Original ContributionsAn emergency department–based randomized trial of nonbronchoscopic bronchoalveolar lavage for early pathogen identification in severe community-acquired pneumonia*,**,★
Introduction
Pneumonia is the leading cause of infectious disease–related mortality in the United States,1 resulting in approximately 500,000 hospitalizations and 45,000 deaths annually.2 With regard to diagnostic strategies for community-acquired pneumonia (CAP), the basic infectious disease principle that the identification of underlying pathogens leads to more specific and effective treatment plans is generally not supported.3 American Thoracic Society guidelines recommend presumptive therapy without an aggressive search for the underlying pathogens.4 Guidelines endorsed by the Infectious Disease Society of America have diverged from this approach in recent years, recommending sputum culture, Gram stain, and pretreatment blood culture testing for patients requiring hospitalization.2 However, routine blood and sputum cultures are insensitive tests for severe CAP (SCAP) pathogen identification.5, 6, 7, 8, 9, 10, 11, 12 Furthermore, sputum cultures may provide misleading information when contaminated with upper airway flora.2, 13 Because of these difficulties encountered during standard efforts to isolate true pathogens for SCAP, treatment for pneumonia is still largely empiric and based on the most likely causes according to patient age, underlying illness, clinical history, and radiographic appearance. Compared with noninvasive modalities, the more invasive techniques of bronchoscopy with protected brushing and lung biopsy provide far more accurate and reliable information about the causes of pneumonia,14, 15, 16, 17, 18, 19 but they have generally not been found to be cost-effective compared with the empiric therapy approach. Furthermore, these invasive techniques are generally performed by specialist physicians and may be difficult to arrange on a consistent and widespread basis in most hospitals.
Bronchoalveolar lavage (BAL) catheterization has been shown to be an inexpensive, safe, and effective alternative to traditional bronchoscopic techniques in the diagnosis of ventilator-associated pneumonia (VAP).20, 21, 22, 23, 24 BAL catheterization can be performed at the bedside by respiratory therapists or nonpulmonary physicians, in contrast to traditional bronchoscopy, which generally requires dedicated facilities and the involvement of a pulmonologist. With a thin, directional (right lung versus left lung), telescoping inner cannula analogous to a protected brush, BAL catheterization provides for relatively simple lavage and sampling of the lower airways in tracheally intubated patients. Additionally, the BAL catheter diameter is much smaller than that of a standard bronchoscope, allowing for easier ventilation during the procedure.
The purpose of this study was to determine whether the institution of a protocol with early emergency department–based BAL catheterization would lead to improved diagnostically useful information in the treatment of tracheally intubated patients with SCAP. Specifically, we hypothesized that in patients randomized to standard care plus BAL catheterization, we would more commonly identify the causative organisms of pneumonia when compared with patients randomized to standard care alone. Additionally, we hypothesized that this increased yield of organisms would more often lead to changes in antibiotic therapy, especially changes to tailored therapy for specific isolated pathogens. Finally, we proposed that this technique could be enacted in the ED setting without significant complications and without delaying the delivery of first-dose antibiotics.
Section snippets
Materials and methods
The study protocol was approved by the hospital's institutional review board committee. This study was conducted from March 1998 through October 1999 in the ED of an urban county hospital (annual census, approximately 125,000). During this time period, we evaluated all adult patients who were admitted with a diagnosis of SCAP, were ventilated with an endotracheal tube or a tracheostomy, and had consent obtainable from a family member or other surrogate. Exclusion criteria were any antibiotic
Results
Of the 64 patients initially evaluated for study participation, 26 met all eligibility criteria. Fourteen patients were excluded because of antibiotic therapy within the past 5 days, 14 were too hypoxic or died too rapidly for study participation, and consent was unobtainable in 10 patients. Of the 26 patients enrolled in the study, 14 patients were randomized to receive standard care, and 12 patients were randomized to the standard care plus BAL catheterization group (see Figure for flow
Discussion
In this prospective randomized trial, pathogens causing SCAP were identified in a significantly higher percentage of patients who received standard care plus BAL catheterization compared with patients who received standard care alone. Although we noted no significant difference between the 2 groups in overall changes in antibiotic regimens, we did observe significantly more antibiotic regimen changes in the BAL group when a positive culture was obtained. The BAL catheterization procedure was
Acknowledgements
Author contributions: All authors contributed to the design and implementation of the study. RMR and MP were the primary writers of the manuscript, while the other authors reviewed the manuscript and made suggestions for its revision. RMR takes overall responsibility for the paper.
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Cited by (0)
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Author contributions are provided at the end of this article.
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Catheters for this study were supplied by Ballard Medical Products, Inc., Draper, UT.
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Address for reprints: Robert M. Rodriguez, MD, Alameda County Medical Center, Highland Hospital Campus, Department of Emergency Medicine, 1411 East 31st Street, Oakland, CA 94602; 510-437-8394, fax 510-308-3959; E-mail,[email protected]