Protected Bronchoalveolar Lavage Research Articles

The lower airways microbiota and antimicrobial peptides indicate dysbiosis in sarcoidosis

BackgroundThe role of the pulmonary microbiome in sarcoidosis is unknown. The objectives of this study were the following: (1) examine whether the pulmonary fungal and bacterial microbiota differed in patients with sarcoidosis compared with controls; (2) examine whether there was an association between the microbiota and levels of the antimicrobial peptides (AMPs) in protected bronchoalveolar lavage (PBAL).MethodsThirty-five sarcoidosis patients and 35 healthy controls underwent bronchoscopy and were sampled with oral wash (OW), protected BAL (PBAL), and left protected sterile brushes (LPSB). The fungal ITS1 region and the V3V4 region of the bacterial 16S rRNA gene were sequenced. Bioinformatic analyses were performed with QIIME 2. The AMPs secretory leucocyte protease inhibitor (SLPI) and human beta defensins 1 and 2 (hBD-1 and hBD-2), were measured in PBAL by enzyme-linked immunosorbent assay (ELISA).ResultsAspergillus dominated the PBAL samples in sarcoidosis. Differences in bacterial taxonomy were minor. There was no significant difference in fungal alpha diversity between sarcoidosis and controls, but the bacterial alpha diversity in sarcoidosis was significantly lower in OW (p = 0.047) and PBAL (p = 0.03) compared with controls. The beta diversity for sarcoidosis compared with controls differed for both fungi and bacteria. AMP levels were significantly lower in sarcoidosis compared to controls (SLPI and hBD-1: p < 0.01). No significant correlations were found between alpha diversity and AMPs.ConclusionsThe pulmonary fungal and bacterial microbiota in sarcoidosis differed from in controls. Lower antimicrobial peptides levels were seen in sarcoidosis, indicating an interaction between the microbiota and the innate immune system. Whether this dysbiosis represents a pathogenic mechanism in sarcoidosis needs to be confirmed in experimental studies.97YC8g-4seJ4v8ufGzjArAVideo

Repeated bronchoscopy in health and obstructive lung disease: is the airway microbiome stable?

ObjectiveLittle is known concerning the stability of the lower airway microbiome. We have compared the microbiota identified by repeated bronchoscopy in healthy subjects and patients with ostructive lung diseaseases (OLD).Methods21 healthy controls and 41 patients with OLD completed two bronchoscopies. In addition to negative controls (NCS) and oral wash (OW) samples, we gathered protected bronchoalveolar lavage in two fractions (PBAL1 and PBAL2) and protected specimen brushes (PSB). After DNA extraction, we amplified the V3V4 region of the 16S rRNA gene, and performed paired-end sequencing (Illumina MiSeq). Initial bioinformatic processing was carried out in the QIIME-2 pipeline, identifying amplicon sequence variants (ASVs) with the DADA2 algorithm. Potentially contaminating ASVs were identified and removed using the decontam package in R and the sequenced NCS.ResultsA final table of 551 ASVs consisted of 19 × 106 sequences. Alpha diversity was lower in the second exam for OW samples, and borderline lower for PBAL1, with larger differences in subjects not having received intercurrent antibiotics. Permutational tests of beta diversity indicated that within-individual changes were significantly lower than between-individual changes. A non-parametric trend test showed that differences in composition between the two exams (beta diversity) were largest in the PSBs, and that these differences followed a pattern of PSB > PBAL2 > PBAL1 > OW. Time between procedures was not associated with increased diversity.ConclusionThe airways microbiota varied between examinations. However, there is compositional microbiota stability within a person, beyond that of chance, supporting the notion of a transient airways microbiota with a possibly more stable individual core microbiome.

Comparative Evaluation of the Role of Nonbronchoscopic and Bronchoscopic Techniques of Distal Airway Sampling for the Diagnosis of Ventilator-Associated Pneumonia.

