CXCL10 could drive longer duration of mechanical ventilation during COVID-19 ARDS.

BACKGROUND: COVID-19-related ARDS has unique features when compared with ARDS from other origins, suggesting a distinctive inflammatory pathogenesis. Data regarding the host response within the lung are sparse. The objective is to compare alveolar and systemic inflammation response patterns, mitochondrial alarmin release, and outcomes according to ARDS etiology (i.e., COVID-19 vs. non-COVID-19). METHODS: Bronchoalveolar lavage fluid and plasma were obtained from 7 control, 7 non-COVID-19 ARDS, and 14 COVID-19 ARDS patients. Clinical data, plasma, and epithelial lining fluid (ELF) concentrations of 45 inflammatory mediators and cell-free mitochondrial DNA were measured and compared. RESULTS: COVID-19 ARDS patients required mechanical ventilation (MV) for significantly longer, even after adjustment for potential confounders. There was a trend toward higher concentrations of plasma CCL5, CXCL2, CXCL10, CD40 ligand, IL-10, and GM-CSF, and ELF concentrations of CXCL1, CXCL10, granzyme B, TRAIL, and EGF in the COVID-19 ARDS group compared with the non-COVID-19 ARDS group. Plasma and ELF CXCL10 concentrations were independently associated with the number of ventilator-free days, without correlation between ELF CXCL-10 and viral load. Mitochondrial DNA plasma and ELF concentrations were elevated in all ARDS patients, with no differences between the two groups. ELF concentrations of mitochondrial DNA were correlated with alveolar cell counts, as well as IL-8 and IL-1ß concentrations. CONCLUSION: CXCL10 could be one key mediator involved in the dysregulated immune response. It should be evaluated as a candidate biomarker that may predict the duration of MV in COVID-19 ARDS patients. Targeting the CXCL10-CXCR3 axis could also be considered as a new therapeutic approach. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03955887.

Significance of Prior Digestive Colonization With Extended-Spectrum ß-Lactamase-Producing Enterobacteriaceae in Patients With Ventilator-Associated Pneumonia.

OBJECTIVES: Ventilator-associated pneumonia is frequent in ICUs. Extended-spectrum ß-lactamase-producing Enterobacteriaceae are difficult-to-treat pathogens likely to cause ventilator-associated pneumonia. We sought to assess the interest of screening for extended-spectrum ß-lactamase-producing Enterobacteriaceae rectal carriage as a way to predict their involvement in ventilator-associated pneumonia. DESIGN: A retrospective cohort study of patients with suspected ventilator-associated pneumonia in a medical ICU was conducted. PATIENTS: Every patient admitted between January 2006 and August 2013 was eligible if subjected to mechanical ventilation for more than 48 hours. Each patient with suspected ventilator-associated pneumonia was included in the cohort. Active surveillance culture for extended-spectrum ß-lactamase-producing Enterobacteriaceae detection was routinely performed in all patients at admission and then weekly throughout the study period. Extended-spectrum ß-lactamase colonization was defined by the isolation of at least one extended-spectrum ß-lactamase-producing Enterobacteriaceae from rectal swab culture. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 587 patients with suspected ventilator-associated pneumonia, 40 (6.8%) were colonized with extended-spectrum ß-lactamase-producing Enterobacteriaceae prior to the development of pneumonia. Over the study period, 20 patients (3.4%) had ventilator-associated pneumonia caused by extended-spectrum ß-lactamase-producing Enterobacteriaceae; of whom, 17 were previously detected as being colonized with extended-spectrum ß-lactamase-producing Enterobacteriaceae. Sensitivity and specificity of prior extended-spectrum ß-lactamase-producing Enterobacteriaceae colonization as a predictor of extended-spectrum ß-lactamase-producing Enterobacteriaceae involvement in ventilator-associated pneumonia were 85.0% and 95.7%, respectively. The positive and negative predictive values were 41.5% and 99.4%, respectively. The positive likelihood ratio was 19.8. CONCLUSIONS: Screening for extended-spectrum ß-lactamase-producing Enterobacteriaceae digestive colonization by weekly active surveillance cultures could reliably exclude the risk of the involvement of such pathogens in patients with ventilator-associated pneumonia in low-prevalence area.

