and without IAI (Pseudomonas aeruginosa, 345 [42.8%] and 24 [42.8%]; Enterobacteriaceae, 264 [32.8%] and 19 [34.0%]; and Staphylococcus aureus, 215 [26.7%] and 17 [30.4%], respectively). Crude ICU mortality was not different between the groups with and without IAI (81 [27.9%] and 747 [32.0%], P = 0.16).

CONCLUSIONS

In our observational study of mechanically ventilated ICU patients with severe sepsis and/or septic shock, VAP occurred less often and later in the group with IAIs compared to the group with infections at other sites.

Failure of empirical systemic antifungal therapy in mechanically ventilated critically ill patients

RATIONALE

Systemic antifungal treatments are empirically administered to the sickest critically ill patients, often without documented invasive fungal infection.

OBJECTIVES

To estimate the impact of systemic antifungal treatment on 30-day survival of patients suspected to have invasive candidiasis.

METHODS

All nonneutropenic, nontransplant recipients managed in five intensive care units intubated for at least 5 days, and free of invasive candidiasis, were included. To account for differences in patients' characteristics recorded daily before study end point, a causal model for longitudinal data was used to assess benefits from antifungal treatment. The composite primary end point was hospital mortality or occurrence of invasive candidiasis.

MEASUREMENTS AND MAIN RESULTS

Among 1,491 patients, 100 (6.7%) received antifungal treatment for a suspected infection. Patients treated with antifungals were more severely ill than untreated patients. Within the 30-day follow-up period, 363 (24.3%) patients died, and 22 (1.5%) exhibited documented invasive candidiasis. After adjustment on baseline and time-dependent confounders (underlying illness, severity, invasive procedures, Candida colonization), and using a marginal structural model for longitudinal data, treatment was not associated with a decreased risk of mortality or of occurrence of invasive candidiasis (hazard ratio, 1.05; 95% confidence interval, 0.56-1.96; P = 0.91).

CONCLUSIONS

This study failed to show outcome benefits for empirical systemic antifungal therapy in the sickest critically ill, nonneutropenic, nontransplanted patients. The post hoc power did not allow us to conclude to an absence of treatment effect especially for specific subgroups. Studies to refine indications for empirical treatment based on surrogate markers of invasive candidiasis are warranted.

Quantitative lipopolysaccharide analysis using HPLC/MS/MS and its combination with the limulus amebocyte lysate assay

Quantitation of plasma lipopolysaccharides (LPSs) might be used to document Gram-negative bacterial infection. In the present work, LPS-derived 3-hydroxymyristate was extracted from plasma samples with an organic solvent, separated by reversed phase HPLC, and quantitated by MS/MS. This mass assay was combined with the limulus amebocyte lysate (LAL) bioassay to monitor neutralization of LPS activity in biological samples. The described HPLC/MS/MS method is a reliable, practical, accurate, and sensitive tool to quantitate LPS. The combination of the LAL and HPLC/MS/MS analyses provided new evidence for the intrinsic capacity of plasma lipoproteins and phospholipid transfer protein to neutralize the activity of LPS. In a subset of patients with systemic inflammatory response syndrome, with documented infection but with a negative plasma LAL test, significant amounts of LPS were measured by the HPLC/MS/MS method. Patients with the highest plasma LPS concentration were more severely ill. HPLC/MS/MS is a relevant method to quantitate endotoxin in a sample, to assess the efficacy of LPS neutralization, and to evaluate the proinflammatory potential of LPS in vivo.

Acute Kidney Injury in Severe Sepsis and Septic Shock in Patients with and without Diabetes Mellitus: A Multicenter Study

Introduction

Whether diabetes mellitus increases the risk of acute kidney injury (AKI) during sepsis is controversial.

Materials and Methods

We used a case-control design to compare the frequency of AKI, use of renal replacement therapy (RRT), and renal recovery in patients who had severe sepsis or septic shock with or without diabetes. The data were from the Outcomerea prospective multicenter database, in which 12 French ICUs enrolled patients admitted between January 1997 and June 2009.

Results

First, we compared 451 patients with severe sepsis or septic shock and diabetes to 3,277 controls with severe sepsis or septic shock and without diabetes. Then, we compared 318 cases (with diabetes) to 746 matched controls (without diabetes). Diabetic patients did not have a higher frequency of AKI (hazard ratio [HR], 1.18; P = 0.05]) or RRT (HR, 1.09; P = 0.6). However, at discharge, diabetic patients with severe sepsis or septic shock who experienced acute kidney injury during the ICU stay and were discharged alive more often required RRT (9.5% vs. 4.8%; P = 0.02), had higher serum creatinine values (134 vs. 103 µmoL/L; P<0.001) and had less often recovered a creatinine level less than 1.25 fold the basal creatinine (41.1% vs. 60.5%; P<0.001).

Conclusions

In patients with severe sepsis or septic shock, diabetes is not associated with occurrence of AKI or need for RRT but is an independent risk factor for persistent renal dysfunction in patients who experience AKI during their ICU stay.

Sepsis severe or septic shock: outcome according to immune status and immunodeficiency profile

OBJECTIVES

This study evaluated the influence of the immune profile on the outcome at day 28 (D28) of patients admitted to the ICU for septic shock or severe sepsis.

METHODS

We conducted an observational study using a prospective multicenter database and included all patients admitted to 11 ICUs for severe sepsis or septic shock from January 1997 to August 2011. Seven profiles of immunodeficiency were defined. The prognostic analysis used a competitive risk model (Fine and Gray), in which being alive at ICU or hospital discharge before D28 competed with death.

