Positional blood pressure change and the risk of hypotension during spinal anesthesia for cesarean delivery: An observational study

BACKGROUND: We investigated whether preoperative positional arterial blood pressure change predicted hypotension and ephedrine requirement during spinal anesthesia for cesarean delivery. METHODS: Arterial blood pressure was measured in 66 women undergoing cesarean delivery in the supine and the right lateral positions. Positional blood pressure change was defined as the difference between mean blood pressure in the right lateral and supine positions. Hypotension (<80% baseline) was recorded, and severe hypotension (<70% baseline) was treated with ephedrine. RESULTS: The mean (range) positional blood pressure change was 11 (3-29) mm Hg, and the incidence of hypotension was 41%. Positional blood pressure change and heart rate correlated with hypotension (P < 0.001 for both) and ephedrine requirement (P = 0.004). Positional blood pressure change in those who developed hypotension was higher than for those without hypotension (mean (SD), 17 (6) vs. 7 (2) mm Hg, P < 0.001). CONCLUSIONS: A preoperative increase in blood pressure after position change may be a good variable to predict hypotension during spinal anesthesia for cesarean delivery. (Anesth Analg 2010;111:712-5).