Endotracheal Aspirate Cultures Research Articles

Ventilator-associated pneumonia: role of colonizers and value of routine endotracheal aspirate cultures

To determine the role of colonizers in the causation of ventilator-associated pneumonia (VAP) and the value of routine pre-VAP endotracheal aspirate (EA) cultures in appropriately treating VAP. A prospective observational cohort study was conducted over a period of 15 months. Two hundred patients on mechanical ventilation for>48h were studied. Acinetobacter spp (33.7%) and Pseudomonas spp (29.8%) were the most common colonizers. Of the 200 patients, 36 developed VAP. In 20 VAP patients, the pre-VAP EA culture-based strategy was not useful. However, in the remaining 16 VAP patients, a pre-VAP EA culture-based strategy would have appropriately treated 13 (81%; 95% confidence interval (CI) 62-100%), in comparison to only nine (56%; 95% CI 32-80%) by the American Thoracic Society (ATS) strategy. The seven patients in whom the ATS guidelines were inappropriate had Acinetobacter spp and Pseudomonas spp resistant to the higher antibiotics recommended by the ATS for multidrug-resistant pathogens. The positive predictive values of Pseudomonas aeruginosa, Acinetobacter baumannii, and methicillin-resistant Staphylococcus aureus (MRSA) isolated from pre-VAP EA cultures were 88%, 83%, and 100%, respectively. VAP patients should be treated based on ATS guidelines, but whenever P. aeruginosa, A. baumannii, and MRSA are isolated from pre-VAP EA cultures, the initial antibiotic therapy should be extended to treat these.

Bacterial Etiology of Early- and Late-Onset Ventilator-Associated Pneumonia as Detected With Gram Stain, Endotracheal Aspirate, and Mini-BAL Cultures

Bacterial Etiology of Early- and Late-Onset Ventilator-Associated Pneumonia as Detected With Gram Stain, Endotracheal Aspirate, and Mini-BAL Cultures

Clinical, radiological and microbiological corroboration to assess the role of endotracheal aspirate in diagnosing ventilator-associated pneumonia in an intensive care unit of a tertiary care hospital, India

Early and accurate diagnosis and follow up of Ventilator-associated pneumonia (VAP) varies considerably with the clinical, radiological and microbiological criteria employed. this study was aimed to correlate serial clinicoradiological findings with microscopy and quantitative culture of consecutive Endotracheal aspirate (ETA) from 50 mechanically ventilated patients along with the antibiogram and risk factor assessment. the results revealed the incidence of VAP to be 42% with a rate of 116/1000 ventilator days in Multidisciplinary Intensive Care Unit (MICU). Early onset VAP was seen in 8 patients and late onset VAP in 13, with no significant age or sex preponderance. the attributable mortality rate was 61.9% which rose with duration of stay. the independent risk factors were multi-organ failure, re-intubation and pleural effusion. the most commonly isolated organisms were Multidrug resistant (MDR) Acinetobacter baumannii (76%) and Pseudomonas aeruginosa (42%). All enterobacterial isolates were Extended spectrum beta lactamases (ESBL) producing organisms and all Staphylococcus aureus isolates were methicillin resistant. Colonization on day 1 resulted in development of VAP on day 4 in 66% of the population studied. Gram stain findings had a significant correlation with the quantitative culture of ETA. Quantitative culture by itself showed a significant progressive increase of specificity in diagnosing VAP on day 7. he strength of association between Clinical Pulmonary Infection Score (CPIS), the microbiological findings and the clinical diagnosis was found to be strong. This study concludes that Gram stain and quantitative culture of ETA can be considered useful for the diagnosis of VAP and a combined clinical, radiological and microbiological approach can be used successfully in the management and follow up of VAP with emphasis on stepping up the VAP prevention bundle protocols.