RESULTS

Among the 1,981 included patients, 607 (31%) were immunocompromised (including nonneutropenic solid tumor [19.6%], nonneutropenic hematologic malignancies [26.3%], and all-cause neutropenia [28%]). Compared with immunocompetent patients, immunocompromised patients were younger, with less comorbidity, were more often admitted for medical reasons, and presented less often with septic shock. The D28 crude mortality was 31.3% in immunocompromised patients and 28.8% in immunocompetent patients (P = .26). However, after adjustment for other prognostic factors, immunodeficiency was an independent risk factor for death at D28 (subdistribution hazard ratio [sHR], 1.37; 95% CI, 1.12-1.67). The immunodeficiency profiles independently associated with death were AIDS (sHR = 1.9), non-neutropenic solid tumor (sHR = 1.8), nonneutropenic hematologic malignancies (sHR = 1.4), and all-cause neutropenia (sHR = 1.7).

CONCLUSIONS

Immunodeficiency is common in patients with severe sepsis or septic shock. Despite a similar crude mortality, immunodeficiency was associated with an increased risk of short-term mortality after multivariate analysis. Neutropenia and specific, but not all, profiles of immunodeficiency were independently associated with an increased risk of death.

Does Catheter-Associated Urinary Tract Infection Increase Mortality in Critically Ill Patients?

Objective.

To produce an accurate estimate of the association between catheter-associated urinary tract infection (UTI) and intensive care unit (ICU) and hospital mortality, controlling for major confounding factors.

Design.

Nested case-control study in a multicenter cohort (the OutcomeRea database).

Setting.

Twelve French medical or surgical ICUs.

Methods.

All patients admitted between January 1997 and August 2005 who required the insertion of an indwelling urinary catheter. Patients who developed catheter-associated UTI (ie, case patients) were matched to control patients on the basis of the following criteria: sex, age ( ± 10 years), SAPS (Simplified Acute Physiology Score) II score ( ± 10 points), duration of urinary tract catheterization, and presence or absence of diabetes mellitus. The association of catheter-associated UTI with ICU and hospital mortality was assessed by use of conditional logistic regression.

Results.

Of the 3,281 patients who had an indwelling urinary catheter, 298 (9%) developed at least 1 episode of catheter-associated UTI. The incidence density of catheter-associated UTI was 12.9 infections per 1,000 catheterization-days. Crude ICU mortality rates were higher among patients with catheter-associated UTI, compared with those without catheter-associated UTI (32% vs 25%, P = .02); the same was true for crude hospital mortality rates (43% vs 30%, P>.01). After matching and adjustment, catheter-associated UTI was no longer associated with increased mortality (ICU mortality: odds ratio [OR], 0.846 [95% confidence interval {CI}, 0.659-1.086]; P = .19 and hospital mortality: OR, 0.949 [95% CI, 0.763-1.181]; P = .64).

Conclusion.

After carefully controlling for confounding factors, catheter-associated UTI was not found to be associated with excess mortality among our population of critically ill patients in either the ICU or the hospital.

Initiation of nutritional support is delayed in critically ill obese patients: a multicenter cohort study

BACKGROUND

A high catabolic rate characterizes the acute phase of critical illness. Guidelines recommend an early nutritional support, regardless of the previous nutritional status.

OBJECTIVE

We aimed to assess whether the nutritional status of patients, which was defined by the body mass index (BMI) at admission in an intensive care unit (ICU), affected the time of nutritional support initiation.

DESIGN

We conducted a cohort study that reported a retrospective analysis of a multicenter ICU database (OUTCOMEREA) by using data prospectively entered from January 1997 to October 2012. Patients who needed orotracheal intubation within the first 72 h and >3 d were included.

RESULTS

Data from 3257 ICU stays were analyzed. The delay before feeding was different according to BMI groups (P = 0.035). The delay was longer in obese patients [BMI (in kg/m²) ≥30; n = 663] than in other patients with either low weight (BMI <20; n = 501), normal weight (BMI ≥20 and <25; n = 1135), or overweight (BMI ≥25 and <30; n = 958). The association between nutritional status and a delay in nutrition initiation was independent of potential confounding factors such as age, sex, and diabetes or other chronic diseases. In comparison with normal weight, the adjusted RR (95% CI) associated with a delayed nutrition initiation was 0.92 (0.86, 0.98) for patients with low weight, 1.00 (0.94, 1.05) for overweight patients, and 1.06 (1.00, 1.12) for obese patients (P = 0.004).

CONCLUSIONS

The initiation of nutritional support was delayed in obese ICU patients. Randomized controlled trials that address consequences of early compared with delayed beginnings of nutritional support in critically ill obese patients are needed.

Acute respiratory distress syndrome and risk of AKI among critically ill patients

BACKGROUND AND OBJECTIVES

Increasing experimental evidence suggests that acute respiratory distress syndrome (ARDS) may promote AKI. The primary objective of this study was to assess ARDS as a risk factor for AKI in critically ill patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was an observational study on a prospective database fed by 18 intensive care units (ICUs). Patients with ICU stays >24 hours were enrolled over a 14-year period. ARDS was defined using the Berlin criteria and AKI was defined using the Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease criteria. Patients with AKI before ARDS onset were excluded.

RESULTS

This study enrolled 8029 patients, including 1879 patients with ARDS. AKI occurred in 31.3% of patients and was more common in patients with ARDS (44.3% versus 27.4% in patients without ARDS; P<0.001). After adjustment for confounders, both mechanical ventilation without ARDS (odds ratio [OR], 4.34; 95% confidence interval [95% CI], 3.71 to 5.10) and ARDS (OR, 11.01; 95% CI, 6.83 to 17.73) were independently associated with AKI. Hospital mortality was 14.2% (n=1140) and was higher in patients with ARDS (27.9% versus 10.0% in patients without ARDS; P<0.001) and in patients with AKI (27.6% versus 8.1% in those without AKI; P<0.001). AKI was associated with higher mortality in patients with ARDS (42.3% versus 20.2%; P<0.001).

CONCLUSIONS

ARDS was independently associated with AKI. This study suggests that ARDS should be considered as a risk factor for AKI in critically ill patients.

