Canadian Critical Care Trials Group. A randomized trial of diagnostic techniques for ventilator-associated pneumonia

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.

Mild hypoglycemia is independently associated with increased risk of mortality in patients with sepsis: a 3-year retrospective observational study

INTRODUCTION

Mild hypoglycemia is associated with increased mortality in critically ill patients. However, data regarding the association between mild hypoglycemia and patient outcomes among patients with sepsis are limited.

METHODS

Patients admitted to a medical ICU for sepsis, as defined by the Surviving Sepsis Campaign guidelines, during a 3-year period were enrolled retrospectively. Data on blood glucose (BG) control parameters and patient outcomes were collected. The primary outcome was the relationship of mild hypoglycemia (defined as minimum BG of 40 to 69 mg/dl during ICU stay) to hospital mortality, and the secondary outcomes were ICU-acquired complication rates, ICU and 1-year mortality rates. A relationship between glucose variability and hypoglycemic events was also investigated.

RESULTS

Three-hundred and thirteen consecutive patients with sepsis were enrolled (mean age, 71.8 ± 11.3 years; male, n = 166; diabetics, n = 102). A total of 14,249 (5.6/day/patient) BG tests were performed, and 175 hypoglycemic events (spontaneous, n = 71; iatrogenic, n = 104) occurred in 80 (25.6%) patients during the ICU stay; severe hypoglycemia (minimum BG level < 40 mg/dl) occurred in 24 (7.7%) patients, and mild hypoglycemia (minimum BG level 40 to 69 mg/dl) was found in 56 (17.9%) patients. The frequency of hypoglycemic events increased with higher glucose variability, and patients with mild hypoglycemia had higher rates of ICU-acquired complications than did those with no hypoglycemia (renal, 36.2% vs. 15.6%, P = 0.003; cardiac, 31.9% vs. 14.3%, P = 0.008; hepatic, 34.0% vs. 18.2%, P = 0.024; bacteremia, 14.9% vs. 4.5%, P = 0.021). Multivariate analysis revealed that mild hypoglycemia was independently associated with increased hospital mortality (odds ratio, 3.43; 95% confidence interval, 1.51 to 7.82), and even a single event was an independent risk factor (odds ratio, 2.98; 95% confidence interval, 1.10 to 8.09). Kaplan-Meier analysis demonstrated that mild hypoglycemia was significantly associated with a lower 1-year cumulative survival rate among patients with sepsis (P < 0.001).

CONCLUSION

Mild hypoglycemia was associated with increased risk of hospital and 1-year mortality, as well as the occurrence of ICU-acquired complications. Physicians thus need to recognize the importance of mild hypoglycemia in patients with sepsis.

Identifying missed opportunities to curtail antimicrobial therapy for presumed ventilator-associated pneumonia using the clinical pulmonary infection score

BACKGROUND

Early discontinuation of antimicrobial therapy for ventilator-associated pneumonia can reduce the emergence of antimicrobial resistance, the occurrence of adverse drug events, and the cost of therapy. Evidence suggests that discontinuation of therapy by day 3 may be appropriate for patients with a clinical pulmonary infection score of 6 or less at baseline and on day 3.

OBJECTIVES

To determine the proportion of patients eligible for antimicrobial discontinuation on day 3 and day 7 of therapy and to determine the proportion of eligible patients for whom antimicrobials were discontinued within these timeframes.

METHODS

A 6-month observational study was conducted from October 3, 2005, to March 31, 2006, in a 27-bed medical-surgical tertiary care intensive care unit. Clinical pharmacists attended daily rounds and prospectively identified patients for inclusion in the study. A study pharmacist retrospectively calculated clinical pulmonary infection scores. Other data were obtained from the quality-improvement database and patient health records for the intensive care unit.

RESULTS

Ninety-two patients were treated for ventilator-associated pneumonia during the study period, of whom 49 were included in the analysis. At day 3, 17 (35%) of the 49 patients were eligible for early discontinuation of antimicrobial therapy, but therapy was discontinued for only 2 (12%) of these 17 patients. At day 7, 10 (32%) of 31 patients were eligible for antimicrobial discontinuation, but therapy was discontinued for only 1 (10%) of these 10 patients.

CONCLUSIONS

A significant opportunity exists at the authors' institution to develop and implement an antimicrobial discontinuation policy that uses the clinical pulmonary infection score to guide antimicrobial use for patients with ventilator-associated pneumonia.

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.

Multiple lung abscesses caused by Actinomyces graevenitzii mimicking acute pulmonary coccidioidomycosis

Actinomyces graevenitzii is a newly recognized Actinomyces species that is seldom isolated from clinical specimens. A case of multiple pulmonary abscesses mimicking acute pulmonary coccidioidomycosis is described in this study, and the findings indicate that this organism is an opportunistic human pathogen.

Effect of continuous oral suctioning on the development of ventilator-associated pneumonia: a pilot randomized controlled trial

BACKGROUND

Both continuous and intermittent aspiration of subglottic secretions by means of specially designed endotracheal tubes containing a separate dorsal lumen that opens into the subglottic region have been shown to be useful in reducing ventilator-associated pneumonia (VAP). However, the high cost of these tubes restricts their use.

OBJECTIVE

The aim of this pilot randomized controlled trial was to test the effect of a low-cost device (saliva ejector) for continuous oral suctioning (COS) on the incidence of VAP in patients receiving mechanical ventilation.