Comparison of the value of initial and serial endotracheal aspirate surveillance cultures in predicting the causative pathogen of ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in the intensive care unit (ICU) and its outcome is affected by the adequacy and timing of initial antibiotic therapy. Recent studies have suggested that surveillance cultures of the lower airways may provide microbiological guidance for initial antibiotic prescription and increase the use of appropriate antibiotic therapy. This study aimed to compare the predictive value of initial and serial surveillance cultures of endotracheal aspirates in predicting the causative pathogen of VAP in patients receiving antibiotic therapy. This was an observational prospective cohort study. Ninety-two patients ventilated for at least 4 days were recruited into the study. Initial (IS-ETA) and serial (SS-ETA) endotracheal aspirate surveillance cultures were obtained on the day of intubation and every second day, respectively. The sensitivity, specificity, and positive and negative predictive values for the causative pathogens of VAP were calculated for each surveillance culture. Ninety-two initial and 252 serial surveillance cultures were obtained during the study period. The sensitivity of IS-ETA culture was 12% and of SS-ETA culture was 44%. The sensitivity of SS-ETA in late-onset VAP was 51%. The value of SS-ETA surveillance cultures was better than IS-ETA surveillance in predicting the causative pathogen of VAP, particularly in late-onset pneumonia.

Descontaminación digestiva selectiva: repercusión en la carga de trabajo y el coste del laboratorio de microbiología y tendencias en la resistencia bacteriana

This study determines the workload and cost of implementing selective digestive decontamination in the microbiology laboratory, and reports the impact on microbial flora and bacterial resistance trends in the intensive care unit (ICU). The total microbiological workload and cost were quantified, as well as the part charged to the petitioning service, in the year before and the year after introducing the procedure. Changes in microbial flora were evaluated and bacterial resistance trends were analyzed over 12 years in 21 sentinel antimicrobial/microorganism combinations. The workload ascribed to the ICU increased by 10% and cost increased by 1.8% in the period after introduction of the procedure (non-significant differences). The increased workload resulting from epidemiological surveillance cultures was compensated by significant reductions in quantitative endotracheal aspirate cultures, blood cultures, exudate cultures, identification tests with antibiograms, and serologies. The procedure has been associated with a significant decrease in Acinetobacter isolates and a significant increase in Enterococcus. Three significant trends of increased resistance were detected, all of them in Pseudomonas aeruginosa (imipenem, tobramycin, and ciprofloxacin). In our hospital, implementation of selective digestive decontamination did not cause a significant increase in the workload or costs in the microbiology laboratory. Selective digestive decontamination was associated with a significant decrease in Acinetobacter, an increase in Enterococcus, and higher resistance to imipenem, tobramycin and ciprofloxacin in P. aeruginosa.

Comparison of two different types of heat and moisture exchangers in ventilated patients

Study Objectives:To compare the efficacy of two different types of Heat and Moisture Exchangers (HME filters) in reducing transmission of infection from the patient to ventilator and vice versa and also its cost effectiveness.Design:Randomized, controlled, double blind, prospective study.Patients and Methods:60 patients admitted to the ICU from May 1, 2007 to July 31, 2007 of either sex, age ranging between 20 and 60 years, requiring mechanical ventilation were screened for the study. Following intubation of the patients, the HME device was attached to the breathing circuit randomly by the chit-in-a box method. The patients were divided into two groups according to the HME filters attached.Results:Both the groups were comparable with respect to age and sex ratio. In Type A HME filters, 80% showed growth on the patient end within 24 h and in 27% filters, culture was positive both on the patient and the machine ends. The organisms detected were Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa and co-related with the endotracheal aspirate culture. After 48 h, 87% filters developed organisms on the patient end, whereas 64% filters were culture positive both on the patient and the machine end. In Type B HME filters, 70% showed growth on patient's end after 24 h. Organisms detected were S. aureus, E. coli, P. aeruginosa and Acinetobacter. Thirty percent of filters were culture negative on both the patient and machine ends. No growth was found on the machine end in any of the filters after 24 h. After 48 h, 73% of the filters had microbial growth on the patient end, whereas only 3% filters had growth (S. aureus) on the machine end only. Seven percent had growth on both the patient as well as the machine ends. The microorganisms detected on the HME filters co-related with the endotracheal aspirate cultures.Conclusion:HME filter Type B (study group) was significantly better in reducing contamination of ventilator from the patient as compared to Type A (control group), which was routinely used in our ICU. Type B filter was found to be effective for at least 48 h. This study can also be applied to patients coming to emergency department (ED) and requiring emergency surgery and postoperative ventilation; and trauma patients like flail chest, head injury etc. requiring ventilatory support to prevent them from acquiring ventilator-associated pneumonia (VAP).

MICROBIOLOGY OF SURVEILLANCE ENDOTRACHEAL ASPIRATE CULTURE IN A COMMUNITY HOSPITAL

PURPOSE: In ventilator associated pneumonia (VAP), the surveillance of endotracheal aspirate (ETA) cultures have been shown to have a good predictive value in identifying its etiology. The purpose of this study is to identify and evaluate the trend of common bacterial isolates on surveillance ETA cultures and their antibacterial susceptibility in our community Hospital.

