Dexamethasone added to mepivacaine prolongs the duration of analgesia after supraclavicular brachial plexus blockade.

BACKGROUND AND OBJECTIVES: Corticosteroids have been used successfully to prolong the duration of local anesthetic action after peripheral nerve and epidural blockade. We hypothesized that the addition of dexamethasone to mepivacaine would prolong the duration of analgesia after ultrasound-guided supraclavicular brachial plexus block for patients undergoing upper-limb surgery. METHODS: After Federal Health Department and institutional review board approval, 45 adult patients undergoing elective hand or forearm surgery under supraclavicular brachial plexus blockade were randomized to receive either 30 mL mepivacaine 1.5% plus dexamethasone 8 mg (4 mg/mL), or 30 mL mepivacaine 1.5% plus 2 mL normal saline. The primary outcome measure was duration of analgesia. Secondary outcomes included onset times of sensory and motor blockade, pain and satisfaction scores, analgesic consumption, and block-related complications. RESULTS: Patient characteristics were similar between groups. The median duration of analgesia was significantly prolonged in the Dexamethasone group (332 mins; interquartile range, 225-448 mins) compared with the Normal Saline group (228 mins; interquartile range, 207-263 mins; P = 0.008). The onset times of sensory and motor block were similar between the groups. Complications were minor and transient and did not differ between groups at 2 weeks postoperatively. CONCLUSIONS: The addition of dexamethasone to mepivacaine prolongs the duration of analgesia but does not reduce the onset of sensory and motor blockade after ultrasound-guided supraclavicular block compared with mepivacaine alone.

Spinal mepivacaine with fentanyl for outpatient knee arthroscopy surgery: a randomized controlled trial.

BACKGROUND: The foremost limitation of local anesthetic solutions for spinal anesthesia in the outpatient setting is prolonged motor blockade and delayed ambulation. The purpose of this study was to determine if the addition of intrathecal fentanyl to low-dose spinal mepivacaine provides adequate anesthesia with shorter duration of functional motor blockade for ambulatory knee surgery compared with spinal mepivacaine alone. METHODS: Following institutional review board approval and informed consent, 34 patients undergoing unilateral knee arthroscopy were enrolled in this study. The patients were randomly assigned to receive either 30 mg of isobaric mepivacaine 1.5% plus fentanyl 10 microg (M + F group) or 45 mg of isobaric mepivacaine 1.5% alone (M group) intrathecally. Postoperatively, the times to achieve sensory block regression to the S1 dermatome and to attain functional motor block recovery enabling ambulation were recorded. All assessments were blinded. RESULTS: The time to completion of Phase I recovery was shorter in the M + F group (104.6 +/- 28.4 min) than in the M group (129.1 +/- 30.4 min; P = 0.023). Regression of sensory blockade to S1 was earlier in the M + F group (118.4 +/- 53.5 min) than in the M group (169.7 +/- 38.9 min; P = 0.003). Patients in the M + F group (176.4 +/- 40.3 min) were able to ambulate significantly earlier than those in the M group (205.6 +/- 31.4 min; P = 0.025). No cases of transient or persistent neurological dysfunction were noted. CONCLUSIONS: When compared with 45 mg isobaric mepivacaine 1.5%, an intrathecal dose of 30 mg isobaric mepivacaine 1.5% plus 10 microg fentanyl produces reliable anesthesia, hastens block regression, shortens stay in Phase I recovery, and enables earlier ambulation for patients undergoing unilateral knee arthroscopy (Registration no. NCT00803725).