Onset of epidural blockade after plain or alkalinized 0.5% bupivacaine.
This double-blind study investigated the effect of adding 1.4% bicarbonate to 0.5% bupivacaine on onset time of sensory and motor blockade after epidural administration. Forty patients were randomly divided into one of two groups. Group 1 received 20 mL of 0.5% bupivacaine (pH, 5.58 +/- 0.12) and group 2 received 20 mL of 0.5% bupivacaine + 0.6 mL of 1.4% bicarbonate (pH, 6.53 +/- 0.06). Onset of temperature sensation loss occurred at L-1 after 5 min in both groups. The first signs of motor impairment were seen after 4 min in three patients in group 1 and two patients in group 2. Maximum motor blockade was reached after 30 min in group 1 and after 36 min in group 2. No difference in motor blockade or upward spread of anesthesia was noted between the two groups. The authors conclude that alkalinization of 0.5% bupivacaine offers no improvement in the onset of epidural blockade.
Verborgh
C
C
Department of Anaesthesiology, Flemish Free University of Brussels, Belgium.
Claeys
M A
MA
Camu
F
F
D000328:Adult; D015360:Analgesia, Epidural; D001639:Bicarbonates / Q000494:pharmacology*; D002045:Bupivacaine; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D009046:Motor Neurons / Q000187:drug effects*; D009407:Nerve Block; D011184:Postoperative Period; D012964:Sodium / Q000494:pharmacology*; D017693:Sodium Bicarbonate; D013697:Thermosensing / Q000187:drug effects
D001639:Bicarbonates; D017693:Sodium Bicarbonate; D012964:Sodium; D002045:Bupivacaine