Increased mortality of ventilated patients with endotracheal Pseudomonas aeruginosa without clinical signs of infection*

To investigate the frequency and outcomes of ventilated patients with newly acquired large burdens of Pseudomonas aeruginosa and to test the hypothesis that large quantities of bacteria are associated with adverse patient outcomes. A prospective, single-center, observational, cohort study. Medical-surgical intensive care units in a tertiary care university hospital. All adult patients requiring > or = 48 hrs of mechanical ventilation and identified as having newly acquired P. aeruginosa in their lower respiratory tracts between October 2002 and April 2006. None. Daily surveillance cultures of endotracheal aspirates were performed on patients intubated > or = 48 hrs; 69 patients with newly acquired P. aeruginosa were enrolled. Daily P. aeruginosa quantification of endotracheal aspirates was performed; clinical signs of infection were noted. Of 45 patients with high P. aeruginosa burdens (> or = 1,000,000 colony-forming units/mL in endotracheal aspirates; > or = 10,000 colony-forming units/mL in bronchoalveolar-lavage), 17 (37.8%) patients did not meet clinical criteria for ventilator-associated pneumonia and had a statistically significant higher risk of death (adjusted hazard ratio, 37.53; 95% confidence interval, 3.79-371.96; p = 0.002) when compared with the patients who had P. aeruginosa ventilator-associated pneumonia. When excluding the ten patients who had ventilator-associated pneumonia attributed to bacteria other than P. aeruginosa or attributed to multiple bacteria including P. aeruginosa, the risk of death remained statistically significant (adjusted hazard ratio, 23.98; 95% confidence interval: 2.49-230.53; p = 0.006). Furthermore, more patients with high P. aeruginosa burdens secreted the type III secretion facilitator protein, PcrV (p = 0.01). A group of patients with large burdens of P. aeruginosa who did not meet clinical criteria for ventilator-associated pneumonia had an increased risk of death when compared with patients who had high P. aeruginosa burdens and met ventilator-associated pneumonia criteria. Patients with high P. aeruginosa burden seemed to possess more virulent strains.

Previous endotracheal aspirate allows guiding the initial treatment of ventilator-associated pneumonia

Any delay in adequate antibiotic treatment compromises the outcome of ventilator-associated pneumonia (VAP). However, the diagnosis and optimal treatment of VAP remain a challenge for intensivists. We assessed the potential impact of using results of routine weekly endotracheal aspirate (EA) cultures to guide initial antibiotic treatment for VAP. Retrospective analysis of prospectively collected data in a medical-surgical intensive care unit (ICU) of a university hospital. We studied 113 VAP episodes and evaluated the concordance between the latest EA and the broncho-alveolar lavage (BAL). We stratified patients into three groups: concordant EA-BAL (concordant group), discordant EA-BAL (discordant group) and EA not performed group. We then compared the adequacy of the antibiotic prescribed initially and outcomes between the three groups. Ninety assessable EA-BAL samples were evaluated. When guided by EA, the initial antibiotic regimen was adequate in 85% of situations, a proportion significantly superior (P < 0.05) to that resulting from application of the ATS guidelines (73%). When clinicians did not have a pre-VAP EA to guide their treatment (EA not performed group), only 61% of treatments were adequate. No significant difference was observed between the three groups for length of mechanical ventilation, length of ICU stay, nonpulmonary nosocomial infections and mortality. Once-a-week routine quantitative EA cultures may help to improve the adequacy of empiric antibiotic therapy for VAP.

Prognostic Role of Clinical and Laboratory Criteria To Identify Early Ventilator-Associated Pneumonia in Brain Injury*