METHODS

The study was conducted in the six-bed medical-surgical ICU of a hospital with over 400 beds that provides comprehensive medical services to the public. The design of this study was a parallel-group randomized controlled trial. While both the experimental and control groups used the conventional endotracheal tube, the saliva ejector was only applied to patients assigned to the experimental group. The device was put between the patient's cheek and teeth, and then connected to 100mmHg of suction for the continuous drainage of saliva.

RESULTS

Fourteen patients were randomized to receive COS and 13 patients were randomized to the control group. The two groups were similar in demographics, reasons for intubation, co-morbidity, and risk factors for acquiring VAP. VAP was found in 3 patients (23.1%; 71 episodes of VAP per 1000 ventilation days) receiving COS and in 10 patients (83.3%; 141 episodes of VAP per 1000 ventilation days) in the control group (relative risk, 0.28; 95% confidence interval, 0.10-0.77; p=0.003). The duration of mechanical ventilation in the experimental group was 3.2 days (SD 1.3), while that in the control group was 5.9 days (SD 2.8) (p=0.009); and the length of ICU stay was 4.8 days (SD 1.6) versus 9.8 days (SD 6.3) for the experimental and control groups, respectively (p=0.019).

CONCLUSION

Continuous clearance of oral secretion by the saliva ejector may have an important role to play in reducing the rate of VAP, decreasing the duration of mechanical ventilation, and shortening the length of stay of patients in the ICU.

Re-evaluation of rejection criteria for endotracheal tube (ETT) specimens from adult patients

The purpose of this study was to determine optimal criteria for microbiology laboratory screening of endotracheal tube (ETT) specimens submitted for bacterial culture from adult patients. ETT specimens from adult patients that were received by two microbiology laboratories were prospectively evaluated and subdivided into one of three study arms with the following criteria: <10 squamous epithelial cells (SECs) per low-power field with bacteria seen on Gram staining (arm 1), >10 SECs per low-power field with bacteria seen on Gram staining (arm 2) and <10 SECs per low-power field with no bacteria seen on Gram staining (arm 3). A fourth study arm (>10 SECs per low-power field with no bacteria seen on Gram staining) was planned but this arm was terminated due to the paucity of specimens meeting these criteria. Isolate evaluation was performed using standard microbiology protocols. A limited chart review was undertaken at one of the institutions, only reviewing patients from which a potential pathogen was recovered on culture. In total, 141 ETT specimens were evaluated. A potential respiratory pathogen was recovered from 54, 37 and 10 % of specimens in study arms 1, 2, and 3, respectively (P<0.0001, comparing between arm 1 and arm 3). For the 23 patients included in the chart review from whom a potential pathogen was recovered on culture, respiratory infection was considered to be present in 50 % (6/12) of patients in arm 1, 66.6 % (6/9) of patients in arm 2 and 100 % (2/2) of patients in arm 3. Therapy was rarely altered based on culture results. In this study, the ETT specimens submitted for bacterial culture were of limited benefit to clinicians. The data presented here support the use of an absence of bacteria on Gram staining as a rejection criterion for ETT specimens. The criterion of >10 SECs per low-power field should be further evaluated in a prospective study of patients with an unequivocal clinical diagnosis of pneumonia.

Impact of Candida species on clinical outcomes in patients with suspected ventilator-associated pneumonia

BACKGROUND

The significance of Candida species in respiratory tract (RT) secretions in critically ill patients is unclear.

METHODS

A retrospective analysis of the Canadian ventilator-associated pneumonia (VAP) trial was conducted. Only patients with suspected VAP whose initial cultures failed to grow any known pathogens were included. Using two fundamentally different statistical techniques that adjusted for important confounding variables, the clinical outcomes of patients with Candida species recovered from RT cultures were compared with patients whose RT cultures were not positive for Candida species.

RESULTS

RT cultures yielded no identifiable bacterial pathogens in 274 patients; 68 patients had Candida species in the RT alone, while 206 patients did not have Candida species recovered from any site. The unadjusted OR of hospital mortality for patients with Candida species was 2.9 (95% CI 1.6 to 5.2; P<0.001). The hazard ratio of time to hospital discharge was 0.54 (95% CI 0.38 to 0.77; P=0.001). Logistic regression analysis demonstrated that age, Acute Physiology score and Chronic Health Evaluation (APACHE) II score, primary diagnosis of respiratory failure, two or more comorbidities and Candida species were independently associated with increased hospital mortality. Similar trends were observed with time to hospital discharge. The association between Candida species and increased mortality remained after controlling for potential confounders using both propensity score stratification and multivariable modelling approaches.

CONCLUSIONS

Patients with suspected VAP, in whom no bacterial pathogen was identified and in whom Candida species were isolated from RT cultures, exhibited a greater burden of illness compared with similar patients without Candida. Whether Candida species colonization of RT secretions is a marker of disease severity or actually contributes to poorer clinical outcomes remains unclear.

Implications of endotracheal tube biofilm in ventilator-associated pneumonia response: a state of concept

INTRODUCTION

Biofilm in endotracheal tubes (ETT) of ventilated patients has been suggested to play a role in the development of ventilator-associated pneumonia (VAP). Our purpose was to analyze the formation of ETT biofilm and its implication in the response and relapse of VAP.

