Does This Patient Have Ventilator-Associated Pneumonia?

Klompas, Michael MD

Durham Veterans Affairs Medical Center and Duke University Medical Center, Durham, NC (Simel)
Deputy Editor, JAMA. (Rennie)
Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; and Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Health Care, Boston.

Corresponding Author: Michael Klompas, MD, Brigham and Women's Hospital, Division of Infectious Diseases, 15 Francis St, PBB-4, Boston, MA 02115 ([email protected]).

Author Contributions: Dr Klompas had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design; acquisition of data; analysis and interpretation of data; drafting of the manuscript; critical revision of the manuscript for important intellectual content; statistical analysis: Klompas.

Financial Disclosures: None reported.

Acknowledgment: I thank Richard Platt, MD, MSc (Harvard Medical School), Karen Welty-Wolfe, MD (Duke University), and L. Brett Caram, MD (Duke University), for thoughtful advice on an earlier version of this article. None of these individuals received any compensation for their contributions

JAMA: The Journal of the American Medical Association 297(14):p 1583-1593, April 11, 2007.

Context

Ventilator-associated pneumonia (VAP) is a common and serious nosocomial infection. Accurate, timely diagnosis enables affected patients to receive appropriate therapy and avoids mistreatment of patients having other conditions.

Objective

To review the published medical literature describing the precision and accuracy of clinical, radiographic, and laboratory data to diagnose bacterial VAP relative to a histological gold standard.

Data Sources

English-language articles identified by a structured search strategy using MEDLINE (January 1966–October 31, 2006) and Google Scholar. Additional articles were identified through the reference lists of studies and review papers identified by the search strategy.

Study Selection

Included studies described clinical findings associated with VAP in 25 or more patients receiving mechanical ventilation who subsequently underwent pulmonary biopsy or autopsy. Fourteen studies describing clinical findings in 655 patients met inclusion criteria.

Data Extraction

Data were abstracted onto a structured form, allowing calculation of the likelihood ratios (LRs) for each sign or combination of findings.

Data Synthesis

The presence or absence of fever, abnormal white blood cell count, or purulent pulmonary secretions do not substantively alter the probability of VAP. However, the combination of a new radiographic infiltrate with at least 2 of fever, leukocytosis, or purulent sputum increases the likelihood of VAP (summary LR, 2.8; 95% confidence interval, 0.97–7.9). The absence of a new infiltrate on a plain chest radiograph lowers the likelihood of VAP (summary LR, 0.35; 95% confidence interval, 0.14–0.87). Fewer than 50% neutrophils on cell count analysis of lower pulmonary secretions makes VAP unlikely (LR range, 0.05–0.10).

Conclusions

Routine bedside evaluation coupled with radiographic information provides suggestive but not definitive evidence that VAP is present or absent. Given the severity of VAP and the frequency of serious conditions that can mimic VAP, clinicians should be ready to consider additional tests that provide further evidence for VAP or that establish another diagnosis.