Nonopioid Analgesics and Cholecystectomy

Nefopam is a centrally-acting anti-nociceptive compound with supraspinal and spinal sites of action. It inhibits monoamine reuptake, modulates descending serotoninergic pain, and may also interact with a dopaminergic pathway. Because its mechanism of action is distinct from that of other analgesic opioids, nefopam may well have a role in analgesic protocols. The role of nefopam in multimodal analgesia has been extensively investigated in laparoscopic cholecystectomy. However, there is general agreement that more studies are needed to determine the ideal multimodal strategy. No previous study has investigated a combination regimen of the three most commonly prescribed non-opioid analgesics (NOA) (nefopam, ketoprofen, and paracetamol) vs ketoprofen and paracetamol combination during sevoflurane-dexmedetomidine based anesthesia on pain control after laparoscopic cholecystectomy.

The aim of our study is to compare a combination regimen of three NOA (nefopam, ketoprofen, and paracetamol) vs ketoprofen and paracetamol combination during sevoflurane-dexmedetomidine based anesthesia on pain control after laparoscopic cholecystectomy. We will try to demonstrate the benefit with the addition of a third NOA, which is the nefopam, to the double-drug regimen including ketoprofen and paracetamol. Our hypothesis is that this combination regimen of three NOA is associated with less postoperative pain, less opioid consumption, shorter length of post-anesthesia care unit (PACU) stay, and fewer opioid-related adverse effects and postoperative complications compared to the double-drug regimen of ketoprofen and paracetamol.

In this prospective randomized double-blind study, 90 patients aged 18 to 64 years, with American Society of Anesthesiologists (ASA) physical status I and II, will be randomly assigned using a computer-generated random number table to one of two treatment groups. Group A will receive sevoflurane-dexmedetomidine based anesthesia with ketoprofen and paracetamol for postoperative pain control, and group B will receive sevoflurane-dexmedetomidine based anesthesia with nefopam, ketoprofen, and paracetamol for postoperative pain control. The primary outcome measure of this study is total morphine consumption in PACU. Normally distributed data will be summarized as mean ± SD and non-normally distributed data will be summarized as median [interquartile range]. This study would have an impact on our current practice and may help find out the best multimodal analgesic strategy to control postoperative pain after laparoscopic cholecystectomy.

Inclusion criteria

• ASA physical status I-II
• Age between 18 and 64 years
• Patients able to give consent

Exclusion criteria

• ASA physical status III to V
• History of chronic pain
• Use of an opioid analgesic within 12 hours prior to surgery
• Alcohol or drug abuse
• Chronic opioid intake
• Morbid obesity
• Psychiatric disorder
• Pregnancy or breast-feeding
• Intolerance to NSAIDSs
• Allergy or contraindication to nefopam (acute angle-closure glaucoma, epilepsy, coronary artery disease, prostate adenoma), to morphine or paracetamol (liver failure), to ketoprofen (increased risk of bleeding, stomach or intestinal ulcer, chronic kidney disease) or to dexmedetomidine (uncontrolled hypertension, heart block greater than first degree, or other clinically significant morbidities)