Assessement of Hemodynamic Changes Associated With Uterine Displacement Using Noninvasive Cardiac Output Monitoring and Transthoracic Echocardiography:

Aortocaval compression is a well-recognized physiologic concern in pregnancy. The gravid
uterus can compress the inferior vena cava, impeding venous return and thereby reducing
stroke volume and cardiac output.

The 2014 Society for Obstetric Anesthesia and Perinatology consensus statement on the
management of cardiac arrest in pregnancy, and the 2010 American Heart Association guideline
on maternal cardiac arrest recommend relieving aortocaval compression during chest
compressions by performing uterine displacement There is currently little information
regarding the hemodynamic differences amongst the recommended uterine displacement
techniques. Previous studies examining the hemodynamic effects of uterine displacement
maneuvers have focused on incidence of hypotension and use of ephedrine.

Noninvasive cardiac output monitoring (NICOM) and transthoracic echocardiography (TTE) are
becoming popular techniques in anesthesiology because they can provide noninvasive, valid,
and precise hemodynamic data.There has been no study specifically examining the hemodynamic
differences between the uterine displacement techniques using NICOM or TTE. While all three
uterine displacement techniques are recommended, whether one technique may maximize maternal
cardiac output is currently unknown.

Inclusion Criteria:

1. Healthy ASA physical status I-II

2. Term parturient

Exclusion Criteria:

1. Woman in labor

2. Presence of maternal medical conditions affecting the cardiovascular system
(including preeclampsia, gestational hypertension)

3. Fetal anomaly or intrauterine growth restriction (< 25th percentile)

4. Maternal renal or endocrine disease