Invasive and noninvasive strategies for management of suspected ventilator-associated pneumonia. A randomized trial

Developing a new, national approach to surveillance for ventilator-associated events*

OBJECTIVE

To develop and implement an objective, reliable approach to surveillance for ventilator-associated events in adult patients.

DESIGN

The Centers for Disease Control and Prevention (CDC) convened a Ventilator-Associated Pneumonia (VAP) Surveillance Definition Working Group in September 2011. Working Group members included representatives of stakeholder societies and organizations and federal partners.

MAIN RESULTS

The Working Group finalized a three-tier, adult surveillance definition algorithm for ventilator-associated events. The algorithm uses objective, readily available data elements and can identify a broad range of conditions and complications occurring in mechanically ventilated adult patients, including but not limited to VAP. The first tier definition, ventilator-associated condition (VAC), identifies patients with a period of sustained respiratory deterioration following a sustained period of stability or improvement on the ventilator, defined by changes in the daily minimum fraction of inspired oxygen or positive end-expiratory pressure. The second tier definition, infection-related ventilator-associated complication (IVAC), requires that patients with VAC also have an abnormal temperature or white blood cell count, and be started on a new antimicrobial agent. The third tier definitions, possible and probable VAP, require that patients with IVAC also have laboratory and/or microbiological evidence of respiratory infection.

CONCLUSIONS

Ventilator-associated events surveillance was implemented in January 2013 in the CDC's National Healthcare Safety Network. Modifications to improve surveillance may be made as additional data become available and users gain experience with the new definitions.

Evaluation of semi-quantitative scoring of Gram staining or semi-quantitative culture for the diagnosis of ventilator-associated pneumonia: a retrospective comparison with quantitative culture

Background

Semi-quantitative Gram stain and culture methods are still commonly used for diagnosing ventilator-associated pneumonia (VAP), due to its convenience. Only a few studies, however, have assessed the reliability of these methods when compared with quantitative cultures, a current standard for the diagnosis of VAP. The objective of this study was to assess the utility of semi-quantitative scores obtained using Gram stains and cultures of endotracheal aspirates when compared with quantitative cultures in the diagnosis of VAP.

Methods

A retrospective chart review of mechanically ventilated patients with clinically suspected VAP in a single intensive care unit was performed. Semi-quantitative scores of Gram stains or culture results were compared with quantitative culture results of endotracheal aspirate for the diagnosis of VAP in 136 samples for 51 patients.

Results

The semi-quantitative scores of Gram stains and the semi-quantitative culture results significantly correlated with the log value of the quantitative culture results (r_s = 0.64 and 0.75). When using a log count ≥6 of quantitative cultures as the reference standard for the diagnosis of VAP, the sensitivity and specificity was 95% and 61% for Gram stain score of ≥1+, and was 42% and 96% for Gram stain score ≥3+, respectively. The sensitivity and specificity was 96% and 40% for the semi-quantitative culture score of ≥2+, and was 59% and 86% for the semi-quantitative culture score of ≥3+, respectively.

Conclusions

Absence of bacteria in semi-quantitative Gram stain and poor growth (≤1+) in semi-quantitative culture method could be utilized to exclude the possibility of VAP, whereas detection of abundant (≥3+) bacteria in semi-quantitative Gram stain could be utilized to strongly suspect VAP.

Suspected ventilator-associated respiratory infection in severely ill patients: a prospective observational study

Introduction

Ventilator-associated respiratory infection (VARI) is an important cause of morbidity in critically-ill patients. Clinical trials performed in heterogeneous populations have suggested there are limited benefits from invasive diagnostic testing to identify patients at risk or to target antimicrobial therapy. However, multiple patient subgroups (for example, immunocompromised, antibiotic-treated) have traditionally been excluded from randomization. We hypothesized that a prospective surveillance study would better identify patients with suspected VARI (sVARI) at high risk for adverse clinical outcomes, and who might be specifically targeted in future trials.

Methods

We performed a prospective observational study in all patients ventilated for greater than 48 hours. sVARI was identified by surveillance for changes in white blood cell count, temperature, sputum, and/or new chest X-ray infiltrates. Indices of disease co-morbidity, as well as mortality, duration of mechanical ventilation, and length of hospital or ICU stay were correlated with sVARI.

Results

Of 1806 patients admitted to the ICU over 14 months, 267 were ventilated for greater than 48 hours, and 77 developed sVARI. Incidence of sVARI was associated with iatrogenic immunosuppression or admission for respiratory illness. Any sVARI, whether suspected ventilator-associated pneumonia (sVAP) or ventilator-associated tracheobronchitis (sVAT), was associated with increased length of stay and duration of mechanical ventilation.

Conclusions

Clinical surveillance for sVARI identifies patients at risk for increased morbidity. Iatrogenically immunosuppressed patients, a subgroup previously excluded from randomized clinical trials, represent a growing proportion of the critically-ill at risk for sVARI who might be targeted for future investigations on diagnostic or therapeutic modalities.

Structure of 2-keto-3-deoxy-D-manno-octulosonate-8-phosphate synthase from Pseudomonas aeruginosa

Pseudomonas aeruginosa is a major cause of opportunistic infection and is resistant to most antibiotics. As part of efforts to generate much-needed new antibiotics, structural studies of enzymes that are critical for the virulence of P. aeruginosa but are absent in mammals have been initiated. 2-Keto-3-deoxy-D-manno-octulosonate-8-phosphate synthase (KDO8Ps), also known as 2-dehydro-3-deoxyphosphooctonate aldolase, is vital for the survival and virulence of P. aeruginosa. This enzyme catalyzes a key step in the synthesis of the lipopolysaccharide (LPS) of most Gram-negative bacteria: the condensation reaction between phosphoenolpyruvate (PEP) and arabinose 5-phosphate to produce 2-keto-3-deoxy-D-manno-octulosonate-8-phosphate (KDO8P). This step is vital for the proper synthesis and assembly of LPS and the survival of P. aeruginosa. Here, the recombinant expression, purification and crystal structure of KDO8Ps from P. aeruginosa are presented. Orthorhombic crystals were obtained by vapor diffusion in sitting drops in the presence of 1 mM phosphoenlpyruvate. The structure reveals the prototypical α/β TIM-barrel structure expected from this family of enzymes and contains a tetramer in the asymmetric unit.

Flexible bronchoscopy

Although bronchoscopy technology continues to evolve at a fairly rapid pace, basic procedures, such as bronchoalveolar lavage, transbronchial lung biopsy, and transbronchial needle aspiration, continue to play a paramount role in the diagnosis of bronchopulmonary diseases. Pulmonologists should be trained in these basic bronchoscopic procedures.

Early antibiotic discontinuation in patients with clinically suspected ventilator-associated pneumonia and negative quantitative bronchoscopy cultures

OBJECTIVES

Preliminary data suggest that antibiotic discontinuation in patients with negative quantitative bronchoscopy and symptom resolution will not increase mortality. Because our hospital algorithm for antibiotic discontinuation rules out ventilator-associated pneumonia in the setting of negative quantitative bronchoscopy cultures, we compared antibiotic utilization and mortality in empirically treated, culture-negative ventilator-associated pneumonia patients whose antibiotic discontinuation was early versus late.

