Spinal anaesthesia inhibits central temporal summation.
In a previous investigation we found that extradural anaesthesia did not adequately inhibit temporal summation of repeated electrical stimuli: pain to repeated stimuli was blocked in only one of 10 patients, and pain thresholds to repeated stimuli were significantly lower than pain thresholds to a single stimulus. In this study we have investigated in 10 patients the effect of spinal anaesthesia on temporal summation, assessed by repeated electrical stimulation of the sural nerve. Plain 0.5% bupivacaine 18 mg was injected at L2-3. The pain threshold to a single electrical stimulus, summation threshold (increase in perception during repeated electrical stimuli with five impulses of the same intensity at 2 Hz), pinprick and cold sensation were assessed. After spinal anaesthesia, pain to both single and repeated stimulation, and pinprick and cold sensation, disappeared in all patients. We conclude that spinal anaesthesia inhibits temporal summation elicited by repeated electrical stimulation.
Curatolo
M
M
Institute of Anaesthesiology and Intensive Care, University of Bern, Inselspital, Switzerland.
Petersen-Felix
S
S
Arendt-Nielsen
L
L
Zbinden
A M
AM
D000293:Adolescent; D000328:Adult; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000494:pharmacology*; D002045:Bupivacaine / Q000494:pharmacology*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D013497:Sural Nerve
D000779:Anesthetics, Local; D002045:Bupivacaine