Does Venous pCO2 Increase by 20 mmHg or More During Apnea Challenge Test?

Study Overview
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Brief Summary
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One required examination for declaration of death by neurological criteria is the apnea challenge test. The apnea challenge test evaluates the medulla brainstem respiratory center response to a rise in CO2. The current guideline requires arterial sampling of CO2 and therefore either arterial puncture or arterial catheter placement for the examination. Arterial catheter is an invasive monitoring device and is not without complications. Recent studies have demonstrated that there is a direct correlation between peripheral venous and arterial blood gas measures and that peripheral venous CO2 measures may be used as alternatives to arterial CO2 measure.The purpose of this study is to evaluate brainstem response during the apnea challenge test to a rise in venous CO2 and correlate it with the rise in arterial measured CO2. The objective of this study is to demonstrate a similar rise between the venous and arterial CO2 during the apnea challenge test and eliminate the necessity of arterial blood sampling for the sole purpose of apnea challenge test in the future.

Official Title
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Does Venous pCO2 Increase by 20 mmHg or More During Apnea Challenge Test?

Conditions
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Brain Death

Intervention / Treatment
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* Procedure: venous blood gas


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 37 weeks gestation up to any adult age Patients admitted to Pediatric Intensive Care unit (PICU), Neonatal Intensive Care Unit (NICU), Medical Intensive Care Unit (MICU) and Cardiothoracic Intensive Care Unit (CTICU) Patients with irreversible brain injury where the attending physician will be performing death by neurological criteria examination as per hospital policy Presence of arterial catheter or arterial blood sampling during apnea challenge test Presence of central venous catheter or easily drawing peripheral intravenous catheter Exclusion Criteria: Age less or equal to 37 weeks gestation Inability to perform apnea challenge test as determined by primary physician Family request for Donation after Cardiac Death (DCD) or withdrawal of Life Sustaining Therapy Bicarbonate infusion within 30 minutes of apnea challenge test

Ages Eligible for Study
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Minimum Age: 1 Week

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental<br>Venous blood gas will be obtained at the same time points as arterial blood gas in the apnea challenge test. | Procedure: venous blood gas<br>* Venous blood gas will be measured at the time of arterial blood gas measurement.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in venous blood CO2 during apnea challenge test |  | During apnea challenge test | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in End Tidal CO2 during apnea challenge test |  | During apnea challenge test | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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brain death, apnea challenge test