METHODS

We performed a prospective, observational study in a medical intensive care unit. Patients mechanically ventilated for more than 24 hours were consecutively included. We obtained surveillance endotracheal aspirates (ETA) twice weekly and, at extubation, ETTs were processed for microbiological assessment and scanning electron microscopy.

RESULTS

Eighty-seven percent of the patients were colonized based on ETA cultures. Biofilm was found in 95% of the ETTs. In 56% of the cases, the same microorganism grew in ETA and biofilm. In both samples the most frequent bacteria isolated were Acinetobacter baumannii and Pseudomonas aeruginosa. Nineteen percent of the patients developed VAP (N = 14), and etiology was predicted by ETA in 100% of the cases. Despite appropriate antibiotic treatment, bacteria involved in VAP were found in biofilm (50%). In this situation, microbial persistence and impaired response to treatment (treatment failure and relapse) were more frequent (100% vs 29%, P = 0.021; 57% vs 14%, P = 0.133).

CONCLUSIONS

Airway bacterial colonization and biofilm formation on ETTs are early and frequent events in ventilated patients. There is microbiological continuity between airway colonization, biofilm formation and VAP development. Biofilm stands as a pathogenic mechanism for microbial persistence, and impaired response to treatment in VAP.

Relationship of vitamin D deficiency to clinical outcomes in critically ill patients

BACKGROUND

Despite the numerous disease conditions associated with vitamin D deficiency in the general population, the relationship of this deficiency to outcome in critically ill patients remains unclear. The objective of this study is to determine the burden of vitamin D deficiency in intensive care unit (ICU) patients and determine if it is associated with poor patient outcomes.

METHODS

The authors conducted an analysis of samples collected from a prospective study of 196 patients admitted to a medical/surgical ICU in a tertiary care hospital. They measured serum 25-hydroxyvitamin D at admission and up to 10 days following admission and followed patients prospectively for 28-day outcomes.

RESULTS

Of analyzable patients, 50 (26%) were deficient (≤30 nmol/L) and 109 (56%) were insufficient (>30 and ≤60 nmol/L). Baseline 25(OH)D levels decreased significantly in all patients after 3 days in the ICU and remained significantly lower through 10 days (P < .001). 25(OH)D status was not significantly associated with 28-day all-cause mortality (hazard ratio [HR], 0.89; 95% confidence interval, [CI] 0.37-2.24). Higher levels of 25(OH)D were associated with a shorter time-to-alive ICU discharge (HR, 2.11; 95% CI, 1.27-3.51). 25(OH)D-deficient patients showed a nonstatistically significant trend toward a higher infection rate (odds ratio [OR], 3.20; 95% CI, 0.784-13.07; P = .11) compared with patients with sufficient levels of 25(OH)D.

CONCLUSIONS

This study demonstrates significant decreases in vitamin D status over the duration of the patient's ICU stay. Low levels of vitamin D are associated with longer time to ICU discharge alive and a trend toward increased risk of ICU-acquired infection.

Performance of the PIRO score for predicting mortality in patients with ventilator-associated pneumonia

The ventilator-associated pneumonia (VAP) PIRO score is a new scoring system based on the PIRO concept. The aim of this study was to validate the PIRO score against the Acute Physiology and Chronic Health Evaluation (APACHE) II and VAP APACHE II in an independent group of VAP patients. Areas under the receiver operating characteristic curves were compared to determine the tests' abilities to predict intensive care unit and 28-day mortality. Variables associated with intensive care unit mortality were evaluated. One hundred and forty-eight intensive care unit patients who met radiographic and clinical criteria for VAP were included. The area under the receiver operating characteristic curves for predicting intensive care unit mortality with the PIRO, APACHE II and VAP APACHE II scores were 0.605 (P=0.03), 0.631 (P=0.01) and 0.724 (P <0.0001), respectively. Areas under the receiver operating characteristic curve for predicting 28-day mortality were 0.614 (P=0.01) for PIRO, 0.633 (P=0.01) for APACHE II and 0.697 (P=0.002) for VAP APACHE II. No differences in area under the receiver operating characteristic curve between scores were found at either endpoint. Variables independently associated with intensive care unit mortality were bacteraemia (adjusted odds ratio 7.16, 95% confidence interval 1.19 to 42.98, P=0.03) and APACHE II (1.06, 1.01 to 1.11, P=0.006). VAP PIRO score was not a good predictor of intensive care unit and 28-day mortality. The low sensitivity and specificity of VAP PIRO score preclude its use clinically.

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.

Attributable mortality of ventilator-associated pneumonia

PURPOSE OF REVIEW

To critically discuss the attributable mortality of ventilator-associated pneumonia (VAP) and potential sources of variation.

RECENT FINDINGS

The review will cover the available estimates (0-50%). It will also explore the source of variation because of definition of VAP (being lower if inaccurate), case-mix issues (being lower for trauma patients), the severity of underlying illnesses (being maximal when the severity of underlying illness is intermediate), and on the characteristics and the severity of the VAP episode. Another important source of variation is the use of poorly appropriate statistical models (estimates biased by lead time bias and competing events). New extensions of survival models which take into account the time dependence of VAP occurrence and competing risks allow less biased estimation as compared with traditional models.

SUMMARY

Attributable mortality of VAP is about 6%. Accurate diagnostic methods are key to properly estimating it. Traditional statistical models should no longer be used to estimate it. Prevention efforts targeted on patients with intermediate severity may result in the most important outcome benefits.

