Quantitative Endotracheal Aspirate Research Articles

Risk Factors for 7-Day and 21-Day Mortality in Patients with Ventilator-Associated Pneumonia Caused by Gram-Negative Multidrug Resistant Bacteria

Objective: Incidence of ventilator-associated pneumonia, caused by gram-negative multidrug resistant bacteria, is on the increase and early mortality rate is high.
 We aimed to investigate the effects of aging, comorbidities, high Charlson comobidity index score, high Acute Physiology and Chronic Health Evaluation II score, leukocytosis, high C-reactive protein level, inappropriate empirical antibiotic therapy and antibiotic resistance on mortality in ventilator-associated pneumonia caused by gram-negative multidrug-resistant bacteria.
 Methods: The study was planned as a retrospective cohort study. Patients aged 18 years and older who were hospitalized between January 01, 2015, and January 01, 2020, diagnosed with ventilator-associated pneumonia, and had Gram-negative multidrug resistant pathogen was detected in blood and/or bronchoalveolar lavage fluid specimen or quantitative endotracheal aspirate cultures were included in the study.
 Results: A total of 370 patients were included in the study. Median age of the patients was 74 (19-95) years. Most frequent bacteria was Acinetobacter baumannii (52.4%). Resistance to ceftriaxone, meropenem, and colistin was 99%, 68%, and 4%, respectively. 7-day and 21-day mortality rates were 38.3% (n=142) and 85.1% (n=315). In multivariate analysis, 7-day mortality was associated with a Charlson comorbidity index score of ≥4, and risk factors for 7-day mortality were septic shock, amikacin resistance, and white blood cell count ≥15000/mm3. Advanced age was found to be a risk factor for 21-day mortality, and a high Acute Physiology and Chronic Health Evaluation II score and a high Charlson comorbidity index score were associated with 21-day mortality. It was found that the risk of 7-day mortality in patients with tracheostomy was lower than in patients without tracheostomy.
 Conclusion:Consideration of clinical scoring systems, closer monitoring of elderly patients, following-up with tracheostomy, may provide a decrease in mortality of ventilator-associated pneumonia, caused by multidrug resistant pathogens.

Quantitative culture of endotracheal aspirate in respiratory ICU

Background Ventilator-associated pneumonia (VAP) is considered a frequent nosocomial complication in intensive care, and it remains a common cause of prolonged hospital stay and death, although there is improvement in diagnosis and therapy. Aim The aim of this study was to detect the type of organism and prevelance of VAP in the respiratory ICUs at Ain Shams University Hospital. Patients and methods A total of 50 patients connected to mechanical ventilation were selected for serial chest radiography, total leukocytic count, and quantitative endotracheal aspirate culture to diagnose new invading tracheobronchial organisms. Results We found direct relation between bypassing of oropharyngeal commensal, invasion of tracheobroncial tree by new microorganisms, and the duration of mechanical ventilation. The percentage of Acinetobacter baumannii was 25.8%, whereas it was 19.3% for Staphylococcus aureus, 16.1% for Pseudomonas aeruginosa, 9.67% for Haemophilus influenza, and 6.4% for each Proteus mirabilis and Citrobacter freundii. Conclusion VAP is a serious problem that leads to high costs in treatment, longer hospital stay, and high rate of mortality and morbidity. Long time of mechanical ventilation is a causative factor. A. baumannii and S. aureus were the most common germs in endotracheal aspirate cultures.

PREVALENCE OF KLEBSIELLA PNEUMONIAE CAUSING VENTILATOR-ASSOCIATED PNEUMONIA (VAP) ISOLATED FROM PEDIATRIC INTENSIVE CARE UNIT AT ASSIUT UNIVERSITY HOSPITAL

Ventilator-associated pneumonia is a common nosocomial infection occurring in patients receiving mechanical ventilation especially in pediatric intensive care units (PICUs). Klebsiella pneumoniae is a multidrug resistant nosocomial pathogen that plays an important role in respiratory tract infection among critically ill patients. This study included 51 pediatric patients had VAP admitted to the Pediatric Intensive Care Unit (PICU) at Assiut university children's hospital through 12-month period from May 2014 to May 2015, using quantitative endotracheal aspirate (EA) culture. K. pneumoniae were isolated by culturing onto blood and MacConkey`s agar plates then incubated aerobically at 35°C for 2448 hrs. and identified by morphology and biochemical tests. K. pneumoniae 19 (37.25%) was the most isolated bacteria that causing VAP in PICU. Antimicrobial susceptibility testing showed that K. pneumoniae isolates were resistant to all commercial available antimicrobial agents that used in the PICU.

