Patient-ventilator Asynchrony in Conventional Ventilation Modes During Short-term Mechanical Ventilation After Cardiac Surgery

Not Applicable

Completed

• Conditions: Thoracic Surgery
• Interventions: Device: VCV+PSV; Device: PCV+PSV

• Registration Number: NCT03141216
• Lead Sponsor: Universidade Federal de Pernambuco

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.

Study Timeline

• Study First Submitted: 2017-02-21
• Study Start: 2017-03-09
• Study First Submitted QC: 2017-05-02
• Study First Posted: 2017-05-05
• Primary Completion: 2017-12-31
• Study Completion: 2017-12-31
• Status Verified: 2019-09
• Last Update Submitted: 2019-09-24
• Last Update Posted: 2019-09-26

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 19

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).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
VCV+PSV	VCV+PSV	volume controlled cycled, assisted-controlled cycled ventilation mode + pressure support ventilation mode. Progression of invasive ventilatory assistance as the patient recovers during post-surgery.
PCV+PSV	PCV+PSV	pressure controlled cycled, assisted-controlled cycled ventilation mode + pressure support ventilation mode. Progression of invasive ventilatory assistance as the patient recovers during post-surgery.

Primary Outcome Measures

Name	Time	Method
electrical impedance measures	5 minutes of recording at each step of mechanical ventilation progression before extubation.	impedance variation data recorded by a tomograph.

Secondary Outcome Measures

Name	Time	Method
arterial gas blood analysis data	up to 12h, following routine care while patients are mechanically ventilated	measures of pH, PaCO2 (mmHg), PaO2 (mmHg), PaO2/FiO2
patient-ventilator synchrony	5 minutes of recording at each step of mechanical ventilation progression before extubation	events of discomfort between patient and ventilator: ineffective efforts and auto-triggering. Expressed in present or ausent.

Trial Locations

Locations (1)

Hospital Real Português de Beneficência em Pernambuco; 🇧🇷 Recife, Pernambuco, Brazil