Initial use of one or two antibiotics for critically ill patients with community-acquired pneumonia: impact on survival and bacterial resistance

INTRODUCTION

Several guidelines recommend initial empirical treatment with two antibiotics instead of one to decrease mortality in community-acquired pneumonia (CAP) requiring intensive-care-unit (ICU) admission. We compared the impact on 60-day mortality of using one or two antibiotics. We also compared the rates of nosocomial pneumonia and multidrug-resistant bacteria.

METHODS

This is an observational cohort study of 956 immunocompetent patients with CAP admitted to ICUs in France and entered into a prospective database between 1997 and 2010.

RESULTS

Initial adequate antibiotic therapy was significantly associated with better survival (subdistribution hazard ratio (sHR), 0.63; 95% confidence interval (95% CI), 0.42 to 0.94; P = 0.02); this effect was strongest in patients with Streptococcus pneumonia CAP (sHR, 0.05; 95% CI, 0.005 to 0.46; p = 0.001) or septic shock (sHR: 0.62; 95% CI 0.38 to 1.00; p = 0.05). Dual therapy was associated with a higher frequency of initial adequate antibiotic therapy. However, no difference in 60-day mortality was found between monotherapy (β-lactam) and either of the two dual-therapy groups (β-lactam plus macrolide or fluoroquinolone). The rates of nosocomial pneumonia and multidrug-resistant bacteria were not significantly different across these three groups.

CONCLUSIONS

Initial adequate antibiotic therapy markedly decreased 60-day mortality. Dual therapy improved the likelihood of initial adequate therapy but did not predict decreased 60-day mortality. Dual therapy did not increase the risk of nosocomial pneumonia or multidrug-resistant bacteria.

Pseudomonas aeruginosa ventilator-associated pneumonia. predictive factors of treatment failure

RATIONALE

The predictive factors of treatment failure for ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa (PA) remain uncertain.

OBJECTIVES

To describe PA-VAP recurrence prognosis and to identify associated risk factors in a large cohort of intensive care unit patients with PA-VAP.

METHODS

From the multicenter OUTCOMEREA database (1997-2011), PA-VAP onset and recurrence were recorded. All suspected cases of VAP were confirmed by a positive quantitative culture of a respiratory sample. Multidrug-resistant PA strains were defined by the resistance to two antibiotics among piperacillin, ceftazidime, imipenem, colistine, and fluoroquinolones (FQ). An extensively resistant PA was defined by resistance to piperacillin, ceftazidime, imipenem, and FQ. A treatment failure was defined as a PA-VAP recurrence or by the death occurrence.

MEASUREMENTS AND MAIN RESULTS

A total of 314 patients presented 393 PA-VAP. Failure occurred for 112 of them, including 79 recurrences. Susceptible, multidrug resistant, and extensively resistant PA represented 53.7%, 32%, and 14.3% of the samples, respectively. Factors associated with treatment failure were age (P = 0.02); presence of at least one chronic illness (P = 0.02); limitation of life support (P = 0.0004); a high Sepsis-Related Organ Failure Assessment score (P < 0.0001); PA bacteremia (P = 0.003); and previous use of FQ before the first PA-VAP (P = 0.0007). The failure risk was not influenced by the strain resistance profile or by the biantibiotic treatment, but decreased in case of VAP treatment that includes FQ (subdistribution hazard ratio, 0.5 [0.3-0.7]; P = 0.0006). However, the strain resistance profile slowed down the intensive care unit discharge hazard (subdistribution hazard ratio, 0.6 [0.4-1.0]; P = 0.048).

CONCLUSIONS

Neither resistance profile nor biantibiotic therapy decreased the risk of PA-VAP treatment failure. However, the profile of PA resistance prolonged the length of stay. Better evaluation of the potential benefit of an initial treatment containing FQ requires further randomized trials.

Prognostic consequences of borderline dysnatremia: pay attention to minimal serum sodium change

Introduction

To assess the prevalence of dysnatremia, including borderline changes in serum sodium concentration, and to estimate the impact of these dysnatremia on mortality after adjustment for confounders.

Methods

Observational study on a prospective database fed by 13 intensive care units (ICUs). Unselected patients with ICU stay longer than 48 h were enrolled over a 14-year period were included in this study. Mild to severe hyponatremia were defined as serum sodium concentration < 135, < 130, and < 125 mmol/L respectively. Mild to severe hypernatremia were defined as serum sodium concentration > 145, > 150, and > 155 mmol/L respectively. Borderline hyponatremia and hypernatremia were defined as serum sodium concentration between 135 and 137 mmol/L or 143 and 145 respectively.

Results

A total of 11,125 patients were included in this study. Among these patients, 3,047 (27.4%) had mild to severe hyponatremia at ICU admission, 2,258 (20.3%) had borderline hyponatremia at ICU admission, 1,078 (9.7%) had borderline hypernatremia and 877 (7.9%) had mild to severe hypernatremia. After adjustment for confounder, both moderate and severe hyponatremia (subdistribution hazard ratio (sHR) 1.82, 95% CI 1.002 to 1.395 and 1.27, 95% CI 1.01 to 1.60 respectively) were associated with day-30 mortality. Similarly, mild, moderate and severe hypernatremia (sHR 1.34, 95% CI 1.14 to 1.57; 1.51, 95% CI 1.15 to 1.99; and 2.64, 95% CI 2.00 to 3.81 respectively) were independently associated with day-30 mortality.

Conclusions

One-third of critically ill patients had a mild to moderate dysnatremia at ICU admission. Dysnatremia, including mild changes in serum sodium concentration, is an independent risk factor for hospital mortality and should not be neglected.

Outcome of ICU patients with Clostridium difficile infection

INTRODUCTION

As data from Clostridium difficile infection (CDI) in intensive care unit (ICU) are still scarce, our objectives were to assess the morbidity and mortality of ICU-acquired CDI.

