Follow-up Neutrophil–Lymphocyte Ratio as a Predictor for Postoperative Pneumonia After Endovascular Treatment in Aneurysmal Subarachnoid Hemorrhage Patients: A Retrospective Analysis

The association between NLR and postoperative pneumonia (POP) in patients with aneurysmal subarachnoid hemorrhage (aSAH) who underwent endovascular treatment remains poorly understood. Patients with aSAH who underwent endovascular treatment between January 2019 and April 2023 were included. The follow-up endpoint was the presence of POP at 30 days postoperatively. Logistic regression analysis was conducted using POP as the dependent variable. NLR was calculated at admission (NLR1), 24 h after endovascular treatment (NLR2), and 3–7 days after endovascular treatment (NLR3). Four prediction models were constructed: Model 1 (variables with p < 0.05, except for the NLR); Model 2 (Model 1 plus NLR1); Model 3 (Model 1 plus NLR2); and Model 4 (Model 1 plus NLR3). Among the 154 patients with aSAH, POP occurred in 101 (65.6%) patients. Higher NLRs at admission (odds ratio [OR] = 1.08; 95% Confidence Interval [CI] 1.02, 1.16; p = 0.019), 24 h postoperatively (OR = 1.14; 95% CI 1.05, 1.25; p = 0.005) and 3-7days postoperatively (OR = 1.17; 95% CI 1.02, 1.38; p = 0.04) were independently associated with the occurrence of POP. Follow-up NLR may be an independent predictor of POP in aSAH patients treated endovascularly. Elevated NLR at admission, 24 h postoperatively and 3–7 days postoperatively correlated with a high risk for POP.