Quantitative culture of endotracheal aspirate and BAL fluid samples in the management of patients with ventilator-associated pneumonia: a randomized clinical trial.

OBJECTIVE: To compare 28-day mortality rates and clinical outcomes in ICU patients with ventilator-associated pneumonia according to the diagnostic strategy used. METHODS: This was a prospective randomized clinical trial. Of the 73 patients included in the study, 36 and 37 were randomized to undergo BAL or endotracheal aspiration (EA), respectively. Antibiotic therapy was based on guidelines and was adjusted according to the results of quantitative cultures. RESULTS: The 28-day mortality rate was similar in the BAL and EA groups (25.0% and 37.8%, respectively; p = 0.353). There were no differences between the groups regarding the duration of mechanical ventilation, antibiotic therapy, secondary complications, VAP recurrence, or length of ICU and hospital stay. Initial antibiotic therapy was deemed appropriate in 28 (77.8%) and 30 (83.3%) of the patients in the BAL and EA groups, respectively (p = 0.551). The 28-day mortality rate was not associated with the appropriateness of initial therapy in the BAL and EA groups (appropriate therapy: 35.7% vs. 43.3%; p = 0.553; and inappropriate therapy: 62.5% vs. 50.0%; p = 1.000). Previous use of antibiotics did not affect the culture yield in the EA or BAL group (p = 0.130 and p = 0.484, respectively). CONCLUSIONS: In the context of this study, the management of VAP patients, based on the results of quantitative endotracheal aspirate cultures, led to similar clinical outcomes to those obtained with the results of quantitative BAL fluid cultures.

Incidence and Outcomes of Ventilator-associated Tracheobronchitis and Pneumonia

BackgroundProlonged intubation with mechanical ventilation carries a risk for ventilator-associated respiratory infections manifest as tracheobronchitis or pneumonia. This study analyzed natural history, incidence, and outcomes of patients developing ventilator-associated tracheobronchitis and pneumonia. MethodsWe studied 188 mixed intensive care unit (ICU) patients intubated ≥48 hours for the development of tracheobronchitis defined as quantitative endotracheal aspirate ≥105 cfu/mL plus at least 2 clinical criteria (fever, leukocytosis, or purulent sputum). Pneumonia was defined as microbiologic criteria for tracheobronchitis and a new and persistent infiltrate on chest radiograph. ResultsAirways of 41 (22%) patients became heavily colonized with a bacterial pathogen(s) at a concentration of ≥105 cfu/mL. Tracheobronchitis developed in 21 (11%) study patients, of which 6 (29%) later progressed to pneumonia. Including these 6 patients, 28 (15%) study patients developed pneumonia. Multidrug-resistant pathogens were isolated in 39% of pneumonia patients. Patients with tracheobronchitis and pneumonia had significantly more ventilator days and longer stays in the ICU (P ≤.02). ConclusionsApproximately one third of tracheobronchitis patients later developed pneumonia. Patients with tracheobronchitis or pneumonia experienced significantly more ventilator days and longer ICU stays, but had no difference in mortality. Better patient outcomes and reduced health care costs may be achieved by earlier treatment of ventilator-associated respiratory infections, manifest as tracheobronchitis or pneumonia.

Usefulness of Quantitative Endotracheal Aspirate Cultures in Intensive Care Unit Patients with Suspected Pneumonia

It is difficult to differentiate pathogens responsible for pneumonia or colonization in patients with an endotracheal tube or in patients that have undergone tracheostomy. We evaluated the clinical usefulness of quantitative endotracheal aspirates cultures and sought to determine the result threshold level for positivity. The authors performed this retrospective cohort study between December 1, 2004 and January 31, 2006. Forty-five suspected pneumonia patients admitted to an intensive care unit (ICU) with quantitative bronchoalveolar lavage (BAL) and endotracheal aspirate (EA) culture results were enrolled. Using a threshold of 105 cfu/mL, 10 of the 45 (22.2%) quantitative EA cultures were positive, as compared with 7 (15.6%) BAL cultures. When BAL culture findings were used as the reference, the sensitivity and specificity of quantitative EA cultures were 85.7% and 89.5%, respectively, at a threshold of 105 cfu/mL, and 85.7% and 94.7%, respectively, at a threshold of 106 cfu/mL. Of the 10 EA culture positive patients, 2 patients with a result of -105 cfu/mL were BAL culture negative. The quantitative EA culture is a useful non-invasive tool for the diagnosis of pneumonia pathogens. It is suggested that a threshold level of 106 cfu/mL is appropriate.

