PEEP Levels Selected by PEEP Titration and PEEP Levels Routinely Used in Post-operative Cardiac Patients With Hypoxemic Respiratory Failure

Sponsor

University of Sao Paulo General Hospital (Other)

Overall Status

Unknown status

CT.gov ID

NCT02056977

Collaborator

Financiadora de Estudos e Projetos (Other)

Enrollment

Location

Arms

Duration (Months)

1.3

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The purpose of this study is to:

Compare PEEP level selected by individualized PEEP titration by electrical impedance tomography and PEEP level routinely used in post-operative cardiac patients with Hypoxemic Respiratory Failure;
Evaluate the agreement between the results of a rapid titration (total procedure duration = 5 min) versus an already validated slow titration (total procedure duration = 40 min) of the same patient, sequentially. Specifically, degree of collapse and degree of distention in each PEEP level, estimated by EIT;
Compare hemodynamics during the two maneuvers of PEEP titration;
Evaluate the efficacy of the selected PEEP (minimum PEEP preventing lung collapse less than 5%) to maintain stable levels of the following variables: arterial oxygenation, respiratory system compliance, and degree of collapse by EIT;
Compare these results (evolution of the three variables, along 4 hours) with the control strategy (default strategy currently used in the institution) group.

Condition or Disease	Intervention/Treatment	Phase
Post Operative Cardiac Surgery ARDS Hypoxemic Respiratory Failure	Other: Titration Other: control	N/A

Detailed Description

The acute respiratory distress syndrome (ARDS) increases the morbidity and mortality of patients admitted to the intensive care unit (ICU). In the postoperative period of cardiac surgery, the use of intraoperative extracorporeal circulation is one of the factors triggering the syndrome, its incidence increasing.

Potentially, a protective ventilatory strategy with optimal positive end expiratory pressure (PEEP) could improve the prognosis of those patients with ARDS.

An already validated maneuver to titrate the ideal PEEP to these patients has a longer duration, about 40 minutes. The lung Electrical impedance tomography (EIT) monitors respiratory system mechanics and intrathoracic lung volume changes and provides information about regional behavior and recruitability of lung tissue and thereby allows shortening titration maneuver, reducing its hemodynamic effects.

Patients in the postoperative period of cardiac surgery with a diagnosis of Hypoxemic Respiratory Failure (PaO2/FiO2 < 250 mmHg, calculated at FiO2 60%, and the presence of bilateral infiltrates on chest radiography), admitted to the surgical ICU from Heart Institute, University of São Paulo.

Recruitment maneuver and PEEP titration maneuver will be monitored by EIT.

All patients will be followed and monitored for 4 hours, with measures of the evolution of alveolar collapse . Hemodynamic and oxygenation data will also be recorded .

Study Design

Study Type:

Interventional

Anticipated Enrollment :

46 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Comparison Between PEEP Levels Selected by Individualized PEEP Titration - Rapid Titration by EIT - and PEEP Levels Routinely Used in Post-operative Cardiac Patients With Hypoxemic Respiratory Failure

Study Start Date :

Feb 1, 2015

Anticipated Primary Completion Date :

Dec 1, 2017

Anticipated Study Completion Date :

Jan 1, 2018

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Titration Individualized PEEP titration by EIT	Other: Titration Individualized PEEP according to PEEP titration monitored by EIT Other Names: Individualized PEEP
Active Comparator: Control PEEP stablished according to the routines at the institution (PEEP table according to the P/F ratio)	Other: control PEEP selected according to a PaO2/FIO2 table as in the routines of the institution Other Names: Control PEEP

Arm

Intervention/Treatment

Experimental: Titration

Individualized PEEP titration by EIT

Other: Titration

Individualized PEEP according to PEEP titration monitored by EIT

Other Names:

Individualized PEEP

Active Comparator: Control

PEEP stablished according to the routines at the institution (PEEP table according to the P/F ratio)

Other: control

PEEP selected according to a PaO2/FIO2 table as in the routines of the institution

Other Names:

Control PEEP

Outcome Measures

Primary Outcome Measures

To test the agreement between the ideal PEEP determined by rapid titration versus and the ideal PEEP determined by the slow PEEP titration maneuver. [2 hours]
Evaluate the agreement between the ideal PEEP determined by the rapid PEEP titration maneuver versus the ideal PEEP determined by the slow PEEP titration maneuver. The degree of collapse and overdistention at each PEEP level, as estimated by EIT, will be also compared during both procedures. Ideal PEEP is the minimum PEEP capable of keeping collapse at < 5%.

Secondary Outcome Measures

Stability of the selected PEEP according to the rapid titration in arterial oxygenation (SpO2, in %), respiratory system compliance (in cmH2O), and degree of collapse by EIT (in %) [4 hours]
Evaluate the stability of the selected PEEP (according to the rapid titration), by analyzing the maintenance of three variables over a four hour period: arterial oxygenation, respiratory system compliance, and degree of collapse by EIT

Other Outcome Measures

Comparison of the PEEP levels selected by the proposed strategy (rapid titration maneuver) and the PEEP levels used in the control group. [4 hours]
To compare the values of PEEP selected by both strategies, and to compare the evolution of the three variables (arterial oxygenation, respiratory system compliance, and degree of collapse by EIT) between propose strategy to control (default strategy currently used in the institution)

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 70 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Immediate postoperative period of myocardial revascularization and/or heart valve surgery (aortic and/or mitral)
Acute respiratory distress syndrome with ratio of partial pressure of arterial oxygen over fraction of inspired oxygen (PaO2:FiO2) no >200 mmHg and bilateral pulmonary infiltrates on XRay consistent with edema, and no clinical evidence of left atrial hypertension (pulmonary capillary wedge pressure <18 mmHg, when available).
Age > 18 and < 70 years old
Absence previous pulmonary disease
Left ventricular ejection fraction > 35%
Absence of previous cardiac surgery and / or lung disease;
Not requiring adjusted volume expansion (pulse pressure delta <13% or legs raising test without hemodynamic changes in cardiac index or mean arterial pressure).
Body mass index < 40 kg/m2
Written inform consent