Postoperative pain after major abdominal surgery: is it gender related? An observational prospective study

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.

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 μg/mL droperidol. Morphine consumption and VAS scores at rest and after cough were recorded 2, 4, 8, 24, and 48 hours postoperatively.

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).

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.