The effect of preemptive magnesium sulfate on postoperative pain in patients undergoing mastectomy: a clinical trial.

OBJECTIVE: The effects of preemptive magnesium sulfate (MgSO4) infusion on perioperative hemodynamics and postoperative analgesia in female patients who underwent mastectomy were evaluated.

PATIENTS AND METHODS: American Society of Anesthesiologists (ASA) I-II female patients aged 18 years and over who underwent mastectomy were randomized into 2 groups, including 34 individuals each. The study group (Group I) was given 50 mg/kg MgSO4 in 250 ml isotonic 30 minutes before the induction, and the control group (Group II) was given 250 ml of normal isotonic solution. Standardized anesthesia was applied. Perioperative oxygen saturation, mean arterial pressure (MAP), pulse (HR), sedation scores (ss) in the recovery unit, Verbal Numeric Rating Scale (VNRS), need for rescuer fentanyl, and analgesic needs in the surgical period were evaluated.

RESULTS: Demographic variables were similar. There was no statistical difference between the two groups in terms of the MAP, HR, and oxygen saturation values measured at entry, post-intubation, 15th, 30th, 45th, 60th minutes, and after extubation. There was a statistically significant difference between the two groups in terms of VNRS scores in the recovery unit and at the 2nd, 4th, 8th, and 12th hours during the postoperative surgical period (p=0.0001, 0.001, 0.001, 0.004, 0.021, respectively). The need for rescue analgesics in the first 2 hours of recovery was found to be lower in the study group (p=0.005). The need for postoperative analgesics in the surgical period was not statistically significant (p=0.1).

CONCLUSIONS: Preemptive use of MgSO4 reduces postoperative VNRS scores without affecting hemodynamic parameters during induction and maintenance of general anesthesia.