Comparison of glucose 7.5% and 0.75% with or without phenylephrine for tetracaine spinal anaesthesia.
OBJECTIVE
To investigate whether a marginally hyperbaric tetracaine solution with or without phenylephrine could produce consistent blocks as compared with a conventionally hyperbaric tetracaine solution injected at L3-4 interspace with the patient in the lateral position.


METHODS
We studied 120 ASA I or II patients scheduled for elective surgery to the lower limb. Patients were randomly divided into four equal groups to receive spinal anaesthesia using tetracaine 0.5% in glucose 0.75% or 7.5%, with or without phenylephrine 0.125%. Neural block was assessed in a double-blind manner by cold, pinprick, and touch sensation, and a modified Bromage scale after the injection of the study drug.


RESULTS
The median (10th, 90th percentiles) peak dermatomal level to pinprick obtained by the solutions in glucose 0.75% was T10 (L1, T5), which was lower than that obtained by the solution in glucose 7.5% extending to T5 (T10, T3) and T5 (T10, T2) with or without phenylephrine, respectively (P < 0.0001). The addition of phenylephrine prolonged the time to two-segment regression but did not change the maximum extent of blocks.


CONCLUSIONS
A marginally hyperbaric tetracaine with or without phenylephrine produced consistent blocks with spread restricted to the lower thoracic segments when administered intrathecally at the L3-4 interspace with the patient in the lateral position.
Sumi
M
M
Department of Anesthesiology, Shimane Medical University, Izumo City, Japan.
Sakura
S
S
Sakaguchi
Y
Y
Saito
Y
Y
Kosaka
Y
Y
D000328:Adult; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D005947:Glucose / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010656:Phenylephrine / Q000008:administration & dosage*; D013748:Tetracaine / Q000008:administration & dosage*
D000779:Anesthetics, Local; D013748:Tetracaine; D010656:Phenylephrine; D005947:Glucose