Association of Preoperative Neutrophil-To-Lymphocyte Ratio and Platelet-To-Lymphocyte Ratio With Postoperative Nausea and Vomiting in Patients Undergoing Laparoscopic Cholecystectomy: A Prospective Observational Cohort Study Publisher

Summary: Can blood inflammation ratios predict nausea after surgery? A 180-patient study linked higher preoperative NLR and PLR to worse postoperative symptoms. #Surgery #Biomarkers

Nazemroaya B ; Rahimi Z ; Kabiri R ; Hematiyan F
Source: Journal of Cellular and Molecular Anesthesia Published:2026

Abstract

Background: Postoperative nausea and vomiting (PONV) remains common and distressing after laparoscopic cholecystectomy, with an incidence ranging from 30% to 80%. Identifying inexpensive and accessible preoperative biomarkers to predict PONV could improve risk stratification and guide antiemetic prophylaxis. Among potential markers, the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are inflammation-based indices that may be associated with PONV; however, the available evidence is limited and inconsistent. Objectives: This study investigated the association of preoperative NLR and PLR with the incidence and severity of PONV in patients undergoing elective laparoscopic cholecystectomy. Methods: In this prospective observational cohort study, 180 adults with American Society of Anesthesiologists (ASA) physical status I-II undergoing elective laparoscopic cholecystectomy were enrolled. Preoperative venous blood samples were analyzed for neutrophil, lymphocyte, and platelet counts, which were used to calculate NLR and PLR. Postoperative nausea and vomiting severity was quantified using the Rhodes Index of Nausea, Vomiting, and Retching during the first postoperative hour, and cumulative 24-hour ondansetron consumption was recorded. Potential perioperative confounders, including anesthetic technique, antiemetic exposure, operation duration, pneumoperitoneum protocol, and perioperative opioid exposure, were addressed through protocol standardization when possible and through descriptive or exploratory analysis when data were available. Hemodynamic variables were monitored perioperatively. Correlation coefficients between inflammatory indices and clinical outcomes were calculated using Spearman's method. Results: The cohort comprised 105 males (58%) and 75 females (42%), with a mean age of 46.98 ± 10.43 years. The mean Rhodes Index score was 11.11 ± 1.40, and the mean ondansetron requirement was 13.09 ± 3.22 mg. Both NLR (3.72 ± 2.42) and PLR (97.22 ± 66.54) showed significant positive correlations with Rhodes Index scores (NLR: r = 0.480, P < 0.001; PLR: r = 0.388, P < 0.001) and the ondansetron dose (NLR: r = 0.489, P < 0.001; PLR: r = 0.465, P < 0.001). No clinically significant perioperative hemodynamic instability was observed. Conclusions: Higher preoperative NLR and PLR values were significantly associated with greater PONV severity, as measured by the Rhodes Index, and higher ondansetron requirements after laparoscopic cholecystectomy. These simple, accessible blood tests may help predict PONV risk in routine practice. Larger multicenter studies are needed to refine cutoff values and improve predictive models by incorporating mechanistic markers. Copyright © 2026, Nazemroaya et al.