///2010 Abstract Details
2010 Abstract Details2019-08-03T15:49:10-05:00

Does maternal mean arterial pressure predict fetal academia better than systolic blood pressure during spinal anesthesia for Cesarean Section ?

Abstract Number: 120
Abstract Type: Original Research

Yusuke MAZDA M.D.1 ; Katsuo TERUI M.D./Ph.D2; Kazumi TAMURA M.D.3; Keiko MIYASHITA M.D.4; Yuichi HASHIMOTO M.D.5; Kenji IWAMURO M.D.6


Spinal anesthesia induced hypotension has been shown to cause fetal bradycardia and fetal academia. Anesthesiologists make every effort to prevent or treat hypotension, usually based on systolic blood pressure. However, uterine blood flow is determined by the mean uterine arterial pressure, mean uterine venous pressure, and uterine vascular resistance. Mean uterine arterial pressure is likely to be affected most by mean systemic arterial pressure, not by the systolic blood pressure. Thus, we tried to determine whether maternal mean arterial pressure (MAP) predicts fetal academia better than systolic blood pressure (SBP) during spinal anesthesia for cesarean section.


After IRB approval, all medical and anesthesia records of the patients who received spinal anesthesia for elective cesarean section at term with healthy singleton fetus in 2009 at our university hospital were retrospectively reviewed using the electronic database. Baseline blood pressure (BP) was defined as the first measurement just after patients arrival to the operating room. Anesthetic management was standardized using prehydration with HES, fixed dose hyperbaric bupivacaine 12 mg, left urerine displacement, and supplemental oxygen. BP was measured every minute using oscillometric method (PB4000, NEC medical systems, Japan) until delivery of the infant. The lowest SBP and MAP during this interval were retrieved from hemodynamics recording printouts. Neonatal conditions were evaluated using umbilical arterial pH, umbilical arterial lactate, Apgar score after one and five minutes of birth, and birth weight.


During this period, 94 patients met the inclusion criteria out of 511 cesarean patients. Among these patients, six cases showed umbilical arterial(UA) pH less than 7.25(fetal academia group). There was no case with UA pH less than 7.0. When compared with remaining 88 cases without fetal academia (no fetal academia group), the lowest MAP of fetal acidemia group was significantly, but the lowest SBP were not. UA lactate was significantly lower in fetal acidemia. There were no differences between the two groups with regard to the dose of ephedrine, uterine incision to delivery interval (table).


Our result suggests that fetal academia is better predicted by maternal mean arterial pressure than commonly used systolic blood pressure, and that maintaining MAP higher than 70mmHg could be the better goal in managing spinal anesthesia induced hypotension.

SOAP 2010