AMBU Bag Manual Ventilation vs. Transport Ventilator Mechanical Ventilation for Transport

Study Overview
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Brief Summary
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This is a clinical trial to compare the oxygenation and ventilation performance between manual ventilation and mechanical ventilation when transporting cardiac patients to the ICU.

Detailed Description
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Following cardiac surgery, patients often require ventilation during transport to the intensive care unit (ICU). Most of the time, manual ventilation using an AMBU bag (AMBU INC. MD, USA) is utilized, but some patients need mechanical ventilation due to concern for oxygenation, ventilation, and hemodynamics. The indication to choose mechanical ventilation over manual ventilation is determined on a case-by-case basis, mostly based on providers' experiences or surgical request, because currently there is no clear clinical evidence behind that. With this clinical study, the investigators intend to build up clinical evidence by comparing oxygenation, ventilation, hemodynamics, and cardiac functions between two arms: manual ventilation using AMBU bag arm and mechanical ventilation using a transport ventilator. Objective: In this study, the investigators plan to compare the effects of transport ventilators (Hamilton C1: Bodaduz, Schweiz) and AMBU bag manual ventilation on oxygenation, ventilation, biventricular function, and hemodynamics. This is a two-arm study. To assess pre and post transport PaO2/FiO2 (P/F ratio), PaCO2, biventricular function, and hemodynamics (including blood pressure, heart rate, pulmonary artery pressure and central venous pressure) in the AMBU bag and Hamilton transport ventilator groups. The investigators hypothesize that using the Hamilton transport ventilator will show a smaller change in P/F ratio, hemodynamics, and biventricular function compared to the AMBU bag group. If true, these findings would support using the Hamilton ventilator for transport in appropriate surgical patients. To perform in-vitro flow analysis using a flow analyzer analyzer (CITREX H5: Buchs, Schweiz) and lung simulator (SmartLung 2000: Buchs, Schweiz) to measure the accuracy of the ventilations of Hamilton C1 ventilator and AMBU bag manual ventilation on different resistance and compliance settings of the lung simulator

Official Title
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Ventilation During Intensive Care Unit Transport After Cardiac Surgeries; When Should we Use a Ventilator?

Conditions
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Oxygenation, Manual Ventilation, Mechanical Ventilation, Point of Care Ultrasound, Cardiac Function Disturbance Postoperative

Intervention / Treatment
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* Device: Hamilton C1 ventilator during transport to the ICU


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Over 18 years old (any gender or race) Cardiac surgery Require postoperative mechanical ventilation and care in the ICU. Exclusion Criteria: Patients' refusal Extubation in OR On mechanical circulatory support Requirement for postoperative therapy with inhaled pulmonary vasodilators (epoprostenol (FLOLAN), inhaled nitric oxide, etc.) Severe RV dysfunction with preoperative echocardiography Contraindication to TEE and pulmonary artery catheter.

Ages Eligible for Study
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Minimum Age: 18 Years

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
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: After IRB approval and obtaining a written informed consent, patients will be randomly assigned to the one of the following 2 arms. However, AMBU bag arm patients may be switched to Hamilton C1 at an anesthesia provider's discretion based on post cardiopulmonary bypass right ventricular function, PaO2/FiO2, and PaCO2. These patients will be excluded from the AMBU bag arm. Arm 1: AMBU bag manual ventilation during transport to the ICU Arm 2: Hamilton C1 ventilator during transport to the ICU
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Arm 1: AMBU bag manual ventilation during transport to the ICU<br> | |
| Experimental: Arm 2: Hamilton C1 ventilator during transport to the ICU<br> | Device: Hamilton C1 ventilator during transport to the ICU<br>* Instead of AMBU bag manual ventilation during transport to the ICU, intervention is using Hamilton C1 ventilator during transport to the ICU<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The visual scale in changes in left ventricular function | Within-group and between-group changes in visual assessment of left ventricular function parameters before and after transport (1: severe hypokinetic, 2: moderate hypokinetic, 3: mild hypokinetic, 4: normal, 5: hyperdynamic) | First visual assessment of left ventricular function Immediately before transport to ICU till the second visual assessment after dropping off the patient at ICU; approximately 30 minutes after the first visual assessment. | 
| The visual scale in changes in right ventricular function | Within-group and between-group changes in visual assessment of right ventricular cardiac function parameters before and after transport (1: severe hypokinetic, 2: moderate hypokinetic, 3: mild hypokinetic, 4: normal, 5: hyperdynamic) | First visual assessment of right ventricular function Immediately before transport to ICU till the second visual assessment after dropping off the patient at ICU; approximately 30 minutes after the first visual assessment. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The changes in PaO2/FiO2 (P/F ratio) | The changes in PaO2/FiO2 (P/F ratio) pre and post transport to ICU. P/F ratio will be assessed on arterial blood gas immediately before and after the transport to ICU, at the same time as the investigators do echocardiographic assessment as described above. | First aortic blood gas analysis Immediately before transport to ICU till the second arterial blood gas analysis after dropping off the patient at ICU; approximately 30 minutes after the first visual assessment. | 
| The changes in PaCO2 | The changes in PaCO2 pre and post transport to ICU. PaCO2 will be assessed on arterial blood gas immediately before and after the transport to ICU, at the same time as the investigators do echocardiographic assessment as described above. | First aortic blood gas analysis Immediately before transport to ICU till the second arterial blood gas analysis after dropping off the patient at ICU; approximately 30 minutes after the first visual assessment. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ventilator, point of care ultrasound, transport