We investigated the role of the clinical pulmonary infection score (CPIS), serum levels of procalcitonin (PCT), C-reactive protein (CRP), and serum amyloid A (SAA) in the detection of patients with early ventilator-associated pneumonia (VAP). Observational study in a university hospital. In 58 patients with severe brain injury receiving mechanical ventilation, CPIS, PCT, CRP and SAA were evaluated at ICU entry and at days 3 to 4 of hospital stay for VAP diagnosis (confirmed by endotracheal aspirate or BAL cultures). We found the following: (1) PCT at entry was increased in patients who later had early VAP develop (25 patients) compared to no VAP (median, 1.4 ng/mL; 25-75 percentiles, 0.14-0.78; vs median, 0.2 ng/mL; 25-75 percentiles, 0.76-2.4, p<0.001; sensitivity, 76%; and specificity, 75%); (2) CPIS increased at the day of VAP diagnosis, compared to entry (median, 6.6+/-1.1 vs 1.5+/-1.1, p<0.001; sensitivity, 97%; specificity, 100%), while other serum inflammatory markers did not change; and (3) deterioration in oxygenation and changes in tracheal secretions were the main determinants of CPIS changes. PCT may be a useful marker to predict which patients subsequently have early VAP. The CPIS could help as an early way to detect the patients with early VAP and who need further diagnostic testing.

Factors Predicting Bacterial Involvement in Severe Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Background: Strategies aiming at reducing antibiotic use are required in the intensive care unit (ICU). Although antibiotic treatment is recommended in patients with severe exacerbation of chronic obstructive pulmonary disease (COPD), a bacterial etiology is found in only a half of these patients. Objectives: The aim of this study was to determine factors predicting bacterial isolation in severe acute exacerbations of COPD. Methods: All patients with severe acute exacerbation of COPD requiring intubation and mechanical ventilation were included in this prospective observational cohort study. At ICU admission, information on endotracheal aspirate purulence and hyperthermia was collected. In all patients, Gram stain and quantitative endotracheal aspirate culture (positive at 10⁶ cfu/ml) were performed. In addition, leukocyte count, C-reactive protein and procalcitonin (PCT) levels were measured. Results: Ninety-eight severe acute exacerbations of COPD requiring intubation and mechanical ventilation were studied. Forty-nine bacteria were isolated at significant threshold in 40 exacerbations. Streptococcus pneumoniae (16%), methicillin-sensitive Staphylococcus aureus (16%) and Hemophilus influenzae (14%) were the most frequently isolated bacteria. PCT >0.5 ng/ml and positive Gram stain of endotracheal aspirate were independently associated with bacterial isolation in severe acute exacerbation of COPD. Positive Gram stain and PCT >0.5 ng/ml had a negative predictive value >95%. Similar results were found after excluding patients with prior antibiotic treatment. Conclusion: Positive Gram stain of endotracheal aspirate and PCT >0.5 ng/ml are independently associated with bacterial isolation in severe acute exacerbation of COPD. These results could be helpful for future interventional studies aiming at reducing antibiotic use in these patients.

Epidemiology, etiology, and diagnosis of hospital-acquired pneumonia and ventilator-associated pneumonia in Asian countries

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are significant public health issues in Asian countries, as they are worldwide. Mortality attributable to HAP and especially VAP can be very high. The present review aims to determine whether the incidence and prevalence of HAP and VAP are higher in Asian countries than in Western countries, whether the organisms causing these nosocomial infections differ etiologically, and whether they are more difficult to treat (ie, demonstrate greater resistance). The implementation of available guidelines can be best achieved through an understanding of local epidemiology, etiology, and resistance patterns, which can facilitate optimal treatment choices. The current review presents data on epidemiology, etiology, and diagnosis of HAP and VAP drawn from an expert panel of clinicians representing 10 Asian countries.

The safety of targeted antibiotic therapy for ventilator-associated pneumonia: A multicenter observational study

Purpose The aim of this study was to determine the safety of targeted antibiotic therapy (TT) in ventilator-associated pneumonia (VAP). Materials and Methods This was a secondary analysis from a multicenter trial of 740 patients with suspected VAP randomized to bronchoscopy or endotracheal aspirate cultures; all received empirical broad-spectrum antibiotics. Patients were grouped by whether they received TT, defined as tailoring or discontinuing antibiotics in response to enrolment culture results. Results For patients with a positive culture (n = 412), baseline demographics, clinical progression of infection and multiple organ dysfunction scores (MODS), and mortality were similar for those on TT (n = 320) or those who did not receive TT (NoTT) (n = 92). The TT group had more days alive and off broad-spectrum antibiotics (14.5 vs 13.2, P = .04). In patients with a negative culture (n = 327), those on TT (n = 230) had similar baseline demographics, less frequent final adjudicated diagnosis of VAP (63.0% vs 76.3%, P = .02), and less severe clinical progression of infection and MODS compared with NoTT (n = 97). The TT group had more days alive and off broad-spectrum antibiotics (15.9 vs 13.1, P < .001), lower δ MODS (2.0 vs 3.0, P = .01), fewer mechanical ventilation days (9.8 vs 14.7, P = .03), and similar mortality compared to NoTT. Conclusions Targeted therapy is associated with less antibiotic use and no evidence of harm in the management of patients with VAP.