Ventilator-associated pneumonia with or without toothbrushing: a randomized controlled trial

Certain guidelines for the prevention of ventilator-associated pneumonia (VAP) recommend oral care with chlorhexidine, but none refer to the use of a toothbrush for oral hygiene. The role of toothbrush use has received scant attention. Thus, the objective of this study was to compare the incidence of VAP in critical care patients receiving oral care with and without manual brushing of the teeth. This was a randomized clinical trial developed in a 24-bed medical-surgical intensive care unit (ICU). Patients undergoing invasive mechanical ventilation for than 24 h were included. Patients were randomly assigned to receive oral care with or without toothbrushing. All patients received oral care with 0.12 % chlorhexidine digluconate. Tracheal aspirate samples were obtained during endotracheal intubation, then twice a week, and, finally, on extubation. There were no significant differences between the two groups of patients in the baseline characteristics. We found no statistically significant differences between the groups regarding the incidence of VAP (21 of 217 [9.7 %] with toothbrushing vs. 24 of 219 [11.0 %] without toothbrushing; odds ratio [OR] = 0.87, 95 % confidence interval [CI] = 0.469-1.615; p = 0.75). Adding manual toothbrushing to chlorhexidine oral care does not help to prevent VAP in critical care patients on mechanical ventilation.

De-escalation therapy: is it valuable for the management of ventilator-associated pneumonia?

In therapy for ventilator-associated pneumonia, it is essential to get initial empiric therapy correct; this is challenging because many patients are infected with multidrug-resistant pathogens. The need for achieving appropriate therapy can lead to broad-spectrum empiric therapy, which can represent antibiotic overuse and promote even more resistance. In an effort to combat this problem, de-escalation therapy has been proposed, with the goals of reducing the number of drugs, the spectrum of therapy, and the duration of therapy. This review examines the factors associated with an effective de-escalation strategy and ways to increase the rates of de-escalation in the future.

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.

The adequacy of timely empiric antibiotic therapy for ventilator-associated pneumonia: an important determinant of outcome

OBJECTIVE

The individual impact of timeliness vs adequacy of empiric antibiotic therapy for a clinical suspicion of ventilator-associated pneumonia (CSVAP) is unknown. Accordingly, in patients with CSVAP and timely initiation of empiric antibiotic therapy, we determined the impact of inadequate therapy (IT).

METHODS

Analysis of a randomized trial of CSVAP treated empirically with meropenem or meropenem plus ciprofloxacin was done. Adequate therapy (AT) was considered present if all pathogens in the index culture were sensitive to the empiric antibiotics; IT was defined as the presence of pathogens resistant to the empiric antibiotics. A priori, for Pseudomonas sp, 2 antibiotics with activity against the organisms were required for AT to be considered present.

RESULTS

Of 739 patients with CSVAP, 350 had positive cultures: 313 (89.4%) had AT, and 37 (10.6%), IT. The IT group had higher intensive care unit (35.1% vs 11.8%, P = .0001) and hospital mortalities (48.7% vs 19.5%, P < .0001), increased mechanical ventilation (15.8 vs 6.8 days, P = .0005), intensive care unit stay (13.5 vs 8.4 days, P = .02), and hospital stay (42.2 vs 27.9 days, P = .04). In multivariate analysis and a separate case control analysis, the odds ratio of hospital mortality with IT was 3.05 (95% confidence interval, 1.25-7.45; P = .01) and 3.00 (95% confidence interval, 1.24-7.24; P = .01), respectively.

CONCLUSION

In the context of early administration of empiric broad spectrum antibiotics for CSVAP, IT is associated with higher morbidity and mortality.

[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.

High prevalence of multidrug-resistant nonfermenters in hospital-acquired pneumonia in Asia

RATIONALE

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) remain important causes of morbidity and mortality. Increasing antimicrobial resistance has aroused the concern of the failure of antibiotic treatment.

OBJECTIVES

To determine the distribution of the bacterial isolates of HAP and VAP, their antimicrobial resistance patterns, and impact of discordant antibiotic therapy on clinical outcome in Asian countries

METHODS

A prospective surveillance study was conducted in 73 hospitals in 10 Asian countries from 2008-2009. A total of 2,554 cases with HAP or VAP in adults were enrolled and 2,445 bacterial isolates were collected from 1,897 cases. Clinical characteristics and antimicrobial resistance profiles were analyzed.

MEASUREMENT AND MAIN RESULTS

Major bacterial isolates from HAP and VAP cases in Asian countries were Acinetobacter spp., Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae. Imipenem resistance rates of Acinetobacter and P. aeruginosa were 67.3% and 27.2%, respectively. Multidrug-resistant rates were 82% and 42.8%, and extensively drug-resistant rates were 51.1% and 4.9%. Multidrug-resistant rate of K. pneumoniae was 44.7%. Oxacillin resistance rate of S. aureus was 82.1%. All-cause mortality rate was 38.9%. Discordant initial empirical antimicrobial therapy increased the likelihood of pneumonia-related mortality (odds ratio, 1.542; 95% confidence interval, 1.127-2.110).

CONCLUSIONS

Acinetobacter spp., P. aeruginosa, S. aureus, and K. pneumoniae are the most frequent isolates from adults with HAP or VAP in Asian countries. These isolates are highly resistant to major antimicrobial agents, which could limit the therapeutic options in the clinical practice. Discordant initial empirical antimicrobial therapy significantly increases the likelihood of pneumonia-related mortality.

