Postoperative Pain after Major Abdominal Surgery: Is It Gender Related? An Observational Prospective Study

Objectives: Gender may be associated with postoperative pain. This study aimed to assess pain intensity and postoperative analgesic requirements in female and male patients scheduled for major abdominal surgery. Methods: Sixty-five patients, 31 men and 34 women, scheduled for major abdominal surgery were recruited. Anesthesia and intraoperative analgesics were standardized in all patients. Postoperatively, all patients had access to a 60 mL PCA pump containing 1 mg/mL morphine and 50 lg/mL droperidol. Morphine consumption and VAS scores at rest and after cough were recorded 2, 4, 8, 24, and 48 hours postoperatively. Results: Of the 65 patients recruited for the study, 30 women and 30 men aged 65 +/- 8.9 and 66 +/- 9.0 years, respectively, were included in the analysis. Morphine consumption was examined 2, 4, 8, 24, and 48 hours after surgery and did not differ in women vs. men (mean +/- standard deviation, 4.4 +/- 3.2 vs. 5 +/- 4.8, 7.2 +/- 4.8 vs. 8.7 +/- 6.9, 10.4 +/- 7.1, vs. 12.5 +/- 8.5, 22.9 +/- 11.6 vs. 25.6 +/- 14.5, and 36.2 +/- 15.7 vs. 39.7 +/- 21.7 mg, P = 0.384). Cumulative morphine consumption was not significantly different in women vs. men when normalized for body mass index (mean +/- standard deviation, 0.17 +/- 0.13, 0.28 +/- 0.20, 0.40 +/- 0.30, 0.88 +/- 0.46, and 1.38 +/- 0.59 mg/kg/m(2) in women and 0.18 +/- 0.18, 0.31 +/- 0.25, 0.46 +/- 0.32, 0.95 +/- 0.54, and 1.47 +/- 0.81 mg/kg/m(2) in men at 2, 4, 8, 24, and 48 hours postoperatively (P = 0.567). Both genders exhibited similar VAS pain scores (mm) at rest and after cough (P = 0.476, P = 0.378, respectively). Conclusions: Postoperative morphine requirements did not differ between female and male patients undergoing major abdominal surgery. Pain intensity reported at rest and after cough did not differ between the 2 groups.