摘要Objective:To evaluate the effects of early bronchoalveolar lavage(BAL)on inflammatory response,oxidative stress,and clinical outcomes in older adult patients with severe pneumonia using generalized estimating equations(GEE).Methods:Eighty-three older adult patients(≥60 years)hospitalized with severe pneumonia between August 2024 and December 2024 were enrolled and assigned to either a control group(n=47),which received standard therapy(including antimicrobials,expectorants,and mechanical ventilation),or an intervention group(n=36),which received additional BAL at 12 and 48 hours post-admission.Clinical efficacy and time to symptom improvement were compared between groups.Serum concentrations of inflammatory markers—interleukin(IL)-6,procalcitonin,and C-reactive protein(CRP)—and oxidative stress markers—superoxide dismutase and malondialdehyde(MDA)—were measured at baseline(T0)and at 24(T1),72(T2),and 144 hours(T3)following admission.Intergroup differences were analyzed using GEE.Results:Compared with the control group,the intervention group demonstrated significantly lower Clinical Pulmonary Infection Score,Acute Physiology and Chronic Health Evaluation Ⅱ score,Murray Lung Injury Score,duration of lung inflammation,and length of hospital stay(all P<0.05).GEE analyses indicated that the intervention group exhibited significantly reduced levels of IL-6,procalcitonin,CRP,and MDA(all P<0.05),and significantly increased superoxide dismutase levels(P<0.05).Conclusions:Early administration of BAL significantly mitigates systemic inflammation and oxidative stress,while improving clinical outcomes in older adult patients with severe pneumonia.These findings support further investigation of broader clinical application of early BAL in this population.