[Spinal anesthesia using hyperbaric bupivacaine HCl for cesarean section].
BACKGROUND
We performed this prospective study to determine the proper amount of hyperbaric bupivacaine hydrochloride as a spinal anesthetic agent for cesarean section.


METHODS
The parturients were randomly allocated to receive one of four spinal agents in a blind manner; tetracaine 10 mg (control), bupivacaine 10, 12.5 and 15 mg. Morphine HCl 0.1 mg was added to each agent and the total volume was adjusted to 3.1 ml with 10% glucose solution.


RESULTS
All the four spinal agents provided an adequate analgesic level (T 5) without serious complications. Among the three dosages of bupivacaine, the time interval requiring for anesthetic level to reach T 5 tended to be shorter with a larger amount of bupivacaine. The incidence of intraoperative supplemental analgesic and hypotension and the dosage of ephedrine used to treat hypotension were greater in the patients anesthetized with tetracaine 10 mg than in those anesthetized with bupivacaine 10 mg, which is equipotent to tetracaine 10 mg.


CONCLUSIONS
1. As a spinal anesthetic agent for cesarean section, hyperbaric bupivacaine is superior to tetracaine. 2. Hyperbaric bupivacaine 10 mg, 12.5 mg or 15 mg can be used safely and effectively as a spinal agent for cesarean section. 3. High dose bupivacaine is recommended in an urgent case, and low dose bupivacaine is recommended when maternal hypotension must be strictly avoided.
Hirao
Osamu
O
Department of Anesthesiology, Osaka Medical Center, Research Institute for Maternal and Child Health, Izumi 594-1101.
Kinouchi
Keiko
K
Haruna
Junichi
J
Matsuda
Yoichi
Y
Kawaraguchi
Yoshitaka
Y
Miyamoto
Yoshikazu
Y
Nakao
Fumiya
F
Taniguchi
Akihiro
A
Fukumitsu
Kazuo
K
Kitamura
Seiji
S
D000773:Anesthesia, Obstetrical; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000009:adverse effects*; D002045:Bupivacaine / Q000008:administration & dosage*; D002585:Cesarean Section; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D009020:Morphine / Q000008:administration & dosage; D011247:Pregnancy; D011446:Prospective Studies; D016037:Single-Blind Method; D013748:Tetracaine / Q000008:administration & dosage; D013997:Time Factors
D000779:Anesthetics, Local; D013748:Tetracaine; D009020:Morphine; D002045:Bupivacaine