Predicting postoperative pain by preoperative pressure pain assessment.
BACKGROUND
The goal of this study was to evaluate whether preoperative pressure pain sensitivity testing is predictive of postoperative surgical pain.


METHODS
Female subjects undergoing lower abdominal gynecologic surgery were studied. A pressure algometer was used preoperatively to determine the pressure pain threshold and tolerance. A visual analog scale (VAS) was used to assess postoperative pain. A State-Trait Anxiety Inventory was used to assess patients' anxiety. Subjects received intravenous patient-controlled analgesia for postoperative pain control. The preoperative pain threshold and tolerance were compared with the postoperative VAS pain score and morphine consumption.


RESULTS
Forty women were enrolled. Their preoperative pressure pain threshold and tolerance were 141 +/- 65 kPa and 223 +/- 62 kPa, respectively. The VAS pain score in the postanesthesia care unit and at 24 h postoperatively were 81 +/- 24 and 31 +/- 10, respectively. Highly anxious patients had higher VAS pain scores in the postanesthesia care unit (P < 0.05). Pressure pain tolerance was significantly correlated with the VAS at 24 h postoperatively (P < 0.001, r = -0.52). Pressure pain tolerance after fentanyl administration (mean, 272 +/- 68 kPa) correlated significantly with morphine consumption in the first 24 h postoperatively (P < 0.002, r = -0.48).


CONCLUSIONS
Assessment of preoperative pressure pain tolerance is significantly correlated with the level of postoperative pain. Pain tolerance assessment after fentanyl was administered and fentanyl sensitivity predicted the dose of analgesics used in the first 24 h after surgery. The algometer is thus a simple, useful tool for predicting postoperative pain and analgesic consumption.
Hsu
Yung-Wei
YW
Department of Anesthesiology, Mackay Memorial Hospital, Taipei, Taiwan. yungwei.hsu@msa.hinet.net
Somma
Jacques
J
Hung
Yu-Chun
YC
Tsai
Pei-Shan
PS
Yang
Chen-Hsien
CH
Chen
Chien-Chuan
CC
D000328:Adult; D016058:Analgesia, Patient-Controlled; D001007:Anxiety / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage; D010147:Pain Measurement; D017288:Pain Threshold; D010149:Postoperative Pain / Q000503:physiopathology*; D011312:Pressure
D009020:Morphine