///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47-06:00

The impact of noninvasive cardiac output monitoring on maternal hemodynamics during cesarean delivery under spinal anesthesia: a randomized controlled trial

Abstract Number: T-62
Abstract Type: Original Research

Anthony Chau M.D.1 ; Michaela K. Farber M.D., M.S.2; Lawrence C. Tsen M.D.3; Xiaoxia Liu M.S.4; Bhavani S. Kodali M.D.5

Introduction: Recent studies have demonstrated that uteroplacental blood flow correlates better with maternal cardiac output (CO) than with maternal systolic blood pressure (SBP) during cesarean delivery (CD) (1,2). However, the impact of hemodynamic management using CO compared to SBP on maternal and fetal outcomes remains unknown. The purpose of this study was to evaluate CO changes during elective CD using CO-based management versus conventional SBP-based management of maternal hemodynamics with the use of a noninvasive CO monitor.

Methods: Healthy parturients scheduled for elective CD under spinal anesthesia (SA) were randomized to control or study groups. A non-invasive CO monitor (ICON®, Osypka Medical, California, USA) was applied to measure CO based on electrical velocimetry. The control group received standard care with CO data blinded to the providers, and vasopressor selection (phenylephrine, ephedrine) was based on physician preference. The study group received vasopressor treatment based on an algorithm integrating CO data with SBP values. All subjects received 1L of Lactated Ringer’s co-load during placement of SA. Hemodynamic data was collected every minute from initiation of SA until delivery of the fetus. Primary outcome was change in mean CO over time. Secondary outcomes were incidence of CO, SBP, and heart rate (HR) maintained within 20% of baseline, total vasopressor use, incidence of nausea and vomiting and neonatal well-being assessed via APGAR scores and umbilical cord gases.

Results: To date, 28 of 50 patients have been recruited with 14 patients in each group. Using mixed model analysis, there was no difference in mean CO between the two groups (p=0.605). However, a significant fluctuation in mean CO over time was observed in the control group (p<0.0001). There were no significant differences in secondary outcomes.

Discussion: For healthy parturients undergoing elective CD under SA, our preliminary results suggest that CO-based hemodynamic management offers no advantage over SBP-based management. Therefore, routine use may not offer additional benefit. Significant fluctuations in mean CO over time in the conventional management group may suggest a role for CO-based management in a subgroup of patients with hemodynamic instability or cardiac dysfunction (e.g. preeclampsia). Further investigation in this population is warranted.


1. McDonald S et al, Anesth Analg 2011

2. Dyer RA et al, Anesthesiology 2008

SOAP 2014