Empirical antifungal therapy with an echinocandin in critically-ill patients: prospective evaluation of a pragmatic Candida score-based strategy in one medical ICU.

BACKGROUND: Invasive candidiasis (IC) is a life-threatening ICU-acquired infection. A strong correlation between time to antifungal therapy (AFT) administration and outcome has been established. Empirical therapy benefit should be balanced with the risk of echinocandin overuse. We assessed therefore a decision rule that aimed at guiding empirical therapy. METHODS: A 45-month prospective cohort study in a teaching medical ICU. All of the patients with suspected IC (uncontrolled sepsis despite broad spectrum antibiotics without any bacterial proven infection in patients with Candida score ≥ 3 points including multifocal Candida sp. colonization) were eligible. The primary endpoint was proven IC diagnosis (i.e., candidemia) following treatment onset. Timing of AFT administration was also investigated in those latter patients. Antifungal therapy step-down and discontinuation was done according to international guidelines in patients with candidemia. Otherwise, echinocandin discontinuation was encouraged in patients without proven IC, excepting when a clinical improvement was achieved without any other explanation that antifungals initiation (i.e., probable IC). In addition, a survival multivariate analysis using a Cox model was conducted. RESULTS: Fifty-one patients were given an echinocandin with respect to our decision rule. Among them, candidemia was diagnosed thereafter in 9 patients. Over the same period, antifungal therapy was triggered by candidemia announcement (i.e., definite therapy) in 12 patients who did not fulfill criteria for empirical therapy before. Time elapsed from candidemia onset to echinocandin therapy initiation was shortened (0.4 [0.5] vs. 2.4 [2.8] hours; p = 0.04) when it was given empirically. In addition, 18 patients clinically improved under empirical antifungal therapy without any obvious other explanation, despite IC remained unproven. Moreover, echinocandin exposure duration was independently related to survival in those patients. Over the same period, our predefined criteria for empirical therapy were overruled in 55 cases. None of them develop IC thereafter. Finally, Our decision rule allowed IC early recognition of proven/probable IC with sensitivity, specificity, positive and negative predictive value of 69.2%, 82.1%, 69.2% and 82.1%, respectively. CONCLUSION: Implementation of pragmatic guidelines for empirical AFT based on CS and fungal colonization assessment could be useful in selecting patients who really benefit from an echinocandin.

Impact of prior statin therapy on the outcome of patients with suspected ventilator-associated pneumonia: an observational study.

INTRODUCTION: Ventilator-associated pneumonia (VAP) is the most commonly acquired infection in intensive care units (ICU). Its outcome is related, at least in part, to the host's response. Statins have anti-inflammatory effects and may thus improve the outcome. We aimed to assess the impact of prior statin use in the setting of VAP. METHODS: A six-year cohort study was conducted in a French ICU at a teaching hospital. All of the patients with suspected VAP were included. Baseline characteristics, outcomes, statin exposure, and the description of suspected episodes were collected prospectively. The primary endpoint was 30-day mortality. Patients who were taking statins before admission to the ICU whether or not treatment was continued thereafter ('previous users' group) were compared to those without prior statin therapy ('statin-naive' group). A survival analysis using a Cox model was conducted in the whole cohort and in the subgroup of prior statin users. RESULTS: Among the 349 patients included, 93 (26.6%) had taken statins. At baseline, these patients were at higher risk of complications than statin-naive ones (for example, older, more likely to be men and to have underlying diseases, greater simplified acute physiology score II (SAPS II)). There was, however, no difference regarding severity at the time VAP was suspected (sequential organ failure assessment (SOFA): 9.0 (4.0 to 16.0) versus 8.0 (4.0 to 17.0); P = 0.11). Nonetheless, 30-day mortality in statin users was not different from that in statin-naive patients (35.5% versus 26.2%, respectively; adjusted hazard ratio (HR) = 1.23 (0.79 to 1.90) 95% confidence interval (CI); P = 0.36). In contrast, after limiting analysis to prior statin users and adjusting for potential confounders, those who continued the treatment had better survival than those who did not (HR = 0.47; (0.22 to 0.97) 95% CI; P = 0.04). CONCLUSIONS: Statin continuation in prior users could provide protective effects in patients with suspected VAP.