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.

Diagnosis of ventilator-associated pneumonia

Introduction Ventilator-associated pneumonia (VAP) is difficult to diagnose. Recent data suggest quantitative endotracheal aspirate (ETA) may be noninferior diagnostically to quantitative bronchoalveolar lavage (BAL). We hypothesized this would be the case. Methods Blind quantitative ETA and BAL were performed on 150 consecutive ventilated patients with suspected VAP in a prospective single-centre medical intensive care unit study over a 2-year inclusion period. Patients were either antibiotic-naive or antibiotic-free for 72 hours. Diagnostic yield, Gram stain and culture results, and impact on antibiotic therapy were assessed. The independent impact of a positive BAL or ETA result on ventilator settings and 28-day mortality was calculated. The BAL/ETA safety was assessed hemodynamically. Results Bronchoalveolar lavage had significantly higher diagnostic yield (49.3% vs 34.0%, P = .01), more frequent impact on antibiotic therapy (usually de-escalation) (48.0% vs 32.7%, P = .01), and greater sensitivity (64.1% vs 42.6%, P = .0003) than ETA. There was moderate intertest agreement and no difference in specificity and positive and negative predictive values. A positive BAL or ETA result did not independently alter the frequency of ventilator changes or 28-day mortality. Both procedures were well tolerated. Conclusion Quantitative BAL is safe and has greater diagnostic utility than ETA for VAP facilitates de-escalation. This study provides support for quantitative BAL in VAP diagnosis.

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.

Randomized trial of combination versus monotherapy for the empiric treatment of suspected ventilator-associated pneumonia*

To compare a strategy of combination therapy with a strategy of monotherapy with broad-spectrum antibiotics for suspected late ventilator-associated pneumonia. Randomized trial. Twenty-eight intensive care units in Canada and the United States. The study included 740 mechanically ventilated patients who developed suspected ventilator-associated pneumonia after 96 hrs in the intensive care unit. Patients known to be colonized or infected with Pseudomonas or methicillin-resistant Staphylococcus aureus or who were immunocompromised were excluded from the study. As initial unblinded therapy, patients were allocated to receive meropenem (1 g every 8 hrs) and ciprofloxacin (400 mg every 12 hrs) or meropenem alone. Before starting antibiotics, patients were also randomized to bronchoalveolar lavage with quantitative cultures or endotracheal aspirates. When culture results were available, physicians were encouraged to adjust antibiotics. Adequacy of antibiotics was defined as the organism present in the enrollment culture having in vitro susceptibility to one or more of the study antibiotics. Baseline characteristics and etiologies of ventilator-associated pneumonia were similar in the two groups. There was no difference in 28-day mortality between the combination and monotherapy groups (relative risk = 1.05, 95% confidence interval 0.78-1.42, p = .74). Duration of intensive care unit and hospital stay, clinical and microbiological treatment response, emergence of antibiotic-resistant bacteria, isolation of Clostridium difficile in stool, and fungal colonization were also similar in the two groups. In a subgroup of patients who had infection due to Pseudomonas species, Acinetobacter species, and multidrug-resistant gram-negative bacilli at enrollment (n = 56), the adequacy of initial antibiotics (84.2% vs. 18.8%, p < .001) and microbiological eradication of infecting organisms (64.1% vs. 29.4%, p = .05) was higher in the combination group compared with the monotherapy group, but there were no differences in clinical outcomes. For critically ill patients who have suspected late ventilator-associated pneumonia and who are at low risk for difficult-to-treat gram-negative bacteria, monotherapy is associated with similar outcomes compared with combination therapy. For those patients at high risk of difficult-to-treat gram-negative bacteria, combination therapy is safe and may be associated with better microbiological and clinical outcomes.

