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).
O'Donnell
Dermot
D
Department of Anesthesia and Pain Management, Toronto Western Hospital, University Health Network, Mc Laughlin Pavilion 2-405, 399 Bathurst Street, Toronto, ON, M5T-2S8, Canada.
Manickam
Baskar
B
Perlas
Anahi
A
Karkhanis
Reena
R
Chan
Vincent W S
VW
Syed
Khalid
K
Brull
Richard
R
D000328:Adult; D000368:Aged; D000556:Ambulatory Surgical Procedures / Q000379:methods; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D000762:Anesthesia Recovery Period; D000775:Anesthesia, Spinal / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use; D001182:Arthroscopy / Q000379:methods*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007278:Injections, Spinal; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D008619:Mepivacaine; D005283:Fentanyl