Endotracheal tube biofilm in critically ill patients during the COVID-19 pandemic : description of an underestimated microbiological compartment.

Biofilm (BF) growth is believed to play a major role in the development of ventilator-associated pneumonia (VAP) in the intensive care unit. Despite concerted efforts to understand the potential implication of endotracheal tube (ETT)-BF dispersal, clinically relevant data are lacking to better characterize the impact of its mesostructure and microbiological singularity on the occurrence of VAP. We conducted a multicenter, retrospective observational study during the third wave of the COVID-19 pandemic, between March and May 2021. In total, 64 ETTs collected from 61 patients were included in the present BIOPAVIR study. Confocal microscopy acquisitions revealed two main morphological aspects of ETT-deposited BF: (1) a thin, continuous ribbon-shaped aspect, less likely monobacterial and predominantly associated with Enterobacter spp., Streptococcus pneumoniae or Viridans streptococci, and (2) a thicker, discontinuous, mushroom-shaped appearance, more likely characterized by the association of bacterial and fungal species in respiratory samples. The microbiological characterization of ETT-deposited BF found higher acquired resistance in more than 80% of analyzed BF phenotypes, compared to other colonization sites from the patient's environment. These findings reveal BF as a singular microbiological compartment, and are of added clinical value, with a view to future ETT-deposited BF-based antimicrobial stewardship in critically ill patients. Trial registration NCT04926493. Retrospectively registered 15 June 2021.

Serum procalcitonin for the early recognition of nosocomial infection in the critically ill patients: a preliminary report.

BACKGROUND: The usefulness of procalcitonin (PCT) measurement in critically ill medical patients with suspected nosocomial infection is unclear. The aim of the study was to assess PCT value for the early diagnosis of bacterial nosocomial infection in selected critically ill patients. METHODS: An observational cohort study in a 15-bed intensive care unit was performed. Seventy patients with either proven (n = 47) or clinically suspected but not confirmed (n = 23) nosocomial infection were included. Procalcitonin measurements were obtained the day when the infection was suspected (D0) and at least one time within the 3 previous days (D-3 to D0). Patients with proven infection were compared to those without. The diagnostic value of PCT on D0 was determined through the construction of the corresponding receiver operating characteristic (ROC) curve. In addition, the predictive value of PCT variations preceding the clinical suspicion of infection was assessed. RESULTS: PCT on D0 was the best predictor of proven infection in this population of ICU patients with a clinical suspicion of infection (AUROCC = 0.80; 95% CI, 0.68-0.91). Thus, a cut-off value of 0.44 ng/mL provides sensitivity and specificity of 65.2% and 83.0%, respectively. Procalcitonin variation between D-1 and D0 was calculated in 45 patients and was also found to be predictive of nosocomial infection (AUROCC = 0.89; 95% CI, 0.79-0.98) with a 100% positive predictive value if the +0.26 ng/mL threshold value was applied. Comparable results were obtained when PCT variation between D-2 and D0, or D-3 and D0 were considered. In contrast, CRP elevation, leukocyte count and fever had a poor predictive value in our population. CONCLUSION: PCT monitoring could be helpful in the early diagnosis of nosocomial infection in the ICU. Both absolute values and variations should be considered and evaluated in further studies.

Procalcitonin kinetics within the first days of sepsis: relationship with the appropriateness of antibiotic therapy and the outcome.

