Current perception thresholds and postoperative pain in schizophrenic patients.
OBJECTIVE
Schizophrenic patients may have less sensitivity to pain; however, pain insensitivity in schizophrenia has not been adequately evaluated. We investigated current perception threshold (CPT) and postoperative pain intensity in patients with long-standing and treated schizophrenia and control patients.


METHODS
We measured CPTs for 2,000 Hz, 250 Hz, and 5 Hz and postoperative pain intensity using a visual analogue scale (VAS) in 50 chronic schizophrenic patients who were on chronic phenothiazine derivatives (> 10 years) and for 25 control patients.


RESULTS
CPTs for 2,000 Hz, 250 Hz, and 5 Hz in schizophrenic patients were 334.2 +/- 112.2, 303.9 +/- 117.1, and 165.0 +/- 72.3, respectively. CPTs for 2,000 Hz, 250 Hz, and 5 Hz in schizophrenic patients were significantly higher than those of control patients. VAS pain scores of schizophrenic patients were 4.0 +/- 1.7 at 2 hours post-operatively and 3.8 +/- 1.5 at 5 hours postoperatively, which were significantly (P < .05) lower than those (5.0 +/- 1.6 and 5.1 +/- 1.9) of the control group.


CONCLUSIONS
Chronic schizophrenic patients have increased current perception threshold and lower VAS pain scores in postoperative pain compared with control patients.
Kudoh
A
A
Department of Anesthesiology, University of Hirosaki School of Medicine, Aomori, Japan.
Ishihara
H
H
Matsuki
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A
D000328:Adult; D000368:Aged; D006801:Humans; D008875:Middle Aged; D010147:Pain Measurement; D017288:Pain Threshold; D010149:Postoperative Pain / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*