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.

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.

Reduced burden of bacterial airway colonization with a novel silver-coated endotracheal tube in a randomized multiple-center feasibility study*

To assess the feasibility and safety of the respiratory infection control (RIC) device, a silver-coated endotracheal tube, and its effect on bacterial burden in the airways. Prospective, randomized, single-blind, multiple-center study. Three hospitals in Spain and one in the United States. Patients were eligible adults who required mechanical ventilation for > or =24 hrs and did not have respiratory infections. One hundred forty-nine patients were intubated and analyzed for safety; 121 were intubated > or =24 hrs and analyzed for tube colonization; 67 had negative baseline quantitative endotracheal aspirates and were analyzed for quantitative endotracheal aspirates colonization. Intubation with the RIC device or a control endotracheal tube. The RIC device was associated with delayed colonization on the tube compared with the control device at the threshold of ++, +++, or > or =10(4) colony-forming units/mL (p = .02, log-rank test; p = .10, Wilcoxon's test) and in quantitative endotracheal aspirates at > or =10(6) colony-forming units/mL (p = .08, log-rank test; p = .05, Wilcoxon's test). The RIC device was associated with reduced colonization rate by days on the tube (p = .04, Wilcoxon's test) and in quantitative endotracheal aspirates (p = .05, Wilcoxon's test) at the same thresholds. The RIC device was associated with lower maximal bacterial burden in tracheal aspirates for 7 days (mean log-transformed burden, 4.2 +/- 2.3 vs. 5.5 +/- 1.7 log colony-forming units/mL; p = .02, Wilcoxon's test). Other between-group differences favored the RIC device but were not significant. Five adverse events were considered device related, including three events in the RIC group and two events in the control group. In this prospectively planned, preliminary analysis, the RIC device was feasible and well tolerated. Larger studies are needed to determine whether delayed colonization, reduced colonization rate, and decreased bacterial burden will decrease the incidence of ventilator-associated pneumonia.

Prospective Comparison of Bronchoalveolar Lavage and Quantitative Deep Tracheal Aspirate in the Diagnosis of Ventilator Associated Pneumonia

Ventilator associated pneumonia (VAP) is common in trauma patients, and accurate diagnosis of VAP may improve survival. With the risk of development of bacterial resistance, we also strive to minimize the use of unnecessary antibiotics. Recent studies suggest that quantitative deep endotracheal aspirate (QDEA) is adequate in VAP diagnosis. We currently use bronchoalveolar lavage (BAL) diagnosis. The purpose of this study was to examine the accuracy of QDEA as compared with BAL in diagnosing VAP in trauma patients. We prospectively compared the results of BAL and QDEA in intubated patients suspected of having VAP during an 8-month period. Indication for BAL was pulmonary infiltrate, systemic inflammatory response syndrome, and C-reactive protein >17 mg/dL at > or =48 hours after admission. Study patients underwent QDEA immediately before BAL, and quantitative cultures were compared for both specimens. The techniques differ in that QDEA involves the direct culture of sputum suctioned from the distal trachea, whereas BAL involves lavage of the bronchoalveolar tree with sterile saline, which is then cultured. VAP was diagnosed on BAL if > or =10(5) cfu/mL was present on culture. The ability of QDEA to diagnose pneumonia was examined at cutoffs of > or =10(5) cfu/mL and > or =10(4) cfu/mL, as compared with BAL at > or =10(5). Sixty-one patients underwent BAL during this period, and 39 of these underwent both BAL and QDEA for the study. Of the 39 studied patients between March 16, 2002, and November 4, 2002, 20 (51%) were found to have VAP by BAL (> or =10(5) cfu/mL). Using this cutoff for QDEA, 18 of 20 (90%) would have been correctly diagnosed. Using > or =10 cfu/mL for QDEA, the rate of correct diagnosis would increase to 19 of 20 (95%). However, of the 19 who did not have pneumonia according to BAL, 6 (31%) would have been incorrectly diagnosed with VAP using the QDEA cutoff of > or =10(5) cfu/mL. A QDEA cutoff of > or =10 (4) cfu/mL would result in the even higher false-positive rate of 8 of 19 patients (42%). Whereas most patients with pneumonia by BAL would have been diagnosed by QDEA, use of QDEA in treatment decisions would have led to needless antibiotic administration in 31% of VAP-negative patients at a cutoff of > or =10(5) cfu/mL and 42% at > or =10(4) cfu/mL. The use of QDEA in VAP diagnosis is limited because of the rate of over-diagnosis. With the increasing problems associated with excess antibiotic use, we believe these results support the use of BAL over QDEA in the diagnosis of VAP in the ventilated trauma patient.

