부산대학교 도서관

Background Culture-negative and culture-positive nosocomial pneumonia have not been sufficiently studied whether they should be regarded as the same group or different in their clinical characteristics and outcomes. Methods A nationwide multicenter retrospective observational cohort study was conducted among patients with hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) admitted to the 13 tertiary or university-affiliated hospitals in Korea from June 1 to Dec 31, 2019 by the Korean HAP/VAP Study Group. Results Among 526 patients with HAP/VAP enrolled out of 206,372 adult hospitalized patients screened, 468 patients with respiratory cultures were eligible. Among them, 257 (54.9%) patients were culture-negative (CN) and 211 (45.1%) were culture-positive CP). Their median age was 71 [62-79] and 69% were males. CN patients had a higher percentage of females (35% vs 26%, P=0.022) and less chronic neurologic disease with lower risk of aspiration compared with CP. Initial SOFA score on diagnosis of pneumonia was lower in CN patients than in CP (CN: 4.4±3.8 vs CP: 6.4±4.2, P < 0.001). As empirical antibiotic use, extendedspectrum penicillin/β-lactamase inhibitors-based antibiotics were used significantly more in the CN group (CN: 62% vs CP: 52%, P=0.021), while carbapenem-based antibiotics were used significantly more in the CP group (CN: 16% vs CP: 26%, P=0.007). CN patients had a lower clinical failure for HAP/VAP (CN: 24% vs CP: 45%, P < 0.001) and a lower hospital mortality rate (CN: 24% vs CP: 35%, P=0.013) than CP patients. In multivariate analysis, culture-negativity was a significant prognostic factor of clinical failure for HAP/VAP (OR: 0.590, 95% CI: 0.367-0.947, P=0.029). Conclusion Patients with CN HAP/VAP had less organ failure, lower rate of treatment failure and favorable hospital mortality than CP patients. This study suggests that CN and CP HAP/VAP patients are clinically different patient groups.