The addition of epinephrine to subarachnoid administered hyperbaric bupivacaine with fentanyl for cesarean delivery: the effect on onset time.
OBJECTIVE
This study examines the effect of epinephrine on the time to achieve a T4 sensory level when added to a hyperbaric bupivacaine-fentanyl mixture for spinal anesthesia.


METHODS
Sixty-nine healthy parturients scheduled for elective cesarean delivery were randomly assigned to three groups. All patients were given 9 mg hyperbaric 0.75% bupivacaine with 25 micrograms fentanyl. Group 1 received no epinephrine while Groups 2 and 3 received 100 micrograms and 200 micrograms epinephrine, respectively. Injection of the spinal anesthetic solutions was performed with the patient in the sitting position. Immediately after drug administration, patients were placed supine with their heads elevated on a pillow and 15 degrees of left uterine displacement was maintained. Vital signs and sensory levels were obtained every minute for 10 minutes.


RESULTS
In Groups 2 and 3, the mean time to T4 sensory level was significantly longer (6.9 minutes and 6.6 minutes, respectively) than in Group 1 (4.6 minutes). As a subset, patients weighing more than 90.8 kg achieved a T4 sensory level faster than did those weighting less than 90.8 kg (3 minutes and 5.1 minutes, respectively), but in both groups epinephrine prolonged the onset time to T4 (5.8 minutes and 7.3 minutes, respectively). Three patients were excluded because of failure to obtain a T4 sensory level.


CONCLUSIONS
The onset time to T4 is related inversely to patient weight, and epinephrine (100 micrograms and 200 micrograms) delays the onset of sensory block to T4 when administered with subarachnoid hyperbaric bupivacaine-fentanyl.
Moore
C H
CH
Department of Anesthesiology, Medical College of Virginia, Richmond 23298-0695.
Wilhite
A
A
Pan
P H
PH
Blass
N H
NH
D000328:Adult; D000773:Anesthesia, Obstetrical; D000775:Anesthesia, Spinal; D002045:Bupivacaine; D002585:Cesarean Section; D004837:Epinephrine; D005260:Female; D005283:Fentanyl; D006801:Humans; D011247:Pregnancy; D013346:Subarachnoid Space; D013997:Time Factors
D005283:Fentanyl; D002045:Bupivacaine; D004837:Epinephrine