DESIGN

Retrospective, observational cohort study.

SETTING

Eight hundred sixty-seven bed, tertiary care, teaching hospital in Hartford, CT.

PATIENTS

Eighty-nine patients with clinically suspected ventilator-associated pneumonia and a negative (<10 colony forming units/mL) quantitative bronchoscopy culture between January 2009 and March 2012. Early discontinuation patients (n = 40) were defined as those who had all antibiotic therapy stopped within one day of final negative culture report, whereas late discontinuation patients (n = 49) had antibiotics stopped later than one day.

MEASUREMENTS

Univariate analyses assessed mortality, antibiotic duration, and frequency of superinfections. Multivariate logistic regression was performed to assess the effect of early discontinuation on hospital mortality.

RESULTS

Patients had a mean ± SD Acute Physiology and Chronic Health Evaluation II score of 26.0 ± 6.0. Mortality was not different between early discontinuation (25.0%) and late discontinuation (30.6%) patients (p = 0.642). Antibiotic duration (days) was also not different for patients who died vs. those who survived (Median [interquartile range]: 3 [1-7.5] vs. 3 [1.75-6.25], respectively, p = 0.87), and when controlling for baseline characteristics and symptom resolution, only Acute Physiology and Chronic Health Evaluation II score was associated with hospital mortality on multivariate analyses. There were fewer superinfections (22.5% vs. 42.9%, p = 0.008), respiratory superinfections (10.0% vs. 28.6%, p = 0.036), and multidrug resistant superinfections (7.5% vs. 35.7%, p = 0.003), in early discontinuation compared with late discontinuation patients.

CONCLUSIONS

In this severely ill population with clinically suspected ventilator-associated pneumonia and negative quantitative bronchoalveolar lavage cultures, early discontinuation of antibiotics did not affect mortality and was associated with a lower frequency of MDR superinfections.

Aspiration pneumonia after stroke: intervention and prevention

Fifteen million strokes occur worldwide each year with 5 million associated deaths and an additional 5 million people left permanently disabled. In the United States, about 780 000 people suffer a new or recurrent stroke each year. There were an estimated total 5.8 million stroke survivors as of 2008. Mortality from stroke is the third leading cause of death in America following heart disease and cancer. Chest infection may affect up to as many as one-third of stroke patients. This increases the morbidity and mortality of this patient population. Pneumonia causes the highest attributable mortality of all medical complications following stroke. A comprehensive multidisciplinary team approach is required at the hospital level. This requires active administrative commitment and participation. Implementation of evidence-based management strategies can improve outcomes and reduce costs. We sought to review the problem of post-stroke pneumonia and discuss strategies for prevention and intervention.

Meropenem Monotherapy for the Treatment of Hospital- Acquired Pneumonia: Results of a Multicenter Trial

The efficacy and tolerability of meropenem as empirical treatment in patients with hospital-acquired pneumonia was determined in a prospective, open-label, non-randomized trial. Patients from 28 centers in the USA received meropenem 1 g every 8 h intravenously. Of 255 patients enrolled, 111 were evaluable for efficacy, including 60 patients with ventilator-associated pneumonia. At end of treatment 74% of patients had a satisfactory clinical response and 64% had this response at follow-up, which could last up to 28 days after treatment. In patients with ventilator-associated pneumonia, a satisfactory clinical response was observed in 68% at the end of treatment and 63% at follow-up. The overall satisfactory response rate for individual pretreatment pathogens ranged from 65% to 100%. This study demonstrates that meropenem monotherapy is effective and well tolerated for patients with hospital-acquired pneumonia, including a subgroup of patients with ventilator-associated pneumonia.

Storage of bronchoalveolar lavage fluid and accuracy of microbiologic diagnostics in the ICU: a prospective observational study

INTRODUCTION

Early initiation of appropriate antimicrobial treatment is a cornerstone in managing pneumonia. Because microbiologic processing may not be available around the clock, optimal storage of specimens is essential for accurate microbiologic identification of pathogenetic bacteria. The aim of our study was to determine the accuracy of two commonly used storage approaches for delayed processing of bronchoalveolar lavage in critically ill patients with suspected pneumonia.

METHODS

This study included 132 patients with clinically suspected pneumonia at two medical intensive care units of a tertiary care hospital. Bronchoalveolar lavage samples were obtained and divided into three aliquots: one was used for immediate culture, and two, for delayed culture (DC) after storage for 24 hours at 4°C (DC4) and -80°C (DC-80), respectively.

RESULTS

Of 259 bronchoalveolar lavage samples, 84 (32.4%) were positive after immediate culture with 115 relevant culture counts (≥104 colony-forming units/ml). Reduced (<104 colony-forming units/ml) or no growth of four and 57 of these isolates was observed in DC4 and DC-80, respectively. The difference between mean bias of immediate culture and DC4 (-0.035; limits of agreement, -0.977 to 0.906) and immediate culture and DC-80 (-1.832; limits of agreement, -4.914 to 1.267) was -1.788 ± 1.682 (P < 0.0001). Sensitivity and negative predictive value were 96.5% and 97.8% for DC4 and 50.4% and 75.4% for DC-80, respectively; the differences were statistically significant (P < 0.0001).

CONCLUSIONS

Bronchoalveolar lavage samples can be processed for culture when stored up to 24 hours at 4°C without loss of diagnostic accuracy. Delayed culturing after storage at -80°C may not be reliable, in particular with regard to Gram-negative bacteria.

Antibiotic resistance in sepsis patients: evaluation and recommendation of antibiotic use

BACKGROUND

The appropriate selection of empirical antibiotics based on the pattern of local antibiotic resistance can reduce the mortality rate and increase the rational use of antibiotics.

AIMS

We analyze the pattern of antibiotic use and the sensitivity patterns of antibiotics to support the rational use of antibiotics in patients with sepsis.

MATERIALS AND METHODS

A retrospective observational study was conducted in adult sepsis patient at one of Indonesian hospital during January-December 2011. Data were collected from the hospital medical record department. Descriptive analysis was used in the processing and interpretation of data.

RESULTS

A total of 76 patients were included as research subjects. Lung infection was the highest source of infection. In the 66.3% of clinical specimens that were culture positive for microbes, Klebsiella pneumoniae, Escherichia coli, Staphylococcus hominis were detected with the highest frequency. The six most frequently used antibiotics, levofloxacin, ceftazidime, ciprofloxacin, cefotaxime, ceftriaxone, and erythromycin, showed an average resistance above 50%.

CONCLUSIONS

The high use of antibiotic with a high level resistance requires a policy to support its rational use. Local microbial pattern based on site infection and pattern of antibiotics sensitivity test can be used as supporting data to optimize appropriateness of empirical antibiotics therapy in sepsis patients.

Incidence and outcomes of ventilator-associated tracheobronchitis and pneumonia

BACKGROUND

Prolonged intubation with mechanical ventilation carries a risk for ventilator-associated respiratory infections manifest as tracheobronchitis or pneumonia. This study analyzed natural history, incidence, and outcomes of patients developing ventilator-associated tracheobronchitis and pneumonia.

