Admission lymphopenia predicts risk of pneumonia and AKI in hospitalized burn injuries

Burn patients are at high risk for infectious complications due to immune dysregulation. This study investigated the relationship between admission lymphopenia (absolute lymphocyte count [ALC] < 1000) and burn injury outcomes. We hypothesized that lymphopenia would be associated with poor outcomes. This is a retrospective cohort study of all adult patients admitted from January 2017 to March 2023 for burn and/or inhalation injuries. Patients who died within 24 h were excluded. Demographics, comorbidities, ALC on admission, frailty status, admission and injury details including total burn surface area (TBSA), 2nd and 3rd degree TBSA, immunodeficient state, hospital course, surgical interventions, burn-specific and non-burn-specific complications, in-hospital mortality, and discharge disposition were collected. Univariate and multivariate analyses were performed to identify variables, including lymphopenia, associated with outcomes. P < 0.05 was considered significant. Of 286 eligible patients, 62 (21.7 %) were lymphopenic on admission. The cohort was predominantly male and white. Lymphopenic patients were older (64.5 y vs. 48 y, p < 0.001) and more likely to be frail (21 % vs. 4 %, p < 0.001). Immune-insufficient state, injury characteristics, hospital length of stay (LOS), LOS/TBSA, ventilator days, skin graft requirements, or in-hospital mortality were not significantly different between the groups. Adjusting for age, gender, frailty, inhalation injury, comorbidities, and %TBSA, lymphopenia was associated with increased risks of developing pneumonia (OR = 4.28 [1.19–15.47], p = 0.026) and AKI (3.90 [1.41–10.77], p = 0.009). Early identification of patients with higher risk for complications is imperative in burn management.