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

Hypotension Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00573274
• Other study ID #: 07-09
• Secondary ID: 07-0225-E
• Status: Completed
• Phase: N/A
• First received: December 12, 2007
• Last updated: July 29, 2009
• Start date: November 2007
• Est. completion date: January 2008

Study information

• Verified date: July 2009
• Source: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Ethics Review Committee
• Study type: Observational

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: January 2008
• Est. primary completion date: January 2008
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years to 50 Years

Eligibility

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 Design

Observational Model: Case-Only, Time Perspective: Prospective

Related Conditions & MeSH terms

• Hypotension

Intervention

Device:
• Physioflow Impedance
6 ECG leads applied to the neck and thorax for the duration of surgery (approximately 1 hour).

Locations

Country	Name	City	State
Canada	Mount Sinai Hospital	Toronto	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Continuous measurement of cardiac output (CO), stroke volume (SV) and/or systemic vascular resistance (SVR) changes.		60 minutes	No