Clinical Trial: Positive Pressure Ventilation and Sternal Closure in HLHS

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Effect of Positive Pressure Ventilation on Hemodynamics Around Delayed Sternal Closure Following Stage 1 Palliation of the Single Ventricle

Brief Summary: This study will examine the cardiopulmonary interactions that occur with increasing ventilator settings (PEEP and PIP) in neonates after stage I palliation for hypoplastic left heart syndrome before and after sternal closure. Outcome measures include oxygen delivery and cardiac output.

Detailed Summary:

The objective of this study is to define the impact of variable levels of PEEP and tidal volume on hemodynamics and lung mechanics around delayed sternal closure after Stage 1 palliation in the single ventricle patient.

The Specific Aims of this work are:

Specific Aim 1: Evaluate hemodynamics and lung mechanics across a range of PEEP (2-12 cm H2O) before and after chest closure, while maintaining consistent ventilation, in infants with single ventricle physiology who undergo delayed sternal closure after Stage 1 palliation surgery.

Specific Aim 2: Evaluate hemodynamics and lung mechanics across a range of tidal volumes (6-15ml/kg) and before and after chest closure, while maintaining consistent ventilation, in infants with single ventricle physiology who undergo delayed sternal closure after Stage 1 palliation surgery.

Hypotheses

1. The effects of PEEP and tidal volume on hemodynamics and lung mechanics will be significantly different before and after sternal closure. We expect that there will be little effect of PEEP or tidal volume when the sternum remains open. Once the sternum is closed, we hypothesize that those with shunted single ventricle physiology will have optimal oxygen delivery and lung mechanics with modest PEEP and tidal volume (U-shaped curves).

Rationale: Delayed sternal closure is commonly used to prevent tissue tamponade and promote favorable hemodynamics in critically ill patients following surgery for congenital heart disease. This technique is frequently employed in shunted single ventricle physiology (i.e.- Norwood patients). While there have been several studies that have shown that sternal closure is a
Sponsor: The Hospital for Sick Children

Current Primary Outcome: Oxygen Delivery calculated from direct measurements of oxygen consumption via respiratory mass spectrometry [ Time Frame: Measurements made 15 minutes after each ventilator change. Total duration of observation is 2.5 hours. ]

Oxygen delivery will be calculated from direct measurements of oxygen consumption via respiratory mass spectrometry and estimates of cardiac output calculated using the Fick equation from measured arterial a venous blood gas samples.


Original Primary Outcome: Same as current

Current Secondary Outcome: Cardiac Output calculated using the Fick Equation [ Time Frame: Measurements made 15 minutes after each ventilator change. Total duration of observation is 2.5 hours. ]

Cardiac output will be calculated using the Fick Equation from direct measurement of oxygen consumption using respiratory mass spectrometry and arterial and venous blood gas samples.


Original Secondary Outcome: Same as current

Information By: The Hospital for Sick Children

Dates:
Date Received: April 5, 2015
Date Started: February 2015
Date Completion: June 2017
Last Updated: April 13, 2016
Last Verified: April 2016