Background:The diagnosis of ventilator-associated pneumonia (VAP) remains a challenge, with clinicians mainly relying on clinical, radiological, and bacteriologic strategies to manage patients with VAP.Aims:To compare the results of non-bronchoscopic and bronchoscopic techniques of distal airway sampling for the diagnosis of VAP.Settings and Design:This was a single-center prospective diagnostic accuracy study done in the 14-bedded intensive care unit of a tertiary care referral hospital.Materials and Methods:Patients aged ≥18 years, on mechanical ventilation for ≥48 h, and with clinical suspicion of VAP (fever, leukocytosis, and increased tracheal secretions) either on admission or during their stay were included. Every patient underwent both procedures for sample collection, first non-bronchoscopic protected bronchoalveolar lavage (NP-BAL) and then bronchoscopic BAL (B-BAL). Clinical Pulmonary Infection Score (CPIS) was calculated for each patient and the collected samples were evaluated in laboratory using standard microbiological techniques.Statistical Analysis Used:The sensitivity, specificity, positive predictive value, and negative predictive value of NP-BAL and B-BAL for the diagnosis of VAP were calculated taking CPIS score of >6 as index test for the diagnosis of VAP.Results:Sixty patients were included in the study. Both NP-BAL and B-BAL had concordance with the CPIS at 69.1%. The concordance between NP-BAL and B-BAL was better at 67.6% with a kappa coefficient of 0.064 (P = −0.593). The yield and sensitivity of NP-BAL were comparable to that of B-BAL.Conclusions:The blind NP-BAL is an equally effective method of airway sampling and could be a better alternative to replace more invasive B-BAL for microbiologic diagnosis of VAP.

Laboratory contamination in airway microbiome studies

BackgroundThe low bacterial load in samples acquired from the lungs, have made studies on the airway microbiome vulnerable to contamination from bacterial DNA introduced during sampling and laboratory processing. We have examined the impact of laboratory contamination on samples collected from the lower airways by protected (through a sterile catheter) bronchoscopy and explored various in silico approaches to dealing with the contamination post-sequencing. Our analyses included quantitative PCR and targeted amplicon sequencing of the bacterial 16S rRNA gene.ResultsThe mean bacterial load varied by sample type for the 23 study subjects (oral wash>1st fraction of protected bronchoalveolar lavage>protected specimen brush>2nd fraction of protected bronchoalveolar lavage; p < 0.001). By comparison to a dilution series of know bacterial composition and load, an estimated 10–50% of the bacterial community profiles for lower airway samples could be traced back to contaminating bacterial DNA introduced from the laboratory. We determined the main source of laboratory contaminants to be the DNA extraction kit (FastDNA Spin Kit). The removal of contaminants identified using tools within the Decontam R package appeared to provide a balance between keeping and removing taxa found in both negative controls and study samples.ConclusionsThe influence of laboratory contamination will vary across airway microbiome studies. By reporting estimates of contaminant levels and taking use of contaminant identification tools (e.g. the Decontam R package) based on statistical models that limit the subjectivity of the researcher, the accuracy of inter-study comparisons can be improved.

Prevalence of Human Herpes Viruses in Bronchoalveolar Lavage of Critically Ill Children Undergoing Mechanical Ventilation at a Pediatric Intensive Care Unit

