Low-Dose, Low-Concentration Levobupivacaine Plus Fentanyl Selective Spinal Anesthesia for Knee Arthroscopy

BACKGROUND: Selective sensory spinal anesthesia preserves lower limb motor function and thus facilitates postanesthesia care unit (PACU) bypass and reduces ambulation recovery time. METHODS: We compared the ambulation time and PACU bypass rate after using 3 low-dose, low-concentration levobupivacaine-fentanyl spinal solutions (5, 4, and 3 mg + 10 μg) in a double-blind study consisting of 90 patients (ASA physical status I and II) scheduled to undergo knee arthroscopy. RESULTS: The 3-mg dose was halted because of a large number of inadequate blocks (50%). Twenty-three percent and 80% of patients from groups 5 mg and 4 mg, respectively, bypassed the PACU (P = 0001). Ambulation took place after 70 minutes (30-130 minutes) (median [range]) in group 5 mg and 45 minutes (23-120 minutes) in group 4 mg (P = 0006). CONCLUSION: Four milligrams levobupivacaine plus 10 μg fentanyl produced adequate surgical anesthesia with the shortest time to ambulation and the highest PACU bypass rate.