Non-invasive Mechanical Ventilation After Cardiac Surgery

Study Overview
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Brief Summary
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Non-invasive mechanical ventilation (NIV) has been used in hypoxic post-operative cardiac patients but more studies are necessary to clarify its respiratory and hemodynamic effects. Therefore, the investigators objective was to study its effects in the oxygenation index (PaO2/FiO2) and in hemodynamic variables in this group of patients.

Detailed Description
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Postoperative cardiac surgery patients having a Swan-Ganz catheter and showing a PaO2/FiO2 between 150 and 300 (with FIO2 0.31), one hour after extubation, were included. Then, the patients were randomized into two groups: control and intervention group. Intervention group used NIV with a bi-level positive airway pressure (an inspiratory pressure to generate a tidal volume of 6ml/kg and an expiratory pressure of 7cmH2O) with a FIO2 0.4. Control group used oxygen by Venturi mask(FIO2 0.4) in order to keep a good oxygenation. In both groups measurements were done in basal situation, one and three hours after beginning the treatment and one hour after stop the treatment (FiO2 0.31). Variables studied included: PaO2/FiO2, PaO2, PaCO2, heart rate (HR), mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP) and cardiac output (CO).

Official Title
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Effects of Non-invasive Mechanical Ventilation on Hemodynamics and Gas Exchanges Parameters After Cardiac Surgery in Patients With Relative Hypoxemia

Conditions
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Heart; Dysfunction Postoperative, Cardiac Surgery

Intervention / Treatment
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* Device: VPAP II®


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Oxygenation index (PaO2/FiO2)between 150 and 300 one hour after extubation following cardiac surgery. Swan-Ganz catheter Exclusion Criteria: Invasive mechanical ventilation more than 24 hours Serious obstructive pulmonary chronic disease (FEV1<40%)

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 85 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

Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: VPAP II®<br>VPAP II® Group | Device: VPAP II®<br>* VPAP group:inspiratory pressure to generate 6ml/kg of weight and expiratory pressure of 7cmH2O plus oxygen therapy (FIO2=40%) during three hours.<br>* Other names: VPAP II -STA (Resmed®);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxygenation index (PaO2/FiO2) |  | 5 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate (HR) |  | 5 hours | 
| Mean arterial pressure (MAP) |  | 5 hours | 
| Pulmonary capillary wedge pressure (PCWP) |  | 5 hours | 
| Cardiac output (CO) |  | 5 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cardiac surgery, Non-invasive ventilation