Clinical Severity and Systemic Inflammatory Indices as Predictors of In-Hospital Mortality After Limb Amputation a Retrospective Cohort Study

<b>Background/Objectives</b>: Major limb amputation is associated with high short-term mortality, yet practical preoperative risk models remain limited. This study aimed to identify easily obtainable preoperative predictors of in-hospital mortality after limb amputation and to develop a compact predictive model. <b>Methods</b>: We retrospectively analyzed 184 adult patients undergoing major or minor limb amputation between January 2021 and July 2025 at a tertiary referral hospital. Preoperative variables included demographics, comorbidities, urgency of surgery, hemoglobin, and complete blood count-derived inflammatory indices: neutrophil-to-lymphocyte ratio (NLR), systemic inflammatory response index (SIRI), and monocyte-to-lymphocyte ratio (MLR). The primary outcome was in-hospital mortality. Multivariable logistic regression was used to construct a compact preoperative model. Model performance was assessed by area under the receiver operating characteristic curve (AUC) and calibration plots. <b>Results</b>: In-hospital mortality occurred in 36 patients (19.6%). Independent predictors in the multivariable model were emergency surgery (OR 4.39, 95% CI 1.83-10.55), age (per 1 SD; OR 1.73, 95% CI 1.16-2.59), SIRI (per 1 SD; OR 1.77, 95% CI 1.19-2.65), and hemoglobin (per 1 SD decrease; OR 0.63, 95% CI 0.43-0.91). The model demonstrated good discrimination (AUC = 0.80) and acceptable calibration. Although not included in the model, intensive care unit and total hospital length of stay were higher among non-survivors. <b>Conclusions</b>: A compact preoperative model incorporating age, urgency of surgery, hemoglobin, and SIRI provides reliable risk stratification for in-hospital mortality after limb amputation. These variables are readily available before surgery, making the model practical for bedside clinical use. Prospective multicenter validation is warranted.