The effect of preoperative neutrophil / lymphocyte ratio on postoperative pain, analgesic consumption and postoperative results in hip arthroplasty surgery

Total hip arthroplasty is a major surgical procedure that is frequently performed and is associated with high postoperative pain scores. Uncontrolled pain can lead to an increase in endocrine, metabolic, cardiovascular, and gastrointestinal complications. The aim of our study is to investigate the relationship between the NLR, which can be calculated easily and inexpensively from routine preoperative complete blood count results and is considered as a systemic inflammation marker, and postoperative pain, analgesic consumption, and postoperative outcomes in total hip arthroplasty. In our retrospective single-center study, medical records of patients who underwent hip arthroplasty in the operating room of Mersin University Faculty of Medicine Hospital between 01/02/2021 and 01/02/2022 were retrospectively reviewed. All data obtained during postoperative follow-ups were collected from patient observation files and algology follow-up forms and recorded in a data collection form for statistical analysis. Using a threshold value of 4 for NLR, patients were divided into two groups, and the results were compared. There were no significant differences between the groups in terms of sociodemographic characteristics, the time of the first administration of additional analgesics, and the time of the patient's initial mobilization (p>0.05). In the NLR>4 group, the total local anesthetic (LA) bolus amount and the total LA milligram amount administered were significantly higher than in the NLR ≤ 4 group (p<0.05). In the NLR>4 group, the 9-hour VAS, 12- hour VAS, 18-hour VAS scores, 24-hour VAS score, and the amount of additional LA administered were significantly higher than in the NLR ≤ 4 group (p<0.05). Our study found that patients with a preoperative NLR level above 4 had higher pain scores at certain hours in the postoperative period, consumed more analgesics, and had a higher frequency of postoperative complications. We believe that the preoperative NLR value can be a guiding parameter in the management of postoperative pain