# Comparative Effects of Oral Pregabalin, Intravenous Magnesium Sulphate, and Their Combination Given Preoperatively on Acute Post-thoracotomy Pain: A Double-Blinded Randomised Study

## TL;DR

This study compares how preoperative pregabalin, magnesium sulphate, and their combination affect post-thoracotomy pain and opioid use.

## Contribution

The study introduces a novel combination of preoperative pregabalin and magnesium sulphate for improved post-thoracotomy pain management.

## Key findings

- The combination group had the lowest morphine consumption and pain scores in the first 24 hours.
- The combination reduced the need for rescue analgesia and postoperative nausea and vomiting.
- Pregabalin alone was more effective than magnesium sulphate alone in reducing opioid use.

## Abstract

Introduction: Post-thoracotomy pain can lead to psychological distress and impair pulmonary function. Effective perioperative pain management is essential to prevent long-term complications. This study assesses the analgesic benefits of intravenous magnesium sulphate and preoperative oral pregabalin, both separately and in combination, in the treatment of acute post-thoracotomy pain.

Methods: Following ethical permission, 75 patients undergoing thoracotomy who were between the ages of 19 and 70 and had Physical Status II or III according to the American Society of Anesthesiologists were assigned to three groups at random: Group MP received 100 ml of normal saline supplemented with 50 mg/kg of intravenous magnesium sulphate and 300 mg of oral pregabalin, Group M received a placebo capsule and 50 mg/kg intravenous magnesium sulphate, and Group P received intravenous saline and 300 mg oral pregabalin. Intravenous infusions were given half an hour before surgery, and oral medicines were given an hour before.

Primary objective: This study aimed to compare 24-hour total morphine consumption (basal patient-controlled analgesia (PCA) infusion + patient-activated boluses) among pregabalin, magnesium sulphate, and combination groups.

Secondary objectives: This study aimed to compare postoperative Visual Analogue Scale (VAS) pain scores (one, two, four, six, eight, 12, 24 hours), duration of analgesia (time to first rescue), number of rescue boluses, incidence of postoperative nausea and vomiting (PONV) requiring treatment, Ramsay Sedation Scale scores, and patient satisfaction.

Results: In the first 24 hours after surgery, Group MP consumed the least amount of morphine (25.44 ± 2.50 mg), followed by Group P (27.00 ± 2.85 mg) and Group M (28.48 ± 2.90 mg). Group MP also had the lowest VAS scores, frequency of rescue analgesia, and incidence of PONV, with Group M showing the highest values (p < 0.001).

Conclusion: Pregabalin and magnesium sulphate administered together prior to surgery successfully lower postoperative pain and the need for opioids in thoracotomy patients.