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174

Volume 164 Number I. Part 2

CONTINUOUS SPINALS OBSTETRICS?

(CS): WHAT IS THEIR PLACE IN

§"'~----'!.:.!hL- D. WallaceX, M.D., and J. Holloway, M.D.

Univ. of TX Southwestern Med. Cntr., Dept. of Anesthesiology , Dallas, Texas

A resurgence of interest in the CS technique has lead to evaluation, in the obstetric population, of several microcatheter systems positioned intrathecally with the goal to provide a titratable anesthetic, using short

acting anesthetics, and a shorter recovery period. 38

wanen requiring elective cesarean sections (CiS)

consented to a randomized prospective IRB approved study

of 3 spinal anesthesia techniques: CS (22g spinal needle/28g catheter), combined spinal-epidural technique (CSET) (25g spinal needle through a 17g Touhy followed

by epidural placement of 20g catheter) , and single shot spinal (SP) (25g Quincke). Intraoperative data evaluated ease and safety of the anesthetic technique, dosing requIrements, blood loss and fetal outcane. Postoperative follow-up assessed block regression time,

recovery roan narcotic requirements, and complications (post dural puncture headache-PDPH, backache, etc.). All

3 methods provided exqellent anesthesia. Significance was noted in the CS group in the number of paresthesias (p=0.030) and passes (p=0.045) required to reach CSF, as

well as CSF loss in drops (p<O. 001) . PDPH was significantly higher in the CS group (p=0.009). Further study IS warranted.

NIFEDIPINE PHARMACOKINIETICS AND PHARMACODYNAMICS DURING THE POSTPARTUM !PERIOD IN PATIENTS WITH PREECLAMPSIA. Barton JR 'Rogers RC,' Wilson DA,' Whybrew LD,' Sibai BM. University of T~nnessee, Memphis.

Eight women with an intrapartum diagnosis of preeclampsia participated in the study. All p*ients received a continuous infusion of magnesium su~ate in the post partum period during nifedipine therapy. Following the obtainrTIent of a 5 ml blood sample, the patient then swallowed orally tHe single study dose of nlfedlpme 10 mg. Post-dose blood samples were obtained at 20, 40, 60, SO, 120, ISO, 240, 360 minutes. The serum was stored at -700 centigrade until analyzed by reverse phas~ high performance liquid chromato­graphy. Blood pressure monitoring was by automated cuff pressure. RESULTS: Nifedipin~ was undetectable In 6/S patients at 360 minutes. The mean +I-S.D. serum ha~-life was 1.35+1-0.3 hours, NII.dipine in Post Partum Patients with a range of 0.96-1.74 with Preeclampsia

hours. Peak serum 2 • ., concentration (Cmax) of E'

IS±2.1 nglml occurred at 40 l minutes, which was the j timing of the second sample ~ collection (Graph). Mean i ,. oral clearance was 8 3.3±1.2 Uhrlkg. Initial nadirs ~ in mean arterial pressure .ll (MAP) were noted at 50 minutes postdose, with an ·+.---..,00,....--r-..... -.,.....-..~400 average reduction in MAP of Time (minute.) 13.8 mmHg. CONCLUSIONS: This study confirmed a shorter half life, a more rapid clearance and lower Cmax for nifedipine com­pared to controls suggesting the need for every 3 to 4 hours dosing when used in postpartum patients with preeclampsia.

SPO Abstracts 295

175 USAGE OF PROSTAGLANDIN E2 (PGE2 ) IN PATIENTS ~ITH ASTHMA.

CV Towers, JA RojasX

, OF Lewis, T Asrat, MP Nageotte,

GG Br i ggsX

Long Beach Memorial Medical Center, UC Irvine Medical Center

PGE 2 is used in obstetrics for pregnancy termination (20

mg suppositories) as well as for cervical ripening (0.5 mg

gel) prior to pregnancy induction. However, its usage in

pat i ents wi th asthma is not recoomended. The package insert

states that usage of PGE2 ;s contraindicated in patients

with active pulmonary disease and should be used with caution

in patients with a history of asthma.

PGE 2 bronchodi lates. lie evaluated

with asthma during a 3 year period.

However, bi ochemi ca II y

PGE 2 usage in patients

10 patients, wi ~ active

asthma and 4 patients with a history of asthma received the

PGE2 suppositories. An additional 16 patients with active

disease and 21 patients with a history of asthma were exposed

to PGE 2 gel. Patients who received the PGE2

gel were

evaluated since drug induced acute asthma exacerbations are

often not dose dependent. There was not a single episode of

asthma exacerbation in the 51 total patients (CI 0% to

6.7%). In conclusion, drug usage in patients with asthma

should always be carefully mont tored, however ; f

obstetrically indicated, the above data would support the use

of PGE2

in pregnant patients wi th asthma.

176 TERBUTALINE, CESAREAN SECTION, AND ACUTE FETAL DISTRESS Vernon Cook" J. A. Spinnato, Cook County Hospital, Chicago, IL., University of Louisville, Louisville, KY

A 10 year chart review indexed 584 Cesarean sections for fetal distress in which the preoperative management of 369 included terbutaline tocolysis (0.25mg intravenous push) within 15 minutes of going to the operating room and 215 which did not. The only maternal side effect was a well tolerated tachycardia (mean pulse 110 ± 19 beats per minute (bpm) vs. 96 ± 18 bpm, p = .0001) which substantially diminished within 20 minutes. Compared to terbutaline alone, concomitant preoperative glycopyrrolate or atropine (n = 119) further elevated the pulse (117 ± 23 bpm, p = .(02) and was more frequently associated with a pulse of ~ 140 bpm (22/119 vs. 20/250, p < .05). Difference in the mean arterial pressure (99.9 ± 13 mmHg vs. 98.5 ± 15 mmHg) was not clinically significant. Preoperative scalp pH values (n = 174) were Similar (7.220 ± .079 vs. 7.227 ± .085, p = .409). Cord pH values (n = 403) were higher when terbutaline was used (7.233 ± .069 vs. 7.216 ± .101, p = .043). Fetuses delivered in the presence of abruptio placenta (n = 43) were particularly improved (7.255 ± .036 vs 7.169 ± .168, p = .(08). Terbutaline tocolysis should be considered in most cases of fetal distress ;;, tl IS well tolerated and facilitates intrauterine resuscitation.