Background: Critically ill children at the intensive care unit frequently develop hospital-acquired pneumonia (HAP). Human herpes viruses (HHVs), primarily or by reactivation may cause bronchopneumonitis in mechanically ventilated patients. The exact prevalence and role of HHVs in morbidity and mortality of pediatric patients undergoing mechanical ventilation is unclear. The current study was conducted to evaluate the prevalence of 5 Herpes viruses by polymerase chain reaction (PCR) method in bronchoalveolar lavage (BAL) samples in critically ill children at a pediatric intensive care unit (PICU). Methods: Overall, 140 bronchoalveolar lavage samples from 83 mechanically ventilated cases were studied. Samples were taken via the mini-BAL technique. Samples were analyzed by qualitative PCR for detection of herpes simplex virus type 1 and 2 (HSV1/HSV2), human herpes virus type 6 and 7 (HHV6/HHV7), Ebstein-Barr virus (EBV), and cytomegalovirus (CMV). Results: Out of 83 cases, 53% (44) were male and 47% (39) were female. The mean age was 29.12 ± 33.67 months (32.53 months in males and 25.29 months in females). The estimated prevalence of HSV1, HHV6, HHV7, EBV, and CMV were 2.4%, 13.2%, 2.4%, 7.2%, and 2.4%, respectively. Conclusions: Molecular study of BAL specimens and investigation of HHVs may be the first step in the evaluation of the possible role of these viruses in the development of viral pneumonia during VAP. The current results are useful for guiding other well-designed studies for correlation of viral load and clinical outcome in ill ventilated children. The Modified protected BAL may be of use as a safe modality in critically ill ventilated pediatric patients for investigation of possible viral (and also bacterial and fungal) infections. Local study of high-risk patients at the PICU and estimation of the true prevalence of HHVs infection may assist in finding the exact role of HHVs in mortality and morbidity of critically ill patients.

Protected sampling is preferable in bronchoscopic studies of the airway microbiome.

The aim was to evaluate susceptibility of oropharyngeal contamination with various bronchoscopic sampling techniques.67 patients with obstructive lung disease and 58 control subjects underwent bronchoscopy with small-volume lavage (SVL) through the working channel, protected bronchoalveolar lavage (PBAL) and bilateral protected specimen brush (PSB) sampling. Subjects also provided an oral wash (OW) sample, and negative control samples were gathered for each bronchoscopy procedure. DNA encoding bacterial 16S ribosomal RNA was sequenced and bioinformatically processed to cluster into operational taxonomic units (OTU), assign taxonomy and obtain measures of diversity.The proportion of Proteobacteria increased, whereas Firmicutes diminished in the order OW, SVL, PBAL, PSB (p<0.01). The alpha-diversity decreased in the same order (p<0.01). Also, beta-diversity varied by sampling method (p<0.01), and visualisation of principal coordinates analyses indicated that differences in diversity were smaller between OW and SVL and OW and PBAL samples than for OW and the PSB samples. The order of sampling (left versus right first) did not influence alpha- or beta-diversity for PSB samples.Studies of the airway microbiota need to address the potential for oropharyngeal contamination, and protected sampling might represent an acceptable measure to minimise this problem.

Comparison between bronchoscopic BAL and non-bronchoscopic BAL in patients with VAP

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. Objective: To compare the diagnostic value of bronchoscopic BAL and non-bronchoscopic protected BAL in patients with VAP. Materials and methods: Twenty patients, clinically diagnosed with VAP, were involved in this research; they were evaluated by bronchoscopic and non-bronchoscopic BAL for diagnosis of VAP. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of bronchoscopic and non-bronchoscopic BAL were calculated, taking clinical pulmonary infection score (CPIS) of ⩾6 as reference standard. Results: There was a good microbiologic concordance and strong correlation between bronchoscopic BAL and non bronchoscopic BAL in diagnosis of VAP. There was a high concordance between CPIS score and both procedures’ results. Percentage of concordance between CPIS and bronchoscopic BAL was 97.5% and with non bronchoscopic BAL was 95%. Gram negative organisms were the commonest organisms isolated by both techniques. Conclusion: Non bronchoscopic BAL is an inexpensive, easy, and useful technique for microbiologic diagnosis of VAP. This finding, if verified, might simplify the approach for the diagnosis of VAP.

Bronchial Colonization in Patients with Non–Small Cell Lung Cancer / Kolonizacija bronha kod bolesnika sa nesitnoćelijskim karcinomom pluća

