Effect of speed of injection on the maximum sensory level for spinal anesthesia using plain bupivacaine 0.5% at room temperature.
OBJECTIVE
The aim of this study was to investigate if a ten-fold difference in speed of injection of a plain solution of bupivacaine 0.5% at room temperature into the subarachnoid space would result in a temperature-dependent change in baricity large enough to be reflected in a significant difference between the maximum levels of sensory blockade.


METHODS
In this prospective study, 40 male patients were randomly assigned to one of two groups. Group 1 patients received 3 ml plain bupivacaine 0.5% (20-22 degrees C) with the speed of injection as fast as possible. Group 2 patients received 3 ml plain bupivacaine 0.5% (20-22 degrees C) at a rate of 0.05 ml/sec. Thirty minutes after subarachnoid injection the maximum level of sensory blockade was determined by pinprick in the anterior axillary line by a blinded observer.


RESULTS
The mean maximum level of sensory blockade in patients of group 1 was T7.5 (median, T7; range, T3-12) and in group 2 patients T6.4 (median, 5.5; range, T3-11), the difference not being statistically significant (p > 0.05).


CONCLUSIONS
There is no clinically relevant influence on the maximum level of sensory blockade when bupivacaine 0.5% at room temperature is injected with a ten-fold difference in speed.
Bucx
M J
MJ
Department of Anesthesiology, Erasmus University Rotterdam, The Netherlands.
Kroon
J W
JW
Stienstra
R
R
D000368:Aged; D000369:Aged, 80 and over; D000775:Anesthesia, Spinal; D002045:Bupivacaine / Q000008:administration & dosage*; D005837:Genitalia, Male / Q000601:surgery*; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D009475:Neurons, Afferent / Q000187:drug effects* / Q000502:physiology; D011446:Prospective Studies; D013346:Subarachnoid Space; D013997:Time Factors
D002045:Bupivacaine