METHODS

We compared patients with ICU-acquired CDI (watery or unformed stools occurring ≥ 72 hours after ICU admission with a stool sample positive for C. difficile toxin A or B) with two groups of controls hospitalized at the same time in the same unit. The first control group comprised patients with ICU-acquired diarrhea occurring ≥ 72 hours after ICU admission with a stool sample negative for C. difficile and for toxin A or B. The second group comprised patients without any diarrhea.

RESULTS

Among 5,260 patients, 512 patients developed one episode of diarrhea. Among them, 69 (13.5%) had a CDI; 10 (14.5%) of them were community-acquired, contrasting with 12 (17.4%) that were hospital-acquired and 47 (68%) that were ICU-acquired. A pseudomembranous colitis was associated in 24/47 (51%) ICU patients. The median delay between diagnosis and metronidazole administration was one day (25th Quartile; 75th Quartile (0; 2) days). The case-fatality rate for patients with ICU-acquired CDI was 10/47 (21.5%), as compared to 112/443 (25.3%) for patients with negative tests. Neither the crude mortality (cause specific hazard ratio; CSHR = 0.70, 95% confidence interval; CI 0.36 to 1.35, P = 0.3) nor the adjusted mortality to confounding variables (CSHR = 0.81, 95% CI 0.4 to 1.64, P = 0.6) were significantly different between CDI patients and diarrheic patients without CDI. Compared to the general ICU population, neither the crude mortality (SHR = 0.64, 95% CI 0.34 to 1.21, P = 0.17), nor the mortality adjusted to confounding variables (CSHR = 0.71, 95% confidence interval (CI) 0.38 to 1.35, P = 0.3), were significantly different between the two groups. The estimated increase in the duration of stay due to CDI was 8.0 days ± 9.3 days, (P = 0.4) in comparison to the diarrheic population, and 6.3 days ± 4.3 (P = 0.14) in comparison to the general ICU population.

CONCLUSIONS

If treated early, ICU-acquired CDI is not independently associated with an increased mortality and impacts marginally the ICU length of stay.

Randomized controlled trial of chlorhexidine dressing and highly adhesive dressing for preventing catheter-related infections in critically ill adults

RATIONALE

Most vascular catheter-related infections (CRIs) occur extraluminally in patients in the intensive care unit (ICU). Chlorhexidine-impregnated and strongly adherent dressings may decrease catheter colonization and CRI rates.

OBJECTIVES

To determine if chlorhexidine-impregnated and strongly adherent dressings decrease catheter colonization and CRI rates.

METHODS

In a 2:1:1 assessor-masked randomized trial in patients with vascular catheters inserted for an expected duration of 48 hours or more in 12 French ICUs, we compared chlorhexidine dressings, highly adhesive dressings, and standard dressings from May 2010 to July 2011. Coprimary endpoints were major CRI with or without catheter-related bloodstream infection (CR-BSI) with chlorhexidine versus nonchlorhexidine dressings and catheter colonization rate with highly adhesive nonchlorhexidine versus standard nonchlorhexidine dressings. Catheter-colonization, CR-BSIs, and skin reactions were secondary endpoints.

MEASUREMENTS AND MAIN RESULTS

A total of 1,879 patients (4,163 catheters and 34,339 catheter-days) were evaluated. With chlorhexidine dressings, the major-CRI rate was 67% lower (0.7 per 1,000 vs. 2.1 per 1,000 catheter-days; hazard ratio [HR], 0.328; 95% confidence interval [CI], 0.174-0.619; P = 0.0006) and the CR-BSI rate 60% lower (0.5 per 1,000 vs. 1.3 per 1,000 catheter-days; HR, 0.402; 95% CI, 0.186-0.868; P = 0.02) than with nonchlorhexidine dressings; decreases were noted in catheter colonization and skin colonization rates at catheter removal. The contact dermatitis rate was 1.1% with and 0.29% without chlorhexidine. Highly adhesive dressings decreased the detachment rate to 64.3% versus 71.9% (P < 0.0001) and the number of dressings per catheter to two (one to four) versus three (one to five) (P < 0.0001) but increased skin colonization (P < 0.0001) and catheter colonization (HR, 1.650; 95% CI, 1.21-2.26; P = 0.0016) without influencing CRI or CR-BSI rates.

CONCLUSIONS

A large randomized trial demonstrated that chlorhexidine-gel-impregnated dressings decreased the CRI rate in patients in the ICU with intravascular catheters. Highly adhesive dressings decreased dressing detachment but increased skin and catheter colonization. Clinical trial registered with www.clinicaltrials.gov (NCT 01189682).

DNAemia detection by multiplex PCR and biomarkers for infection in systemic inflammatory response syndrome patients

Fast and reliable assays to precisely define the nature of the infectious agents causing sepsis are eagerly anticipated. New molecular biology techniques are now available to define the presence of bacterial or fungal DNA within the bloodstream of sepsis patients. We have used a new technique (VYOO®) that allows the enrichment of microbial DNA before a multiplex polymerase chain reaction (PCR) for pathogen detection provided by SIRS-Lab (Jena, Germany). We analyzed 72 sepsis patients and 14 non-infectious systemic inflammatory response syndrome (SIRS) patients. Among the sepsis patients, 20 had a positive blood culture and 35 had a positive microbiology in other biological samples. Of these, 51.4% were positive using the VYOO® test. Among the sepsis patients with a negative microbiology and the non-infectious SIRS, 29.4% and 14.2% were positive with the VYOO® test, respectively. The concordance in bacterial identification between microbiology and the VYOO® test was 46.2%. This study demonstrates that these new technologies offer great hopes, but improvements are still needed.

Severe hypothermia increases the risk for intensive care unit-acquired infection

BACKGROUND

Although hypothermia is widely accepted as a risk factor for subsequent infection in surgical patients, it has not been well defined in medical patients. We sought to assess the risk of acquiring intensive care unit (ICU)--acquired infection after hypothermia among medical ICU patients.

