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Effects of epinephrine and clonidine on plasma concentrations of spinal bupivacaine
Author(s) -
Boico O.,
Bonnet F.,
Mazoit J. X.
Publication year - 1992
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1992.tb03544.x
Subject(s) - medicine , bupivacaine , clonidine , epinephrine , anesthesia , blockade , group b , local anesthetic , surgery , receptor
ASA II–III patients, scheduled for peripheral vascular surgery, were included in a study designed to assess the effect of spinal epinephrine and clonidine on plasma concentrations of spinally administered 0.5% glucose‐free bupivacaine. Patients were allocated randomly to three groups to receive via a spinal catheter 22.5 mg (4.5 ml) of bupivacaine alone (Group B, 9 patients) or combined with 0.3 mg epinephrine (Group BE, 10 patients) or 0.15 mg clonidine (Group BC, 10 patients). Sensory blockade was assessed by pin‐prick and motor blockade on the Bromage scale. Bupivacaine plasma concentrations were measured by gas chromatography. A trend to prolongation of local anaesthetic blockade was documented in patients receiving bupivacaine plus epinephrine or clonidine. (Time to regression of sensory blockade to L2: 170 ± 75 min in Group B, 230 ± 50 min in Group BE, 232 ± 64 min in Group BC.) The maximum peak concentration (C max ), the time to reach C max (T max ) and the time‐concentration curve from 0–180 min (AUC) were not different for the three groups (C max 228 ± 112 ng · ml ‐1 in Group B, 215 ± 103 ng · ml ‐1 in Group BE, 234 ± 159 ng · ml ‐1 in Group BC; T max 41 ± 34 min in Group B, 59 ± 31 min in Group BE, 68 ± 32 min in Group BC; AUC 31.0 ± 1.7 mg · ml ‐1 · min ‐1 in Group B, 27.3 ± 1.1 mg · ml ‐1 · min ‐1 in Group BE, 27.0 ± 1.1 mg · ml ‐1 · min ‐1 in Group BC). The results of this study suggest that epinephrine and clonidine do not decrease blood resorption of spinal bupivacaine.