Microbiology and Outcomes of Institutionalized Patients with Stroke-associated Pneumonia: A Prospective Observational Study

Abstract Background: The attributable mortality and microbial etiology of stroke-associated pneumonia (SAP) vary among different studies. We intednd to determine the microbiology and outcomes of SAP in lower respiratory tract (LRT) for patients with invasive mechanical ventilation (MV).Methods: In this prospective observational study, included patients were divided into SAP and non-SAP based on comprehensive analysis of symptom, imaging and laboratory results. Baseline characteristic, clinical characteristic, microbiology and outcomes were recorded and evaluated.Results: Of 185 patients, 41.6% developed SAP after onset of stroke, and they had lower proportion of non-smoker (p=0.016), lower GCS score (p<0.001), higher serum CRP score (p<0.001) at ICU admission, and higher proportion of males (p<0.001) and hypertension (p=0.018) than patients with non-SAP. Gram-negative aerobic bacilli were the predominant organisms isolated (78%), followed by Gram-positive aerobic cocci (29.9%). Out of 19 isolated pathogens, main pathogens included K. pneumoniae, S. aureus, H. influenzae, A. baumannii, P. aeruginosa, E. aerogens, Serratia marcescens, and Burkholderia cepacia. SAP significantly prolonged length of MV (p<0.001) and duration of ICU stays (p<0.001), shorten MV-free days by 28 (p<0.001), caused elevated vasopressor application (p=0.002) and 60-day mortality (p=0.001).Conclusion: Microbiology of SAP is similar to early-phase HAP and VAP. SAP significantly prolongs duration of MV and lengths of ICU stays, but also markedly increase 60-day mortality.Trial registration: ChiCTR2000028849; http://www.chictr.org.cn/index.aspx, Registered 05 January 2020.