Safety of De-Escalating Empiric Antimicrobial Agents in Trauma Patients with Indigenous Oral Flora Ventilator-Associated Pneumonia

Background: Ventilator-associated pneumonia (VAP) is a frequently occurring nosocomial infection in critically ill trauma patients. When bronchoalveolar lavage (BAL) returns with indigenous oral flora (IOF), de-escalating antimicrobial therapy is challenging. Patients and Methods: This is a retrospective review of trauma patients who received broad-spectrum empiric antimicrobial therapy for clinical VAP, and whose BAL culture resulted with >100,000 CFU/mL of IOF from September 1, 2017 to September 1, 2020. Patients were identified using the trauma database and microbiology reports of BALs with IOF. This review evaluated the effect of antibiotic de-escalation on recurrent or persistent pneumonia. Results: Of 51 trauma patients with clinical VAP and IOF, 18 patients (35.3%) had antimicrobial agents de-escalated. De-escalation was driven primarily by the discontinuation of vancomycin, with the continuation of a β-lactam antibiotic as monotherapy for the remainder of the treatment course (n = 15; 86.7%). The overall rate of either persistent or recurrent VAP in the cohort was 10%, and this did not differ statistically between those who received de-escalation therapy after isolation of IOF and those who did not (16.7% vs. 6.1%; p = 0.224), however, the incidence of acute kidney injury (AKI) was higher in the non-de-escalation group (39.4% vs. 11.1%; p = 0.034). There was no statistical difference in ventilator days, intensive care unit (ICU) length of stay, or hospital length of stay between treatment groups. Conclusions: Trauma patients who develop VAP with isolated BAL cultures of IOF or mixed flora can safely have anti-methicilllin-resistant Staphylococcus aureus (MRSA) antimicrobial agents discontinued, and this may result in decreased rates of AKI.

Risk stratification for the development of a subsequent pneumonia after a nondiagnostic bronchoalveolar lavage

BACKGROUND

Broncho-alveolar lavage (BAL) is an invasive bedside procedure to define type and concentration of pathologic organisms causing ventilator associated pneumonia (VAP). We evaluated if the absence of pathogens on final results represented a lavage aspect of the BAL as a therapeutic procedure to eliminate organisms.

METHODS

BAL results collected from 2008 to 2009 were stratified as positive (POS) ≥ 100,000 cfu), indeterminate (INT) ≤ 100,000 cfu pathologic organisms, or negative defined as mixed flora (MF) or sterile (STR). The INT, MF, and STR results were assessed by incidence of a subsequent POS sample.

RESULTS

Nine-hundred forty-nine BALs performed on 490 SICU patients were interpreted as POS in 227 patients (46%). 237 non- POS patients needed a subsequent BAL. Any pathogen on the first BAL (INT group) indicates a high likelihood for subsequent BAL which will be POS. Monthly cumulative sum analysis (CUSUM) of yield was unable to identify any specific period in which BAL performance varied from trend.

CONCLUSION

MF and STR represent adequate sampling of secretions that are clinically benign. Any pathogen, regardless of concentration, should be considered a biomarker for future pneumonia. CUSUM analysis suggest better training in timing and indication may decrease unnecessary procedures yielding negative results.