Noninvasive cardiac output monitoring during general anesthesia for Cesarean delivery in a patient with severe aortic stenosis

Abstract

Purpose: The anesthetic management of women with severe aortic stenosis (AS) undergoing Cesarean delivery (CD) remains controversial. We used a relatively new bioreactance technology to highlight the continuous hemodynamic changes related to anesthesia, delivery, and recovery in a parturient with severe AS. Clinical features: A 29-yr-old woman, New York Heart Association Class II, with a congenital bicuspid aortic valve and AS presented for CD at 36.5 weeks of gestation. The estimated aortic valve area on echocardiogram was 0.75 cm 2, and the maximal transvalvular gradient was 64 mmHg. Cesarean delivery was performed under general anesthesia with an epidural catheter placed prior to induction for postoperative analgesia. Noninvasive cardiac output (CO) monitoring based on bioreactance was used throughout the procedure. Cardiac output increased from 7-12 L•min -1 following delivery primarily due to an increase in stroke volume. Both stroke volume variation and total peripheral resistance decreased, while the patient's heart rate did not change. Increased stroke volume, likely associated with decreased afterload and increased preload, contributed to an increase in CO from 7-12 L•min -1. Conclusion: Continuous CO data obtained from bioreactance-based monitoring suggests that pregnant women with severe AS may experience an increase in CO under certain circumstances. This result is in keeping with data obtained from non-pregnant individuals and is an interesting finding that warrants further study. Noninvasive CO monitoring may improve our understanding of the peripartum changes in women with heart disease. © 2011 Canadian Anesthesiologists' Society.