Mojave toxin-type ascending flaccid paralysis after an envenomation by a Southern Pacific Rattlesnake in a dog

OBJECTIVE

To describe the clinical presentation and case management of a dog that developed ascending flaccid paralysis after being envenomated by a Southern Pacific rattlesnake.

CASE SUMMARY

A dog was presented after it was bitten by a Southern Pacific rattlesnake. Only mild local edema and a minor coagulapathy developed, which is atypical for the Southern Pacific envenomation where hemotoxic effects are more commonly observed. Instead, a severe, rapidly progressing, ascending flaccid paralysis leading to acute respiratory failure, consistent with Mojave toxin, was seen. The patient was treated with repeated doses of antivenin and supported with mechanical ventilation. Despite clinical improvement of the paralysis over subsequent 3 days and successful weaning off the ventilator, the dog decompensated and succumbed to acute respiratory distress syndrome.

NEW OR UNIQUE INFORMATION PROVIDED

The geographic region where this envenomation occurred has a documented population of Southern Pacific rattlesnakes with Mojave toxin in their venom. To the knowledge of the authors, this is the first reported case in the veterinary literature of an ascending flaccid paralysis, consistent with Mojave toxin, developing after an envenomation by a Southern Pacific rattlesnake.

[Nosocomial pneumonia. Prevention and diagnostic]

Pneumonia occurring more than 48 h after induction of mechanical ventilation is called ventilator-associated pneumonia (VAP). VAP is the most common nosocomial infection in intensive care medicine and is associated with prolonged intensive care and hospital stay and a higher mortality. The main pathomechanism for development of ventilator-associated pneumonia is not so much the mechanical ventilation per se but more the pathogens passing along the tube towards the lungs. Avoidance of tracheal intubation, strict hygienic measures, reduction of oropharyngeal colonization and the avoidance of microaspiration are the most promising prevention strategies. Therapeutic success in treatment of VAP is coupled to an early diagnosis and therapy. Suspicion of pneumonia is based on clinical and radiologic criteria. Biomarkers and microbiological findings are important for follow-up and reevaluation of the suspected diagnosis.

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.

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.

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.

Ventilator-associated pneumonia: update on etiology, prevention, and management

Ventilator-associated pneumonia (VAP) remains one of the most important nosocomial infections in the intensive care unit and has been the focus of much recent research. New evidence on VAP preventive measures includes evidence for the efficacy of changes in endotracheal tube cuff design and materials, drainage of subglottic secretions, saline instillation prior to tracheal suctioning, patient positioning, oral decontamination, aerosolized antibiotics, and probiotic use. In the absence of a clinical reference standard, the diagnosis of VAP remains problematic. Although extensive research on invasive sampling techniques for microbiological confirmation has been conducted, current evidence suggests that endotracheal aspirates are equivalent. Promising new diagnostic methods include non-culture-based microbiological techniques and biomarkers. The treatment of VAP continues to evolve. Shorter antibiotic treatment duration is effective. As well, novel methods of antimicrobial delivery to maximize antibiotic effectiveness and the use of inflammatory biomarkers to guide duration of antibiotic therapy show promise.

Healthcare-associated pneumonia: approach to management

Healthcare-associated pneumonia patients have worse outcomes and a different microbiologic profile than those with community-acquired pneumonia, including a greater risk for multidrug-resistant (MDR) organism infection. Risks include hospitalization for 2 or more days within 90 days, presentation from a nursing home or long-term care facility, attending a hospital or hemodialysis clinic, receiving intravenous therapy within 30 days, and immunosuppression. Ability to predict infection with MDR organisms varies, and the relative frequency of MDR organisms varies by geographic region. Initial treatment is broad-spectrum empiric antibiotics.

Comparison of ventilator-associated pneumonia (VAP) rates between different ICUs: Implications of a zero VAP rate

OBJECTIVE

Ventilator-associated pneumonia (VAP) is associated with significant morbidity and mortality. Measures to reduce the incidence of VAP have resulted in institutions reporting a zero or near-zero VAP rates. The implications of zero VAP rates are unclear. This study was done to compare outcomes between two intensive care units (ICU) with one of them reporting a zero VAP rate.

DESIGN, SETTING AND PATIENTS

This study retrospectively compared VAP rates between two ICUs: Utah Valley Regional Medical Center (UVRMC) with 25 ICU beds and American Fork Hospital (AFH) with 9 ICU beds. Both facilities are under the same management and attended by a single group of intensivists. Both ICUs have similar nursing and respiratory staffing patterns. Both ICUs use the same intensive care program for reduction of VAP rates. ICU outcomes between AFH (reporting zero VAP rate) and UVRMC (VAP rate of 2.41/1000 ventilator days) were compared for the years 2007-2008.

MEASUREMENTS AND MAIN RESULTS

UVRMC VAP rates during 2007 and 2008 were 2.31/1000 ventilator days and 2.5/1000 ventilator days respectively compared to a zero VAP rate at AFH. The total days of ventilation, mean days of ventilation per patient and mean duration of ICU stay per patient was higher in the UVRMC group as compared to AFH ICU group. There was no significant difference in mean age and APACHE II score between ICU patients at UVRMC and AFH. There was no statistical difference in rates of VAP and mortality between UVRMC and AFH.

