Efficacy of preoperative oral pyridoxine in preventing postoperative nausea and vomiting in patients undergoing laparoscopic abdominal surgeries

Postoperative nausea and vomiting (PONV) are common complications following surgery and anaesthesia, affecting up to 30 percent of general surgical patients and up to 80 percent of those at high risk. PONV not only causes significant discomfort and dissatisfaction but can also lead to serious complications such as dehydration, wound dehiscence, aspiration pneumonia, and prolonged hospital stay, ultimately increasing healthcare costs. Effective prevention of PONV is essential for improving the quality of perioperative care and patient outcomes. Risk factors for PONV include both patient-related factors—such as female gender, non-smoking status, and postoperative opioid use and surgery-specific risks, particularly in laparoscopic, gynecological, breast, and ENT procedures. In laparoscopic surgeries, pneumoperitoneum leads to serotonin release and stimulation of nausea pathways. The Apfel Simplified Risk Score, based on patient factors, is commonly used to predict PONV risk. Current guidelines recommend a multimodal approach using combinations of antiemetic drugs such as 5-HT3 antagonists (e.g., ondansetron), corticosteroids (e.g., dexamethasone), NK-1 antagonists (e.g., aprepitant), and antidopaminergic agents. Despite this, PONV remains a frequent issue, prompting ongoing research into alternative therapies. Pyridoxine (vitamin B6), known for its antiemetic effect in pregnancy, is safe, cost-effective, and plays a role in neurotransmitter synthesis, particularly GABA. Although proven effective in obstetrics, its use in surgical patients is limited. Previous study shows intravenous pyridoxine reduced PONV in gynecologic laparoscopic surgery. However, its role in other surgeries and the efficacy of oral pyridoxine remain unstudied. This study aims to evaluate oral pyridoxine as an adjunct to ondansetron and dexamethasone for preventing PONV in adults undergoing elective laparoscopic abdominal surgeries. The hypothesis is that the addition of oral pyridoxine is superior to standard antiemetic prophylaxis and, it reduces the incidence of PONV in patients undergoing laparoscopic abdominal surgeries.

Aim

To study the efficacy of preoperative oral pyridoxine in preventing postoperative nausea and vomiting in patients undergoing laparoscopic abdominal surgeries.

Objectives

1. To compare the incidence of postoperative nausea, vomiting and retching up to 24 hours after laparoscopic surgery between patients receiving a combination of pyridoxine, ondansetron, and dexamethasone versus those receiving ondansetron and dexamethasone alone.
2. To compare the severity of postoperative nausea and vomiting in both the groups.
3. To compare the use of rescue antiemetics up to 24 hours in both the groups.
4. To monitor for any drug-related adverse events in the group receiving pyridoxine.
5. To compare the patient-reported satisfaction scores with respect to peri-operative management of PONV in both the groups.

Methodology

This randomized, double-blind, placebo-controlled trial aims to assess the efficacy of oral pyridoxine in preventing postoperative nausea and vomiting (PONV). Eligible patients will be randomly assigned into two groups using a computer-generated sequence with allocation concealment via sealed opaque envelopes. Group P (Pyridoxine) will receive 200 mg oral pyridoxine, dexamethasone at induction, and ondansetron before extubation. Group C (Control) will receive a matching oral placebo along with the same antiemetic regimen. All patients, surgeons, anaesthetists, assessors, and statisticians will remain blinded to group allocation. Preoperatively, patients will undergo Apfel scoring for PONV risk, provide informed consent, and complete a comprehensive pre-anaesthetic evaluation. Standard ASA fasting protocols and premedication with oral alprazolam 0.25 mg will be followed. On surgery day, standard monitors will be applied, and anaesthesia induction will be done using IV fentanyl, propofol, and vecuronium or cisatracurium. Intubation will follow, and anaesthesia will be maintained with sevoflurane in a 50-50 oxygen-nitrous oxide mixture. Postoperatively, patients will be monitored for 24 hours for nausea, vomiting, and retching, assessed using standard definitions and a 5-point Likert scale. Rescue antiemetic (IV metoclopramide 10 mg) will be provided if needed. Pain scores, opioid use, and patient satisfaction will be recorded. All data will be documented by a blinded assessor using standardized proformas.

Outcome Measures

Following observations will be recorded in all the patients:

1. The total incidence of postoperative nausea, retching and vomiting will be observed up to 24 hours in both the groups.
2. The severity of postoperative nausea and vomiting will be measured using Likert scale and then compared in both the groups.
3. The total use of rescue antiemetics up to 24 hours will be recorded in both the groups.
4. Any drug-related adverse event (like headache, tingling, numbness etc) will be recorded up to 24 hours in the group receiving pyridoxine.
5. The patient-reported satisfaction scores will be observed after 24 hours with respect to peri-operative management of postoperative nausea and vomiting in both the groups.