Inferior Vena Cava Assessment in Term Pregnancy Using Ultrasound: a Feasibility Study of Subxiphoid and RUQ Views

Overview

This study is to assess the feasibility of 2 different ultrasound views of the inferior vena cava (IVC), a large vein that returns blood to the heart. Ultrasound is safe in pregnancy and, is regularly used to evaluate the fetus. It is hoped that imaging of the IVC will then allow us to determine the fluid status of the parturient which could be helpful in treating hemodynamic instability. This study will not involve any change in management of the participating patients.

Anesthesiology consultants and trainees with US experience will first perform scans from the RUQ view starting on the mid-axillary line at the T4 intercostal space, looking to obtain a view of the IVC as it enters the right atrium (RA). Following successful acquisition, the examiner will perform scan from the subxiphoid position, looking to obtain the same view of the IVC transitioning into the RA. Primary endpoint will be time to obtaining quality of images. The investigator will use a stopwatch to time acquisition of images. If the duration of scanning exceeds ten minutes, the scan will be discontinued and labeled as failed. Each image will be separately reviewed by 2 different US specialists with extensive US experience. Images will be assessed according to a Likert scale from 1 to 5. (Very poor (1), poor (2), acceptable (3), good (4), very good (5)) Secondary endpoints will be assessed as follows: 1. Acceptability: all patients participating in the study will complete a questionnaire to assess acceptability. 2. Comfort: During the exam the patient will have the option to suspend the scan by stating they are uncomfortable and wish to stop. Each request will be noted and taken into the account at data analysis. Furthermore, patients will be given a questionnaire at the end of the scan and asked to rate their comfort level during procedure according to Likert scale. (Very comfortable (5), comfortable (4), equivocal (3), uncomfortable (2), very uncomfortable (1)) 3. Ease of exam: Examiner will rate the ease of image acquirement according to Likert scale. (impossible (1), difficult (2), equivocal (3), easy (4), very easy (5))

Conditions