METHODS

We studied 188 mixed intensive care unit (ICU) patients intubated ≥48 hours for the development of tracheobronchitis defined as quantitative endotracheal aspirate ≥10(5) cfu/mL plus at least 2 clinical criteria (fever, leukocytosis, or purulent sputum). Pneumonia was defined as microbiologic criteria for tracheobronchitis and a new and persistent infiltrate on chest radiograph.

RESULTS

Airways of 41 (22%) patients became heavily colonized with a bacterial pathogen(s) at a concentration of ≥10(5) cfu/mL. Tracheobronchitis developed in 21 (11%) study patients, of which 6 (29%) later progressed to pneumonia. Including these 6 patients, 28 (15%) study patients developed pneumonia. Multidrug-resistant pathogens were isolated in 39% of pneumonia patients. Patients with tracheobronchitis and pneumonia had significantly more ventilator days and longer stays in the ICU (P ≤.02).

CONCLUSIONS

Approximately one third of tracheobronchitis patients later developed pneumonia. Patients with tracheobronchitis or pneumonia experienced significantly more ventilator days and longer ICU stays, but had no difference in mortality. Better patient outcomes and reduced health care costs may be achieved by earlier treatment of ventilator-associated respiratory infections, manifest as tracheobronchitis or pneumonia.

[Bacterial ecology of nosocomial infection in intensive care unit of Laquintinie hospital Douala, Cameroon]

Introduction

L'objectif principal de notre étude était d'identifier les bactéries associées à l'infection nosocomiale, dans le service de réanimation, de l'hôpital Laquintinie de Douala en vue d'améliorer la prise en charge et diminuer la létalité.

Méthodes

Il s'agissait d'une étude transversale et descriptive, menée du 1er mars au 31 mai 2011.Tous les patients hospitalisés depuis au moins 48 h étaient inclus dans l’étude et ceux présentant une infection documentée à l'admission étaient exclus. L'analyse des donnés a été faite par le logiciel SPSS 16.Les tests de Khi deux pour la signification.

Résultats

La prévalence de l'infection nosocomiale était de 12%, elle concernait des personnes âgées de plus de 60 ans et présentant une infection urinaire dans 79% des cas. La létalité était de 72% pour une durée moyenne de séjour de 11,7 ± 12,1 jours. Les bactéries responsables étaient en majorité des bactéries gram positifs (BGN), dont E coli dans 23,1% et les cocci gram positifs(CGP), dans 15,4% des cas.

Conclusion

L’étude de la résistance aux antibiotiques, montre une multi résistance, dont il faut tenir compte en mettant en place une stratégie de prévention active.

Ventilator-associated pneumonia is characterized by excessive release of neutrophil proteases in the lung

BACKGROUND

Ventilator-associated pneumonia (VAP) is characterized by neutrophils infiltrating the alveolar space. VAP is associated with high mortality, and accurate diagnosis remains difficult. We hypothesized that proteolytic enzymes from neutrophils would be significantly increased and locally produced inhibitors of human neutrophil elastase (HNE) would be decreased in BAL fluid (BALF) from patients with confirmed VAP. We postulated that in suspected VAP, neutrophil proteases in BALF may help identify "true" VAP.

METHODS

BAL was performed in 55 patients with suspected VAP and in 18 control subjects. Isolation of a pathogen(s) at > 10⁴ colony-forming units/mL of BALF dichotomized patients into VAP (n = 12) and non-VAP (n = 43) groups. Matrix metalloproteinases (MMPs), HNE, inhibitors of HNE, and tissue inhibitors of matrix metalloproteinases (TIMPs) were quantified. Plasminogen activator (PA) activity was estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and zymography.

RESULTS

Neutrophil-derived proteases HNE, MMP-8, and MMP-9 were significantly increased in cell-free BALF from patients with VAP as compared with those without VAP (median values: HNE, 2,708 ng/mL vs 294 ng/mL, P < .01; MMP-8, 184 ng/mL vs 5 ng/mL, P < .01; MMP-9, 310 ng/mL vs 11 ng/mL, P < .01). HNE activity was also significantly increased in VAP (0.45 vs 0.01 arbitrary units; P < .05). In contrast, no significant differences were observed for protease inhibitors, TIMPs, or PAs. HNE in BALF, at a cutoff of 670 ng/mL, identified VAP with a sensitivity of 93% and specificity of 79%.

CONCLUSIONS

Neutrophil proteases are significantly elevated in the alveolar space in VAP and may contribute to pathogenesis. Neutrophil proteases appear to have potential in suspected VAP for distinguishing true cases from "non-VAP" cases.

Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) as a diagnostic marker of ventilator-associated pneumonia

OBJECTIVE

To determine the utility of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) levels in bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) samples from patients who underwent bronchoscopy for a clinical suspicion of ventilator-associated pneumonia (VAP), to categorize patients as VAP positive and VAP negative, when compared to quantitative culture results of BALF.

METHODS

Observational study conducted on admitted patients in the trauma-surgical, medical-cardiac, burn, and neurosurgical ICUs of Harborview Medical Center between March 2009 and May 2010. BALF and EBC samples were obtained from 45 patients with clinically suspected VAP. Bronchoscopy was performed on the day of clinically suspected VAP. sTREM-1 levels in EBC and BAL fluid were measured using quantikine human TREM-1 immunoassay. VAP was diagnosed by quantitative cultures of BALF.

RESULTS

The concentrations of sTREM-1 in BALF and EBC did not correlate with VAP status. sTREM-1 levels did not discriminate VAP positive from VAP negative patients, when compared to quantitative cultures of BALF as the gold standard. Using a cutoff value of 204 pg/mL for BALF sTREM-1 levels resulted in a sensitivity of 79% and a specificity of 23%. A cutoff value of 10 pg/mL for EBC sTREM-1 levels resulted in a sensitivity of 42% and a specificity of 50%.

CONCLUSIONS

EBC and BALF sTREM-1 levels did not effectively categorize patients as VAP positive or VAP negative when using direct bronchoscopic quantitative culture samples as the comparison standard.

Bilateral versus unilateral bronchoalveolar lavage for the diagnosis of ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) complicates the clinical course of critically injured intubated patients. Bronchoscopic bronchoalveolar lavage (BAL) represents an invasive and accurate means of VAP diagnosis. Unilateral and blinded techniques offer less invasive alternatives to bronchoscopic BAL. This study evaluated clinical criteria as well as unilateral directed versus bilateral BAL for VAP diagnosis.

METHODS

A retrospective chart review of 113 consecutive intubated trauma patients with clinically suspected VAP undergoing unilateral versus bilateral BAL was performed with comparison of positive culture results (>10(4) colony-forming units [CFU]/mL). Culture results were compared with chest radiograph (CXR) infiltrates and white blood cell (WBC) count elevation.

RESULTS

Bilateral BAL was more likely to be positive than unilateral BAL (50.4% vs. 25.5%). In 37.1% of bilateral BALs, there was discordance between the sides of positivity or the bacteria isolated. A CXR infiltrate and WBC count elevation did not predict positive BAL.

CONCLUSIONS

Clinical indicators of VAP are inaccurate, and bilateral bronchoscopic BAL is more likely than unilateral BAL to provide a positive sample in intubated trauma patients. Techniques that do not sample both lungs reliably should be avoided for diagnosis in this patient population.