CONCLUSIONS

During comparisons of VAP rate between institutions, a zero VAP rate needs to be considered in the context of overall ventilator days, mean durations of ventilator stay and ICU mortality.

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.

Severity of ICU-acquired pneumonia according to infectious microorganisms

PURPOSE

To assess the severity of intensive care unit (ICU)-acquired pneumonia (ICUAP) according to the bacteria involved, classified into seven groups: third-generation cephalosporin-resistant non-fermenting Gram-negative bacilli (resistant C3NF); sensitive C3NF; methicillin-resistant Staphylococcus aureus; methicillin-sensitive Staphylococcus aureus; extended-spectrum beta-lactamase-producing Enterobacteriaceae; Enterobacteriaceae not producing extended-spectrum beta-lactamase; Haemophilus influenzae and Streptococcus pneumoniae.

METHODS

Over a 4-year period, sequential organ failure assessment (SOFA) score was prospectively measured daily in 453 adult patients with ICUAP. ICUAP severity was evaluated by the severity of sepsis and by the occurrence of new organ dysfunctions or failures (OD/F) during ICUAP.

RESULTS

Septic shock occurred in 21% of all cases of ICUAP. The occurrence of new OD/F during ICUAP was similar regardless of the identified microorganism. These new OD/F represented less than 11% of SOFAmax, defined as the sum of all OD/F occurring at any time during the ICU stay. There was a significant association between SOFApreICUAP, defined as the sum of all the OD/F occurring before ICUAP, and ICUAP severity. In the multivariate analysis, the type of bacteria was not a risk factor (RF) for occurrence of septic shock and mortality. Age and SOFApreICUAP were RF for the sepsis severity. The ICUAP severity was an RF for ICU mortality.

CONCLUSIONS

ICUAP was responsible for a minor proportion of OD/F occurring during the ICU stay. Severity of ICUAP was related to clinical status prior to ICUAP, but not to the type of bacteria. ICU mortality depended on the severity of ICUAP.

[Positive bronchoalveolar lavage and quantitative cultures results in suspected late-onset ventilator associated penumonia evaluation--retrospective study]

INTRODUCTION

Bronchoalveolar lavage (BAL) with quantitative cultures has been used in order to increase ventilator associated pneumonia (VAP) diagnosis specificity, although the accurate technique for this entity diagnosis remains controversial.

OBJECTIVES

To evaluate the influence of using positive BAL and quantitative cultures results in microbiologic diagnosis and treatment of patients with suspected late VAP and prior antibiotherapy.

MATERIAL AND METHODS

Retrospective analysis of intensive care unit (UCI) patients, during a one year period, with clinical suspicion of late VAP and prior use of antibiotics that presented a growth in BAL cultures.

RESULTS

Of 243 BAL performed, there were 71 (29.2%) positive cultures (60 patients, 76.7% male, 54 ± 19 years). BAL was done after 13 days (median) of invasive mechanical ventilation, 11 days of ICU antibiotherapy and in the day in which a new antibiotic for VAP suspicion was started. Colony forming units (CFU)/ml count was performed in 71.8% and endotracheal aspirate (ETA) simultaneously collected for qualitative analysis in 85.9%. Therapeutic approach was changed in 38.0%: correction (16.9%), de-escalation (12.7%) and directed antibiotherapy start (8.4%). Therapeutic changes were made in the presence of CFU > 10(4) in 84.2% and in agreement with ETA in 70.8%. In cases in which antibiotherapy was maintained (62.0%), quantitative cultures would have allowed de-escalation in 9.1%. Changes in prescription were more frequent when CFU was > 10(4) (48.5%), comparing with situations in which counts were lower and BAL analysis was qualitative (28.9%), p = 0.091. There were no significant differences between patients submitted to different therapeutic approaches concerning to ICU mortality or length of stay.

CONCLUSION

In late onset VAP, positive BAL and quantitative cultures allowed therapeutic changes, leading to antibiotic adequacy and consumption reduction, which can however be maximised.

The diagnostic dilemma of ventilator-associated pneumonia in critically ill children

OBJECTIVE

A review of the existing literature on ventilator-associated pneumonia in children with emphasis on problems in diagnosis.

DATA SOURCES

A systematic literature review from 1947 to 2010 using Ovid MEDLINE, PubMed, Cochrane Central Register of Controlled Trials, and ISI Web of Science using key words "ventilator associated pneumonia" and "children." Where pediatric data were lacking, appropriate adult studies were reviewed and similarly referenced.

STUDY SELECTION

Two hundred sixty-two pediatric articles were reviewed and data from 48 studies selected. Data from 61 adult articles were also included in this review.

DATA EXTRACTION AND SYNTHESIS

Ventilator-associated pneumonia is the second most common nosocomial infection and the most common reason for antibiotic use in the pediatric intensive care unit. Attributable mortality is uncertain but ventilator-associated pneumonia is associated with significant morbidity and cost. Diagnosis is problematic in that clinical, radiologic, and microbiologic criteria lack sensitivity and specificity relative to autopsy histopathology and culture. Qualitative tracheal aspirate cultures are commonly used in diagnosis but lack specificity. Quantitative tracheal aspirate cultures have sensitivity (31-69%) and specificity (55-100%) comparable to bronchoalveolar lavage (11-90% and 43-100%, respectively) but concordance for the same bacterial species when compared with autopsy lung culture was better for bronchoalveolar lavage (52-90% vs. 50-76% for quantitative tracheal aspirate). Staphylococcus aureus and Pseudomonas species are the most common organisms, but microbiologic flora change over time and with antibiotic use. Initial antibiotics should offer broad-spectrum coverage but should be narrowed as clinical response and cultures dictate.