SUMMARY Lower airways are sterile, but many researchers have reported the existence of bronchial colonization with pathogenic and non-pathogenic microorganisms in smokers and patients with chronic obstructive pulmonary disease (COPD) and lung cancer. The aim of this study was to determine the existence and type of bronchial colonization in patients with non-small cell lung cancer (NSCLC), as well as to determine whether colonization depends on patient's age, smoking habit, pulmonary function and body mass index (BMI). Another aim was to estimate whether colonization causes early postoperative complications. Fifty-five subjects with pathohistologically confirmed non-small cell lung cancer in the resectable stage and good performance status (ECOG 0 or 1) participated in this cross-sectional study. We assessed patient's degree of smoking, calculated their BMI and determined the existence and severity of chronic obstructive pulmonary disease if there was one. The patients underwent a flexible bronchoscopy when biopsy samples were taken with protected specimen brush (PSB) and bronchoalveolar lavage (BAL); the retrieved samples were inoculated. Colonization was marked by an increase in the number of bacteria, yielding &gt;10³CFU⁄L. In our study, bronchial colonization was found in 21 patients (38%). Potentially pathogenic microorganisms were isolated in 13 patients (Streptococcus pneumonia was found in five patients, Streptococcus B haemoliticus and Pseudononans in three patients each, Haemophilus influencae and Enterobacter in one patient each). Potentially non-pathogenic microorganisms were isolated in 8 patients (Streptococcus viridans was found in 7 patients and Achromobacter xylosoxidans in 1 patient). Patients' sex, age, smoking habit, body mass index and severity of chronic obstructive pulmonary disease were not statistically significant for developing bronchial colonization. Only one operated patient developed postoperative pneumonia, but he had not previously been diagnosed with bronchial colonization

Pathogenic analysis of solid organ transplant recipients with pulmonary opportunistic infections via bronchoscopy

To evaluate the diagnostic utility of bronchoscopy in solid organ transplant recipients with pulmonary opportunistic infections. From December 2006 to September 2011, 117 cases of bronchoscopy with protected specimen brush and bronchoalveolar lavage were performed in 114 solid organ transplant recipients at Tianjin First Central Hospital. The indication for bronchoscopy was suspected pulmonary infections. The bronchoscopic manifestations were described and the specimens analyzed with regards to bacteriology, cytomegalovirus, P carinii, mycobacterium tuberculosis and other fungal cultures. A definite infectious etiology was confirmed in 63 patients (53.8%). And opportunistic infections were the most frequent etiology (56/63, 88.9% including 7 cases with two mixed opportunistic infections). Among 63 pathogens, P carinii was demonstrated in 36 episodes, cytomegalovirus in 24 episodes and mycobacterium tuberculosis in 3 episodes. Bacterial infections (mainly Gram-negative) accounted for 16 of 63 episodes (25.9% including 9 cases with mixed opportunistic/bacterial infection). In accordance with the diagnostic results, antibiotic treatment was changed in 45 cases. As an extremely useful tool, bronchoscopy is of great value for pathogenic detection in transplant recipients with suspected pulmonary infections, especially for opportunistic infections. And the bronchoscopic findings may guide targeted antimicrobial therapy.

Evaluación de la concordancia entre dos métodos de lavado broncoalveolar para el diagnóstico microbiológico de la neumonía en pacientes con asistencia respiratoria mecánica

Microbiological diagnosis of pneumonia allows the optimal use of antibiotics in mechanically ventilated patients. That is why samples of bronchoscopic bronchoalveolar lavage had been quantitatively cultivated, but this procedure is not always possible. To evaluate the microbiological concordance between respiratory samples obtained by non-bronchoscopic protected bronchoalveolar lavage compared to the bronchoscopic ones, and to find out whether concordance was affected by previous use of antibiotics or the time of pneumonia onset. Prospective study conducted at Hospital Universitario San Vicente de Paúl, in 38 patients with suspected pneumonia in mechanical ventilation. Bronchoalveolar lavage specimens were taken by two methods, the traditional one and non-bronchoscopic bronchoalveolar lavage, using a telescoping preformed tip catheter (Balcath). All samples were processed using conventional microbiologic protocols. Considering flexible bronchoscopy with bronchoalveolar lavage as the gold standard, cultures allowed the identification of at least one respiratory pathogen in 60.5% of cases. Diagnostic agreement was achieved in 82% of patients and 79% of microbiologic isolates. Using the Cohen's kappa coefficient, general concordance between both methods was 0.76 [0.60-0.93]; but in those who received previously antibiotics was 0.26 [0.05-0.48], versus 1.0 in those who did not (p<0.0001). Concordance did not differ significantly when cases of early or late pneumonia were compared. Concordance between non-bronchoscopic and bronchoscopic bronchoalveolar lavage is good in mechanically ventilated patients with pneumonia. However, the use of antibiotics previously, but not the time of pneumonia presentation, significantly decreases that concordance.