Ventilator-associated complications, including infection-related complications: the way forward

Acute respiratory failure represents the most common condition requiring admission to an adult intensive care unit. Ventilator-associated pneumonia (VAP) has been used as a marker of quality for patients with respiratory failure. Hospital-based process-improvement initiatives to prevent VAP have been successfully used. The use of ventilator-associated complications (VACs) has been proposed as an objective marker to assess the quality of care for this patient population. The use of evidence-based bundles targeting the reduction of VACs, as well as the conduct of prospective studies showing that VACs are preventable complications, are reasonable first-steps in addressing this important clinical problem.

Pulmonary emergencies: pneumonia, acute respiratory distress syndrome, lung abscess, and empyema

This article describes the clinical presentation of pneumonia, acute respiratory distress syndrome, lung abscess, and empyema: life-threatening infections of the pulmonary system. The etiology and risk factors for each of these conditions are described, diagnostic approaches are discussed, and evidence-based management options are reviewed.

Ventilator-associated pneumonia rates at major trauma centers compared with a national benchmark: a multi-institutional study of the AAST

BACKGROUND

Ventilator-associated pneumonia (VAP) rates reported by the National Healthcare Safety Network (NHSN) are used as a benchmark and quality measure, yet different rates are reported from many trauma centers. This multi-institutional study was undertaken to elucidate VAP rates at major trauma centers.

METHODS

VAP rate/1,000 ventilator days, diagnostic methods, institutional, and aggregate patient data were collected retrospectively from a convenience sample of trauma centers for 2008 and 2009 and analyzed with descriptive statistics.

RESULTS

At 47 participating Level I and II centers, the pooled mean VAP rate was 17.2 versus 8.1 for NHSN (2006-2008). Hospitals' rates were highly variable (range, 1.8-57.6), with 72.3% being above NHSN's mean. Rates differed based on who determined the rate (trauma service, 27.5; infection control or quality or epidemiology, 11.9; or collaborative effort, 19.9) and the frequency with which VAP was excluded based on aspiration or diagnosis before hospital day 5. In 2008 and 2009, blunt trauma patients had higher VAP rates (17.3 and 17.6, respectively) than penetrating patients (11.0 and 10.9, respectively). More centers used a clinical diagnostic strategy (57%) than a bacteriologic strategy (43%). Patients with VAP had a mean Injury Severity Score of 28.7, mean Intensive Care Unit length of stay of 20.8 days, and a 12.2% mortality rate. 50.5% of VAP patients had a traumatic brain injury.

CONCLUSIONS

VAP rates at major trauma centers are markedly higher than those reported by NHSN and vary significantly among centers. Available data are insufficient to set benchmarks, because it is questionable whether any one data set is truly representative of most trauma centers. Application of a single benchmark to all centers may be inappropriate, and reliable diagnostic and reporting standards are needed. Prospective analysis of a larger data set is warranted, with attention to injury severity, risk factors specific to trauma patients, diagnostic method used, VAP definitions and exclusions, and reporting guidelines.

LEVEL OF EVIDENCE

III, prognostic study.

Is the gram stain useful in the microbiologic diagnosis of VAP? A meta-analysis

In a meta-analysis examining respiratory specimen Gram stain for diagnosis of ventilator-associated pneumonia, absence of bacteria on Gram stain had a high negative predictive value, but a positive Gram stain correlated poorly with organisms recovered in culture. Rapid and accurate diagnosis of ventilator-associated pneumonia (VAP) is a major challenge and no generally accepted gold standard exists for VAP diagnosis. We conducted a meta-analysis to examine the role of respiratory specimen Gram stain to diagnose VAP, and the correlation with final culture results. In 21 studies, pooled sensitivity of Gram stain for VAP was 0.79 (95% confidence interval [CI], .77-0.81; P < .0001) and specificity was 0.75 (95% CI, .73-.78; P < .0001). Negative predictive value of Gram stain for a VAP prevalence of 20%-30% was 91%, suggesting that VAP is unlikely with a negative Gram stain but the positive predictive value of Gram stain was only 40%. Pooled kappa was 0.42 for gram-positive organisms and 0.34 for gram-negative organisms, suggesting fair concordance between organisms on Gram stain and recovery by culture. Therefore, a positive Gram stain should not be used to narrow anti-infective therapy until culture results become available.

Ventilator-associated pneumonia: a review

Ventilator-associated pneumonia (VAP) is the most common infection seen in intensive care units (ICUs); it accounts for one-fourth of the infections occurring in critically ill patients and is the reason for half of antibiotic prescriptions in mechanically ventilated patients. In addition to being a financial burden on ICUs, it continues to contribute significantly to the morbidity and mortality of ICU patients, with an estimated attributable mortality rate of 8% to 15%. While the pathophysiology of VAP remains relatively unchanged, diagnostic techniques and preventive measures are constantly evolving. The focus of this article is on recent trends in VAP epidemiology, modifiable risk factors, diagnostic techniques, challenges in management, and current data on the prevention of VAP. Important messages that the reader should take away include: 1) There is no gold standard for the diagnosis of VAP; whenever VAP is suspected, if feasible, a quantitative culture should be obtained by invasive or noninvasive methods (whichever is more readily available before initiation of antibiotics); 2) Suspicion based on clinical features should prompt the initiation of a broad spectrum of antibiotics depending on suspected pathogens; 3) Close attention should be paid to de-escalation of antibiotics once microbiological results become available or as the patient starts responding clinically; the ideal duration of treatment should be 8 days instead of the conventional 10 to 14 days, except in situations where Pseudomonas may be suspected or the patient's comorbidities dictate otherwise; and 4) Prevention remains the key to reducing the burden of VAP. We promote the proven preventive measures of using noninvasive ventilation when possible, semirecumbent patient positioning, continuous aspiration of subglottic secretions, and oral chlorhexidine washes along with stress ulcer prophylaxis only after careful assessment of the risks versus benefits.

Extravascular lung water predicts progression to acute lung injury in patients with increased risk*

OBJECTIVES

To compare the extravascular lung water index and other markers of disease severity in patients with acute lung injury vs. patients at risk for development of acute lung injury and to determine their ability to predict progression to acute lung injury in patients at risk.

DESIGN

Extravascular lung water index, dead space fraction, PaO2/FIO2, and other markers of disease severity were measured prospectively in 29 patients daily for 5 days after admission to the intensive care unit. Patients had acute lung injury as defined by the American European Consensus Committee criteria or had risk factors for development of it.

SETTING

The intensive care units of an academic tertiary referral hospital.

MEASUREMENTS AND MAIN RESULTS

The mean extravascular lung water index on day 1 for patients who progressed to acute lung injury was higher than for those who did not (15.5 ± 7.4 mL/kg vs. 8.7 ± 2.3 mL/kg; p = .04). None of the other physiologic parameters tested discriminated progression to acute lung injury to include the mean physiologic dead space (0.61 ± 0.06] vs. 0.59 ± 0.10; p = .67), PaO2/FIO2 ratio (322 ± 35 vs. 267 ± 98; p = .15), and static lung compliance (30.9 ± 13.5 vs. 38.5 ± 11.7; p = .24). An extravascular lung water index cutoff value on day 1 of 10 mL/kg had a 63% sensitivity, 88% specificity, positive predictive value of 83%, and negative predictive value of 70% to predict progression to acute lung injury. There was no difference in extravascular lung water index between those who progressed to acute lung injury vs. those who had acute lung injury (14.3 ± 4.7 vs. 15.5 ± 7.4; p = .97).

