Assessing the feasibility of a randomised, double-blinded, placebo-controlled trial to investigate the role of intraperitoneal ropivacaine in gastric bypass surgery: a protocol

Perioperative Pain Management in Bariatric Anesthesia

Weight loss (bariatric) surgery is the most commonly performed elective surgical procedure in patients with morbid obesity. In this review, we provide an evidence-based update on perioperative pain management in bariatric anesthesia. We mention some newer preoperative aspects—medical optimization, physical preparation, patient education, and psychosocial factors—that can all improve pain management. In the intraoperative period, with bariatric surgery being almost universally performed laparoscopically, we emphasize the use of non-opioid adjuvant infusions (ketamine, lidocaine, and dexmedetomidine) and suggest some novel regional anesthesia techniques to reduce pain, opioid requirements, and side effects. We discuss some postoperative strategies that additionally focus on patient safety and identify patients at risk of persistent pain and opioid use after bariatric surgery. This review suggests that the use of a structured, step-wise, severity-based, opioid-sparing multimodal analgesic protocol within an enhanced recovery after surgery (ERAS) framework can improve postoperative pain management. Overall, by incorporating all these aspects throughout the perioperative journey ensures improved patient safety and outcomes from pain management in bariatric anesthesia.

Effect of intraperitoneal local anesthesia on enhanced recovery outcomes after bariatric surgery: a randomized controlled pilot study

Background:

Patients with extreme obesity are at high risk for adverse perioperative events, especially when opioid-centric analgesic protocols are used, and perioperative pain management interventions in bariatric surgery could improve safety, outcomes and satisfaction. We aimed to evaluate the impact of intraperitoneal local anesthesia (IPLA) on enhanced recovery after bariatric surgery (ERABS) outcomes.

Methods:

We conducted a prospective double-blind randomized controlled pilot study in adherence to an a priori peer-reviewed protocol. Patients undergoing laparoscopic Roux-en-Y gastric bypass surgery (LRYGB) with an established ERABS protocol between July 2014 and February 2015 were randomly allocated to receive either IPLA with 0.2% ropivacaine (intervention group) or normal saline (control group). We measured pain scores, analgesic consumption and adverse effects. Functional prehabilitation outcomes, including peak expiratory flow (PEF) and the Six Minute Walk Test (6MWT) and Quality of Recovery Survey-40 (QoR-40) scores, were assessed before surgery, and 1 day and 7 days postoperatively.

Results:

One hundred patients were randomly allocated to the study groups, of whom 92 completed the study, 46 in each group. There were no statistically significant differences between the 2 groups in baseline characteristics or any primary or secondary outcomes. Pain scores and analgesic consumption were low in both groups. There were no adverse events. Significant declines in PEF and 6MWT and QoR-40 scores were noted on postoperative day 1 in both groups; the values returned to baseline on postoperative day 7 in both groups.

Conclusion:

Intraperitoneal local anesthesia with ropivacaine did not reduce postoperative pain or analgesic consumption when administered intraoperatively to patients undergoing LRYGB. Standardization of the ERABS protocol benefited patients, with functional prehabilitation outcomes returning to baseline postoperatively. Trial registration:ClinicalTrials.gov no. NCT 02154763

Intraoperative use of methadone improves control of postoperative pain in morbidly obese patients: a randomized controlled study

Objectives

Surgical patients still commonly experience postoperative pain. With the increasing prevalence of obesity, there is a growing demand for surgical procedures by this population. Intraoperative use of methadone has not been well assessed in this population.

Materials and methods

Patients with a body mass index of 35 kg/m² or more undergoing bariatric surgery were randomly assigned to receive either fentanyl (group F) or methadone (group M) in anesthesia induction and maintenance. The primary outcome was morphine consumption during the first 24 hours after surgery through a patient-controlled analgesia device. Secondary outcomes were pain scores at rest and while coughing, opioid related side effects, and patient satisfaction. The patients were also evaluated 3 months after surgery for the presence of pain, dysesthesia, or paresthesia at surgical site.

Results

Postoperative morphine consumption was significantly higher for patients receiving fentanyl than methadone during the postoperative period at 2 hours (mean difference [MD] 6.4 mg; 95% CI 3.1-9.6; P<0.001), 2-6 hours (MD 11.4 mg; 95% CI 6.5-16.2; P<0.001), 6-24 hours (MD 10.4 mg; 95% CI 5.0-15.7; P<0.001), and 24-48 hours (MD 14.5 mg; 95% CI 3.9-25.1; P=0.01). Patients from group F had higher pain scores until 24 hours postoperatively, higher incidence of nausea and vomiting, lower satisfaction, and more evoked pain at surgical scar at the 3-month postoperative evaluation than group M.

Conclusion

Intraoperative methadone can safely lower postoperative opioid consumption and improve postoperative pain scores compared with fentanyl in morbidly obese patients.