Bronchoscopic diagnosis of pulmonary infiltrates in granulocytopenic patients with hematologic malignancies: BAL versus PSB and PBAL

Treatment of patients with hematologic malignancies is often complicated by severe respiratory infections. Bronchoscopy is generally to be used as a diagnostic tool in order to find a causative pathogen. In a prospective study the combination of protected specimen brush (PSB) and protected bronchoalveolar lavage (PBAL) was compared with bronchoalveolar lavage (BAL) for evaluated feasibility and diagnostic yield in granulocytopenic patients with hematologic malignancies and pulmonary infiltrates. All specimens from 63 bronchoscopic procedures (35 BAL and 28 PSB-PBAL) were investigated by cytological examination and various microbiological tests. If clinically relevant and feasible, based on the clinical condition and/or the presence of thrombocytopenia, lung tissue samples were obtained. The majority of the 58 included patients were diagnosed as having acute myeloid leukaemia and developed a severe neutropenia (BAL-group: 27 days; PSB-PBAL group: 30 days). Microbiological and cytological examination of 63 bronchoscopic procedures (35 BAL and 28 PSB-PBAL) yielded causative pathogens in 9 (26%) patients of the BAL-group and 8 (29%) patients of the PSB-PBAL group (PSB and PBAL 4 each). Aspergillus fumigatus was the pathogen most frequently (13%) detected. Using all available examinations including the results of autopsy, a presumptive diagnosis was established in 43% of the patients in the BAL group and 57% of those in the PSB-PBAL group; in these cases microbial aetiology was correctly identified in 67% and 57%, respectively. The complication rate was of these procedures were low, and none of the patients experienced serious complications due to the invasive techniques. Our results showed that modern bronchoscopic techniques such as PSB and PBAL did not yield better diagnostic results compared to BAL in granulocytopenic patients with hematologic malignancies and pulmonary infiltrates. In approximately half of the cases a presumptive diagnosis was made by bronchoscopic procedures.

NOSOCOMIAL PNEUMONIA IN ELDERLY PATIENTS FOLLOWING CARDIAC SURGERY

Summary Objective To identify modifiable risk factors of nosocomial pneumonia (NP) in elderly patients post-cardiac surgery. Design A case-control study. Setting Post-operative intensive care unit of a tertiary-level university affiliated hospital. Subjects Seventy three case-control pairs. Case patients referred to elderly patients who developed pneumonia post-cardiac surgery. Controls subjects were matched for age, gender, type of surgery, forced expiratory volume in 1s (FEV 1 ), and ejection fraction. Measurements Baseline sociodemograpahic information, Charlson Comorbidity Index score, intra- and post-operative data were collected. When suspected, the presence of NP was confirmed by quantitative culture of protected bronchoalveolar lavage fluid ⩾10 3 colony forming unit/ml or positive blood/pleural fluid culture identical to that recovered from respiratory samples. Results The incidence of NP in elderly post-heart surgery was 8.3%. The mean duration after heart surgery to the occurrence of pneumonia was 7.2±4.9 days. Four variables were found to be significantly related to the development of NP by multivariate analysis: Charlson Index >2 (adjusted odds ratio [AOR] 4.7; 95% confidence interval [CI], 1.9–11.4; P 0.001 ), reintubation (AOR 6.2; 95% CI, 1.1–36.1; P = 0.04 ), transfusion ⩾4 units of PRBC (AOR 2.8; 95% CI, 1.2–6.3; P = 0.01 ), and the mean equivalent daily dose of morphine (AOR 4.6; 95% CI, 1.4–14.6; P = 0.01 ). Conclusions Although there are limited effective measures to lessen the burden of comorbidities, avoiding reintubation, finding a substitute to allogenic blood transfusion, and improved assessment of pain management could reduce the rate of NP in the post-operative period of cardiac surgery in the elderly population.