METHODS

Adults (≥18 years) admitted to French ICUs for at least 2 days between April 2000 and November 2010 were included. Surgical patients were excluded. Patient were classified as having had mild hypothermia (35.0°C-35.9°C), moderate hypothermia (32°C-34.9°C), or severe hypothermia (<32°C), and were followed for the development of pneumonia or bloodstream infection until ICU discharge.

RESULTS

A total of 6237 patients were included. Within the first day of admission, 648 (10%) patients had mild hypothermia, 288 (5%) patients had moderate hypothermia, and 45 (1%) patients had severe hypothermia. Among the 5256 patients who did not have any hypothermia at day 1, subsequent hypothermia developed in 868 (17%), of which 673 (13%), 176 (3%), and 19 (<1%) patients had lowest temperatures of 35.0°C-35.9°C, 32.0°C-34.9°C, and <32°C, respectively. During the course of ICU admission, 320 (5%) patients developed ICU-acquired bloodstream infection and 724 (12%) patients developed ICU-acquired pneumonia. After controlling for confounding variables in multivariable analyses, severe hypothermia was found to increase the risk for subsequent ICU-acquired infection, particularly in patients who did not present with severe sepsis or septic shock.

CONCLUSIONS

The presence of severe hypothermia is a risk factor for development of ICU-acquired infection in medical patients.

A model to predict short-term death or readmission after intensive care unit discharge

OBJECTIVE

Early unplanned readmission to the intensive care unit (ICU) carries a poor prognosis, and post-ICU mortality may be related, in part, to premature ICU discharge. Our objectives were to identify independent risk factors for early post-ICU readmission or death and to construct a prediction model.

DESIGN

Retrospective analysis of a prospective database was done.

SETTING

Four ICUs of the French Outcomerea network participated.

PATIENTS

Patients were consecutive adults with ICU stay longer than 24 hours who were discharged alive to same-hospital wards without treatment-limitation decisions.

MAIN RESULTS

Of 5014 admitted patients, 3462 met our inclusion criteria. Age was 60.6 ± 17.6 years, and admission Simplified Acute Physiology Score II (SAPS II) was 35.1 ± 15.1. The rate of death or ICU readmission within 7 days after ICU discharge was 3.0%. Independent risk factors for this outcome were age, SAPS II at ICU admission, use of a central venous catheter in the ICU, Sepsis-related Organ Failure Assessment and Systemic Inflammatory Response Syndrome scores before ICU discharge, and discharge at night. The predictive model based on these variables showed good calibration. Compared with SAPS II at admission or Stability and Workload Index for Transfer at discharge, discrimination was better with our model (area under receiver operating characteristics curve, 0.74; 95% confidence interval, 0.68-0.79).

CONCLUSION

Among patients without treatment-limitation decisions and discharged alive from the ICU, 3.0% died or were readmitted within 7 days. Independent risk factors were indicators of patients' severity and discharge at night. Our prediction model should be evaluated in other ICU populations.

Primary outcomes for resuscitation science studies: a consensus statement from the American Heart Association

BACKGROUND AND PURPOSE

The guidelines presented in this consensus statement are intended to serve researchers, clinicians, reviewers, and regulators in the selection of the most appropriate primary outcome for a clinical trial of cardiac arrest therapies. The American Heart Association guidelines for the treatment of cardiac arrest depend on high-quality clinical trials, which depend on the selection of a meaningful primary outcome. Because this selection process has been the subject of much controversy, a consensus conference was convened with national and international experts, the National Institutes of Health, and the US Food and Drug Administration.

METHODS

The Research Working Group of the American Heart Association Emergency Cardiovascular Care Committee nominated subject leaders, conference attendees, and writing group members on the basis of their expertise in clinical trials and a diverse perspective of cardiovascular and neurological outcomes (see the online-only Data Supplement). Approval was obtained from the Emergency Cardiovascular Care Committee and the American Heart Association Manuscript Oversight Committee. Preconference position papers were circulated for review; the conference was held; and postconference consensus documents were circulated for review and comments were invited from experts, conference attendees, and writing group members. Discussions focused on (1) when after cardiac arrest the measurement time point should occur; (2) what cardiovascular, neurological, and other physiology should be assessed; and (3) the costs associated with various end points. The final document underwent extensive revision and peer review by the Emergency Cardiovascular Care Committee, the American Heart Association Science Advisory and Coordinating Committee, and oversight committees.

RESULTS

There was consensus that no single primary outcome is appropriate for all studies of cardiac arrest. The best outcome measure is the pairing of a time point and physiological condition that will best answer the question under study. Conference participants were asked to assign an outcome to each of 4 hypothetical cases; however, there was not complete agreement on an ideal outcome measure even after extensive discussion and debate. There was general consensus that it is appropriate for earlier studies to enroll fewer patients and to use earlier time points such as return of spontaneous circulation, simple "alive versus dead," hospital mortality, or a hemodynamic parameter. For larger studies, a longer time point after arrest should be considered because neurological assessments fluctuate for at least 90 days after arrest. For large trials designed to have a major impact on public health policy, longer-term end points such as 90 days coupled with neurocognitive and quality-of-life assessments should be considered, as should the additional costs of this approach. For studies that will require regulatory oversight, early discussions with regulatory agencies are strongly advised. For neurological assessment of post-cardiac arrest patients, researchers may wish to use the Cerebral Performance Categories or modified Rankin Scale for global outcomes.

CONCLUSIONS

Although there is no single recommended outcome measure for trials of cardiac arrest care, the simple Cerebral Performance Categories or modified Rankin Scale after 90 days provides a reasonable outcome parameter for many trials. The lack of an easy-to-administer neurological functional outcome measure that is well validated in post-cardiac arrest patients is a major limitation to the field and should be a high priority for future development.

