Study objective: To investigate postoperative pain and current perception thresholds in chronic depression in patients who are treated with antidepressants.
Design: Prospective, randomized study.
Setting: Hakodate Watanabe Hospital and Hirosaki National Hospital.
Patients: 30 patients with major depression and 30 control patients who underwent abdominal surgery with general anesthesia.
Interventions: Postoperative pain scores via visual analog scale (0-100), current perception thresholds at 5, 250, and 2000 Hz.
Measurements and main results: Postoperative pain scores of depressed patients at 8 and 16 hours after the end of anesthesia were 36.2 +/- 10.4 and 33.4 +/- 8.5, which were significantly higher than 25.2 +/- 9.3 and 22.7 +/- 8.5 scores of the control patients. Current perception thresholds at 5 Hz, 250 Hz, and 2000 Hz in depressed patients were 38.2 +/- 6.7, 76.1 +/- 11.3, and 190.8 +/- 19.2, respectively. There were no significant differences between the depressed patients and control patients in current perception thresholds at 5 Hz, 250 Hz, and 2000 Hz. We found that visual analog scale scores in depressed patients at 8 and 16 hours after the end of anesthesia correlated with the Hamilton Depression Scale scores before operation.
Conclusions: The degree of postoperative pain in depressed patients who take antidepressants depends on their depressive state.