The effect of subarachnoid lidocaine and combined subarachnoid lidocaine and epidural bupivacaine on electrical sensory thresholds.
Eight patients undergoing abdominal surgery received a combination of spinal anesthesia (catheter at L2-3 level) and epidural anesthesia (catheter at T10-11 level). Sensory thresholds to electrical stimulation were measured at the S1, L1, T10, and T5 levels before injection, after spinal anesthesia, and after the addition of epidural anesthesia. Subarachnoid injections with 5% lidocaine (without dextrose) were given until a T4 sensory level to pinprick was obtained (mean dose, 175 mg lidocaine). The mean sensory thresholds were increased from 2.2 +/- 0.3, 2.4 +/- 0.4, 2.9 +/- 0.4, and 3.8 +/- 0.4 mA to 21.3 +/- 4.3, 13.3 +/- 4.9, 10 +/- 4.4, and 10.6 +/- 4.3 mA, respectively (p less than 0.05 at all levels). The addition of 5 ml 0.5% epidural bupivacaine further increased the mean sensory thresholds to 26.9 +/- 3.1, 21.7 +/- 4.1, 21.3 +/- 4.1, and 17.5 +/- 4.7 mA, respectively (p less than 0.05 at all levels). Combined subarachnoid and epidural local anesthetics provide an enhanced afferent block not obtainable by either technique alone.
Dirkes
W E
WE
Department of Anesthesia, University of Cincinnati College of Medicine, Ohio.
Rosenberg
J
J
Lund
C
C
Kehlet
H
H
D000368:Aged; D000767:Anesthesia, Epidural; D000775:Anesthesia, Spinal; D002045:Bupivacaine; D004338:Drug Combinations; D006801:Humans; D008012:Lidocaine; D008875:Middle Aged; D012684:Sensory Thresholds / Q000187:drug effects*
D004338:Drug Combinations; D008012:Lidocaine; D002045:Bupivacaine