Impact of ureido/carboxypenicillin resistance on the prognosis of ventilator-associated pneumonia due to Pseudomonas aeruginosa

Introduction

Although Pseudomonas aeruginosa is a leading pathogen responsible for ventilator-associated pneumonia (VAP), the excess in mortality associated with multi-resistance in patients with P. aeruginosa VAP (PA-VAP), taking into account confounders such as treatment adequacy and prior length of stay in the ICU, has not yet been adequately estimated.

Methods

A total of 223 episodes of PA-VAP recorded into the Outcomerea database were evaluated. Patients with ureido/carboxy-resistant P. aeruginosa (PRPA) were compared with those with ureido/carboxy-sensitive P. aeruginosa (PSPA) after matching on duration of ICU stay at VAP onset and adjustment for confounders.

Results

Factors associated with onset of PRPA-VAP were as follows: admission to the ICU with septic shock, broad-spectrum antimicrobials at admission, prior use of ureido/carboxypenicillin, and colonization with PRPA before infection. Adequate antimicrobial therapy was more often delayed in the PRPA group. The crude ICU mortality rate and the hospital mortality rate were not different between the PRPA and the PSPA groups. In multivariate analysis, after controlling for time in the ICU before VAP diagnosis, neither ICU death (odds ratio (OR) = 0.73; 95% confidence interval (CI): 0.32 to 1.69; P = 0.46) nor hospital death (OR = 0.87; 95% CI: 0.38 to 1.99; P = 0.74) were increased in the presence of PRPA infection. This result remained unchanged in the subgroup of 87 patients who received adequate antimicrobial treatment on the day of VAP diagnosis.

Conclusions

After adjustment, and despite the more frequent delay in the initiation of an adequate antimicrobial therapy in these patients, resistance to ureido/carboxypenicillin was not associated with ICU or hospital death in patients with PA-VAP.

Administration of hydrogen sulfide via extracorporeal membrane lung ventilation in sheep with partial cardiopulmonary bypass perfusion: a proof of concept study on metabolic and vasomotor effects

Introduction

Although inhalation of 80 parts per million (ppm) of hydrogen sulfide (H₂S) reduces metabolism in mice, doses higher than 200 ppm of H₂S were required to depress metabolism in rats. We therefore hypothesized that higher concentrations of H₂S are required to reduce metabolism in larger mammals and humans. To avoid the potential pulmonary toxicity of H₂S inhalation at high concentrations, we investigated whether administering H₂S via ventilation of an extracorporeal membrane lung (ECML) would provide means to manipulate the metabolic rate in sheep.

Methods

A partial venoarterial cardiopulmonary bypass was established in anesthetized, ventilated (fraction of inspired oxygen = 0.5) sheep. The ECML was alternately ventilated with air or air containing 100, 200, or 300 ppm H₂S for intervals of 1 hour. Metabolic rate was estimated on the basis of total CO₂ production (V˙CO2) and O₂ consumption (V˙O2). Continuous hemodynamic monitoring was performed via indwelling femoral and pulmonary artery catheters.

Results

V˙CO2, V˙O2, and cardiac output ranged within normal physiological limits when the ECML was ventilated with air and did not change after administration of up to 300 ppm H₂S. Administration of 100, 200 and 300 ppm H₂S increased pulmonary vascular resistance by 46, 52 and 141 dyn·s/cm⁵, respectively (all P ≤ 0.05 for air vs. 100, 200 and 300 ppm H₂S, respectively), and mean pulmonary artery pressure by 4 mmHg (P ≤ 0.05), 3 mmHg (n.s.) and 11 mmHg (P ≤ 0.05), respectively, without changing pulmonary capillary wedge pressure or cardiac output. Exposure to 300 ppm H₂S decreased systemic vascular resistance from 1,561 ± 553 to 870 ± 138 dyn·s/cm⁵ (P ≤ 0.05) and mean arterial pressure from 121 ± 15 mmHg to 66 ± 11 mmHg (P ≤ 0.05). In addition, exposure to 300 ppm H₂S impaired arterial oxygenation (P_aO₂ 114 ± 36 mmHg with air vs. 83 ± 23 mmHg with H₂S; P ≤ 0.05).

Conclusions

Administration of up to 300 ppm H₂S via ventilation of an extracorporeal membrane lung does not reduce V˙CO2 and V˙O2, but causes dose-dependent pulmonary vasoconstriction and systemic vasodilation. These results suggest that administration of high concentrations of H₂S in venoarterial cardiopulmonary bypass circulation does not reduce metabolism in anesthetized sheep but confers systemic and pulmonary vasomotor effects.

Health-related quality of life in family members of intensive care unit patients

OBJECTIVE

The intensive care unit (ICU) experience has been reported to cause adverse health effects in families during and after the ICU stay. The objective of this study was to evaluate health-related quality of life (HRQOL) in relatives of patients 90 days after ICU discharge or death.

DESIGN

Multicenter observational study.

SETTING

Twenty-one ICUs in France.

PARTICIPANTS

Among 459 eligible relatives of ICU patients, 284 (62%) were included in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

During a telephone interview, the SF-36 was completed to assess HRQOL 90 days after ICU discharge or death. The physical component summary score of the SF-36 was normal (89/100 [66-94]) but the mental component summary score showed substantial impairments (emotional role, 67 [50-80]; social functioning, 70 [60-90]; vitality, 60 [45-70]; and mental health, 60 [48-2]). Moreover, 35.9% of relatives were taking anxiolytic or antidepressant drugs, and 8.4% were taking psychotropic agents prescribed since the discharge or death of the patient. Among factors independently associated with a worse mental score, 2 were patient-related (admission for shock or implementation of end-of-life decision), 6 were family-related (older age, female gender, child of the patient, low income, chronic disease, and newly prescribed psychotropic medications), and 1 was related to the ICU experience (perceived conflicts between ICU staff and relatives).

