[Duration and quality of postoperative analgesia after brachial plexus block for shoulder surgery: ropivacaine 0.5% versus ropivacaine 0.5% plus clonidine].
OBJECTIVE
Some authors have found that nerve blocks with local anesthetics may last longer if clonidine is added. The present study analyzed the duration and quality of analgesia provided by an interscalene brachial plexus block for shoulder surgery using 0.5% ropivacaine or 0.5% ropivacaine with added clonidine.


METHODS
Thirty patients were assigned to two groups for double-blind study. The block was performed with 0.5% ropivacaine (40 mL) in group A and with 0.5% ropivacaine (40 mL) and clonidine (40 micrograms) in group B. General anesthesia was provided with propofol in continuous perfusion. Ventilation was spontaneous through a laryngeal mask. After stimulation of the brachial plexus nerves, the anesthesiology administered the assigned drug or drugs. The patient was instructed to remember the time of reversion of the sensory-motor block. Postoperative analgesia was assessed on a visual analog scale at 2, 4, 6, 8 and 24 hours.


RESULTS
The mean times until reversion of the sensory-motor block and the assessments of pain at 4, 6, 8 and 24 hours in the two groups were not significantly different.


CONCLUSIONS
Adding 40 micrograms of clonidine to 200 mg of 0.5% ropivacaine does not prolong the sensory-motor block or improve the quality of analgesia in the early postoperative period.
D000759:Adjuvants, Anesthesia / Q000008:administration & dosage / Q000627:therapeutic use*; D000328:Adult; D000577:Amides / Q000008:administration & dosage / Q000627:therapeutic use*; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D001917:Brachial Plexus; D003000:Clonidine / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D010149:Postoperative Pain / Q000628:therapy*; D017060:Patient Satisfaction; D000077212:Ropivacaine; D012782:Shoulder / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000627:therapeutic use
D000759:Adjuvants, Anesthesia; D000577:Amides; D000779:Anesthetics, Local; D014662:Vasoconstrictor Agents; D000077212:Ropivacaine; D003000:Clonidine
Duración y calidad de la analgesia postoperatoria después del bloqueo del plexo braquial para cirugía del hombro: ropivacaína 0,5% frente a ropivacaína 0,5% con clonidina.