Abstract
【Purpose】Spinal anesthesia-induced hypotension has been shown to cause fetal bradycardia and fetal acidemia. Although anesthesiologists attempt to prevent or treat hypotension by controlling systolic blood pressure (SBP), organ perfusion, including the uterus, is most affected by mean arterial pressure (MAP). Thus, we investigated whether maternal MAP predicts fetal acidemia better than SBP during spinal anesthesia for cesarean delivery.
【Methods】All medical and anesthesia records of patients, who received spinal anesthesia for elective cesarean delivery at term with a healthy singleton fetus at our hospital in 2009, were retrospectively reviewed. Anesthetic management was standardized. Blood pressure was measured non-invasively every minute from induction of anesthesia to delivery of the infant. The lowest SBP and MAP during this interval were retrieved from electronic anesthesia records and neonatal conditions were also evaluated.
【Results】A total of 94 of 511 cesarean patients met the inclusion criteria. Among these patients, six had an umbilical arterial pH < 7.25 (lower UA pH group). Compared with the remaining 88 cases with UA pH
≥7.25, minimum MAP was significantly lower in the lower UA pH group, though the minimum SBP was not different. Additionally, all patients in the lower UA pH group had a minimum MAP of < 70 mmHg. No differences between the two groups in the dose of vasopressors administered or uterine incision to delivery interval were found.
【Conclusions】Our results suggest that maternal MAP is associated with lower UA pH better than SBP. Maintaining MAP above 70 mmHg may be an important target in managing spinal anesthesia-induced hypotension.