INTRODUCTION: Management of the early stage of sepsis is a critical issue. As part of it, infection control including appropriate antibiotic therapy administration should be prompt. However, microbiological findings, if any, are generally obtained late during the course of the disease. The potential interest of procalcitonin (PCT) as a way to assess the clinical efficacy of the empirical antibiotic therapy was addressed in the present study. METHODS: An observational cohort study including 180 patients with documented sepsis was conducted in our 15-bed medical intensive care unit (ICU). Procalcitonin measurement was obtained daily over a 4-day period following the onset of sepsis (day 1 (D1) to D4). The PCT time course was analyzed according to the appropriateness of the first-line empirical antibiotic therapy as well as according to the patient outcome. RESULTS: Appropriate first-line empirical antibiotic therapy (n = 135) was associated with a significantly greater decrease in PCT between D2 and D3 (DeltaPCT D2-D3) (-3.9 (35.9) vs. +5.0 (29.7), respectively; P < 0.01). In addition, DeltaPCT D2-D3 was found to be an independent predictor of first-line empirical antibiotic therapy appropriateness. In addition, a trend toward a greater rise in PCT between D1 and D2 was observed in patients with inappropriate antibiotics as compared with those with appropriate therapy (+5.2 (47.4) and +1.7 (35.0), respectively; P = 0.20). The D1 PCT level failed to predict outcome, but higher levels were measured in the nonsurvivors (n = 51) when compared with the survivors (n = 121) as early as D3 (40.8 (85.7) and 21.3 (41.0), respectively; P = 0.04). Moreover, PCT kinetics between D2 and D3 were also found to be significantly different, since a decrease >or= 30% was expected in the survivors (log-rank test, P = 0.04), and was found to be an independent predictor of survival (odds ratio = 2.94; 95% confidence interval 1.22 to 7.09; P = 0.02). CONCLUSIONS: In our study in an ICU, appropriateness of the empirical antibiotic therapy and the overall survival were associated with a greater decline in PCT between D2 and D3. Further studies are needed to assess the utility of the daily monitoring of PCT in addition to clinical evaluation during the early management of sepsis.

Corporeal Compression at the Onset of Septic shock (COCOONs): a compression method to reduce fluid balance of septic shock patients.

Fluid overload in septic intensive care unit (ICU) patients is common and strongly associated with poor outcome. There is currently no treatment for capillary leak, which is mainly responsible for high positive fluid balance (FB) in sepsis. We hypothesized that increasing interstitial pressure with extensive corporeal compression would reduce FB. The objective of this study was to evaluate the feasibility, efficacy, and safety of a compression treatment during sepsis. This pilot, two-center, single-arm trial enrolled critically ill, non-surgical, septic patients receiving mechanical ventilation. The therapeutic intervention was the early application of compression bandages on more than 80% of the body surface. The primary outcome was negative net FB on day 7. The primary endpoint was reached in 29 of 45 patients (64%) with available data, for a planned objective of 26. By day 4, cumulative FB was 7280 ml [3300-9700]. SOFA- and aged-matched patients from a historical cohort had a significantly higher FB at 1, 2 and 7 days. Tolerance was good, although low-stage pressure ulcers were observed in 16 patients (26%). No effect on intra-abdominal pressure or respiratory plateau pressure was observed. In conclusion, corporeal compression demonstrated potential efficacy in limiting FB during septic shock, with acceptable feasibility and tolerance.

Adhering to the procalcitonin algorithm allows antibiotic therapy to be shortened in patients with ventilator-associated pneumonia.

