A prospective, double-blinded, randomized, clinical trial comparing the efficacy of 40 mg and 60 mg hyperbaric 2% prilocaine versus 60 mg plain 2% prilocaine for intrathecal anesthesia in ambulatory surgery.
BACKGROUND
In this prospective, double-blind, randomized trial we compared 60 mg and 40 mg of 2% hyperbaric prilocaine with 60 mg of 2% plain prilocaine for spinal anesthesia in terms of sensory block onset in outpatients undergoing elective short-duration (<60 minutes) surgery under spinal anesthesia.


METHODS
Ninety patients were enrolled and randomly allocated to receive 1 of the 3 treatments. Times to sensory and motor block onsets, time to the maximum sensory block level, readiness for surgery, time to first urinary voiding, time to Bromage's score 0, and side effects were registered blindly. A blinded observer also questioned patients about transient neurological symptoms 24 hours and 7 days after spinal anesthesia.


RESULTS
Mean times to achieve a T10 level of sensory block were comparable in the 3 groups. However, 20% of patients receiving plain prilocaine did not achieve a T10 level. The 2 hyperbaric dosages (60 mg and 40 mg) showed significantly faster times to motor block onset (P = 0.0091, P = 0.0097), to the maximum sensory block level (P = 0.0297, P = 0.0183), to motor block offset (P = 0.0004, P < 0.0001), and to first urinary voiding (P = 0.0013, P = 0.0002, respectively) than did plain prilocaine. No major adverse reactions or transient neurological symptoms were observed in the study.


CONCLUSIONS
Spinal anesthesia with 60 mg or 40 mg of 2% hyperbaric prilocaine is comparable to 60 mg of 2% plain prilocaine in terms of onset of sensory block at T10. The hyperbaric solution showed faster times to motor block onset and shorter duration of surgical block, suggesting its superiority for the ambulatory setting.
Department of Anesthesiology, University of Pittsburgh Medical Center, 5230 Center Avenue, Suite M-104, Pittsburgh, PA 15232, USA.
Claudio
C
Camponovo
Andrea
A
Fanelli
Daniela
D
Ghisi
Daniela
D
Cristina
Guido
G
Fanelli
D000328:Adult; D000368:Aged; D000556:Ambulatory Surgical Procedures; D000775:Anesthesia, Spinal / Q000009:adverse effects; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D002626:Chemistry, Pharmaceutical; D004311:Double-Blind Method; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects; D011318:Prilocaine / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D012677:Sensation / Q000187:drug effects; D013997:Time Factors; D016896:Treatment Outcome
D000779:Anesthetics, Local; D011318:Prilocaine