Correlation of intracellular organisms with quantitative endotracheal aspirate.

The presence of intracellular organisms (ICOs) in polymorphonuclear cells obtained from respiratory secretions is a possible method for rapid diagnosis of ventilator-associated pneumonia. We correlated ICOs with quantitative endotracheal aspirate (QA) in intubated patients. Consecutive intubated patients in the surgical intensive care unit had respiratory samples obtained every 2 days until extubation. Two thresholds for ICOs and quantitative culture were examined. Sensitivity, specificity, and positive and negative predictive values were calculated using QA as reference. One hundred one samples were obtained from 35 patients. Colony counts >or= 100,000 were found in 34 samples; 60 samples had colony counts >or= 10,000. Antibiotic use did not affect the sensitivity or specificity of ICOs. Sensitivity of ICOs was 39% to 85%, and specificity was 82% to 97%. Positive predictive value was 70% to 96%, and negative predictive value was 50% to 91%. ICOs provide a quick method for establishing the presence of a significant bacterial load in the respiratory tract. Accuracy of ICOs in predicting a positive QA is not affected by concurrent antibiotics.

Nosocomial pneumonia: emerging concepts in diagnosis, management, and prophylaxis.

Nosocomial pneumonia is a dynamic disease with multiple etiologic agents and a changing natural history. The highest attack rates and mortality occur in patients with ventilator-associated pneumonia. Diagnosis of nosocomial pneumonia is often made by clinical criteria that are sensitive but lack specificity. The use of quantitative endotracheal aspirates or bronchoscopy with bronchoalveolar lavage and protected specimen brush clearly improve diagnostic specificity and outcome in patients who are mechanically ventilated. The rapid spread of multidrug-resistant, spp, and has made initial empiric therapy more difficult. Management principles include the use of techniques for more accurate diagnosis and early antimicrobial therapy with appropriate agents along with careful analysis of culture results, clinical response, and potential complications of pneumonia and therapy. Strategies for prophylaxis are of critical importance for risk reduction, improvement in patient outcome, and reduction of hospital costs.

Quantitative Culture of Endotracheal Aspirates in the Diagnosis of Ventilator-Associated Pneumonia in Patients With Treatment Failure

To study the correlation of bacteriology between quantitative cultures of protected specimen brush (PSB), BAL, and quantitative endotracheal aspirate (QEA) in ventilator-associated pneumonia (VAP) patients with treatment failure. Prospective observational clinical study. A 15-bed medical ICU of tertiary medical center. Forty-eight patients receiving mechanical ventilation with clinical suspected VAP who had been treated with antibiotics for at least 72 h without improvement. QEA, PSB, and BAL were performed with patients receiving antibiotics. The diagnostic thresholds for QEA, PSB, and BAL were 10(5), 10(3), and 10(4) cfu/mL, respectively. Microbial culture findings were positive in 24 BAL samples (50%), in 23 PSB samples (48%), and in 28 QEA samples (58%). The correlations between of QEA vs PSB and QEA vs BAL were significant (rho = 0.567 and rho = 0.620, p < 0.01, respectively). The most commonly isolated microorganisms were Acinetobacter baumannii (27%), Staphylococcus aureus (24%), Stenotrophomonas maltophilia (15%), and Pseudomonas aeruginosa (10%). Using the predetermined criteria, bacterial pneumonia was diagnosed in 28 of 48 suspected VAP episodes based on PSB and/or BAL results. The diagnostic efficiency of QEA at threshold of 10(5) cfu/mL had a sensitivity of 92.8% and a specificity of 80%. QEA correlated with PSB and BAL in patients with suspected VAP who responded poorly to the existent antibiotic treatment. QEA missed only two cases of bacterial pneumonia diagnosed by invasive PSB and/or BAL with acceptable sensitivity and specificity. More importantly, QEA is noninvasive and easily repeatable. Early use of QEA is helpful to clinical physicians in decision making with regard to antibiotics use.