PURPOSE: Ventilator-associated pneumonia (VAP) increases exposure to antibiotics. Physicians are however reluctant to shorten treatment, arguing this could lead to failures and worse outcome. Monitoring procalcitonin (PCT) has proven effective for decreasing exposure to antibiotics in randomized controlled trials, but additional "real-life" studies are needed. MATERIALS AND METHODS: All patients with VAP in whom ABT was stopped before death or discharge were included in this 5-year prospective cohort study. Patients in whom ABT was stopped in accordance with the algorithm ("PCT-guided" group: ABT withdrawal strongly encouraged if PCT < 0.5 ng/mL or < 80% peak value) were compared to those with ABT continuation despite PCT decrease ("not PCT-guided" group). The primary endpoint was ABT duration. The secondary endpoint was unfavorable VAP outcome (i.e. death or relapse). RESULTS: We included 157 of the 316 patients with microbiologically-proven VAP. The algorithm was overruled in 81 patients (51.6%). ABT duration was significantly longer in these patients than in the PCT-guided group (9.5 vs. 8.0 days; p = .02), although baseline and VAP characteristics did not differ. The rate of unfavorable outcomes was comparable (46.9% vs. 51.3%; p = .69). CONCLUSIONS: PCT-guided ABT adherence appears safe for patients with VAP and is likely to reduce exposure to antibiotics.

Impact of previous sepsis on the accuracy of procalcitonin for the early diagnosis of blood stream infection in critically ill patients.

BACKGROUND: Blood stream infections (BSI) are life-threatening infections in intensive care units (ICU), and prognosis is highly dependent on early detection. Procalcitonin levels have been shown to accurately and quickly distinguish between BSI and noninfectious inflammatory states in critically ill patients. It is, however, unknown to what extent a recent history of sepsis (namely, secondary sepsis) can affect diagnosis of BSI using PCT. METHODS: review of the medical records of every patient with BSI in whom PCT dosage at the onset of sepsis was available between 1st September, 2006 and 31st July, 2007. RESULTS: 179 episodes of either primary (n = 117) or secondary (n = 62) sepsis were included. Procalcitonin levels were found to be markedly lower in patients with secondary sepsis than in those without (6.4 [9.5] vs. 55.6 [99.0] ng/mL, respectively; p < 0.001), whereas the SOFA score was similar in the two groups. Although patients in the former group were more likely to have received steroids and effective antibiotic therapy prior to the BSI episode, and despite a higher proportion of candidemia in this group, a low PCT value was found to be independently associated with secondary sepsis (Odd Ratio = 0.33, 95% Confidence Interval: 0.16-0.70; p = 0.004). Additional patients with suspected but unconfirmed sepsis were used as controls (n = 23). Thus, diagnostic accuracy of PCT as assessed by the area under the receiver-operating characteristic curves (AUROCC) measurement was decreased in the patients with secondary sepsis compared to those without (AUROCC = 0.805, 95% CI: 0.699-0.879, vs. 0.934, 95% CI: 0.881-0.970, respectively; p < 0.050). CONCLUSION: In a critically ill patient with BSI, PCT elevation and diagnosis accuracy could be lower if sepsis is secondary than in those with a first episode of infection.

Serum procalcitonin elevation in critically ill patients at the onset of bacteremia caused by either Gram negative or Gram positive bacteria.

BACKGROUND: In the ICU, bacteremia is a life-threatening infection whose prognosis is highly dependent on early recognition and treatment with appropriate antibiotics. Procalcitonin levels have been shown to distinguish between bacteremia and noninfectious inflammatory states accurately and quickly in critically ill patients. However, we still do not know to what extent the magnitude of PCT elevation at the onset of bacteremia varies according to the Gram stain result. METHODS: Review of the medical records of every patient treated between May, 2004 and December, 2006 who had bacteremia caused by either Gram positive (GP) or Gram negative (GN) bacteria, and whose PCT dosage at the onset of infection was available. RESULTS: 97 episodes of either GN bacteremia (n = 52) or GP bacteremia (n = 45) were included. Procalcitonin levels were found to be markedly higher in patients with GN bacteremia than in those with GP bacteremia, whereas the SOFA score value in the two groups was similar. Moreover, in the study population, a high PCT value was found to be independently associated with GN bacteremia. A PCT level of 16.0 ng/mL yielded an 83.0% positive predictive value and a 74.0% negative predictive value for GN-related bacteremia in the study cohort (AUROCC = 0.79; 95% CI, 0.71-0.88). CONCLUSION: In a critically ill patient with clinical sepsis, GN bacteremia could be associated with higher PCT values than those found in GP bacteremia, regardless of the severity of the disease.

