Implementation of Bronchoscopic Techniques in the Diagnosis of Ventilator-associated Pneumonia to Reduce Antibiotic Use

Abstract

In intensive care units, a large proportion of antibiotics are prescribed for presumed episodes of ventilator-associated pneumonia (VAP). VAP is usually diagnosed on a combination of clinical, radiographic, and microbiologic criteria with a high sensitivity but low specificity for VAP. As a result, patients may receive antibiotics unnecessarily. Specificity can be increased by the addition of quantitative cultures of samples of protected specimen brush (PSB) and bronchoalveolar lavage (BAL) to the diagnostic criteria. We prospectively analyzed the effects of implementation of PSB and BAL in the diagnosis of VAP on antibiotic prescription. PSB and/or BAL were performed in patients who fulfilled the clinical, radiographic, and microbiologic criteria for VAP. Based on quantitative cultures of PSB and/or BAL, patients were categorized into three groups: VAP microbiologically proven (Group 1; n = 72); clinical suspicion of VAP not confirmed microbiologically (Group 2; n = 66); and patients in whom bronchoscopy could not be performed (Group 3; n = 17). In Group 1, antibiotic therapy was instituted empirically in 40 patients (56%) (Group 1a) and after obtaining culture results in the other 32 patients (Group lb). Adjustment of therapy, based on culture results, occurred in 14 (35%) patients in Group la. In Group 2 empiric therapy was instituted in 34 (52%) patients (Group 2a) and dIscontinued within 48 h in 17 of them (50%). In Group 3, 17 (100%) patients were treated with antibiotics. Among the 66 patients in whom a clinical suspicion of VAP was not confirmed, only 18 (27%) were treated with antibiotics, and antibiotic therapy was withheld in 48 (35%) of 138 patients who underwent bronchoscopy. Withholding of antibiotic therapy had no negative effect on the recurrence of a clinical suspicion of VAP or on mortality rates. We conclude that addition of bronchoscopic techniques to the criteria for VAP may help to reduce antibiotic use. However, the definite benefits and cost-effectiveness of these techniques should be analyzed in a randomized study.

Ventilator-Associated Pneumonia

“…As such, negative invasive test results ostensibly identify patients who can have antibiotic drug therapy safely discontinued, whereas positive test results indicate a requirement for continued treatment. Despite the lack of demonstrable mortality benefit, this approach seems to reduce antimicrobial use [59][60][61] and might lead to reduced total cost of care and less antibiotic resistance. Two studies 60,61 analyzing total cost of care of invasive diagnosis reached discordant conclusions principally on the basis of antimicrobial cost difference; both used bronchoscopy, adding substantially to the cost of diagnosis.…”

Appropriateness and delay to initiate therapy in ventilator-associated pneumonia

“…Outcome studies indicate that there are several factors related to mortality in VAP [2][3][4][5][6]. Delay in the initiation of therapy in pneumonia increases the risk of death in both community-acquired and nosocomial pneumonia [7,8].…”

Non-Ventilator ICU-Acquired Pneumonia After Cardiothoracic Surgery: Accuracy of Diagnostic Tools and Outcomes

“…Importantly, negative microbiological results did not lead the physicians to discontinue empirical antibiotic therapy. 4 Nevertheless, several studies have confirmed that empirical antibiotics can be safely discontinued after 72 h or completely withheld 6,[31][32][33] with no adverse effect on VAP recurrence or mortality in subjects with negative cultures. Invasive diagnostic testing may increase physician confidence and provide valuable guidance for deciding whether to limit or discontinue antibiotic treatment.…”