Spinal Anesthesia With Hyperbaric Levobupivacaine 0.75% for Ambulatory Knee Arthroscopy: A Double Blind, Randomized Clinical Trial Comparing Three Low Doses
Spinal Anesthesia With Hyperbaric Levobupivacaine 0.75% for Ambulatory Knee Arthroscopy: A Double Blind, Randomized Clinical Trial Comparing Three Low Doses
The purpose of this study is to evaluate motor block probability throughout time and clinical profile when using three different doses of HLBP 0.75% (7.5, 9.37 and 11.25 mg) by a unilateral spinal block technique.
Previous IRB approval and informed consent, 180 ASA I-II adults under ambulatory knee arthroscopy will be randomly allocated to receive unilateral spinal anesthesia with 7.5 (group Levo-7.5, n=59), 9.37(group Levo-9.37, n=61) and 11.25 (group Levo-11.25, n=60) mg of HLBP 0.75% using a 27-gauge Whitacre needle at a rate of 0.1 ml/ seg. and lateral decubitus position maintained for 5 min after injection.
An independent observer will evaluate motor (modified Bromage scale) and sensory (transcutaneal electrical stimulation at T10, L1, L3, and S1 dermal segments) levels and presence of adverse events immediately after return to supine, at the end of surgery and each 10 min from admission to PACU until home discharge conditions.
Trans-cutaneal electrical stimulation (TES) will be made with a PNS (Ministim® model MS- IV, Organon, Dublin, Irland) using 50-Hz tetanus stimuli for 5 seg. from 10 to 60 mA 3,4.
Inclusion Criteria:
Exclusion Criteria: