Influence of the Method of Alleviation of Aorto-Caval Compression on the Trans-Hepatic Ultrasound-Assessed Inferior Vena Cava Diameter In Pregnant Patients

Influence of the Method of Alleviation of Aorto-Caval Compression on the Trans-Hepatic Ultrasound-Assessed Inferior Vena Cava Diameter In Pregnant Patients: An Observational Study of the Left Lateral Tilt and of the Left Uterine Displacement

Cardiac arrest during pregnancy is rare but may result in poor maternal and fetal outcome. Because of its rare occurrence and ethical issues this topic is not very well studied and many questions pertaining to maternal resuscitation remain unanswered. One of the challenging aspects of cardiopulmonary resuscitation in a term pregnant patient is the ideal positioning during chest compressions. International societies have made recommendations regarding management of pregnant patients during cardiac arrest. They advocate the use of left lateral position with 30 degrees tilt or manual uterine displacement. However these recommendations are not based on high level of evidence. Ultrasound has been used to visualize the change in diameter of great vessels to determine the volume status or adequacy of blood circulation of these patients. This approach can be used to study the adequacy of blood circulation of pregnant patients in different positions. The objective of this study is to compare the change in Inferior vena cava diameter obtained with pregnant women in either the left lateral tilt or in the supine position with a manual uterine displacement, compared to the left lateral position and the supine position.

Our hypothesis is that the inferior vena cava diameter obtained in the supine position with manual left uterine displacement would be larger as compared to that obtained with women positioned with a 30-degree tilt.

Study Overview

• Status: Completed
• Conditions: Pregnancy; Cardiac Arrest
• Intervention / Treatment: Device: Ultrasound

Detailed Description

Using the non-invasive technology of ultrasound we will be able to determine the degree of aorto-caval compression in pregnant women placed in different positions. The results of this study will help us to determine the optimal patient positioning for each individual. This in future may help us in improving outcomes not only during labor and anesthesia, but also during maternal resuscitation in critical cases.

The results of this study will help us to determine the best technique to minimize aorto-caval compression in the term pregnant patient. The results of this study will be useful to establish firm maternal resuscitation guidelines. We will be able to determine the optimal maternal position during cardiopulmonary resuscitation and this may improve both maternal and fetal resuscitation outcomes.

• Study Type: Observational
• Enrollment (Actual): 30

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G1X5
      • Mount Sinai Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

Non-laboring, term prengnant women with singleton pregnancies who are admitted at Mount Sinai Hospital for induction of labor, elective cesarean section or for observation for any medical reason.

Description

Inclusion Criteria:

• ASA I or II
• Term pregnancy (36-40 weeks)
• Singleton pregnancy

Exclusion Criteria:

• Patients with known cardiac disease, severe preeclampsia on medication
• Multiple gestation
• Breech presentation
• Patients unable to comply with the 4 positions (left lateral, left tilt, supine and supine with manual displacement)
• Patients unable or unwilling to consent

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Term pregnant patients; ASA I-II term (36-40 weeks) non-laboring women with singleton pregnancies who are admitted at MSH for induction of labor, elective cesarean section or for observation for any medical reason. These patients will be examined in 4 positions with the ultrasound.	Device: Ultrasound; The IVC will be visualized and images obtained using the intercostal window in both longitudinal and transverse planes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
IVC maximum diameter	The IVC maximum diameter in each position (measured during expiration).	20 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fetal Heart Rate	The fetal heart rate will be monitored during the last minute of observation in each position.	20 minutes
Maternal vitals	Maternal blood pressure and heart rate will be monitored during the last minute of observation in each position.	20 minutes
IVC minimum diameter	The IVC minimum diameter in each position (measured during inspiration).	20 minutes
IVC Index	IVC index (IVI) = IVC(max)-IVC (min)/IVC(max)	20 minutes

Collaborators and Investigators

• Sponsor: Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Study record dates

Study Major Dates

• Study Start: November 1, 2013
• Primary Completion (Actual): December 1, 2013
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: November 6, 2013
• First Submitted That Met QC Criteria: November 6, 2013
• First Posted (Estimate): November 13, 2013

Study Record Updates

• Last Update Posted (Estimate): June 4, 2014
• Last Update Submitted That Met QC Criteria: June 3, 2014
• Last Verified: June 1, 2014

More Information

Terms related to this study

• Keywords: Ultrasound; Pregnancy; Cardiopulmonary Resuscitation; Inferior Vena Cava
• Additional Relevant MeSH Terms: Heart Diseases; Cardiovascular Diseases; Heart Arrest
• Other Study ID Numbers: 13-09