Nosocomial pneumonia in elderly patients following cardiac surgery

To identify modifiable risk factors of nosocomial pneumonia (NP) in elderly patients post-cardiac surgery. A case-control study. Post-operative intensive care unit of a tertiary-level university affiliated hospital. Seventy three case-control pairs. Case patients referred to elderly patients who developed pneumonia post-cardiac surgery. Controls subjects were matched for age, gender, type of surgery, forced expiratory volume in 1s (FEV(1)), and ejection fraction. Baseline sociodemograpahic information, Charlson Comorbidity Index score, intra- and post-operative data were collected. When suspected, the presence of NP was confirmed by quantitative culture of protected bronchoalveolar lavage fluid 10(3) colony forming unit/ml or positive blood/pleural fluid culture identical to that recovered from respiratory samples. The incidence of NP in elderly post-heart surgery was 8.3%. The mean duration after heart surgery to the occurrence of pneumonia was 7.2+/-4.9 days. Four variables were found to be significantly related to the development of NP by multivariate analysis: Charlson Index >2 (adjusted odds ratio [AOR] 4.7; 95% confidence interval [CI], 1.9-11.4; P<0.001), reintubation (AOR 6.2; 95% CI, 1.1-36.1; P=0.04), transfusion 4 units of PRBC (AOR 2.8; 95% CI, 1.2-6.3; P=0.01), and the mean equivalent daily dose of morphine (AOR 4.6; 95% CI, 1.4-14.6; P=0.01). Although there are limited effective measures to lessen the burden of comorbidities, avoiding reintubation, finding a substitute to allogenic blood transfusion, and improved assessment of pain management could reduce the rate of NP in the post-operative period of cardiac surgery in the elderly population.

Indicators of potentially drug-resistant bacteria in severe nursing home-acquired pneumonia.

Knowledge of the determinant factors responsible for the presence of antimicrobial-resistant pathogens in severe nursing home-acquired pneumonia (NHAP) is deemed essential for antibiotic selection. Data for institutionalized patients with cases of severe pneumonia confirmed by culture of protected bronchoalveolar lavage fluid samples (> or =10(3) cfu/mL) during a 36-month period were analyzed. A classification tree with a sensitivity of 100% was developed using binary recursive partitioning to predict which patients are unlikely to have drug-resistant pathogen (DRP)-related pneumonia. Of the 88 patients who satisfied the inclusion criteria, 17 had at least 1 DRP recovered from the lower respiratory tract. The predictor variables were the Activity of Daily Living score and previous use of antibiotics. Prospective application of the model in 47 patients over a 24-month period yielded a sensitivity of 100% (95% confidence interval [CI], 71.3%-100%) and a specificity of 69.4% (95% CI, 51.9%-83.6%). The use of the tree may provide a more rational basis for selecting initial therapy for severe NHAP after it is validated in a large prospective study.

Diagnosis of Ventilator‐Associated Pneumonia: Where Do We Go from Here?

Diagnosis of Ventilator‐Associated Pneumonia: Where Do We Go from Here?

An evaluation of the Gram stain in protected bronchoalveolar lavage fluid for the early diagnosis of ventilator-associated pneumonia.

