The relationship between neutrophil to lymphocyte ratio and postoperative pain in total knee and hip arthroplasty

Abstract Background and objectives: Neutrophil to lymphocyte ratio is a simple, cost-effective and easily applicable inflammation indicator that is being used frequently in mortality, morbidity and prognosis studies in the recent years. We evaluated the relationship between neutrophil to lymphocyte ratio and postoperative pain in patients undergoing total hip arthroplasty and total knee arthroplasty. Material and methods: We included 101 patients who preferred spinal anesthesia and intravenous patient-controlled analgesia in accordance and divided them into two groups, total hip arthroplasty and total knee arthroplasty. We recorded demographic information, duration of operation, length of hospital stay, analgesics consumption, neutrophil to lymphocyte ratio results and postoperative pain using Visual Analog Scale. Results: The morphine consumption of the patients was as follows in group total hip arthroplasty and total knee arthroplasty: at the 4th hour: 7.38 mg, 7.80 mg; 8th hour: 12.19 mg, 13.29 mg; 12th hour: 16.94 mg, 19.18 mg; 24th hour: 25.97 mg, 27.98 mg; 48th hour: 36.38 mg, 39.59 mg. The Visual Analog Scale scores of the patients was as follows in group total hip arthroplasty and total knee arthroplasty: at the 4th hour: 4.10, 4.51; 8th hour: 3.02, 3.43; 12th hour: 2.29, 2.55; 24th hour: 1.90, 1.87; 48th hour: 1.08, 1.13. In group total hip arthroplasty, we found a statistically significant association between postoperative neutrophil to lymphocyte ratio and the Visual Analog Scale values on the 48th hour in a positive direction (r = 0.311; P = 0.031; P < 0.05). Conclusion: Neutrophil to lymphocyte ratio can be accepted as a relatively objective method for the diagnosis of postoperative pain