RT Journal Article
SR Electronic
T1 Speed of Injection Does Not Affect Subarachnoid Distribution of Plain Bupivacaine 0.5%
JF Regional Anesthesia: The Journal of Neural Blockade in Obstetrics, Surgery, & Pain Control
JO Reg Anesth Pain Med
FD BMJ Publishing Group Ltd
SP 208
OP 210
DO 10.1136/rapm-00115550-199015040-00009
VO 15
IS 4
A1 Stienstra, Rudolf
A1 Van Poorten, Frans
YR 1990
UL http://rapm.bmj.com/content/15/4/208.abstract
AB Three milliliters of plain bupivacaine 0.5%, previously warmed to 37°C, was injected into the subarachnoid space in two groups of 20 patients. In Group 1, speed of injection of the bupivacaine solution was as fast as possible (mean, 0.54 ml/second), whereas in Group 2 the bupivacaine solution was administered at a rate of 0.05 ml/second. Patients were kept sitting for 3 minutes after completion of the subarachnoid injection. All observations were made by an observer unaware of the speed of injection. There were no statistically significant differences in onset to maximal level of sensory block (17.2 minutes in Group 1 versus 19 minutes in Group 2) or complete motor block of the lower limbs (9 minutes in both groups). The difference in the maximal level of sensory block as determined by pinprick (T4.9 in Group 1 versus T3.4 in Group 2) was statistically significant; this difference may be explained by the fact that the plain solution of bupivacaine 0.5% at 37°C is hypobaric and patients in Group 2 were in the sitting position for 1 minute longer when measured from the start of the subarachnoid injection. It is concluded that a tenfold difference in speed of injection does not significantly affect subarachnoid spread or onset of sensory and motor block with 0.5% bupivacaine.