Abstract
INTRODUCTION: One in five women experiences high-intensity pain after a cesarean section. OBJECTIVE: Evaluation of the effectiveness of low-dose ketamine in the prevention of high-intensity pain in women with a low pain threshold after cesarean section. MATERIALS AND METHODS: A randomized controlled trial (RCT) was conducted on 90 women who underwent elective cesarean section (CS) under spinal anesthesia. Women were stratified into two categories: normal and low pain threshold. Within each subgroup, the patients were randomized into three groups: intraoperative intravenous administration of ketamine at a dose of 0.25 mg/kg; 0.5 mg/kg, and control group. The time to first request for analgesia and total tramadol dose during the first postoperative day were recorded. The frequency of adverse reactions was analyzed. RESULTS: The median and interquartile range (IQR) for mean pain intensity in the first day, pain on movement, and pain at rest 24 hours after CS were significantly higher in the control group compared to the ketamine groups (p < 0.001). Time to first requirement of analgesia increased in the ketamine 0.5 mg/kg group 190.0 [175.0–195.0] minutes compared with the control group 130.0 [130.0–140.0] minutes with p < 0.001. Tramadol consumption on the first day was significantly lower in the ketamine groups compared with the control groups (p < 0.001). Between-group statistically significant differences in the studied pain indicators in the ketamine groups (0.5 and 0.25 mg/kg) were not observed in either patients with a normal or low pain threshold (p > 0.005). Adverse effects (distorted reality and visual impairment) at the minimum dosage of 0.25 mg/kg were observed exclusively in patients with a normal pain threshold. CONCLUSIONS: For patients with an initially low pain threshold, the use of ketamine at a dose of 0.25 mg/kg has the best efficacy and safety profile.
Publisher
Practical Medicine Publishing House