Effects of noninvasive ventilation after cardiovascular surgery: A Randomized Clinical Trial

• Register: REBEC
• Last refreshed on: 29 April 2013
• Main ID: RBR-8jgwpr
• Date of registration: 25/09/2011
• Primary sponsor: Alessandra Preisig - Brazil
• Public title: Effects of noninvasive ventilation after cardiovascular surgery: A Randomized Clinical Trial
• Scientific title: Effects of noninvasive mechanical ventilation on the hemodynamic and ventilatory parameters in post-cardiac surgery patients who developed hypoxemia after tracheal extubation
• Date of first enrolment: 01/04/2010
• Target sample size: 42
• Recruitment status: data analysis completed
• URL: http://www.ensaiosclinicos.gov.br/rg/RBR-8jgwpr/
• Study design: Controlled Clinical Trial, single-arm, randomized, open.

Countries of recruitment

Brazil

Contacts

• Name: Alessandra Werlang
• Affiliation: Irmandade da Santa Casa de Misericórdia de Porto Alegre

• Name: Alessandra Werlang
• Affiliation: Irmandade da Santa Casa de Misericórdia de Porto Alegre

Key inclusion & exclusion criteria

Inclusion criteria: Postoperative cardiovascular surgery (valve replacement, thoracoabdominal aortic surgery and/or coronary artery bypass graft (CABG);
Sternal incision and pulmonary artery catheter from surgical ward
Both genders, aged between 18 and 80 years.
Exclusion criteria: Severe chronic obstructive pulmonary disease,
Previous neurological disease and inability to understand;
More than 24 hours on mechanical ventilation;
Surgical revision for bleeding after tracheal extubation;
Emergency surgery;
Swan-Ganz catheter nonfunctioning

Age minimum: 18Y
Age maximum: 80Y
Gender: -

Health Condition(s) or Problem(s) studied

Respiration, artificial; thoracic surgery; anoxia
C14

Intervention(s)

The interventions were performed after inclusion in the study, each subject was submitted to only one intervention, with total duration of four consecutive hours for each patient.

The control group received oxygen therapy by Venturi mask with FiO2 = 0.4 and the intervention group received oxygen (FiO2 = 0.4) and bi-level non-invaisve ventilatio (NIV) with an inspiratory positive airway pressure (IPAP) to generate tidal volume between 5-6mL/kg and expiratory positive airway pressure (EPAP) of 7cmH2O. To ensure that both groups received the same FiO2, the intervention group was monitored with an oxygen analyzer, connected to the oronasal mask and kept at FiO2 = 0.4 for three consecutive hours.

Primary Outcome(s)

The study hypothesis was that could improve gas exchange (oxygenation index, partial pressure of oxygen in arterial blood and arterial oxygen saturation) with the use of bilevel noninvasive ventilation. To evaluate this outcome, we collected blood samples (arterial blood gases) at four time points: baseline, one hour and three hours after the placement of the mask and one hour after stopping the intervention.

Secondary Outcome(s)

The analysis of hemodynamic variables was made by measuring the pulmonary artery catheter (Swan-Ganz) that was inserted into the surgical ward, via the internal jugular vein. The following variables were measured: heart rate (HR), mean arterial pressure (MAP), mean pulmonary artery pressure (MPAP), central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP). To measure the cardiac output (CO), 10ml of saline (0.9%) were injected manually at room temperature and was calculated by the thermodilution curve. All measurements were repeated 4-5 times, excluding outliers and held an average of three measurements. Indirect variables obtained: cardiac index (CI), systolic volume index (SVI), left ventricular stroke work index (LVSWI), right ventricle stroke work index (RVSWI), systemic vascular resistance index (SVRI) and pulmonary vascular resistance index (PVRI).

Secondary ID(s)

1751/07

Source(s) of Monetary Support

Irmandade da Santa Casa de Misericórdia de Porto Alegre - Brazil

Secondary Sponsor(s)

Faculdade de Medicina da Universidade Federal do Rio Grande do Sul (UFRGS) - Brazil

Irmandade da Santa Casa de Misericórdia de Porto Alegre - Brazil