Expiratory Time Constant in Mechanically Ventilated Patients

Sponsor

East Slovak Institute for Cardiovascular Diseases (Other)

Overall Status

Completed

CT.gov ID

NCT05827640

Collaborator

(none)

Enrollment

Location

2.5

Actual Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Determining expiratory time constants in mechanically ventilated patients

Condition or Disease	Intervention/Treatment	Phase
Comparing Six Different Methods to Obtain Expiratory Time Constant	Other: data recording using conventional ventilation strategies (PCV and VCV)

Detailed Description

Adult patients (n = 30) undergoing elective cardiac surgery with extracorporeal circulation (ECC) were included. Patients were excluded from the study if they had any known lung disease or had previous thoracic surgery. After the surgery, all patients were transferred to the intensive care unit (ICU) and connected to well-established Servo-U (Maquet, Getinge AB, Solna, Sweden) mechanical ventilator. First, the ventilation mode was set to mandatory volume-controlled ventilation (VCV) for 15 minutes. After that, mandatory pressure-controlled ventilation (PCV) for another 15 minutes was commenced. All patients were in supine position, sedated and paralyzed using continuous infusion of propofol and atracurium with no spontaneous breathing efforts. During VCV, an end-inspiratory pause (TPAUSE 10%) has been added to obtain inspiratory plateau pressure (P PLAT) under static conditions. Respiratory variables in VCV for all patients were as follows: PEEP 6 - 9 cmH 2 O depending on the local protocol, protective tidal volume (Vt) of 7 ml/kg/PBW, T PAUSE was set to 10%, I:E ratio of 1:2, rise time 5% and the respiratory rate was 14 breaths/min. After 15 minutes, VCV was changed to PCV with the same ventilator setting with inspiratory pressure set in the way to best match the Vt during the VCV. ARDSNet tables were used to determine PBW for all patients.

A novel device enabling data acquisition (Dr. Wave, Quadrus Medical Technologies, NY, White Plains, USA) has been connected to the Servo-U ventilator after admission to the ICU to record flow, pressure, and volume waveforms. All data in the study were derived from measurements and calculations from this device and included: Peak Inspiratory Pressure (PIP), PPLAT, PEEP, expiratory tidal volume (Vt) respiratory system compliance (C RS ), airway resistance (RTOT) and the peak expiratory flow rate (PEFR).

Based on obtained data of flow, volume and pressure during PCV and VCV, six different methods to determined expiratory time constant were examined

Study Design

Study Type:

Observational

Actual Enrollment :

30 participants

Observational Model:

Cohort

Time Perspective:

Prospective

Official Title:

Determining Expiratory Time Constant in Mechanically Ventilated Patients

Actual Study Start Date :

Nov 15, 2022

Actual Primary Completion Date :

Jan 30, 2023

Actual Study Completion Date :

Jan 30, 2023

Outcome Measures

Primary Outcome Measures

Expiratory time constant [3 months]
Six different methods to assess expiratory time constants in mechanically ventilated patients

Secondary Outcome Measures

Validity of expiratory time constant definition [3 months]
To prove if three time constant correspond to actual first time constant multiplied by the factor of 3

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria: cardiac surgery with extracorporeal circulation

Exclusion Criteria:

known pulmonary disease
previous thoracic surgery
poor preoperative cardiac status

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	East Slovak Institute for Cardiovascular Diseases	Košice		Slovakia	040 01

Sponsors and Collaborators

East Slovak Institute for Cardiovascular Diseases

Investigators

Study Director: Dušan Rybár, PhD, East Slovak Institute for Cardiovascular Diseases

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

Filip Depta MD, MD, East Slovak Institute for Cardiovascular Diseases

ClinicalTrials.gov Identifier:

NCT05827640

Other Study ID Numbers:

www.vusch.sk

First Posted:

Apr 25, 2023

Last Update Posted:

Apr 25, 2023

Last Verified:

Apr 1, 2023

Individual Participant Data (IPD) Sharing Statement:

Undecided

Plan to Share IPD:

Undecided

Studies a U.S. FDA-regulated Drug Product:

Studies a U.S. FDA-regulated Device Product:

Keywords provided by Filip Depta MD, MD, East Slovak Institute for Cardiovascular Diseases

expiratory time constant, mechanical ventilation, exhalation

Study Results

No Results Posted as of Apr 25, 2023