Development of a Prediction Model for Postoperative Hypoproteinemia in Patients Undergoing Microsurgical Reconstructive Surgery: A Prospective Observational Study

AIM: To investigate the risk factors for postoperative hypoproteinemia in patients undergoing microsurgical reconstructive surgery and to develop a prediction model to support nurses in identifying patients at high risk. DESIGN: A prospective observational study. METHODS: A convenience sample of 192 patients with limb-destructive injury admitted to the Department of Orthopaedics at a tertiary hospital between September 2021 and March 2023 was enrolled. Patients were classified into hypoproteinemia (serum albumin < 35 g/L) and non-hypoproteinemia (serum albumin ≥ 35 g/L) groups based on serum albumin levels measured within the first 72 h postoperatively. Multivariable logistic regression was used to develop a predictive model. Receiver operating characteristic curve analysis was performed to assess model discrimination performance. RESULTS: The prevalence of postoperative hypoproteinemia in this cohort was 72.4%. Statistically significant between-group differences were observed for body mass index, smoking status, wound size, operating time, intraoperative blood loss, amount of fluid rehydration on the day after surgery, preoperative total protein level, preoperative albumin level, preoperative red blood cell count, preoperative haematocrit (Hct), preoperative haemoglobin (Hb) level, and the Mangled Extremity Severity Score (MESS). Multivariable logistic regression analysis showed that higher preoperative albumin level (odds ratio [OR] = 0.837 per 1 g/L increase) and higher preoperative Hb level (OR = 0.958 per 1 g/L increase) were independently associated with lower odds of postoperative hypoproteinemia, whereas longer operating time (OR = 1.967 per 1h increase) was associated with increased odds. The area under the ROC curve (AUC) for the combined model was 0.915. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.