Impact of a stay in the intensive care unit on the preparation of Advance Directives: Descriptive, exploratory, qualitative study.

BACKGROUND: Our objective was to assess, through a qualitative, exploratory study, the thought processes of patients regarding the formulation of advance directives (AD) after a stay in the ICU. METHODS: The study was conducted from May to July 2016 using telephone interviews performed by four senior ICU physicians. Inclusion criteria were: patients discharged from ICU to home>3 months earlier. Semi-directive interviews with patients focused on 5 main points surrounding AD. RESULTS: In total, among 159 eligible patients, data from 94 (59%) were available for analysis. Among all those interviewed, 83.5% had never heard of "advance directives". Only 2% had executed AD before ICU admission, and 7% expressed a desire to prepare AD further to their ICU stay. Among the barriers to preparation of AD, lack of information was the main reason cited for not executing AD. Patients noted the following in their AD: withdrawal of life-support in case of vegetative/minimally conscious state or when there is no longer any hope, in case of uncontrollable pain, and if impossible to wean from mechanical ventilation. CONCLUSION: The ideal time to engage patients in these discussions is most likely well before an acute health event occurs, although this warrants further investigation both before and after ICU admissions.

Mr-Proadm Elevation Upon Icu Admission Predicts the Outcome of Septic Patients and is Correlated with Upcoming Fluid Overload.

BACKGROUND: Among septic patients admitted to the intensive care unit (ICU), early recognition of those with the highest risk of death is of paramount importance. We evaluated the prognostic value of Procalcitonin (PCT), mid regional-proadrenomedullin (MR-proADM), copeptine and CT-proendothelin 1 (CT-ProET 1) concentrations. METHODS: This was a prospective cohort study, which included 173 septic patient admitted to one ICU. Blood samples for biomarker measurements were obtained upon admission and on day 5. The predictive value of each biomarker regarding the risk of death at day 28 was assessed. The fluid balance was evaluated from admission to day 5. RESULTS: All cause ICU mortality was 36.4%. All the biomarkers except CT-ProET-1 were significantly more elevated in the non-survivors than in the survivors upon day 1. This was especially true for MR-proADM (8.6 [5.9] vs. 4.4 [3.9] nmol/L; P < 0.0001) and for the CT-proET-1/MR-proADM ratio (52.9 [22.4] vs. 31.3 [26.6] arbitrary units; P < 0.0001). The best AUROCC values on day 1 were obtained with MR-ProADM and the CT-proET-1/MR-proADM ratio as well (0.75 [0.67-0.85] and 0.82 [0.75-0.89]; 95% CI, respectively). An improved accuracy was achieved on day 5. Moreover, MR-ProADM baseline levels and fluid balance over the 5-day period following ICU admission were strongly correlated (Rho = 0.41; P < 0.001). CONCLUSIONS: In patients admitted to the ICU with sepsis, MR-ProADM on admission was the best predictor of short-term clinical outcome if compared with others. This could be related to its ability to predict fluid sequestration.

Incidence and Predictors of New-Onset Atrial Fibrillation in Septic Shock Patients in a Medical ICU: Data from 7-Day Holter ECG Monitoring.

