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

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.