Measuring Cardiac Output and Stroke Volume Using the Physioflow Impedance Device in Pregnant Patients

Pilot Study Measuring Cardiac Output and Stroke Volume Using Non-Invasive Thoracic Impedance With the Physioflow Impedance Device in Pregnant Patients Undergoing Cesarean Section Under Spinal Anesthesia

Pregnant patients having a cesarean section (CS) under spinal anesthesia experience a variety of hemodynamic changes, such as hypotension due to decreases in cardiac output (CO), stroke volume (SV) and/or systemic vascular resistance (SVR). Measurement of these hemodynamic parameters classically requires insertion of a pulmonary artery catheter (PAC) into the heart. However, this invasive method carries significant complications and its use is now reserved for the more critically ill patients. We hypothesize that the Physioflow Impedance device can be used as a reliable non-invasive monitor to measure hemodynamic parameters during elective CS under spinal anesthesia.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The Physioflow Impedance device employs a continuous non-invasive method of measuring ten cardiac hemodynamic parameters including flow, resistance, contractility and fluid content. It involves the application of electrocardiogram (ECG) leads on the neck and the thorax to measure resistance of pulsatile blood flow. Its benefits are that it is non-invasive, low cost, and easy to operate. Thoracic impedance has been validated against the gold standard method of PAC. Although the Physioflow device has been validated in non-pregnant patients, its use in pregnant patients is very limited.

Moderate to severe hypotension, experienced by these awake patients, can cause significant undesirable symptoms of dizziness, shortness of breath, nausea and vomiting, and also compromise fetal well-being. The etiology of hypotension is multi-factorial,and it is postulated that decreases in cardiac output (CO), stroke volume (SV) and/or systemic vascular resistance (SVR) may precede decreases in blood pressure. Continuous measurement of CO and SV by the Physioflow Impedance device may provide a better understanding of the cause of hypotension so that future management of these patients may include pharmacological interventions used prior to hypotension in order to avoid any undesirable symptoms.

Study Type

Observational

Enrollment (Actual)

20

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

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

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 50 years (ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

Healthy volunteers having an elective cesarean section.

Description

Inclusion Criteria:

  • Women undergoing elective cesarean section
  • Women classified as ASA 1 & 2

Exclusion Criteria:

  • Patients unable to communicate in English
  • Patients with significant cardiac disease
  • Height less than 4 feet or greater than 7 feet
  • Weight less than 67 lbs or greater than 341 lbs

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
1
Elective cesarean section patients
6 ECG leads applied to the neck and thorax for the duration of surgery (approximately 1 hour).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Continuous measurement of cardiac output (CO), stroke volume (SV) and/or systemic vascular resistance (SVR) changes.
Time Frame: 60 minutes
60 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Kong Eric You-Ten, MD, Mount Sinai Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2007

Primary Completion (ACTUAL)

January 1, 2008

Study Completion (ACTUAL)

January 1, 2008

Study Registration Dates

First Submitted

December 12, 2007

First Submitted That Met QC Criteria

December 12, 2007

First Posted (ESTIMATE)

December 14, 2007

Study Record Updates

Last Update Posted (ESTIMATE)

July 30, 2009

Last Update Submitted That Met QC Criteria

July 29, 2009

Last Verified

July 1, 2009

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 07-09
  • 07-0225-E

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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