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

Study Overview
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Brief Summary
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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.

Detailed Description
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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))

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

Conditions
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Hypotension, Hypovolemic Shock

Intervention / Treatment
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* Radiation: Ultrasound


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults pregnant females, Age 18-45, Term pregnancy Parturients not in established labor Singleton pregnancies Exclusion Criteria: Advanced labor, Multiple gestations, Maternal or fetal distress, BMI > 45. Inability to obtain informed consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Radiation: Ultrasound|Evaluating the feasibility and efficacy of IVC ultrasound imaging through the RUQ and subxiphoid view in term parturients. Patient Acceptability of procedure Patient Comfort: Ease of exam for the examiner|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to obtaining good Quality IVC images through RUQ and subxiphoid window |  | 60 seconds | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient Acceptability of procedure | Would you agree to have similar ultrasound scans again? Yes/No | 10 seconds | 
| patient comfort | Please rate your comfort during the ultrasound scan, on a scale of 1 to 5. Where 5 is very comfortable and 0 is not comfortable | 10 seconds | 
| Ease of exam for the examiner | 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) | 10 seconds |