CONCLUSIONS

Ventilator-associated pneumonia is an important nosocomial infection in the pediatric intensive care unit. Conclusions regarding epidemiology, treatment, and outcomes are greatly hampered by the inadequacies of current diagnostic methods. We recommend a more rigorous approach to diagnosis by using the Centers for Disease Control and Prevention algorithm. Given that ventilator-associated pneumonia is the most common reason for antibiotic use in the pediatric intensive care unit, more systematic studies are sorely needed.

Telavancin versus vancomycin for hospital-acquired pneumonia due to gram-positive pathogens

The results from two methodologically identical double-blind studies indicate that telavancin is noninferior to vancomycin based on clinical response in the treatment of hospital-acquired pneumonia due to Gram-positive pathogens.

Background. Telavancin is a lipoglycopeptide bactericidal against gram-positive pathogens.

Methods. Two methodologically identical, double-blind studies (0015 and 0019) were conducted involving patients with hospital-acquired pneumonia (HAP) due to gram-positive pathogens, particularly methicillin-resistant Staphylococcus aureus (MRSA). Patients were randomized 1:1 to telavancin (10 mg/kg every 24 h) or vancomycin (1 g every 12 h) for 7–21 days. The primary end point was clinical response at follow-up/test-of-cure visit.

Results. A total of 1503 patients were randomized and received study medication (the all-treated population). In the pooled all-treated population, cure rates with telavancin versus vancomycin were 58.9% versus 59.5% (95% confidence interval [CI] for the difference, –5.6% to 4.3%). In the pooled clinically evaluable population (n = 654), cure rates were 82.4% with telavancin and 80.7% with vancomycin (95% CI for the difference, –4.3% to 7.7%). Treatment with telavancin achieved higher cure rates in patients with monomicrobial S. aureus infection and comparable cure rates in patients with MRSA infection; in patients with mixed gram-positive/gram-negative infections, cure rates were higher in the vancomycin group. Incidence and types of adverse events were comparable between the treatment groups. Mortality rates for telavancin-treated versus vancomycin-treated patients were 21.5% versus 16.6% (95% CI for the difference, –0.7% to 10.6%) for study 0015 and 18.5% versus 20.6% (95% CI for the difference, –7.8% to 3.5%) for study 0019. Increases in serum creatinine level were more common in the telavancin group (16% vs 10%).

Conclusions. The primary end point of the studies was met, indicating that telavancin is noninferior to vancomycin on the basis of clinical response in the treatment of HAP due to gram-positive pathogens.

Multinational, observational study of procalcitonin in ICU patients with pneumonia requiring mechanical ventilation: a multicenter observational study

Introduction

The intent of this study was to determine whether serum procalcitonin (PCT) levels are associated with prognosis, measured as organ dysfunctions and 28-day mortality, in patients with severe pneumonia.

Methods

This was a multicenter, observational study of critically ill adult patients with pneumonia requiring mechanical ventilation conducted in 10 academic hospitals in Canada, the United States, and Central Europe. PCT was measured daily for 14 days using an immuno-luminometric assay.

Results

We included 175 patients, 57 with community acquired pneumonia (CAP), 61 with ventilator associated pneumonia (VAP) and 57 with hospital acquired pneumonia (HAP). Initial PCT levels were higher in CAP than VAP patients (median (interquartile range: IQR); 2.4 (0.95 to 15.8) vs. 0.7 (0.3 to 2.15), ng/ml, P < 0.001) but not significantly different to HAP (2.2 (0.4 to 8.0) ng/ml). The 28-day ICU mortality rate for all patients was 18.3% with a median ICU length of stay of 16 days (range 1 to 142 days). PCT levels were higher in non-survivors than in survivors. Initial and maximum PCT levels correlated with maximum Sequential Organ Failure Assessment (SOFA) score r² = 0.50 (95% CI: 0.38 to 0.61) and r² = 0.57 (0.46 to 0.66), respectively. Receiver operating curve (ROC) analysis on discrimination of 28-day mortality showed areas under the curve (AUC) of 0.74, 0.70, and 0.69 for maximum PCT, initial PCT, and Acute Physiology and Chronic Health Evaluation (APACHE) II score, respectively. The optimal cut-off to predict mortality for initial PCT was 1.1 ng/ml (odds ratio: OD 7.0 (95% CI 2.6 to 25.2)) and that for maximum PCT was 7.8 ng/ml (odds ratio 5.7 (95% CI 2.5 to 13.1)).

Conclusions

PCT is associated with the severity of illness in patients with severe pneumonia and appears to be a prognostic marker of morbidity and mortality comparable to the APACHE II score.