CONCLUSIONS

The SF-36 showed evidence of impaired mental health in relatives of ICU patients 90 days after discharge. Better end-of-life care, psychiatric support after the ICU experience, and better conflict prevention and resolution are potential targets for improvement.

Attributable mortality of ventilator-associated pneumonia: respective impact of main characteristics at ICU admission and VAP onset using conditional logistic regression and multi-state models

PURPOSE

Methods for estimating the excess mortality attributable to ventilator-associated pneumonia (VAP) should handle VAP as a time-dependent covariate, since the probability of experiencing VAP increases with the time on mechanical ventilation. VAP-attributable mortality (VAP-AM) varies with definitions, case-mix, causative microorganisms, and treatment adequacy. Our objectives here were to compare VAP-AM estimates obtained using a traditional cohort analysis, a multistate progressive disability model, and a matched-cohort analysis; and to compare VAP-AM estimates according to VAP characteristics.

METHODS

We used data from 2,873 mechanically ventilated patients in the Outcomerea database. Among these patients from 12 intensive care units, 434 (15.1%) experienced VAP; of the remaining patients, 1,969 (68.5%) were discharged alive and 470 (16.4%) died. With the multistate model, VAP-AM was 8.1% (95% confidence interval [95%CI], 3.1-13.1%) for 120 days' complete observation, compared to 10.4% (5.6-24.5%) using a matched-cohort approach (2,769 patients) with matching on mechanical ventilation duration followed by conditional logistic regression. VAP-AM was higher in surgical patients and patients with intermediate (but not high) Simplified Acute Physiologic Score II values at ICU admission. VAP-AM was significantly influenced by time to VAP but not by resistance of causative microorganisms. Higher Logistic Organ Dysfunction score at VAP onset dramatically increased VAP-AM (to 31.9% in patients with scores above 7).

CONCLUSION

A multistate model that appropriately handled VAP as a time-dependent event produced lower VAP-AM values than conditional logistic regression. VAP-AM varied widely with case-mix. Disease severity at VAP onset markedly influenced VAP-AM; this may contribute to the variability of previous estimates.

Corticosteroid treatment and intensive insulin therapy for septic shock in adults: a randomized controlled trial

CONTEXT

Corticosteroid therapy induces potentially detrimental hyperglycemia in septic shock. In addition, the benefit of adding fludrocortisone in this setting is unclear.

OBJECTIVES

To test the efficacy of intensive insulin therapy in patients whose septic shock was treated with hydrocortisone and to assess, as a secondary objective, the benefit of fludrocortisone.

DESIGN, SETTING, AND PATIENTS

A multicenter, 2 x 2 factorial, randomized trial, involving 509 adults with septic shock who presented with multiple organ dysfunction, as defined by a Sequential Organ Failure Assessment score of 8 or more, and who had received hydrocortisone treatment was conducted from January 2006 to January 2009 in 11 intensive care units in France.

INTERVENTIONS

Patients were randomly assigned to 1 of 4 groups: continuous intravenous insulin infusion with hydrocortisone alone, continuous intravenous insulin infusion with hydrocortisone plus fludrocortisone, conventional insulin therapy with hydrocortisone alone, or conventional insulin therapy with intravenous hydrocortisone plus fludrocortisone. Hydrocortisone was administered in a 50-mg bolus every 6 hours, and fludrocortisone was administered orally in 50-microg tablets once a day, each for 7 days.

MAIN OUTCOME MEASURE

In-hospital mortality.

RESULTS

Of the 255 patients treated with intensive insulin, 117 (45.9%), and 109 of 254 (42.9%) treated with conventional insulin therapy died (relative risk [RR], 1.07; 95% confidence interval [CI], 0.88-1.30; P = .50). Patients treated with intensive insulin experienced significantly more episodes of severe hypoglycemia (<40 mg/dL) than those in the conventional-treatment group, with a difference in mean number of episodes per patient of 0.15 (95% CI, 0.02-0.28; P = .003). At hospital discharge, 105 of 245 patients treated with fludrocortisone (42.9%) died and 121 of 264 (45.8%) in the control group died (RR, 0.94; 95% CI, 0.77-1.14; P = .50).

CONCLUSIONS

Compared with conventional insulin therapy, intensive insulin therapy did not improve in-hospital mortality among patients who were treated with hydrocortisone for septic shock. The addition of oral fludrocortisone did not result in a statistically significant improvement in in-hospital mortality.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00320099.

Study of prone positioning to reduce ventilator-associated pneumonia in hypoxaemic patients

The aim of the present study was to examine whether prone positioning (PP) affects ventilator associated-pneumonia (VAP) and mortality in patients with acute lung injury/adult respiratory distress syndrome. 2,409 prospectively included patients were admitted over 9 yrs (2000-2008) to 12 French intensive care units (ICUs) (OUTCOMEREA). The patients required invasive mechanical ventilation (MV) and had arterial oxygen tension/inspiratory oxygen fraction ratios <300 during the first 48 h. Controls were matched to PP patients on the PP propensity score (+/-10%), MV duration longer than that in PP patients before the first turn prone, and centre. VAP incidence was similar in the PP and control groups (24 versus 13 episodes.1,000 patient-days MV(-1) respectively, p = 0.14). After adjustment, PP did not decrease VAP occurrence (HR 1.64 (95% CI 0.70-3.84); p = 0.25) but significantly delayed hospital mortality (HR 0.56 (95% CI 0.39-0.79); p = 0.001), without decreasing 28-day mortality (37% in both groups). Post hoc analyses indicated that PP did not protect against VAP but, when used for >1 day, might decrease mortality and benefit the sickest patients (Simplified Acute Physiology Score >50). In ICU patients with hypoxaemic acute respiratory failure, PP had no effect on the risk of VAP. PP delayed mortality without decreasing 28-day mortality. PP >1 day might decrease mortality, particularly in the sickest patients.

