Validation of Venous Cannulae Flow Ratings

Cardiopulmonary Bypass Clinical Trial

Official title:

Validation of Venous Cannulae Flow Ratings of the DLP Right Angle Cannulaes Utilizing Ultrasound Transit Time Technology

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT00906906
• Other study ID #: 122007-025
• Status: Recruiting
• Phase: N/A
• First received: May 19, 2009
• Last updated: May 20, 2009
• Start date: January 2008
• Est. completion date: June 2009

Study information

• Verified date: May 2009
• Source: University of Texas Southwestern Medical Center
• Contact: Richard Ginther, CCP
• Phone: 214-456-5000
• Email: richard.ginther[@]utsouthwestern.edu
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Observational

Clinical Trial Summary

The purpose of this study is to characterize blood flow in the plastic tubing of a heart-lung bypass machine during heart surgery. Technical specifications provided by the manufacturer do not consider varying hemodynamic conditions such as temperature and hemoglobin levels which affect blood viscosity and ultimately blood flow to and from the patient during heart-lung bypass.

The investigator wishes to perform a prospective study of the heart-lung bypass tubing in children that require heart-lung bypass during heart surgery.

Description:

During bypass, venous drainage is essential for maintaining proper perfusion of a pediatric patient. The quality of venous drainage has a large impact on the level of care the patient is provided. This study will investigate blood flow velocities through right angle venous cannulae which are utilized during bypass. The flows from each cannulae will be analyzed by using doppler flow probes which employ Transit Time Technology. This type of technology has crystals within the flow probes which send magnetic signals through the tubing with the purpose to determine the most accurate flows of blood. There is little evidence that identifies the actual amount of blood flow generated from each venous cannulae in a clinical setting. Manufacturers of venous cannulae for CPB publish flow ratings for the different sized cannulae available. These flow ratings are gathered from data produced in a non-clinical lab and are often very inaccurate. Because of this inaccuracy, selection is based on experience rather than published clinical data. This study would be instrumental in determining any and all potential risks or benefits to the patient as a result of the amount of drainage provided by the venous cannulae during bypass. A sample size of 50 patients (n=50) over one day old will be utilized for this study. The specific venous cannulae sizes that will be analyzed are the 12Fr, 14Fr, 16Fr, 18Fr, 20Fr, 24Fr, & 28Fr DLP (DLP and Fr are the type and size of cannulae, respectively) right angle cannulae. The doppler flow probes that will be utilized during this study are reusable, non-invasive, clamp-on devices which measure blood flow through the CPB tubing. Each patient will have one flow probe placed on each venous cannulae prior to starting CPB. Bypass itself will not be altered in anyway. Hemoglobin blood levels, blood temperature, and pressure from the venous line will be recorded throughout CPB and are digitally sampled via the CPB machine (e.g. no blood draw required). To further examine the quality of venous drainage, a pressure transducer will be attached to the venous line measuring the amount of negative pressure being generated by the venous cannulae. The negative pressure line will be attached to the venous line at a stopcock that is already present in our CPB circuit. Each cannulae size will be analyzed three times to acquire the proper amount of data needed to fulfill the statistical and practical needs for the study. A descriptive analysis of the continuous and categorical data will be performed using means, standard deviations, confidence intervals, proportions, and frequency distributions. Statistical testing will include parametric and non-parametric bi-variate and multi-variate techniques as appropriate to the variables' level of measurement and distributions.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 50
• Est. completion date: June 2009
• Est. primary completion date: December 2008
• Accepts healthy volunteers: No
• Gender: Both
• Age group: N/A to 18 Years

Eligibility

Inclusion Criteria:

• All Patients that require cardiopulmonary bypass during cardiac surgery.

Exclusion Criteria:

• The only exclusion criteria would be if CPB is not required for surgical repair.

Study Design

Observational Model: Cohort, Time Perspective: Prospective

Related Conditions & MeSH terms

• Cardiopulmonary Bypass

Intervention

Device:
• Doppler probes
Probes to be placed on CPB tubing to measure blood flow

Locations

Country	Name	City	State
United States	Children's Medical Center Dallas	Dallas	Texas

Sponsors (2)

Lead Sponsor	Collaborator
University of Texas Southwestern Medical Center	Children's Medical Center Dallas

Country where clinical trial is conducted

United States,