We investigated the usefulness and reliability of the Gram stain value versus quantitative cultures in the early diagnosis of ventilator-associated pneumonia (VAP) using the protected bronchoalveolar lavage (PBAL). One hundred four mechanically ventilated patients (age = 52 +/- 19; SAPS II = 38 +/- 15) with a strong suspicion of VAP were consecutively included. One hundred sixteen PBAL were performed and mini-bronchoalveolar lavage were analyzed using the Gram stain standard method and the conventional quantitative culture technique. VAP diagnosis was based on a positive quantitative culture of mini-bronchoalveolar lavage fluid (cutoff > or = 10(3) CFU/mL). A final diagnosis of VAP was established in 67 patients and there was no infection in 49 cases. Regarding detection of bacteria using the Gram stain, we found a sensitivity of 76.2%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 75.4%. There was a good agreement with the final diagnosis (kappa statistic 0.73; concordance 86.2%). The degree of qualitative agreement between Gram stain and quantitative cultures was analyzed in the VAP group: the correlation was complete in 39% (26 of 67 VAP), partial in 28% (19 of 67 VAP) and there was no correlation in 33% (22 of 67 VAP). We conclude that despite its overall "good agreement," the Gram stain is of limited use for the rapid diagnosis of VAP and unreliable for the early adaptation of empirical antimicrobial therapy when using the noninvasive PBAL procedure.

An Evaluation of the Gram Stain in Protected Bronchoalveolar Lavage Fluid for the Early Diagnosis of Ventilator-Associated Pneumonia

Implications We investigated the reliability of direct examination versus quantitative cultures in the early diagnosis of ventilator-associated pneumonia using the protected bronchoalveolar lavage in 104 patients. Regarding detection of bacteria using the Gram stain, we found low sensitivity and negative predictive value and high specificity and positive predictive value. We investigated the usefulness and reliability of the Gram stain value versus quantitative cultures in the early diagnosis of ventilator-associated pneumonia (VAP) using the protected bronchoalveolar lavage (PBAL). One hundred four mechanically ventilated patients (age = 52 ± 19; SAPS II = 38 ± 15) with a strong suspicion of VAP were consecutively included. One hundred sixteen PBAL were performed and mini-bronchoalveolar lavage were analyzed using the Gram stain standard method and the conventional quantitative culture technique. VAP diagnosis was based on a positive quantitative culture of mini-bronchoalveolar lavage fluid (cutoff ≥ 103 CFU/mL). A final diagnosis of VAP was established in 67 patients and there was no infection in 49 cases. Regarding detection of bacteria using the Gram stain, we found a sensitivity of 76.2%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 75.4%. There was a good agreement with the final diagnosis (kappa statistic 0.73; concordance 86.2%). The degree of qualitative agreement between Gram stain and quantitative cultures was analyzed in the VAP group: the correlation was complete in 39% (26 of 67 VAP), partial in 28% (19 of 67 VAP) and there was no correlation in 33% (22 of 67 VAP). We conclude that despite its overall “good agreement,” the Gram stain is of limited use for the rapid diagnosis of VAP and unreliable for the early adaptation of empirical antimicrobial therapy when using the noninvasive PBAL procedure.

Protected Bronchoalveolar Lavage for the Diagnosis of HIV-Associated Pneumonia

Abstract: The aim of protected bronchoalveolar lavage (PBAL) is to improve the diagnostic yield in bacterial pneumonia by combining the high sensitivity of bronchoalveolar lavage (BAL) with the specificity of the protected specimen brush (PSB). We evaluated PBAL and PSB in patients infected with human immunodeficiency virus (HIV) known to have a high incidence of bacterial pneumonia and colonization of the tracheohronchial tree. Sixty-three consecutive episodes with symptoms suggestive of pneumonia were investigated prospeetively. A comprehensive microbiologic workup was performed, including quantitative cultures for bacterial agents. Each episode was classified as “pneumonia,” “control,” or “non-infectious infiltrates.” Fifty-one episodes were identified as pneumonia. A definite microbial etiology could be established in 34/51 (67% cases, including a bacterial etiology in 15/51 (29%). The sensitivity for definite and probable bacterial pneumonia was 13/22 (59%) for PSB and 15/22 (68%) for PBAL (p value not significant). Specificity was 8/8 (100%), but there were 4 false-positive results in cultures of PSB and in cultures of PBAL effluent in patients with infiltrates on chest radio-graphs. PBAL effluent had a significantly higher mean bacterial index and specific bacterial index than PSB (5.4 ± 4.9 vs. 3.3 ± 3.2, p < 0.01, and 5.6 ± 0.8 vs. 3.8 ± 2.1. p < 0.001). The yield for Pneumocystis carinii was 13/15 (87%). PBAL, as compared to PSB, had a similar diagnostic yield for bacterial pneumonia. Both techniques were highly specific, but the specificity may be lower in patients with abnormal chest radiographs. PBAL most accurately reflected the bacterial load of the area investigated, and also conserved the yield of BAL reported for P. carinii. PBAL is a rational technique for the diagnosis of pneumonia in patients with HIV.

