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

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

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.

Study Overview

• Status: Completed
• Conditions: Thoracic Surgery
• Intervention / Treatment: Device: VCV+PSV; Device: PCV+PSV

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 Type: Interventional
• Enrollment (Actual): 19
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • Pernambuco
    • Recife, Pernambuco, Brazil, 52010-040
      • Hospital Real Português de Beneficência em Pernambuco

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 63 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 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.	Device: VCV+PSV; invasive mechanical mechanical modes by volume cycling and by pressure support which the patients will be submitted to before weaning. Post-operative mechanical ventilation average time: 6 hours after ICU admission.; Other Names: volume controlled ventilation mode; pressure support ventilation mode
Experimental: 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.	Device: PCV+PSV; invasive mechanical mechanical modes by pressure cycling and by pressure support which the patients will be submitted to before weaning. Post-operative mechanical ventilation average time: 6 hours after ICU admission.; Other Names: pressure controlled ventilation mode; pressure support mode

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
electrical impedance measures	impedance variation data recorded by a tomograph.	5 minutes of recording at each step of mechanical ventilation progression before extubation.

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Universidade Federal de Pernambuco
• Collaborators: Real Hospital Português de Beneficência em Pernambuco
• Investigators: Principal Investigator: WAGNER S LEITE, Universidade Federal de Pernambuco; Study Chair: Shirley Lima Campos, Universidade Federal de Pernambuco

Publications and helpful links

Helpful Links

• Right ventricular function during one-lung ventilation: effects of pressure-controlled and volume-controlled ventilation
• Effect of a protective-ventilation strategy on mortality in the acute respiratory distress syndrome.
• Tidal ventilation distribution during pressure-controlled ventilation and pressure support ventilation in post-cardiac surgery patients.
• Monitoring perioperative changes in distribution of pulmonary ventilation by functional electrical impedance tomography.
• Refining ventilatory treatment for acute lung injury and acute respiratory distress syndrome.
• Bedside waveforms interpretation as a tool to identify patient-ventilator asynchronies.
• Volume-controlled versus pressure-controlled ventilation-volume guaranteed mode during one-lung ventilation
• Ultrasonographic diagnostic criterion for severe diaphragmatic dysfunction after cardiac surgery.

Study record dates

Study Major Dates

• Study Start (Actual): March 9, 2017
• Primary Completion (Actual): December 31, 2017
• Study Completion (Actual): December 31, 2017

Study Registration Dates

• First Submitted: February 21, 2017
• First Submitted That Met QC Criteria: May 2, 2017
• First Posted (Actual): May 5, 2017

Study Record Updates

• Last Update Posted (Actual): September 26, 2019
• Last Update Submitted That Met QC Criteria: September 24, 2019
• Last Verified: September 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: 03021991

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: to be shared are: data provided by electrical impedance tomograph, by ultrasound and general clinical one (such as blood pressure, oxygen supplementary concentration, heart rate, respiratory rate, mechanical ventilation duration, surgery duration). These data will be available for sharing after the end of the study and it will be obtained by a copy in a USB flash drive.

Study Data/Documents

1. Study Protocol
   Information comments: Search for "buscar pesquisas aprovadas" and fill the the blanks with research title and investigator's full name

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No