Ultra-low dose combined spinal-epidural anesthesia with intrathecal bupivacaine 3.75 mg for cesarean delivery: a randomized controlled trial.
BACKGROUND
We wished to investigate the feasibility of an ultra low-dose combined spinal-epidural technique in providing surgical anesthesia for uncomplicated cesarean deliveries in a randomized, double-blind controlled trial.


METHODS
Forty-four normotensive, non-obese patients were randomized to receive either intrathecal hyperbaric bupivacaine 3.75 mg (low dose group, n=22) or 9 mg (conventional group, n=22), in addition to intrathecal fentanyl 25 microg, morphine 100 microg, and epidural 1.5% lidocaine 3 mL. Sensorimotor anesthesia and hemodynamic data were assessed at 2.5-min intervals for the first 15 min.


RESULTS
The maximal sensory block achieved in the low-dose group was significantly lower than that in the conventional group (median T3, [range T2-T6] vs. T2 [C2-T6], P<0.001) with a longer time taken to reach maximal sensory block. The low-dose group had less motor block, faster sensory regression to T10 dermatome and faster motor recovery to Bromage 0 (all P<0.001). The block failed to reach T6 bilaterally within 10 min in one patient in the low-dose group and two in the conventional group, with no significant difference in the need for epidural supplementation before or after delivery of the baby. The low-dose group experienced less hypotension (14% vs. 73%, P<0.001) with less ephedrine usage (0.68 vs. 17.5 mg, P<0.001). There was no difference in operating conditions and other side effects (shivering, pruritus).


CONCLUSIONS
We conclude that this technique results in a significantly lower incidence of maternal hypotension and has a role in high-risk parturients in whom maintenance of stable hemodynamics is imperative.
Teoh
W H L
WH
Department of Women's Anesthesia, KK Women's and Children's Hospital, Singapore. teohwendy@yahoo.com
Thomas
E
E
Tan
H M
HM
D000328:Adult; D000767:Anesthesia, Epidural; D000773:Anesthesia, Obstetrical / Q000379:methods*; D000775:Anesthesia, Spinal; D019162:Anesthetics, Combined / Q000008:administration & dosage*; D002045:Bupivacaine / Q000008:administration & dosage*; D002585:Cesarean Section; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005240:Feasibility Studies; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage; D006801:Humans; D009020:Morphine / Q000008:administration & dosage; D011247:Pregnancy
D019162:Anesthetics, Combined; D009020:Morphine; D005283:Fentanyl; D002045:Bupivacaine