Bronchoalveolar Lavage in the Diagnosis of Ventilator-Associated Pneumonia: To Quantitate or Not, That is the Question

Quantitative bronchoalveolar lavage (BAL) is used to diagnose ventilator-associated pneumonia (VAP). We prospectively compared semiquantitative (SQ) and quantitative (Qu) culture of BAL for VAP diagnosis. Ventilated patients suspected of VAP underwent bronchoscopic BAL. BAL fluid was examined by both Qu (colony-forming units [CFUs]/mL) and SQ culture (none, sparse, moderate, or heavy) and results were compared. VAP was defined as 105 CFU/mL or greater on Qu culture. Over 36 months, 319 BALs were performed. Sixty-three of 319 (20%) showed diagnostic growth by Qu culture identifying a total of 81 organisms causing VAP. All 63 specimens showed growth of some organism(s) on SQ culture with 79 of 81 causative organisms identified and two ( Pseudomonas, one; Corynebacterium, one) not identified. The remaining 256 specimens did not meet the threshold for VAP by the Qu method. Among these, 79 did not show any growth on SQ culture. Among the 240 specimens showing some growth on SQ culture, a total of 384 organisms were identified. VAP rates in relation to strength of growth on SQ culture were: sparse, 10 of 140 (7%); moderate, 24 of 147 (16%); and heavy, 45 of 97 (46%). Sensitivity (Sn), specificity (Sp), positive (PPV), and negative (NPV) predictive values of SQ culture of BAL fluid for the diagnosis of VAP were 97, 21, 21, and 97 per cent, respectively. Nonquantitative culture of BAL fluid is fairly accurate in ruling out VAP (high Sn and NPV). It however has poor Sp and PPV and using this method will lead to unnecessary antimicrobial use with its attendant complications of toxicity, cost, and resistance.

Diagnosis, management and prevention of ventilator-associated pneumonia: an update

Ventilator-associated pneumonia (VAP) affects 10-20% of mechanically ventilated patients and is associated with increased morbidity and mortality and high costs. Early diagnosis is crucial for rapid appropriate antimicrobial therapy to be instituted, but debate remains as to the optimal diagnostic strategy. Noninvasive clinical-based diagnosis is rapid but may not be as accurate as invasive techniques. Increased use of biomarkers and advances in genomics and proteomics may help speed up diagnosis. Management of VAP relies principally on appropriate antimicrobial therapy, which should be selected according to individual patient factors, such as previous antibacterial therapy and length of hospitalization or mechanical ventilation, and local infection and resistance patterns. In addition, once bacterial culture and sensitivity results are available, broad-spectrum therapy should be de-escalated to provide a more specific, narrower-spectrum cover. Optimum duration of antibacterial therapy is difficult to define and should be tailored to clinical response. Biomarker levels may be useful to monitor response to therapy. With the high morbidity and mortality, prevention of VAP is important and several strategies have been shown to reduce the rates of VAP in mechanically ventilated patients, including using noninvasive ventilation where possible, and semi-recumbent positioning. Other potentially beneficial preventive techniques include subglottal suctioning, oral decontamination strategies and antimicrobial-coated endotracheal tubes, although further study is needed to confirm the cost effectiveness of these strategies.

We should abandon randomized controlled trials in the intensive care unit

The randomized controlled trial is seen by many as the summit of evidence-based medicine, yet, in the intensive care unit, randomized controlled trials can be challenging to conduct, and results are often difficult to interpret and apply. Many randomized controlled trials in intensive care patients have not demonstrated beneficial effects of the intervention under investigation often despite good preclinical and even previous randomized controlled trial evidence. There are many reasons for these negative results including problems with timing, end point selection, and heterogeneous populations. In this article, we will discuss the limitations of randomized controlled trials in the intensive care unit population and highlight the importance of considering other study designs in the challenging intensive care unit environment.

Effects of three approaches to standardized oral hygiene to reduce bacterial colonization and ventilator associated pneumonia in mechanically ventilated patients: a randomised control trial

BACKGROUND

Ventilator associated pneumonia remains an important concern in the intensive care unit (ICU). An increasing body of evidence shows that mortality and morbidity can be reduced by implementing a range of preventive strategies, including optimizing oral hygiene.

AIM

The aim of this feasibility study was to test two oral hygiene strategies on the effects of microbial colonization of dental plaque with respiratory pathogens (primary outcome) and incidence of ventilator associated pneumonia (secondary outcome).

METHODS

A single blind randomised comparative study was conducted in a 20-bed adult intensive care unit in a university hospital. Patients with an expected duration of mechanical ventilation more than 48 h were eligible. Patients were randomised to one of three study regimens (Group A control, second hourly oral rinse with sterile water, Group B sodium bicarbonate mouth wash second hourly, and Group C twice daily irrigations with chlorhexidine 0.2% aqueous oral rinse and second hourly irrigations with sterile water). All study options included cleaning with a toothbrush and non foaming toothpaste.

RESULTS

Data from a total of 109 patients were analyzed. Group A 43, Group B 33 and Group C 33 (mean age: 58 ± 17 years, simplified acute physiology score II: 44 ± 14 points). On admission no significant differences were found between groups for all clinical data. While Group B showed a greater trend to reduction in bacterial colonization no significant differences could be demonstrated at Day 4 of admission (p=0.302). The incidence of ventilator associated pneumonia was evenly spread between Groups B and C (5%) while Group A was only 1%.

CONCLUSIONS

While a number of studies have advocated the use of various mouth rinses in reducing colonization of dental plaque a standardized oral hygiene protocol which includes the use of mechanical cleaning with a toothbrush may be a factor in the reduction of colonization of dental plaque with respiratory pathogens. This feasibility study provides data to inform future adequately powered studies.