Comparison of the effect of general and regional anesthesia on neutrophil lymphocyte ratio in knee arthroscopy surgeries

Aim: It has been shown in clinical practice that the neutrophil/lymphocyte ratio (NLR) can be used as a marker of systemic inflammation in different diseases. It is an easy, practical and inexpensive method to measure, it has been used as a valuable method in the diagnosis and prognosis of various diseases since in recent years. In this study, we aimed to investigate the effects of general and regional anesthesia on neutrophil lymphocyte ratio and the effects of NLR on postoperative pain in patients who underwent knee arthroscopy. Material and Methods: The study was planned as a prospective, cross-sectional study between September 1, 2020 and April 1, 2021, after the approval of the document numbered 24237859-547 and protocol number 2020/208 by the Scientific Research Ethics Committee of KTU Faculty of Medicine on 17.09.2020. A total of 46 patients from 2 groups, including general and regional anesthesia groups, consisting of 23 people aged between 18-75 years, in the ASA I-III risk group, who underwent knee arthroscopy in the orthopedic operating room over a 6-month period, were included in the study. One day before the operation, pre-anesthetic examinations of all patients were performed, patients with suitable conditions for the study were informed about the study, and written informed consent was obtained. Numeric Rating Scale (NRS) score was explained in detail to the patients to evaluate their pain levels. The neutrophil/lymphocyte ratios (NLR), age, gender, weight, ASA risk scores, telephone numbers and residence addresses of the patients were recorded before the operation. In calculating sample width, Power was determined by taking at least 0.90 and Type-1 error 0.05. Descriptive statistics for continuous variables in the study; Expressed as Mean and Standard Deviation; expressed as number (n) and percentage (%) for categorical variables. Shapiro-Wilk (n<50) and Skewness-Kurtosis tests were used to determine whether the continuous measurement averages were normally distributed, and because the variables were normally distributed, parametric tests were applied. The independent T-test was calculated to compare the mean of measurements according to the General-Spinal anesthesia groups. ANOVA was used for repeated measurements in the comparison of measurements according to measurement times/hours separately in each anesthesia group. Results: There was no statistically significant difference between the anesthesia groups in terms of age, gender, body mass index, anesthesia and operation time. Intraoperative NLR mean: 1.51 (std.dev.: 0.83) in the general anesthesia group; In the spinal anesthesia group, intraoperative NLR mean: 2.20 (std.dev.: 0.87) was determined, and the independent variable was p:0.008 (p<0.05). A significant difference was observed in the decrease in intraoperative NLR value in the general anesthesia group. In the general anesthesia group, postoperative 1st hour NRS mean: 6.09 (std.dev.: 2.61); In the spinal anesthesia group, postoperative 1st hour NRS mean: 1.61 (std.dev.: 1.41) was determined, and the independent variable was p:0.001 (p<0.05). A significant difference was observed in the decrease in the postoperative 1st hour NRS value in the spinal anesthesia group. Conclusion: We compared the NLR and NRS measurements of the patients who underwent knee arthroscopy according to the anesthesia groups, a statistical difference was observed. We attributed the higher intraoperative NLR in the spinal anesthesia group to inflammation caused by subarachnoid puncture. In the NRS measurements that we used as the pain scale, the average of the preoperative NRS measurement rates in the general anesthesia and spinal anesthesia groups was found to be the same. We thought that the higher postoperative NRS and NLR in the general anesthesia group may be due to the postoperative analgesic effect of spinal anesthesia suppressing inflammation. We think that more studies on NLR are necessary in terms of being a guide for both anesthesia and postoperative pain. Key Words:Knee arthroscopy, Neutrophil Lymphocyte Ratio, Regional Anesthesia.