Predicting neonatal sepsis in ventilated neonates

To show the value of serial endotracheal aspirate culture in predicting organisms causing sepsis in ventilated neonates. We studied 100 newborns in Zeynep Kamil Maternity and Children's Training and Research Hospital Neonatal Intensive Care Unit. Endotracheal aspirate and blood cultures were taken first on the third day and then once a week till extubation. Blood and endotracheal cultures showed the same organism only in 17.6% of the patients. There was no relationship among 86.4% of the patients. The rate of culture positivity increased as the birth weight decreased, gestation week got smaller and the duration of intubation prolonged. The antibiotherapy arranged according to the endotracheal aspirate cultures is not suitable for a possible sepsis agent. Moreover, resistant organisms may occur in hospitals if the antibiotics used unnecessarily.

Imipenem-Resistant Pseudomonas aeruginosa : Risk Factors for Nosocomial Infections

The aim of this study was to determine the risk factors for nosocomial infections of imipenem-resistant Pseudomonas aeruginosa (IRPA). A prospective case-control study was performed at a tertiary care hospital in Ankara from January to December 2004. The patients with nosocomial P. aeruginosa infection were included in the study. The features of the patients with IRPA infections were compared to those with imipenem-sensitive P. aeruginosa (ISPA) infections. Only the first isolation of P. aeruginosa was considered. Nosocomial infections were defined according to Center for Disease Control (CDC) criteria. IRPA was isolated from 75 (44.1%) patients, and ISPA was isolated from 95 (55.9%) patients during the study period. IRPA were most frequently isolated from endotracheal aspirate (19%) cultures (p=0.048), whereas ISPA were most frequently isolated from urine (28%) cultures (p=0.023). In multivariate analysis, a longer duration of hospital stay until P. aeruginosa isolation (odds ratio [OR], 1.027; 95% confidence interval [CI], 1.002-1.054, p=0.034), arterial catheter administration (OR, 2.508; 95% CI, 1.062-5.920, p=0.036), vancomycin (OR, 2.882; 95% CI, 1.130-7.349, p=0.027), piperacillin-tazobactam (OR, 6.425; 95% CI, 2.187-18.875, p=0.001), and imipenem (OR, 3.580; 95% CI, 1.252-10.245, p=0.017) treatment within the 14 days before isolation of IRPA were independently associated with imipenem resistance. It was concluded that treatment with imipenem, vancomycin and piperacillin-tazobactam were major risk factors for IRPA infections in hospitalized patients. The nosocomial occurrence of IRPA was also strongly related to the duration of hospital stay, arterial catheter administration.

Role of quantitative endotracheal aspirate and cultures as a surveillance and diagnostic tool for ventilator associated pneumonia: A pilot study

Accurate diagnosis and appropriate treatment of ventilator associated pneumonia (VAP) is crucial for good outcomes. Endotracheal suctioning is performed in ventilated patients as part of routine care and for tracheal toileting. We evaluated if quantitative endotracheal aspirate (ETA) was a suitable alternative to bronchoalveolar lavage (BAL) for suspected VAP. In addition we assessed if surveillance ETA guided antibiotic selection for subsequent VAP. Prospective study in the surgical intensive care unit (ICU) of a tertiary hospital in India. Two hundred consecutive patients with mean (standard deviation) APACHE II score of 12.3+/-5 and requiring mechanical ventilation beyond 48 hours underwent surveillance ETA cultures. A second ETA and BAL were performed if the patient developed features of VAP. The threshold for microbiological diagnosis of VAP was taken as 10 5 colony forming units/ml (cfu/ml) for ETA and 10 4 cfu/ml for BAL. The sensitivity and specificity of surveillance and concurrent ETA aspirate cultures were compared with BAL cultures. VAP was suspected clinically and corroborated radiologically in 27/177 patients (15.3%). Although microbiological support for VAP was obtained by ETA in 19 patients, bronchoscopy was possible only in 13 patients, 8 of whom had isolates at significant threshold. Of the 16 organisms isolated from BAL, 11 were of significant threshold with 9/11 (82%) BAL isolates having a similar antibiogram to a concurrent ETA. Only one BAL isolate (9%), at significant threshold, was not isolated on a concurrent ETA. On the other hand just 6/11 BAL isolates (55%) had an identical antibiogram to surveillance ETA. BAL had 3 additional isolates (27%) at significant threshold not isolated on surveillance ETA. Concurrent quantitative ETA could substitute BAL cultures for VAP. Surveillance ETA at 48 hours of ventilation does not appear to assist with antibiotic selection for a subsequent VAP.

