The effect of pH adjustment of 2% mepivacaine on epidural anesthesia.
Two-hundred men, scheduled for elective meniscectomy under epidural anesthesia, were randomly assigned to receive either a standard 2% mepivacaine solution (n = 100) or a pH adjusted 2% mepivacaine solution (pHAS, n = 100). The pHAS was freshly prepared before the block by adding 0.1 mEq of NaHCO3 per ml of mepivacaine solution. After a test-dose, the anesthetic solution was injected to produce a level of sensory anesthesia to T10. The mean duration of anesthesia and the mean dose of mepivacaine used were comparable between the groups. Patients in the pHAS group showed a significant shortening of onset time in T10 and in S2 segment (p less than .001). Grade 3 motor blockade was achieved in the same number of patients, but a faster motor block was observed in the pHAS group (p less than .05). Regression of both sensory and motor blockade in the two groups was not significantly different.
Capogna
G
G
Department of Anesthesiology, Fatebenefratelli Isola Tiberina General Hospital, Rome, Italy.
Celleno
D
D
Tagariello
V
V
D000328:Adult; D000767:Anesthesia, Epidural; D001639:Bicarbonates / Q000008:administration & dosage; D004311:Double-Blind Method; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008619:Mepivacaine; D012964:Sodium / Q000008:administration & dosage; D017693:Sodium Bicarbonate
D001639:Bicarbonates; D017693:Sodium Bicarbonate; D012964:Sodium; D008619:Mepivacaine