Testing of a new pneumatic device to cause pain in humans.
BACKGROUND
Surgical pain typically combines superficial and deep pain. We wished to generate pain that resembled surgical pain, reliably and reproducibly, in volunteers.


METHODS
We constructed a computer-controlled pneumatic device to apply pressure to the anterior tibia. The reproducibility of the pain was tested by rating the pressure that caused pain rated 4-5 on a visual analogue scale (VAS) on days 0, 7, and 24 in 10 volunteers. The effect of remifentanil (0.025, 0.05, 0.075, and 0.1 microg kg-1 min-1) on pain tolerance in another set of volunteers (n=11) was used as an indirect measure of the reliability of pain production.


RESULTS
The pressure needed (0.7 (0.3) to 0.9 (0.4) atm (mean (SD)) to induce pain rated 4-5 (VAS) did not vary, showing long-term reproducibility of the method. When pressure was applied to cause increasing pain in volunteers (n=11) 0.05 microg kg-1 min-1 remifentanil increased pain tolerance by 50%. An approximate doubling of the dose (0.1 microg kg-1 min-1) increased pain tolerance significantly more. The linear logarithmic dose-effect relationship shows that the device causes pain reliably, and this can be reduced with opioid treatment.


CONCLUSIONS
This pneumatic device can apply pain reliably and reproducibly.
Schubert
H M
HM
Department of Trauma Surgery and Sports Medicine, University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria. heinrich.schubert@uibk.ac.at
Lorenz
I H
IH
Zschiegner
F
F
Kremser
C
C
Hohlrieder
M
M
Biebl
M
M
Kolbitsch
C
C
Moser
P L
PL
D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004867:Equipment Design; D006801:Humans; D007262:Infusions, Intravenous; D008279:Magnetic Resonance Imaging; D008297:Male; D010146:Pain / Q000503:physiopathology*; D017288:Pain Threshold; D010880:Piperidines / Q000008:administration & dosage; D011312:Pressure; D000077208:Remifentanil; D015203:Reproducibility of Results; D013977:Tibia
D000701:Analgesics, Opioid; D010880:Piperidines; D000077208:Remifentanil