Perioperative management of acute pain by multimodal analgesia after laparoscopic sleeve gastrectomy: a prospective cohort study

Background: Bariatric surgery has been shown to be the most effective treatment in achieving and maintaining weight loss and reducing obesity-related morbidities. Adequate measurement and control of pain allows for better postoperative outcomes and substantial reduction of complications, especially in subjects with morbid obesity. The aim of this study was to investigate the efficacy of postoperative analgesia via the utilization of a multimodal approach and to determine predictors of postoperative pain severity in patients undergoing laparoscopic sleeve gastrectomy (LSG). Methods: This is a prospective cohort study designed to evaluate a perioperative multimodal analgesia protocol (i. e. subcutaneous/subfascial and intraperitoneal instillation of Ropivacaine; nonsteroidal anti-inflammatory agents; paracetamol and minimal dose of oral opioids) in subjects undergoing LSG. Evaluation of postoperative analgesia was performed at 1, 4 and 24 h after surgery through employment of chromatic visual analogue scales (VAS). Results: Between February and June 2019, a total of 48 consecutive patients affected by morbid obesity (mean BMI 41.83±5.51 kg/m2) underwent LSG. Mean operative time was 106±31.56 min. Only 8 patients (16.6%) required Morphine rescue in order to bring VAS at rest to ≤5. Pearsons’ coefficient showed a negative pCO2 correlation before surgery and both VAS scores measured at rest and during activity at different time points. P/F ratio and pCO2 measured before surgery were strong predictors of VAS >5 at rest and during activity (AUC=0.981 and AUC=0.980, respectively). Conclusions: The identification of pain predictors could aid in foreseeing those patients requiring supplementary analgesia. Hence, a tailored analgesia protocol could be performed for each patient, improving pain management and perioperative outcomes. A multimodal analgesic protocol appears to represent the gold standard in the treatment of acute postoperative pain, especially in patients with morbid obesity, who require a rapid retrieval of physiologic functions in order to reduce the risk of postoperative complications