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

Common respiratory viral infections: Bilateral versus unilateral bronchoalveolar lavage versus endotracheal aspiration

Data about the diagnostic efficiency of bilateral bronchoalveolar lavage (BAL) samples and endotracheal aspirates (EA) testing for common viral respiratory infections are scarce. We analyzed data from 167 cases, where bilateral BAL samples were tested, and from 101 cases, where BAL samples and EA were tested. Multiplex polymerase chain reaction (PCR) was performed with the fast track diagnostics viral respiratory panel, producing data on the adenovirus, coronavirus, enterovirus, human metapneumovirus, bocavirus, influenza virus, parainfluenza virus, rhinovirus, and respiratory syncytial virus status of patients with respiratory disease symptoms. In the bilateral BAL cohort, 46 (27.5%) cases were positive for at least one of the viruses mentioned above in both samples. Discrepant results (virus not detected on one side) were seen in six (3.6%) cases. In the BAL versus EA cohort, 12 (11.9%) cases were positive in both materials, discrepant results (only one material being positive) were observed in 11 (10.9%) cases, with seven (63.6%) BAL samples, and four (36.4%) EA being positive. Bilateral sampling does not significantly improve the diagnostic efficiency of BAL for the detection of common respiratory viral pathogens via PCR. The diagnostic quality of EA and BAL samples for the detection of common viral respiratory pathogens is comparable.

Diagnostic Yield of Bronchoalveolar Lavage in Immunocompromised Children

Results from early studies in the diagnostic yield of bronchoalveolar lavage (BAL) in immunocompromised adults and children were variable. This prospective study aimed to determine the diagnostic yield of BALs in immunocompromised children over the first 18 months of service at a newly established children's hospital. Relationship between BAL results and changes in antimicrobial management was also studied. Twenty-one bronchoscopic BALs were performed on 18 children; 14 BALs (66.7%) yielded at least 1 pathogen and 7 (33.3%) yielded no pathogen. Two pathogens were found in 2 samples, and 1 pathogen was identified in 12 samples. Bacteria (n = 7 patients), viruses (n = 8 patients) and fungus (Pneumocycstis jirovecii in one patient) were yielded. Of the 21 BALs, 8 (38.1%) were associated with changes in antimicrobial management (Fisher's exact test, p = 0.018). No significant side effects such as pneumothorax or pulmonary hemorrhages were observed in this series. In conclusion, BAL in immunocompromised children is rewarding and has potential to impact on antimicrobial management.

The Effect of Lung Lavage Volume Return on the Diagnosis of Ventilator-Associated Pneumonia

BACKGROUND

Bronchoalveolar lavage (BAL) is a commonly used tool in the diagnosis of ventilator-associated pneumonia (VAP). Previous protocols recommend 30% lavage return, though no studies have investigated this relationship. This study aims to assess the influence of BAL volume return on VAP diagnosis.

MATERIALS AND METHODS

A retrospective review was performed of a prospectively maintained database for BAL performed from January 2015 to January 2016 in the trauma and surgical ICU at a level 1 trauma center. In total, 147 ventilated patients with clinical suspicion for pneumonia underwent 264 BALs. A protocol was used with five aliquots of 20 cc of saline instilled. Quantitative cultures were performed with 10ˆ5 colony-forming organisms as the threshold for VAP diagnosis. BAL was repeated at 6-8 d on 50 patients. Univariate and multivariate regression analyses were performed to investigate the predictors of VAP diagnosis.

RESULTS

Patients with >40% lavage return had increased rates of VAP diagnosis (odds ratio [OR] 2.86, P = 0.002). Increasing volume return also trended toward a lower false-negative rate. Temperature, leukocytosis, and X-ray infiltrate were not associated with increased VAP diagnosis. Concurrent antibiotic therapy at the time of BAL predicted decreased VAP diagnosis (OR 0.58, P = 0.04). On multivariable analysis, only >40% return remained associated with increased rate of VAP diagnosis (OR 4.00, P = 0.004).

CONCLUSIONS

This study found that >40% lavage volume return was associated with increased VAP diagnosis. Clinicians should consider the reliability of a negative BAL if clinical suspicion of VAP is high and lavage return is <40%. Additional investigation is needed to further elucidate this association.