Justification of the expediency of using harmless analgesia in bariatric surgery: prospective randomized study

BACKGROUND: The presence of various comorbid conditions in patients with obesity increases operational risk, and high sensitivity to sedatives and opioid drugs can contribute to their aggravation.

OBJECTIVE: To compare and evaluate two methods of perioperative analgesia, namely, multimodal without opioid and non-opioid when performing longitudinal gastric resection for patients with morbid obesity using the enhanced recovery after surgery protocol.

MATERIALS AND METHODS: A prospective randomized study of patients with morbid obesity was conducted. Depending on the type of analgesic component of anesthesia, the patients are divided into two groups. In both groups, low-flow desflurane inhalation was used; in group 1 (n=30), the technique of non-opioid analgesia was used, which included intraoperative infusion of ketamine, dexmedetomidine, lidocaine, and magnesium sulfate. In group 2 (n=30), traditional combined anesthesia using fentanyl was administered. In the postoperative period, the infusion of the above drugs continued for 10 h in group 1. Central and peripheral hemodynamic parameters, and the depth of anesthesia were studied, and TOF-monitoring was carried out. Postoperative rehabilitation was assessed based on the time of extubation, achievement of 13 points on the PARS scale, first getting up on one’s feet, appearance of overstrain, and gas discharge. Postoperative analgesia was assessed on a 10-point visual analog scale, and anesthesia-related complications were recorded.

RESULTS: Surgical intervention under low-flow inhalation anesthesia based on desflurane in combination with multimodal opioid-free analgesia reduced the need for opioid analgesics intraoperatively (in group 1, the fentanyl dose was 0.2 [01; 0.2] mg; in group 2 — 0.4 [0.3; 0.5] mg; p=0.002), provided less fluctuation of intraoperative hemodynamic parameters (AvBP: stage 1: group 1 — 102 [100; 103]; group 2 — 102 [98; 105], p=0.96; stage 2: group 1 — 93 [90; 95]; group 2 — 96 [93; 99], p=0.003; stage 3: group 1 — 95 [95; 97]; group 2 — 100 [96; 102], p <0.001; stage 4: group 1 — 95 [92; 97]; group 2 — 98 [98; 101], p <0.001; CI stage 1: group 1 — 49±2.2; group 2 — 49.5±2.2, p=0.39; stage 2: group 1 — 44.4±2; group 2 — 44.6±2.1, p=0.26; stage 3: group 1 — 45.5±2.11; group 2 — 50.6±2.8, p=0.001; stage 4: group 1 — 44.5±2.1; group 2 — 48.8±2.5 p <0.001), and contributed to a lower level of pain and faster rehabilitation. In addition, anesthesia-related complications such as postoperative nausea and vomiting, hypoxemia, and dysphoria were less frequently recorded.

CONCLUSION: The use of multimodal non-opioid analgesia contributes to a lesser fluctuation in hemodynamic parameters, a low level of postoperative pain, early activation of patients and restoration of peristalsis, and a decrease in the number of postoperative complications in patients who underwent longitudinal gastric resection for morbid obesity.