Clinical trial NCT03141216: Patient-ventilator Asynchrony in Conventional Ventilation Modes During Short-term Mechanical Ventilation After Cardiac Surgery
Official title: Effects of Mechanical Ventilation on Controlled Volume, Controlled Pressure and Pressure Support in the Immediate Postoperative Period of Cardiac Surgery on Pulmonary Electrical Impedance and Patient-ventilator Asynchrony: a Parallel Clinical Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Thoracic Surgery
Lead sponsor: Universidade Federal de Pernambuco
Sponsor class: OTHER
Collaborators: name: Real Hospital Português de Beneficência em Pernambuco
First posted: 2017-05-05
Enrollment: 19
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: A parallel group study is a simple and commonly used clinical design which compares two treatments. Usually a test therapy is compared with a standard therapy. The allocation of subjects to groups is usually achieved by randomisation. The groups are typically named the treatment group and the control group. Parallel group designs do not require the same number of subjects in each group, although often similar numbers are observed. The design is commonly used in randomised controlled trials. Statistical analysis often boils down to a simple t-test of the between group difference in the outcome, which is usually a mean or a proportion.
Primary purpose: DIAGNOSTIC

Brief summary: This study evaluates the effects of VCV, PCV and PSV ventilatory modes during the immediate postoperative period on the variables resulting from regional and global pulmonary electrical impedance and diaphragmatic mobility, as well as perform ventilator synchrony analysis in PSV mode by mechanical ventilator. Half of the participants will receive VCV followed by PSV for weaning, while the other half will receive PCV followed by PSV for weaning.

Detailed description: In the immediate postoperative period of cardiac surgery, patients are found under mechanical ventilatory support. Commonly, they are ventilated in controlled and assisted-controlled volume (VCV) or pressure (PCV) modes, with weaning at pressure support (PSV).

Systematic reviews indicate that there is no difference between the VCV and PCV ventilatory modes for some clinical outcomes or that the existing evidence is insufficient. The distribution of regional ventilation and diaphragmatic mobility can be measured from the use of electrical impedance tomography (EIT) and diaphragmatic ultrasonography (US) to clarify the physiological changes and / or mechanisms of adaptation of the organism submitted to controlled modes cycled at volume or at pressure and spontaneously flow cycled mode.

Besides EIT and US measures, gasometric, hemodynamic and respiratory data will also be recorded. The statistical analysis will be considered α≤0.05 for a statistically significant difference.

Eligibility criteria: Inclusion Criteria:

* IMC 18.5-29.9 kg/m²
* Two thoracic tubes (one mediastinal and one left-sided pleural)
* under mechanical ventilation after surgery
* submitted to intraoperative extracorporeal circulation

Exclusion Criteria:

* Over 2h of cardiopulmonary bypass
* Over 12h of post-operative mechanical ventilation
* Post-operative bleeding above 500 ml in the first hour or above 300 ml in the first two hours
* History of special conditions (neuromuscular and chronic pulmonary disease, thoracic deformity, abdominal distension).

Primary outcomes:
measure: electrical impedance measures
timeFrame: 5 minutes of recording at each step of mechanical ventilation progression before extubation.
Secondary outcomes:
measure: arterial gas blood analysis data
timeFrame: up to 12h, following routine care while patients are mechanically ventilated
measure: patient-ventilator synchrony
timeFrame: 5 minutes of recording at each step of mechanical ventilation progression before extubation
Other outcomes:
Locations:
city: Recife
country: Brazil
facility: Hospital Real Português de Beneficência em Pernambuco
state: Pernambuco
Study officials:
affiliation: Universidade Federal de Pernambuco
name: WAGNER S LEITE
role: PRINCIPAL_INVESTIGATOR
affiliation: Universidade Federal de Pernambuco
name: Shirley Lima Campos
role: STUDY_CHAIR
References: