Treatment outcomes and predictors of clinical response in patients with community-acquired pneumonia at Hai Phong International Hospital: A retrospective cohort study

Abstract

Background: Community-acquired pneumonia (CAP) remains a leading cause of morbidity and mortality worldwide, with antimicrobial resistance (AMR) posing a critical challenge in low- and middle-income countries, including Vietnam. Local data on antibiotic use, resistance, and treatment outcomes are essential to guide empirical therapy and stewardship.  Methods: We conducted a retrospective study of 1,418 adult patients hospitalized with CAP at Hai Phong International Hospital, Vietnam, from 2020 to 2024. Clinical characteristics, inflammatory markers, CURB-65 severity scores, antibiotic regimens, and outcomes were extracted from medical records. Microbiological culture and susceptibility data were analyzed according to CLSI/EUCAST standards. Treatment response was assessed by clinical symptoms, biomarkers, and hospital outcomes. Results: The majority of patients were elderly (≥60 years: 76.0%) and male (53.1%). Frequent comorbidities included hypertension (53.4%) and diabetes (37.8%). At admission, 72.6% had elevated CRP and 65.7% had elevated procalcitonin. Most patients presented with cough (51.2%) and fever (43.8%). CURB-65 scores indicated low-to-moderate risk in 85.5% of cases. Fluoroquinolone monotherapy was the most common initial regimen (48.8%), followed by carbapenem monotherapy (11.6%). Combination therapy accounted for 25.1% of cases, though de-escalation was applied in only 9.4%. Clinical improvement was observed in 75.3% and cure in 20.5% of patients, with significant reductions in WBC (p<0.0001) and CRP (p<0.0001). However, high resistance rates were found in Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae. Conclusion: CAP patients in this Vietnamese cohort were predominantly elderly with multiple comorbidities and frequent use of broad-spectrum antibiotics. Despite overall favorable outcomes, inappropriate reliance on fluoroquinolones and carbapenems, coupled with high AMR rates, underscores the urgent need for hospital-based antimicrobial stewardship, adherence to evidence-based guidelines, and expansion of local resistance surveillance to optimize CAP management.