The addition of fentanyl to local anesthetics affects the quality and duration of cervical plexus block: a randomized, controlled trial.
BACKGROUND
Cervical plexus block is frequently associated with unsatisfactory sensory blockade. In this randomized, double-blind, placebo-controlled trial, we examined whether the addition of fentanyl to local anesthetics improves the quality of cervical plexus block in patients undergoing carotid endarterectomy (CEA).


METHODS
Seventy-seven consecutive adult patients scheduled for elective CEA were randomized to receive either fentanyl 1 mL (50 microg) or saline placebo 1 mL in a mixture of 10 mL bupivacaine 0.5% and 4 mL lidocaine 2% for deep cervical plexus block. Superficial cervical plexus block was performed using a mixture of 10 mL bupivacaine 0.5% and 5 mL lidocaine 2%. Pain was assessed using the verbal rating scale (0-10; 0 = no pain, 10 = worst pain imaginable), and propofol in 20-mg IV bolus doses was given to patients reporting verbal rating scale >3 during the procedure. Rescue medication consumption during surgery and analgesia requirements over the next 24 hours, as well as onset of sensory blockade, were recorded. A P value <0.05 was regarded as statistically significant.


RESULTS
Fewer patients in the fentanyl group (4 of 38, 10.5%) required propofol compared with the placebo group (26 of 39, 66.7%; P < 0.001). In comparison with the placebo group, the fentanyl group consumed less propofol (median 0 [0-60] vs 60 [0-160] mg, respectively; P < 0.001), required postoperative analgesia less frequently (22 of 38 patients, 57.9% vs 35 of 39 patients, 89.7%, respectively; P = 0.002), and requested the first analgesic after surgery later (median 5.8 [1.9-15.6] vs 3.1 [1.0-11.7] hours, respectively; P < 0.001), whereas the onset time of sensory blockade was similar in both groups (median 12 [9-18] vs 15 [9-18] minutes, respectively; P = 0.18).


CONCLUSIONS
The addition of fentanyl to local anesthetics improved the quality and prolonged the duration of cervical plexus block in patients undergoing CEA.
Sindjelic
Radomir P
RP
Institute of Anesthesia and Resuscitation, Clinical Center of Serbia, Belgrade University Medical School, Dr. Koste Todorovica 8, 11000 Belgrade, Serbia.
Vlajkovic
Gordana P
GP
Davidovic
Lazar B
LB
Markovic
Dejan Z
DZ
Markovic
Miroslav D
MD
D000759:Adjuvants, Anesthesia; D000368:Aged; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D002045:Bupivacaine; D002572:Cervical Plexus; D004311:Double-Blind Method; D023381:Endpoint Determination; D005260:Female; D005283:Fentanyl; D006801:Humans; D008012:Lidocaine; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D015742:Propofol; D017211:Treatment Failure
D000759:Adjuvants, Anesthesia; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D008012:Lidocaine; D005283:Fentanyl; D002045:Bupivacaine; D015742:Propofol