Balanced Opioid-free Anesthesia with Dexmedetomidine versus Balanced Anesthesia with Remifentanil for Major or Intermediate Noncardiac Surgery.

BACKGROUND: It is speculated that opioid-free anesthesia may provide adequate pain control while reducing postoperative opioid consumption. However, there is currently no evidence to support the speculation. The authors hypothesized that opioid-free balanced anesthetic with dexmedetomidine reduces postoperative opioid-related adverse events compared with balanced anesthetic with remifentanil. METHODS: Patients were randomized to receive a standard balanced anesthetic with either intraoperative remifentanil plus morphine (remifentanil group) or dexmedetomidine (opioid-free group). All patients received intraoperative propofol, desflurane, dexamethasone, lidocaine infusion, ketamine infusion, neuromuscular blockade, and postoperative lidocaine infusion, paracetamol, nefopam, and patient-controlled morphine. The primary outcome was a composite of postoperative opioid-related adverse events (hypoxemia, ileus, or cognitive dysfunction) within the first 48 h after extubation. The main secondary outcomes were episodes of postoperative pain, opioid consumption, and postoperative nausea and vomiting. RESULTS: The study was stopped prematurely because of five cases of severe bradycardia in the dexmedetomidine group. The primary composite outcome occurred in 122 of 156 (78%) dexmedetomidine group patients compared with 105 of 156 (67%) in the remifentanil group (relative risk, 1.16; 95% CI, 1.01 to 1.33; P = 0.031). Hypoxemia occurred 110 of 152 (72%) of dexmedetomidine group and 94 of 155 (61%) of remifentanil group patients (relative risk, 1.19; 95% CI, 1.02 to 1.40; P = 0.030). There were no differences in ileus or cognitive dysfunction. Cumulative 0 to 48 h postoperative morphine consumption (11 mg [5 to 21] versus 6 mg [0 to 17]) and postoperative nausea and vomiting (58 of 157 [37%] versus 37 of 157 [24%]; relative risk, 0.64; 95% CI, 0.45 to 0.90) were both less in the dexmedetomidine group, whereas measures of analgesia were similar in both groups. Dexmedetomidine patients had more delayed extubation and prolonged postanesthesia care unit stay. CONCLUSIONS: This trial refuted the hypothesis that balanced opioid-free anesthesia with dexmedetomidine, compared with remifentanil, would result in fewer postoperative opioid-related adverse events. Conversely, it did result in a greater incidence of serious adverse events, especially hypoxemia and bradycardia.

Effect of opioid-free anaesthesia on postoperative epidural ropivacaine requirement after thoracic surgery: A retrospective unmatched case-control study.

INTRODUCTION: Patients undergoing thoracic surgery are at risk of severe postoperative pain. Post-thoracotomy pain relief is usually provided with thoracic epidural analgesia (TEA). Intraoperative use of opioids may result in hyperalgesia and increase analgesics consumption. We investigated the effect of opioid-free anaesthesia (OFA) on epidural ropivacaine requirement after thoracotomy. METHODS: This retrospective study compared postoperative epidural ropivacaine requirement of patients undergoing open thoracotomy and receiving either opioid-based anaesthesia (OBA group) or a non-opioid regimen including clonidine, ketamine and lidocaine (OFA group). All patients received postoperative multimodal analgesia including both epidural analgesia and intravenous analgesics. The primary outcome was the cumulative first 48 postoperative hours epidural ropivacaine consumption. Secondary outcomes included postoperative pain scores, requirement for postoperative morphine titration, total opioid analgesics consumption within the first 48 postoperative hours, incidence of nausea and vomiting, intraoperative haemodynamic. RESULTS: From January 2015 to February 2018, 50 patients received an OBA and 25 received an OFA. The cumulative first 48 postoperative hours epidural ropivacaine consumption was significantly higher in the OBA-group (919 ± 311 mg versus 693 ± 270 mg, P = 0.002). Numerical Rating Scale at 6 and 24 h were significantly lower in the OFA-group (1[0-2] versus 3 [1-5], P = 0.0005 and 1[0-2] versus 3.5 [1-5], P = 0.001). In post-anaesthesia care unit, the proportion of patients requiring morphine was significantly higher in the OBA-group (42% versus 4%, P < 0.001). During anaesthesia, the OBA-group required more vasopressor support, while there were more hypertensive events in the OFA-group. CONCLUSION: OFA might reduce ropivacaine consumption, early postoperative pain scores and requirement for morphine titration after thoracotomy.

POFA trial study protocol: a multicentre, double-blind, randomised, controlled clinical trial comparing opioid-free versus opioid anaesthesia on postoperative opioid-related adverse events after major or intermediate non-cardiac surgery.

INTRODUCTION: Reducing opioid consumption during and after surgery has been recommended for more than 10 years. Opioid-free anaesthesia (OFA) is a multimodal anaesthesia associating hypnotics, NMDA antagonists, local anaesthetics, anti-inflammatory drugs and α-2 agonists. Proofs of the effect of OFA on reducing opioid-related adverse effects after major or intermediate non-cardiac surgery are still scarce. We hypothesised that the reduced opioid consumption allowed by OFA compared with standard of care will be associated with a reduction of postoperative opioid-related adverse events. METHODS/ANALYSIS: The POFA trial is a prospective, randomised, parallel, single-blind, multicentre study of 400 patients undergoing elective intermediate or major non-cardiac surgery. Patients will be randomly allocated to receive either a standard anaesthesia protocol or an OFA. The primary outcome measure is the occurrence of a severe postoperative opioid-related adverse event within the first 48 hours after extubation defined as: postoperative hypoxaemia or postoperative ileus or postoperative cognitive dysfunction. In addition, each component of the primary outcome measure will be analysed separately. Data will be analysed on the intention-to-treat principle and a per-protocol basis. ETHICS AND DISSEMINATION: The POFA trial has been approved by an independent ethics committee for all study centres. Participant recruitment begins in November 2017. Results will be published in international peer-reviewed medical journals. TRIAL REGISTRATION NUMBER: NCT03316339; Pre-results.