CONCLUSIONS

Elevated extravascular lung water index is a feature of early acute lung injury and discriminates between those with acute lung injury and those without. Furthermore, extravascular lung water index predicts progression to acute lung injury in patients with risk factors for development of acute lung injury 2.6 ± 0.3 days before the patients meet American European Consensus Committee criteria for it. These 2.6 ± 0.3 days may then represent missed opportunity for therapeutic intervention and improved outcome.

Differences in management and mortality with a bronchoalveolar lavage-based diagnostic protocol for ventilator-associated pneumonia

BACKGROUND

Directed antibiotic therapy based on accurate bacteriology is critical to ventilator-associated pneumonia (VAP) treatment. Bronchoalveolar lavage (BAL) has been reported to be more accurate than endotracheal sputum aspirate (ESA) in VAP diagnosis. Our objective was to determine the frequency with which BAL results differ from ESA cultures and the outcomes of VAP with a BAL-based VAP protocol.

METHODS

Prospectively collected microbiologic data on all trauma patients with VAP from 2007 through 2009 were reviewed. Per protocol, a positive ESA prompts a BAL and initiation of broad empiric antibiotics with de-escalation based on BAL results. Patients diagnosed with VAP by the protocol were compared with those diagnosed outside of the protocol using univariate and multivariate linear regression analysis. Concordance of ESA and BAL results was evaluated, and cause of death was determined.

RESULTS

Of 137 patients with VAP, 96 were diagnosed by the protocol (protocol group) and had 102 pairs of cultures. Twenty-six patients (27%) with 28 pairs of cultures (27.4%) had discordant results. Of discordant pairs, 17 (61%) showed bacteria of a different Gram's stain. Methicillin-sensitive Staphylococcus aureus was the most common causative organism. Mortality was lower in the protocol group (6.3%) than the nonprotocol group (22%, p = 0.014) and mechanically ventilated patients without VAP (24%, p = 0.35) but with comparable Injury Severity Score (ISS). VAP-attributable mortality in the protocol group was 1%.

CONCLUSIONS

Use of a BAL-based diagnostic protocol affects management of trauma patients with VAP by improving identification of causative microorganisms and is associated with low overall mortality and VAP-attributable mortality.

Direct testing of bronchoalveolar lavages from ventilator-associated pneumonia patients

In line with a rapid de-escalation of empirical antimicrobial therapy, this study assessed the validity of an E-test-based direct specimen testing method on bronchoalveolar lavage (BAL) samples from ventilator-associated pneumonia (VAP) patients. E-test strips were directly applied onto Mueller-Hinton agar plates seeded with BAL samples and read after 24 h of incubation. In parallel, the BAL samples were analyzed by the routine diagnostic laboratory. The microbroth dilution approach was used as a control method. In a cohort of 20 patients, 135 microorganism-antibiotic combinations were studied. Total agreement between the 2 methods was achieved for 88.9% combinations, with 1.5% very major errors (isolates susceptible by E-test and reported resistant by the diagnostic laboratory) and 9.6% major errors (isolates resistant by E-test and reported susceptible by the diagnostic laboratory). These results indicate that applying E-test directly on BAL samples is a promising method for obtaining susceptibility data after 24 h in critical patients with VAP.

Ventilator-associated pneumonia: a comprehensive review

Ventilator-associated pneumonia (VAP) is the most frequent and severe infection acquired in the intensive care unit, leading to prolonged mechanical ventilation and excess mortality. This article reviews the different aspects of VAP, such as risk factors, causative agents, and approaches to diagnosis, treatment, and prevention. Several aspects of VAP are still considered controversial.

Quantitative versus qualitative cultures of respiratory secretions for clinical outcomes in patients with ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is a common infectious disease in intensive care units (ICUs). The best diagnostic approach to resolve this condition remains uncertain.

OBJECTIVES

To evaluate whether quantitative cultures of respiratory secretions are effective in reducing mortality in immunocompetent patients with VAP, compared with qualitative cultures. We also considered changes in antibiotic use, length of ICU stay and mechanical ventilation.

SEARCH METHODS

We searched The Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL) Issue 2, 2011, which contains the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to June Week 4, 2011), EMBASE (1974 to June 2011) and LILACS (1982 to June 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing respiratory samples processed quantitatively or qualitatively, obtained by invasive or non-invasive methods from immunocompetent patients with VAP and which analysed the impact of these methods on antibiotic use and mortality rates.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed and trials identified in the search results and assessed studies for suitability, methodology and quality. We analysed data using Review Manager software. We pooled the included studies to yield the risk ratio (RR) for mortality and antibiotic change with 95% confidence intervals (CI).

MAIN RESULTS

Of the 4459 references identified from the electronic databases, five RCTs (1367 patients) met the inclusion criteria. Three studies compared invasive methods using quantitative cultures versus non-invasive methods using qualitative cultures, and were used to answer the main objective of this review. The other two studies compared invasive versus non-invasive methods, both using quantitative cultures. We combined all five studies to compare invasive versus non-invasive interventions for diagnosing VAP. The studies that compared quantitative and qualitative cultures (1240 patients) showed no statistically significant differences in mortality rates (RR 0.91; 95% CI 0.75 to 1.11). The analysis of all five RCTs showed there was no evidence of reduction in mortality in the invasive group versus the non-invasive group (RR 0.93; 95% CI 0.78 to 1.11). There were no significant differences between the interventions with respect to the number of days on mechanical ventilation, length of ICU stay or antibiotic change.

AUTHORS' CONCLUSIONS

There is no evidence that the use of quantitative cultures of respiratory secretions results in reduced mortality, reduced time in ICU and on mechanical ventilation, or higher rates of antibiotic change when compared to qualitative cultures in patients with VAP. Similar results were observed when invasive strategies were compared with non-invasive strategies.

[Analysis of 208 flexible bronchoscopies performed in an intensive care unit]

OBJECTIVE

To describe the main indications, clinical results and complications associated with fibrobronchoscopy in the Intensive Care Unit (ICU).

DESIGN

A retrospective, single-center observational study was carried out. Setting. Seventeen beds in a medical/surgical ICU. Patients. Consecutive patients undergoing fibrobronchoscopy during their stay in the ICU over a period of 5 years.

INTERVENTIONS

Flexible bronchoscopy performed by an intensivist. Main variables of interest. Flexible bronchoscopy indications and complications derived from the procedure.

RESULTS

A total of 208 flexible bronchoscopies were carried out in 192 patients admitted to the ICU. Most of the procedures (193 [92.8%]) were performed in mechanically ventilated patients. The average patient age was 58 ± 16 years, with an APACHE II score at admission of 19 ± 7. The most frequent indication for flexible bronchoscopy was diagnostic confirmation of initially suspected pneumonia (148 procedures), with positive bronchoalveolar lavage findings in 46%. The most frequent therapeutic indication was the resolution of atelectasis (28 procedures). Other indications were the diagnosis and treatment of pulmonary hemorrhage, the aspiration of secretions, control of percutaneous tracheotomy, and difficult airway management. The complications described during the procedures were supraventricular tachycardia (3.8%), transient hypoxemia (6.7%), and slight bleeding of the bronchial mucosal membrane (2.4%).

