Multivariate study of risk factors for arterial hypotension in pregnant patients at term undergoing Caesarean section under subarachnoid anesthesia

OBJECTIVES: The most common and potentially dangerous complication of spinal anesthesia for cesarean section is arterial hypotension. The aim of this study was to analyze maternal and gestational factors that might affect risk of arterial hypotension in full-term parturients undergoing cesarean section. MATERIAL AND METHOD: We enrolled full-term parturients scheduled for elective cesarean section under spinal anesthesia. Spinal puncture was performed at L2-L3 using an atraumatic Sprotte-type needle. We administered 12.5 mg of hyperbaric 0.5% bupivacaine and 12.5 micrograms of fentanyl. Arterial hypotension was defined as a decrease in systolic pressure of at least 20% or a decrease to a pressure below 100 mmHg. Multivariate analysis was performed to identify factors related to the presentation of hypotension appearing in the interval between spinal puncture and birth. RESULTS: The incidence of arterial hypotension was 33.3%. Statistical analysis revealed that integrity of the amniotic sac, parity and elective cesarean were significantly associated with a higher incidence of arterial hypotension (p < 0.03). CONCLUSIONS: Identifying risk for multiparous parturients with intact amniotic sacs scheduled for elective cesarean can be worthwhile if greater preventive measures are taken in such patients to reduce the incidence and intensity of arterial hypotension.