A Phase 4 interventional study of Lidocaine Hydrochloride and Ketamine in Laparoscopic Bariatric Surgery, sponsored by Mahidol University. Completed at 1 site in Thailand. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-05-09.
Sponsored by Mahidol University · Phase 4, Interventional, and Treatment
The most effective long-term treatment for obesity is bariatric surgery, however, postoperative pain control is challenging in these group of population. Opioid-sparing technique with multimodal analgesia is recommended but the evidence supported is still limited. Multimodal analgesia, particularly lidocaine and ketamine, has been used effectively in various type of surgery. However, the evidence supported their use in obese patients undergoing bariatric surgery is limited.
The prevalence of obesity and associated diseases have been increasing in recent decades. From 1980 to 2013, the number of adults with BMI more than 25 kg/m2 increased from 28.8% to 36.9% in men, and from 29.8% to 38% in women. According to World Health Organization (WHO), the prevalence of overweight among adults in Thailand in 2016 was 32.6%, markedly increased from 2011 which was 23.9%. To date, the most effective long-term treatment for obesity is bariatric surgery because of significantly reducing body fat, the development of new obesity-related conditions, and overall mortality. However, postoperative complications, particularly respiratory complication, are concerned because obesity is associated with respiratory compromise and sleep-disordered breathing. The 2016 guideline for perioperative care in bariatric surgery developed by enhanced recovery after surgery (ERAS) society state that, regarding to current evidence, there is no specific anesthetic agents or techniques for bariatric surgery, however, multimodal analgesia should be used to reduce opioid consumption and opioid-related complications such as respiratory depression, postoperative nausea and vomiting and ileus. Moreover, several studies supported opioid-sparing technique to avoid respiratory complications.
Intravenous lidocaine is widely used to reduce postoperative pain and to reduce perioperative opioid as a multimodal analgesia. From Cochrane review, perioperative lidocaine can decrease pain at rest, postoperative ileus and postoperative nausea and vomiting in elective and urgent surgery. Few trials in obese patients underwent laparoscopic bariatric surgery found that lidocaine infusion can decrease opioid consumption. However, the supported evidence is still limit. Ketamine has been used for postoperative analgesia as well, as an effective adjunct to decrease opioid consumption in various types of surgery, including open bariatric surgery. Moreover, the recent retrospective study (Tovikkai P, in press) found that there was a positive interaction between intraoperative lidocaine infusion and ketamine for decreasing opioid consumption in obese patients underwent laparoscopic bariatric surgery. However, the benefit of lidocaine and ketamine for postoperative pain in obese patients underwent laparoscopic bariatric surgery is still debated.
Therefore, we designed this study to examine the effect of intraoperative lidocaine infusion and intraoperative lidocaine infusion combined with intraoperative low-dose ketamine infusion on opioid consumption in obese patients undergoing laparoscopic bariatric surgery.
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Exclusion Criteria:
Participants in this arm will receive intra-operative lidocaine and ketamine infusion as adjunctive drugs for pain control. All medication is dosed based on calculated lean body weight (LBW) by Janmahasatian formula.
Drug: Lidocaine Hydrochloride · Drug: Ketamine
Participants in this arm will receive only intra-operative ketamine infusion as adjunctive drugs for pain control. All medication is dosed based on calculated lean body weight (LBW) by Janmahasatian formula.
Drug: Lidocaine Hydrochloride · Drug: Placebo
Participants in this arm will receive normal saline, same volume as lidocaine and ketamine.
Drug: Placebo
lidocaine will be given 1.5 mg/kg bolus at induction then 2mg/kg/hr until the end of surgery.
Also known as: Li
Ketamine will be given 0.35 mg/kg bolus at induction then 0.2 mg/kg/hr until the end of surgery.
Also known as: Ke
Normal saline will be given with the same rate of lidocaine or ketamine.
Also known as: Normal Saline
Opioid consumption
Opioid consumption at 24 hr post-operation using Morphine Milligram equivalents(MME)
Time frame: 24-hour
Score of post-extubation cough
post-extubation cough graded by care giver using modified Minogue scales, which defined grade1 as no coughing or muscular stiffness, grade 2 as coughing once or twice, or transient cough response to removal of tracheal tube that resolved with extubation, grade 3 as ≤ 3 coughs lasting 1-2 seconds, or total duration of coughing last ≤ 5 seconds and grade 4 as ≥ 4 coughs with each lasting \> 2 seconds, total duration of coughing last \> 5 seconds.
Time frame: up to 24 hours (at extubation period after surgery finished)
operative time
time since incision started until the last suture done recorded in minutes.
Time frame: intraoperative (since the incision started until finished the last suture)
anesthetic time
time since anesthetic started until finished and patient out of room recorded in minutes.
Time frame: intraoperative (since anesthetic started until patient out of the operating room)
the length of hospital stay
time since admission until discharge recorded in hours.
Time frame: until 30-day postoperation
numbers of participants with postoperative complications
cardiac arrhythmia, myocardial infarction, respiratory compromised, reintubation, readmission.
Time frame: until 30-day postoperation
Score of sore throat
sore throat score grading by self-assessment score, which defined grade 0 as no sore throat, grade 1 as minimal sore throat, grade 2 as moderate sore throat and grade 3 as severe sore throat.
Time frame: assess at 24-hour post-operation
Plan to share: No
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