CONCLUSIONS

A microbiological diagnosis of pneumonia and the resolution of atelectasis are the most frequent indications for flexible bronchoscopy in critically ill patients. Flexible bronchoscopy performed by an intensivist in ICU is a safe procedure.

[Should the diagnosis of ventilator associated pneumonia be improved?]

Ventilator associated pneumonia (VAP) is the leading nosocomial infection in intensive care. It is associated with increased ICU and hospital stay, an increased use of antibiotics, and greater hospital costs. The recently launched Pneumonia Zero project (NZ) undoubtedly constitutes a challenge for professionals in the ICU, and has been designed to reduce the high incidence rates described. It is necessary to establish the true incidence, and whether the latter is influenced by the diagnostic method employed. The lack of a reference standard for the microbiological diagnosis of VAP has generated controversy over the diagnostic algorithms to be used, with the distinction of two strategies: a noninvasive or clinical strategy based on upper respiratory tract cultures, and an invasive method based on the use of quantitative cultures of samples from the lower respiratory tract obtained by bronchoscopic techniques. Despite the recommendations of scientific societies, which do not justify the use of qualitative tracheal aspirates in the microbiological diagnosis of VAP, this method is still routinely used. This study underscores the need to stop using qualitative tracheal aspirates as a routine diagnostic method for VAP, recommending the use of bronchoscopic techniques or quantitative tracheal aspirates.

Short-course versus prolonged-course antibiotic therapy for hospital-acquired pneumonia in critically ill adults

BACKGROUND

Pneumonia is the most common hospital-acquired infection affecting patients in the intensive care unit (ICU). However, the optimal duration of antibiotic therapy for hospital-acquired pneumonia (HAP) is uncertain.

OBJECTIVES

To assess the effectiveness of short versus prolonged-course antibiotic administration for HAP in critically ill adults, including patients with ventilator-associated pneumonia (VAP).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 1), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1950 to February week 4, 2011), EMBASE (1974 to March 2011), LILACS (1985 to March 2011) and Web of Science (1985 to March 2011).

SELECTION CRITERIA

We considered all randomised controlled trials (RCTs) comparing fixed durations of antibiotic therapy, or comparing a protocol intended to limit duration of therapy with standard care, for HAP (including patients with VAP) in critically ill adults.

DATA COLLECTION AND ANALYSIS

Two review authors conducted data extraction and assessment of risk of bias. We contacted trial authors for additional information.

MAIN RESULTS

Eight studies (1703 patients) were included. Methodology varied considerably and we found little evidence regarding patients with a high probability of HAP who were not mechanically ventilated. For patients with VAP, a short seven to eight-day course of antibiotics compared with a prolonged 10 to 15-day course (three studies, N = 508) increased 28-day antibiotic-free days (odds ratio (OR) 4.02; 95% confidence interval (CI) 2.26 to 5.78) and reduced recurrence of VAP due to multi-resistant organisms (OR 0.44; 95% CI 0.21 to 0.95), without adversely affecting other outcomes. However, for cases of VAP due to non-fermenting Gram-negative bacilli (NF-GNB), recurrence was greater after short-course therapy (OR 2.18; 95% CI 1.14 to 4.16; two studies, N = 176), though other outcome measures did not significantly differ. Discontinuation strategies utilising clinical features (one study; N = 302) or procalcitonin (three studies; N = 323) led to a reduction in duration of therapy and, in the procalcitonin studies, increased 28-day antibiotic-free days (mean difference (MD) 2.80; 95% CI 1.39 to 4.21) without negatively affecting other outcomes.

AUTHORS' CONCLUSIONS

We conclude that for patients with VAP not due to NF-GNB, a short fixed-course (seven or eight days) antibiotic therapy may be more appropriate than a prolonged course (10 to 15 days). Use of an individualised strategy (incorporating clinical features or serum procalcitonin) appears to safely reduce duration of antibiotic therapy for VAP.

Interpreting positive cultures of endotracheal aspirates: factors associated with treatment decisions in ventilated neonates

AIMS

Diagnosis of ventilator-associated pneumonia in newborns is challenging because of ease of colonisation, non-specific chest radiograph changes and lack of a consensus definition. The aims of this study were to review treatment decisions in neonates with culture-positive endotracheal aspirate and to assess impact on respiratory outcomes using blinded review of radiological studies.

METHODS

Charts from all very low birthweight neonates ventilated for >48 h and with positive culture were assessed. Chest radiographs were reviewed by a radiologist masked to the grouping of the episode (treated/not treated). Clinical, investigational and radiological features used in practice were assessed on impact on treatment decisions. Association between treatment and outcomes was assessed.

RESULTS

Seventy-four episodes of culture-positive endotracheal aspirate were analysed in 38 babies. Fifty-eight episodes were treated with antibiotics. Gestational age at birth and birthweight in both groups (treated vs. non-treated) were statistically comparable (25.5 ± 3.1 vs. 27.2 ± 2.3 weeks and 809 ± 302 vs. 870 ± 262 g). Comparative chest radiographs were available in 51 of 58 treated episodes; deterioration was noted in 42 (82.3%). Ventilatory parameters were significantly higher in the treatment group and showed a significant improvement after antibiotics. Twenty-three babies developed chronic lung disease. Odds ratio (of having chronic lung disease when treatment is initiated) was 4.5 (95% confidence interval = 0.97-20.8, P= 0.06).

CONCLUSIONS

Treated culture-positive aspirate episodes were accompanied by higher ventilatory requirements, increased symptoms and elevated septic markers. Need for treatment was associated with greater likelihood of developing chronic lung disease.

The management of community-acquired pneumonia in infants and children older than 3 months of age: clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America

Evidenced-based guidelines for management of infants and children with community-acquired pneumonia (CAP) were prepared by an expert panel comprising clinicians and investigators representing community pediatrics, public health, and the pediatric specialties of critical care, emergency medicine, hospital medicine, infectious diseases, pulmonology, and surgery. These guidelines are intended for use by primary care and subspecialty providers responsible for the management of otherwise healthy infants and children with CAP in both outpatient and inpatient settings. Site-of-care management, diagnosis, antimicrobial and adjunctive surgical therapy, and prevention are discussed. Areas that warrant future investigations are also highlighted.

The Sequential Organ Failure Assessment score and copeptin for predicting survival in ventilator-associated pneumonia

INTRODUCTION

Ventilator-associated pneumonia remains the most common nosocomial infection in the critically ill and contributes to significant morbidity. Eventual decisions regarding withdrawal or maximal therapy are demanding and rely on physicians' experience. Additional objective tools for risk assessment may improve medical judgement. Copeptin, reflecting vasopressin release, as well as the Sequential Organ Failure Assessment (SOFA) score, reflecting the individual degree of organ dysfunction, might qualify for survival prediction in ventilator-associated pneumonia. We investigated the predictive value of the SOFA score and copeptin in ventilator-associated pneumonia.