PURPOSE: We investigated incidence, risk factors for new-onset atrial fibrillation (NAF), and prognostic impact during septic shock in medical Intensive Care Unit (ICU) patients. METHODS: Prospective, observational study in a university hospital. Consecutive patients from 03/2011 to 05/2013 with septic shock were eligible. Exclusion criteria were age <18 years, history of AF, transfer with prior septic shock. Included patients were equipped with long-duration (7 days) Holter ECG monitoring. NAF was defined as an AF episode lasting >30 seconds. Patient characteristics, infection criteria, cardiovascular parameters, severity of illness, support therapies were recorded. RESULTS: Among 66 patients, 29(44%) developed NAF; 10 (34%) would not have been diagnosed without Holter ECG monitoring. NAF patients were older, with more markers of heart failure (troponin and NT-pro-BNP), lower left ventricular ejection fraction (LVEF), longer QRS duration and more nonsustained supra ventricular arrhythmias (<30s) on day 1 than patients who maintained sinus rhythm. By multivariate analysis, age (OR: 1.06; p = 0.01) and LVEF<45% (OR: 13.01, p = 0.03) were associated with NAF. NAF did not predict 28 or 90 day mortality. CONCLUSIONS: NAF is common, especially in older patients, and is associated with low ejection fraction. We did not find NAF to be independently associated with higher mortality.

The "lung pulse": an early ultrasound sign of complete atelectasis.

OBJECTIVE: Complete atelectasis can be immediately generated by selective intubation. A dynamic lung ultrasound sign can be described as the association of absent lung sliding with the perception of heart activity at the pleural line, a sign which was called "lung pulse." We examined whether this sign be used promptly to confirm complete atelectasis due to selective intubation. DESIGN AND SETTING: Prospective study in the medical intensive care unit of a university-affiliated teaching hospital. PATIENTS: Consecutive patients with no history of respiratory disorders and needing intubation were enrolled. Fifteen patients with selective intubation of the right lung were compared with 30 patients with nonselective intubation and 15 healthy volunteers. INTERVENTIONS: The "lung pulse" was sought at the left anterolateral chest wall in intubated patients. Healthy subjects were studied during breathing and apnea. RESULTS: A left "lung pulse" was immediately present in 14 of 15 patients with right selective intubation, and absent, with normal lung sliding, in all 30 correctly intubated patients and in all 15 healthy subjects during breathing. All healthy subjects exhibited a "lung pulse" in apnea. The "lung pulse" had a sensitivity of 93% and a specificity of 100% for the diagnosis of complete atelectasis following selective intubation in patients without previous respiratory disorders. CONCLUSIONS: The "lung pulse" is a sign of complete atelectasis which is observable immediately before radiological changes. Its absence which is correlated with the absence of selective intubation and of conserved lung inflation can eliminate the need for confirmation radiography.

Early patterns of static pressure-volume loops in ARDS and their relations with PEEP-induced recruitment.

OBJECTIVE: Evaluation of low-flow pressure-volume loop at the bedside in ARDS, as an aid to assess recruitment produced by PEEP. MATERIALS AND METHODS: Low-flow pressure-volume loop at the bedside were obtained on the first day of respiratory support in 54 successive pulmonary ARDS patients (49 of whom had pneumonia) treated between April 1999 and June 2002. From the loop obtained at ZEEP, we determined manually the lower inflexion point (LIP). By superimposing the pressure-volume loop at ZEEP and at PEEP, we evaluated recruitment obtained at a constant elastic pressure of 20 cm H2O. RESULTS: We observed two different types of loops, according to the pattern of the inflation limb. In type 1 (38 cases) the inflation limb was characterized by an inflexion zone, resulting from a progressive or a sudden improvement in compliance. In type 2 (16 patients) the inflation limb was virtually linear, without significant improvement in compliance during inflation, which remained particularly low (26+/-9 cm H2O). Use of a low PEEP (6+/-2 cm H2O) produced a substantial recruitment in type-1 patients (74+/-53 ml), which was marginally improved by a higher PEEP (89+/-54 ml). In type 2, recruitment produced by PEEP was significantly lower (48+/-26 ml, p=0.006). CONCLUSION: Pressure-volume loop at bedside confirmed that a low PEEP was sufficient to obtain recruitment in ARDS. This study also individualized a group of pulmonary ARDS patients exhibiting a markedly reduced compliance, in whom recruitment obtained by PEEP was limited.

