Red cell distribution width (RDW) and serum albumin concentration are associated with postoperative outcomes. However, the usefulness of the RDW/albumin ratio in burn surgery remains unclear. Therefore, we evaluated the association between RDW/albumin ratio and 90-day mortality after burn surgery. Between 2013 and 2020, a retrospective review of patients in a burn intensive care unit (ICU) was performed. Receiver operating characteristic curve, multivariate Cox logistic regression, multivariate logistic regression and Kaplan–Meier analyses were conducted to evaluate the association between RDW/albumin ratio and 90-day mortality after burn surgery. Additionally, prolonged ICU stay rate (>60 days) and ICU stay were assessed. Ninety-day mortality was 22.5% (210/934) in burn patients. Risk factors for 90-day mortality were RDW/albumin ratio at postoperative day 1, age, American Society of Anesthesiologists physical status, diabetes mellitus, inhalation injury, total body surface area burned, hypotensive event and red blood cell transfusion volume. The area under the curve of the RDW/albumin ratio at postoperative day 1 to predict 90-day mortality, after adjusting for age and total body surface area burned, was 0.875 (cut-off value, 6.8). The 90-day mortality was significantly higher in patients with RDW/albumin ratio >6.8 than in those with RDW/albumin ratio ≤6.8 (49.2% vs 12.3%, p < 0.001). Prolonged ICU stay rate and ICU stay were significantly higher and longer in patients with RDW/albumin ratio >6.8 than in those with RDW/albumin ratio ≤6.8 (34.5% vs 26.5%; 21 [11–38] vs 18 [7–32] days). RDW/albumin ratio >6.8 on postoperative day 1 was associated with higher 90-day mortality, higher prolonged ICU stay rate and longer ICU stay after burn surgery.

Burn injury in elderly patients can result in poor outcomes. Prognostic nutritional index (PNI) can predict the perioperative nutritional status and postoperative outcomes. We aim to evaluate the risk factors, including PNI, for one-year mortality after burn surgery in elderly patients. Burn patients aged ≥65 years were retrospectively included. PNI was calculated using the following equation: 10 × serum albumin level (g/dL) + 0.005 × total lymphocyte count (per mm³). Cox regression, receiver operating characteristic curve and Kaplan–Meier survival analyses were performed to evaluate the risk factors for postoperative one-year mortality. Postoperative one-year mortality occurred in 71 (37.6%) of the 189 elderly burn patients. Risk factors for one-year mortality were PNI on postoperative day one (hazard ratio (HR) = 0.872; 95% CI = 0.812–0.936; p < 0.001), Sequential Organ Failure Assessment score (HR = 1.112; 95% CI = 1.005–1.230; p = 0.040), American Society of Anesthesiologists physical status (HR = 2.064; 95% CI = 1.211–3.517; p = 0.008), total body surface area burned (HR = 1.017; 95% CI = 1.003–1.032; p = 0.015) and preoperative serum creatinine level (HR = 1.386; 95% CI = 1.058–1.816; p = 0.018). The area under the curve of PNI for predicting one-year mortality after burn surgery was 0.774 (optimal cut-off value = 25.5). Patients with PNI ≤25.5 had a significantly lower one-year survival rate than those with PNI >25.5 (32.1% vs 75.9%, p < 0.001). PNI on postoperative day one was associated with postoperative one-year mortality in elderly burn patients. The postoperative one-year survival rate was lower in patients with PNI ≤25.5 than in those with PNI >25.5. These findings indicate the importance of identifying elderly burn patients with low PNI, thereby reducing the mortality after burn surgery.