METHODS

One hundred one patients with ventilator-associated pneumonia were prospectively assessed. Death within 28 days after ventilator-associated pneumonia onset was the primary end point.

RESULTS

The SOFA score and the copeptin levels at ventilator-associated pneumonia onset were significantly elevated in nonsurvivors (P = .002 and P = .017, respectively). Both markers had different time courses in survivors and nonsurvivors (P < .001 and P = .006). Mean SOFA (average SOFA of 10 days after VAP onset) was superior in predicting 28-day survival as compared with SOFA and copeptin at ventilator-associated pneumonia onset (area under the curve, 0.90 vs 0.73 and 0.67, respectively).

CONCLUSIONS

The predictive value of serial-measured SOFA significantly exceeds those of single SOFA and copeptin measurements. Serial SOFA scores accurately predict outcome in ventilator-associated pneumonia.

Tracheal aspirate Gram stain has limited sensitivity and specificity for detecting Staphylococcus aureus

BACKGROUND AND OBJECTIVE

The increasing incidence of respiratory infections due to methicillin resistant Staphylococcus aureus has resulted in increased empirical use of antibiotics active against this pathogen. There are limited data available as to whether the Gram stain of respiratory tract secretions accurately predicts growth of S. aureus. We theorized that the distinctive morphology of S. aureus would allow rapid, accurate identification of the organism in respiratory secretions.

METHODS

The authors reviewed all available Gram stains of tracheal aspirates sent to our hospital's microbiology laboratory between 1 April 2008 and 31 October 2008, while blinded to the culture result, and recorded the presence or absence of organisms with a morphology consistent with S. aureus. These results were correlated with the semiquantitative culture result.

RESULTS

Among 136 tracheal aspirates studied, 50 (37%) grew S. aureus. The Gram stain was read as positive for organisms consistent with S. aureus in 34 of these. Among 86 samples that did not grow S. aureus, the Gram stain was read as negative in 62. Therefore, the Gram stain had a sensitivity of 68%, a specificity of 72%, a negative predictive value of 80% and a positive predictive value of 59% for culture of S. aureus. False negative Gram stains were more likely when the culture revealed only rare or small growth of S. aureus (P = 0.01).

CONCLUSIONS

In this study, the tracheal aspirate Gram stain read by an experienced clinician who was not a microbiologist, was not accurate enough to reliably predict the growth of S. aureus.

Severe, non-bacteremic infections in ICU patients

The present article is an update of the literature on various types of infections in ICU patients: ventilator-associated pneumonia, community-acquired pneumonia, the impact of the increasing vancomycin MIC in Staphylococcus aureus in the treatment of infections caused by this microorganism and the usefulness of biomarkers in identifying or ruling out septic complications in ICU patients. A multidisciplinary group of Spanish physicians with an interest in infections in critically-ill patients selected the most important recently published papers produced in the field. One of the members of the group discussed the content of each of the selected papers, with a critical appraisal by other members of the panel.

Prognostic value of dynamic soluble triggering receptor expressed on myeloid cells in bronchoalveolar lavage fluid of patients with ventilator-associated pneumonia

BACKGROUND AND OBJECTIVE

The aim of this study was to investigate the time course, and correlation with prognosis, of BAL fluid concentrations of soluble triggering receptor expressed on myeloid cells (sTREM-1) in patients with ventilator-associated pneumonia (VAP).

METHODS

The study included 35 patients with clinically diagnosed VAP, eight of whom were BAL fluid culture-negative and 27 BAL fluid culture-positive (16 survivors, 11 non-survivors). sTREM-1 levels were measured in BAL fluid of these mechanically ventilated patients, at the time of diagnosis, on days 4-5 and on days 7-9. The time course of this biomarker and its prognostic value for outcome in patients with culture-positive VAP were assessed.

RESULTS

sTREM-1 concentrations were significantly greater in culture-positive VAP patients than in culture-negative VAP patients. sTREM-1 levels decreased significantly with time in surviving patients with culture-positive VAP, but increased significantly with time in non-survivors. In contrast, PaO(2)/fraction of inspired oxygen (FiO(2)) increased significantly with time in survivors and decreased significantly with time in non-survivors. At a cut-off value of -10 pg/mL 7-9 days after initial diagnosis, sTREM levels had a sensitivity of 90% and a specificity of 87.5% for predicting mortality.

CONCLUSIONS

sTREM-1 concentrations in BAL fluid are of potential prognostic value in patients with VAP.

Clinical practice guidelines for hospital-acquired pneumonia and ventilator-associated pneumonia in adults

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are important causes of morbidity and mortality, with mortality rates approaching 62%. HAP and VAP are the second most common cause of nosocomial infection overall, but are the most common cause documented in the intensive care unit setting. In addition, HAP and VAP produce the highest mortality associated with nosocomial infection. As a result, evidence-based guidelines were prepared detailing the epidemiology, microbial etiology, risk factors and clinical manifestations of HAP and VAP. Furthermore, an approach based on the available data, expert opinion and current practice for the provision of care within the Canadian health care system was used to determine risk stratification schemas to enable appropriate diagnosis, antimicrobial management and nonantimicrobial management of HAP and VAP. Finally, prevention and risk-reduction strategies to reduce the risk of acquiring these infections were collated. Future initiatives to enhance more rapid diagnosis and to effect better treatment for resistant pathogens are necessary to reduce morbidity and improve survival.

A study of ventilator-associated pneumonia: Incidence, outcome, risk factors and measures to be taken for prevention

Ventilator-associated pneumonia (VAP) is a major cause of hospital morbidity and mortality despite recent advances in diagnosis and accuracy of management. However, as taught in medical science, prevention is better than cure is probably more appropriate as concerned to VAP because of the fact that it is a well preventable disease and a proper approach decreases the hospital stay, cost, morbidity and mortality. The aim of the study is to critically review the incidence and outcome, identify various risk factors and conclude specific measures that should be undertaken to prevent VAP. We studied 100 patients randomly, kept on ventilatory support for more than 48 h. After excluding those who developed pneumonia within 48 h, VAP was diagnosed when a score of ≥6 was obtained in the clinical pulmonary infection scoring system having six variables and a maximum score of 12. After evaluating, the data were subjected to univariate analysis using the chi-square test. The level of significance was set at P<0.05. It was found that 37 patients developed VAP. The risk factor significantly associated with VAP in our study was found to be duration of ventilator support, reintubation, supine position, advanced age and altered consciousness. Declining ratio of partial pressure to inspired fraction of oxygen (PaO₂/FiO₂ ratio) was found to be the earliest indicator of VAP. The most common organism isolated in our institution was Pseudomonas. The incidence of early-onset VAP (within 96 h) was found to be 27% while the late-onset type (>96 h) was 73%. Late-onset VAP had poor prognosis in terms of mortality (66%) as compared to the early-onset type (20%). The mortality of patients of the non-VAP group was found to be 41% while that of VAP patients was 54%. Targeted strategies aimed at preventing VAP should be implemented to improve patient outcome and reduce length of intensive care unit stay and costs. Above all, everyone of the critical care unit should understand the factors that place the patients at risk of VAP and utmost importance must be given to prevent VAP.

