Postoperative pain relief quality after cesarean section using a stress monitor (Neon FSC system): prospective single-center randomized clinical comparative study

BACKGROUND: The objective assessment of pain levels during labor, postpartum period, and effectiveness of analgesic response remains difficult. We suppose that the dynamics of the activity of the sympathetic nervous system by measuring the galvanic skin response may become a promising method for solving this problem.

OBJECTIVE: To evaluate the effectiveness of various multimodal analgesia regimens after cesarean section using the NeonFSC stress monitoring system.

MATERIALS AND METHODS: A prospective single-center clinical comparative study was conducted to evaluate the effectiveness of various postoperative multimodal analgesia regimens in 48 postpartum women who underwent elective cesarean section under spinal anesthesia. For postoperative analgesia, group 1 (n=24) underwent a TAP block, and ketorolac and tramadol were prescribed, and group 2 (n=24) received only ketorolac and tramadol. Randomization was made using the envelope method. The visual analog scale (VAS) and NeonFSC system were used to assess the effectiveness of postoperative pain relief. The observation time was 19–22 h.

RESULTS: The patients were comparable in age, gestational age, physical status, method of pain management and delivery. At baseline and during the 2-h postoperative period, the median and distribution of visual analogue scale pain scores did not show a statistically significant difference between groups. During the study period, the highest level of spectral power of skin conductance (SC) was recorded in group 2. Baseline skin conductance variability (SCV) values were comparable between groups (p >0.001). Lower SCV values were noted in patients of group 1, compared to group 2, at night (p=0.003 vs p <0.001). The median values of the level of total spectral power of skin conductivity (DASS) in patients of group 1 were 1.5–2 times lower, starting from the second hour until the end of observation.

CONCLUSION: The NeonFSC system can be a component of an objective assessment of the effectiveness of analgesia after cesarean section.