A new bronchoscopic technique for the diagnosis of bacterial pneumonia in HIV-positive patients

The aim of the present study was to evaluate in HIV-positive patients with bacterial pneumonia, the diagnostic value of a new endoscopic technique that uses a single catheter to perform a telescopic plugged catheter (TPC) followed by a modified protected bronchoalveolar lavage (mpBAL). Fifty-eight HIV-positive patients with respiratory infection were included in the study. Samples from TPC and mpBAL were cultured quantitatively. Standard bronchoalveolar lavage was performed to rule out opportunistic infections. According to the clinical and microbiological results, patients were classified in the study group (27 with bacterial pneumonia) or the control group (31 without bacterial pneumonia). Sensitivity of TPC was 56% [95% confidence intervals (CI) 37–75%] and its specificity was 100%; these figures were 56% (CI, 37–75%) and 94% (CI, 86–100%) for mpBAL. When both techniques were assessed together, sensitivity increased to 70% (CI, 53–87%). The use of a single catheter reduced the cost of the originally described pBAL procedure by approximately 50%. The use of a single catheter to perform a TPC followed by a mpBAL can improve the diagnostic yield in HIV-positive patients with bacterial pneumonia, and reduces its cost.

Diagnostic yield and therapeutic impact of flexible bronchoscopy in lung transplant recipients

BACKGROUND Bronchoalveolar lavage and transbronchial biopsy are often used for definitive diagnosis of lung rejection and infection in lung transplant recipients. Although protected specimen brushing is of value in nosocomial bacterial pneumonia, its role in lung transplant recipients had not been widely reported. The aim of the study is to review the diagnostic yield and therapeutic impact of flexible bronchoscopy with the use of a combination of bronchoalveolar lavage, protected specimen brushing, and transbronchial biopsy in lung transplant recipients. METHODS We reviewed flexible bronchoscopy data in 83 transplant recipients between February 1990 and March 1995. Only those with bronchoalveolar lavage, protected specimen brushing, and transbronchial biopsy were included in the analysis. There were 282 bronchoscopies performed for clinically suspected lung rejection or infection (clinical bronchoscopy) and 38 bronchoscopies for follow-up of a previously detected histologic abnormality (follow-up bronchoscopy). RESULTS The total yields for rejection and infection for clinical and follow-up bronchoscopies were 67.4% and 58.9%, respectively. Acute rejection was detected with transbronchial biopsy in 26.2% and 34.2% of clinical and follow-up bronchoscopies, respectively. Cytomegalovirus pneumonitis was detected with transbronchial biopsy in 4.0% and 11.4% of clinical and follow-up bronchoscopies, respectively. Overall, bacteria was the most common cause of lower respiratory tract infection. When used together, protected specimen brushing and bronchoalveolar lavage were complementary techniques for detection of bacterial lower respiratory tract infection with a significantly higher proportion detected with protected specimen brushing ( > or = 10(3) colony forming units/ml) compared with bronchoalveolar lavage ( > or = 10(5) colony forming units/ml) (p < 0.001). Complications were hemorrhage (1.9%), pneumothorax (2.5%) and transient hypoxemia (10.5%). The results had an impact on management of rejection and infection in 57.8% of clinical and 39.5% of follow-up bronchoscopies. CONCLUSIONS We conclude that bronchoscopy, with the use of a combination of bronchoalveolar lavage, protected specimen brushing, and transbronchial biopsy, is safe with a high diagnostic yield and therapeutic impact for treating lung transplant recipients.