Candida spp. airway colonization could promote antibiotic-resistant bacteria selection in patients with suspected ventilator-associated pneumonia.

OBJECTIVE: Candida spp. airway colonization could promote development of ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa, a potentially multidrug-resistant (MDR) bacteria, and worsen the outcome of VAP regardless of pathogen. We therefore address the question of the risk of MDR bacteria isolation within the airway of patients with suspected VAP, whether Candida spp. is present or not. DESIGN AND SETTING: Prospective observational study in a teaching hospital. PATIENTS AND METHODS: Consecutive patients with suspected VAP were included. Respiratory tract secretions were seeded on specific medium for yeast isolation in addition to standard culture. Outcome as well as presence of MDR bacteria were assessed according to fungal colonization. RESULTS: 323 suspected VAP were analysed. Among these, 181 (56 %) cases presented with Candida spp. airway colonization. Colonized and noncolonized patients were similar regarding baseline characteristics, prior exposure to antibiotics and VAP severity. However, mortality rate was greater in patients with fungal airway colonization than in those without (44.2 versus 31.0 %, respectively; p = 0.02). In addition, MDR bacteria isolation was 31.5 % in patients with Candida spp. colonization versus 23.2 % in those without (p = 0.13). Moreover, Candida spp. airway colonization was one independent risk factor for MDR bacteria isolation [odds ratio (OR) = 1.79, 95 % confidence interval 1.05-3.05; p = 0.03], in addition to the time elapsed between intensive care unit (ICU) admission and VAP suspicion. CONCLUSIONS: In patients with suspected VAP, Candida spp. airway colonization is frequent and associated with increased risk for MDR bacteria isolation. This could worsen outcome and should therefore be considered when choosing an empiric antibiotic therapy.

Low stretch ventilation strategy in acute respiratory distress syndrome: eight years of clinical experience in a single center.

CONTEXT: In recent years, protective ventilation with airway pressure limitation has constituted a major advance in acute respiratory distress syndrome treatment and has led to a substantial improvement in prognosis. With this therapeutic rationale, one may even question nowadays whether the severity of respiratory failure still influences mortality. OBJECTIVE: To determine whether the severity of respiratory failure, scored according to the usual criteria, still influences mortality in acute respiratory distress syndrome patients when a low stretch ventilation was used and to assess the impact on mortality of other nonpulmonary organ dysfunction, particularly circulatory failure. DESIGN AND SETTING: A retrospective study conducted in the medical intensive care unit of a French university hospital from October 1993 to December 2001. PATIENTS A total of 150 acute respiratory distress syndrome patients who were administered uniform protective ventilation with a limited plateau pressure (<30 cm H2O), a low positive end-expiratory pressure (<10 cm H2O), and the same strategy concerning hemodynamic support and dialysis when required. MAIN OUTCOME AND MEASURES: Mean age, general severity index (Simplified Acute Physiologic Score II), number of associated organ failures (Logistic Organ Dysfunction Score), respiratory severity indices (Pao2/Fio2, Lung Injury Severity Score), and severity of initial circulatory failure (circulatory failure present at admission or that developed during the first 48 hrs) were compared, according to recovery or death, and evaluated by a logistic regression model, which allows simultaneous control of multiple factors. RESULTS: The average mortality rate for the whole group was 38%, with 93 patients recovering after an average duration of mechanical ventilation of 18 +/- 13 days. The major factor significantly and independently associated with probability of dying was the severity of circulatory failure (p =.0001, odds ratio = 10.17). Patients free from initial circulatory failure (39 patients) had a 95% recovery rate. CONCLUSION: With our low stretch strategy, the severity of circulatory failure was the main determinant of acute respiratory distress syndrome prognosis. Patients with isolated respiratory failure during the first 48 hrs of respiratory support have an excellent chance of recovery when treated with protective ventilation associated with a low positive end-expiratory pressure.