Ratios of Neutrophils and Platelets to Lymphocytes as Predictors of Postoperative Intensive Care Unit Admission and Length of Stay in Bariatric Surgery Patients: A Retrospective Study.

: This study aimed to investigate the role of the pre- and postoperative neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in predicting intensive care unit (ICU) admission and postoperative length of stay (LOS) in bariatric surgery. : We retrospectively analysed 96 patients who underwent bariatric surgery at our institution. The NLR and PLR were calculated in the pre- and postoperative stages. Changes in pre- and postoperative hematological ratios were compared using the Wilcoxon signed-rank test. The optimal cutoff values and area under the curve (AUC) for each ratio were calculated using receiver operating characteristic (ROC) analysis. Multivariate linear regression analysis was used to assess the relationship between each ratio and the postoperative LOS after adjusting for age, sex, and American Society of Anesthesiologists (ASA) score. : The median age of our patients was 35.50 years, and 54.2% were male. The preoperative NLR showed a significant increase from 1.44 to 6.38 postoperatively ( < 0.001). The PLR increased from 107.08 preoperatively to 183.58 postoperatively, < 0.001). ROC analysis showed that the postoperative NLR was a moderate to high predictor of ICU admission (AUC = 0.700, optimal cutoff point = 5.987). The postoperative PLR had less predictive power for ICU admission (AUC = 0.641, optimal cutoff point = 170.950). Ratios that had a statistically significant relationship with the postoperative LOS were the preoperative NLR (standardized β [95% CI]: 0.296 [0.115-0.598]), postoperative NLR (0.311 [0.034-0.161]), and postoperative PLR (0.236 [0.000-0.005]). : The NLR and PLR demonstrated an independent relationship with the postoperative LOS after bariatric surgery and the predictive ability of ICU admission. Both ratios might be useful as simple markers to predict patient outcome after surgery.