Prognostic Nutritional Index and the Risk of Postoperative Complications After Spine Surgery: A Meta-Analysis

A low prognostic nutritional index (PNI) may reflect malnutrition, which has been associated with poor prognosis in patients with various clinical conditions. The aim of the systematic review and meta-analysis was to investigate the association between preoperative PNI and risk of postoperative complications in adult patients after spine surgery.

An extensive search was conducted on PubMed, Embase, and Web of Science to identify relevant cohort studies. Random-effects models were employed to combine the findings, taking into account the potential influence of heterogeneity.

Ten cohort studies involving 3,249 patients receiving spine surgeries were included. Pooled results showed that a low preoperative prognostic nutritional index (PNI) was associated with an increased risk of overall postoperative complications in these patients (odds ratio [OR]: 1.82, 95% confidence interval [CI]: 1.42 to 2.34, P < 0.001; I² = 49%). Specifically, a preoperative malnutrition as evidenced by a low PNI was associated with a higher incidence of postoperative delirium (OR: 2.36, 95% CI: 1.52 to 3.66, P < 0.001; I² = 38%) and surgical site infection (OR: 1.41, 95% CI: 1.15 to 1.73, P = 0.001; I² = 0%). Sensitivity analyses by excluding one study at a time did not significantly change the results (P all <0.05).

A preoperative low prognostic nutritional index (PNI) may be a risk factor of increased incidence of overall postoperative complications, postoperative delirium, and surgical site infection in adult patients after spine surgeries.