Comparison of bronchoscopic and non-bronchoscopic techniques for diagnosis of ventilator associated pneumonia

Background:

The diagnosis of ventilator associated pneumonia (VAP) remains a challenge because the clinical signs and symptoms lack both sensitivity and specificity and the selection of microbiologic diagnostic procedure is still a matter of debate.

Aims and Objective:

To study the role of various bronchoscopic and non-bronchoscopic diagnostic techniques for diagnosis of VAP.

Settings and Design:

This prospective comparative study was conducted in a medical ICU of a tertiary care center.

Materials and Methods:

Twenty-five patients, clinically diagnosed with VAP, were evaluated by bronchoscopic and non-bronchoscopic procedures for diagnosis. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of various bronchoscopic and non-bronchoscopic techniques were calculated, taking clinical pulmonary infection score (CPIS) of ≥6 as reference standard.

Results:

Our study has shown that for the diagnosis of VAP, bronchoscopic brush had a sensitivity, specificity, PPV and NPV of 94.9% [confidence interval (CI): 70.6–99.7], 57.1% (CI: 13.4–86.1), 85% (CI: 61.1–96) and 80% (CI: 21.9–98.7), respectively. Bronchoscopic bronchoalveolar lavage (BAL) had a sensitivity, specificity, PPV and NPV of 77.8% (CI: 51.9–92.6), 71.8% (CI: 24.1–94), 87.3% (CI: 60.4–97.8) and 55.5% (CI: 17.4–82.6), respectively. Sensitivity, specificity, PPV and NPV for non–bronchoscopic BAL (NBAL) were 83.3% (CI: 57.7–95.6), 71.43% (CI: 24.1–94), 88.2% (CI: 62.3–97.4) and 62.5% (CI: 20.2–88.2), respectively. Endotracheal aspirate (ETA) yield was only 52% and showed poor concordance with BAL (κ-0.351; P-0.064) and NBAL (k-0.272; P-0.161). There was a good microbiologic concordance among different bronchoscopic and non-bronchoscopic distal airway sampling techniques.

Conclusion:

NBAL is an inexpensive, easy, and useful technique for microbiologic diagnosis of VAP. Our findings, if verified, might simplify the approach for the diagnosis of VAP.

Diagnostic tests for agents of community-acquired pneumonia

Lower respiratory infections are the major cause of death due to infectious disease in the United States and worldwide. Most forms of community-acquired pneumonia (CAP) are treatable, and there is consensus that the selection of antimicrobial agents is notably simplified if the pathogen is defined. The rich history of CAP studies in the prepenicillin era showed that an etiologic diagnosis was established in >90% of cases, but the 2009 data from Medicare indicate that a probable pathogen is now detected in <10% according to a review of the records of >17,000 patients hospitalized with CAP. This review addresses the issue of the state of the art of microbiological studies of CAP in terms of the realities of current-day practice. Unfortunately, the desire for better data to achieve pathogen-directed treatment clashes with a multitude of harsh realities, including cost, Centers for Medicare and Medicaid Services (CMS) requirements for antibiotics to be administered within 6 h of disease onset, guidelines that discourage any microbiological studies in most cases, belief in empiricism that is well supported by at least 1 prospective study, the decline of microbiological analysis standards in most laboratories, and the devastating impact of the Clinical Laboratory Improvement Amendments (CLIA) regulations that led to the demise of "the house staff laboratory" and the distancing of microbiological analysis from the site of care. Microbiological principles are reviewed, with emphasis on specimen source, pathogenic potential of isolates, concentrations, impact of antecedent antibiotics, and the "Washington criteria" for expectorated sputum. The recommendation is that the high-quality microbiological analysis that is still achieved in some places should be retained but that to advance the field on the basis of the contemporary realities, two goals should be adopted: First is the broad use of antigen tests for Streptococcus pneumoniae and Legionella pneumophila with interpretation by clinical staff under the CLIA waiver for low-complexity tests. The second and more ambitious recommendation is the adoption of molecular techniques, with particular emphasis on nucleic acid detection, which is rapid and sensitive and has already been developed for virtually all recognized pulmonary pathogens. This may be the ultimate solution for many laboratories, and it is likely to have selected use.

Prompting physicians to address a daily checklist and process of care and clinical outcomes: a single-site study

RATIONALE

Checklists may reduce errors of omission for critically ill patients.

OBJECTIVES

To determine whether prompting to use a checklist improves process of care and clinical outcomes.

METHODS

We conducted a cohort study in the medical intensive care unit (MICU) of a tertiary care university hospital. Patients admitted to either of two independent MICU teams were included. Intervention team physicians were prompted to address six parameters from a daily rounding checklist if overlooked during morning work rounds. The second team (control) used the identical checklist without prompting.

MEASUREMENTS AND MAIN RESULTS

One hundred and forty prompted group patients were compared with 125 control and 1,283 preintervention patients. Compared with control, prompting increased median ventilator-free duration, decreased empirical antibiotic and central venous catheter duration, and increased rates of deep vein thrombosis and stress ulcer prophylaxis. Prompted group patients had lower risk-adjusted ICU mortality compared with the control group (odds ratio, 0.36; 95% confidence interval, 0.13-0.96; P = 0.041) and lower hospital mortality compared with the control group (10.0 vs. 20.8%; P = 0.014), which remained significant after risk adjustment (odds ratio, 0.34; 95% confidence interval, 0.15-0.76; P = 0.008). Observed-to-predicted ICU length of stay was lower in the prompted group compared with control (0.59 vs. 0.87; P = 0.02). Checklist availability alone did not improve mortality or length of stay compared with preintervention patients.

CONCLUSIONS

In this single-site, preliminary study, checklist-based prompting improved multiple processes of care, and may have improved mortality and length of stay, compared with a stand-alone checklist. The manner in which checklists are implemented is of great consequence in the care of critically ill patients.

Guidelines for hospital-acquired pneumonia and health-care-associated pneumonia: a vulnerability, a pitfall, and a fatal flaw

The 2005 American Thoracic Society and Infectious Disease Society of America's guidelines for pneumonia introduced the new category of health-care-associated pneumonia, which increased the number of people to whom the guidelines for multidrug-resistant pathogens applied. Three fundamental issues inherent in the definition of hospital-acquired pneumonia and health-care-associated pneumonia undermined the credibility of these guidelines and the applicability of their recommendations: a vulnerability, a pitfall, and a fatal flaw. The vulnerability is the extreme heterogeneity of the population of patients. The fatal flaw is the failure to accurately diagnose hospital-acquired pneumonia and ventilator-associated pneumonia; inability to distinguish colonisation from infection in respiratory-tract cultures renders the guidelines inherently unstable. The pitfall is spiralling empiricism of antibiotic use for severely ill patients in whom infection might not be present. A vicious circle of antibiotic overuse leading to emergence of resistant microflora can become established, leading to unnecessary use of empirical broad-spectrum combination antibiotics and increased mortality. Controlled studies now show that administration of broad-spectrum combination antibiotic therapy can lead to increased mortality in uninfected patients. Proposed solutions include the use of individualised assessment of patients. Health-care-associated pneumonia should be broken down into several distinct subgroups so narrow-spectrum antibiotic therapy can be used. Emphasis should be placed on defining the microbial cause of the pneumonia rather than reflex administration of empirical combination therapy.