Post-cardiac arrest syndrome: Epidemiology, pathophysiology, treatment, and prognostication: A scientific statement from the International Liaison Committee on Resuscitation; the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; the Council on Stroke (Part 1)

AIM OF THE REVIEW

To review the epidemiology, pathophysiology, treatment and prognostication in relation to the post-cardiac arrest syndrome.

METHODS

Relevant articles were identified using PubMed, EMBASE and an American Heart Association EndNote master resuscitation reference library, supplemented by hand searches of key papers. Writing groups comprising international experts were assigned to each section. Drafts of the document were circulated to all authors for comment and amendment.

RESULTS

The 4 key components of post-cardiac arrest syndrome were identified as (1) post-cardiac arrest brain injury, (2) post-cardiac arrest myocardial dysfunction, (3) systemic ischaemia/reperfusion response, and (4) persistent precipitating pathology.

CONCLUSIONS

A growing body of knowledge suggests that the individual components of the postcardiac arrest syndrome are potentially treatable.

Model for predicting short-term mortality of severe sepsis

Introduction

To establish a prognostic model for predicting 14-day mortality in ICU patients with severe sepsis overall and according to place of infection acquisition and to sepsis episode number.

Methods

In this prospective multicentre observational study on a multicentre database (OUTCOMEREA) including data from 12 ICUs, 2268 patients with 2737 episodes of severe sepsis were randomly divided into a training cohort (n = 1458) and a validation cohort (n = 810). Up to four consecutive severe sepsis episodes per patient occurring within the first 28 ICU days were included. We developed a prognostic model for predicting death within 14 days after each episode, based on patient data available at sepsis onset.

Results

Independent predictors of death were logistic organ dysfunction (odds ratio (OR), 1.22 per point, P < 10^-4), septic shock (OR, 1.40; P = 0.01), rank of severe sepsis episode (1 reference, 2: OR, 1.26; P = 0.10 ≥ 3: OR, 2.64; P < 10^-3), multiple sources of infection (OR; 1.45, P = 0.03), simplified acute physiology score II (OR, 1.02 per point; P < 10^-4), McCabe score ([greater than or equal to]2) (OR, 1.96; P < 10^-4), and number of chronic co-morbidities (1: OR, 1.75; P < 10^-3, ≥ 2: OR, 2.24, P < 10^-3). Validity of the model was good in whole cohorts (AUC-ROC, 0.76; 95%CI, 0.74 to 0.79; and HL Chi-square: 15.3 (P = 0.06) for all episodes pooled).

Conclusions

In ICU patients, a prognostic model based on a few easily obtained variables is effective in predicting death within 14 days after the first to fourth episode of severe sepsis complicating community-, hospital-, or ICU-acquired infection.

Chlorhexidine-impregnated sponges and less frequent dressing changes for prevention of catheter-related infections in critically ill adults: a randomized controlled trial

CONTEXT

Use of a chlorhexidine gluconate-impregnated sponge (CHGIS) in intravascular catheter dressings may reduce catheter-related infections (CRIs). Changing catheter dressings every 3 days may be more frequent than necessary.

OBJECTIVE

To assess superiority of CHGIS dressings regarding the rate of major CRIs (clinical sepsis with or without bloodstream infection) and noninferiority (less than 3% colonization-rate increase) of 7-day vs 3-day dressing changes.

DESIGN, SETTING, AND PATIENTS

Assessor-blind, 2 x 2 factorial, randomized controlled trial conducted from December 2006 through June 2008 and recruiting patients from 7 intensive care units in 3 university and 2 general hospitals in France. Patients were adults (>18 years) expected to require an arterial catheter, central-vein catheter, or both inserted for 48 hours or longer.

INTERVENTIONS

Use of CHGIS vs standard dressings (controls). Scheduled change of unsoiled adherent dressings every 3 vs every 7 days, with immediate change of any soiled or leaking dressings.

MAIN OUTCOME MEASURES

Major CRIs for comparison of CHGIS vs control dressings; colonization rate for comparison of 3- vs 7-day dressing changes.

RESULTS

Of 2095 eligible patients, 1636 (3778 catheters, 28,931 catheter-days) could be evaluated. The median duration of catheter insertion was 6 (interquartile range [IQR], 4-10) days. There was no interaction between the interventions. Use of CHGIS dressings decreased the rates of major CRIs (10/1953 [0.5%], 0.6 per 1000 catheter-days vs 19/1825 [1.1%], 1.4 per 1000 catheter-days; hazard ratio [HR], 0.39 [95% confidence interval {CI}, 0.17-0.93]; P = .03) and catheter-related bloodstream infections (6/1953 catheters, 0.40 per 1000 catheter-days vs 17/1825 catheters, 1.3 per 1000 catheter-days; HR, 0.24 [95% CI, 0.09-0.65]). Use of CHGIS dressings was not associated with greater resistance of bacteria in skin samples at catheter removal. Severe CHGIS-associated contact dermatitis occurred in 8 patients (5.3 per 1000 catheters). Use of CHGIS dressings prevented 1 major CRI per 117 catheters. Catheter colonization rates were 142 of 1657 catheters (7.8%) in the 3-day group (10.4 per 1000 catheter-days) and 168 of 1828 catheters (8.6%) in the 7-day group (11.0 per 1000 catheter-days), a mean absolute difference of 0.8% (95% CI, -1.78% to 2.15%) (HR, 0.99; 95% CI, 0.77-1.28), indicating noninferiority of 7-day changes. The median number of dressing changes per catheter was 4 (IQR, 3-6) in the 3-day group and 3 (IQR, 2-5) in the 7-day group (P < .001).

CONCLUSIONS

Use of CHGIS dressings with intravascular catheters in the intensive care unit reduced risk of infection even when background infection rates were low. Reducing the frequency of changing unsoiled adherent dressings from every 3 days to every 7 days modestly reduces the total number of dressing changes and appears safe.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00417235.