Diagnostic strategies for nosocomial pneumonia

This review describes advances in clinical and microbiological modalities for diagnosis of nosocomial pneumonia and the role of biological markers. Serial assessments with the clinical pulmonary infection score identifies nonsurvivors and allows discontinuation of antibiotics when there is low suspicion of pneumonia. Studies evaluating its clinical utility show mixed results. A meta-analysis revealed that an invasive approach does not affect mortality but reduces costs, antibiotic exposure, and multidrug resistance. In contrast to these findings, a recent trial comparing nonquantitative endotracheal aspirate and quantitative bronchoalveolar lavage cultures showed similar clinical outcomes and antibiotic utilization. The role of quantitative endotracheal aspirate for diagnosis of pneumonia not related to mechanical ventilation was recently evaluated. Procalcitonin and soluble triggering receptor expressed on myeloid cells-1 aid in diagnosis, identify sepsis related to ventilator-associated pneumonia and patients with worst outcomes. The diagnostic modality chosen depends on availability, personnel experience, and the patient's clinical status. Recent guidelines support the use of quantitative cultures in an integrated clinical and microbiological algorithm. The decision to adjust antibiotics involves clinical reassessment and interpretation of culture results. Biological markers have a potential role as screening and prognostic tools.

R2269 Quantitative cultures of endotracheal aspirate in the diagnosis of ventilator-associated pneumonia

R2269 Quantitative cultures of endotracheal aspirate in the diagnosis of ventilator-associated pneumonia

Diagnostic yield of quantitative endotracheal aspirates in patients with severe nursing home-acquired pneumonia

IntroductionDiagnostic strategies based on tracheal aspirates in patients with severe nursing home-acquired pneumonia have not previously been evaluated. The objectives of the study were to investigate, in patients with severe nursing home-acquired pneumonia, the diagnostic value of quantitative endotracheal aspirate (QEA) cultures using increasing interpretative cutoff points, as compared with bronchoalveolar lavage (BAL) and protected specimen brush (PSB) quantitative cultures.MethodsSeventy-five nursing home patients requiring mechanical ventilation for suspected pneumonia were studied. Endotracheal aspirate, PSB, and BAL samples were obtained consecutively. The diagnostic yield of QEA at thresholds raging from 103 to 107 colony-forming units (cfu)/ml was assessed by calculating sensitivities, specificities, and accuracy rates. A receiver operator characteristic curve for the series of cutoff points was constructed.ResultsForty-nine patients were diagnosed with pneumonia either by BAL (≤ 104 cfu/ml) or PSB (≤ 103 cfu/ml). Diagnostic accuracy of QEA was most favorable at 104 cfu/ml. At this threshold, endotracheal aspirates coincided with both BAL and PSB in 30 cases, whereas partial agreement was observed in 14 cases. This resulted in sensitivity and specificity of 90% (95% confidence interval 78% to 97%) and 77% (95% confidence interval 56% to 91%), respectively. QEA findings correlated significantly with both PSB and BAL quantitative cultures (r = 0.71 [P < 0.001] and r = 0.77 [P < 0.001], respectively).ConclusionQEA may be used as a diagnostic tool to determine the presence of pneumonia in ventilated patients admitted from nursing homes when bronchoscopic procedures are not feasible or available.

The simple and the simpler in pneumonia diagnosis

In the absence of a perfect 'gold standard' for diagnosing pneumonia, comparing diagnostic performance between techniques remains controversial. El Solh and coworkers present a study evaluating use of quantitative endotracheal aspirate culture to enhance diagnostic accuracy in pneumonia patients admitted from nursing homes. We discuss the use of quantitative cultures and thresholds to differentiate between colonization and infection in pneumonia patients; we also consider the inaccuracy of diagnostic studies, which compromises the reproducibility of these data in clinical practice.