Pulmonary and Ventilatory Effects of Trigger Modulation in Intubated ICU

Sponsor

University Hospital, Clermont-Ferrand (Other)

Overall Status

Recruiting

CT.gov ID

NCT04041817

Collaborator

(none)

Enrollment

Location

Arm

34.1

Anticipated Duration (Months)

0.9

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Pressure support ventilation allows intubated ICU patients to breathe spontaneously. Among specific settings, the adjustment of the trigger value (or threshold for triggering the ventilator) has not been explored to date. The trigger threshold corresponds to the sensitivity of the ventilator to detect patient's inspiratory effort and then deliver the predefined pressure support to inflate the lungs and deliver a tidal volume. The purpose of this study is to explore the influence of trigger level on pulmonary and ventilatory physio (-patho)logical parameters in spontaneously breathing ICU patients.

Condition or Disease	Intervention/Treatment	Phase
ICU Patients Intubation Spontaneously Breathing Pulmonary Function Tracheotomy	Other: Trigger setting of pressure support ventilation	N/A

Detailed Description

The use of invasive mechanical ventilation is one of the most frequent therapies in intensive care units (ICUs). There are several types of indications, depending on the failure: essentially neurological, hemodynamic or respiratory.

In recent years, the notion of lung damage induced by mechanical ventilation (VILI) has led to major changes in ventilator settings in both ICUs and operative rooms (Ors). The reduction of the tidal volume (TV) to 6-8 mL/kg of ideal body weight, the use of an individualized positive end-of-expiratory pressure (PEEP) and the possible use of pulmonary aeration optimization therapies (alveolar recruitment manoeuvres, prone positioning sessions...) have become essential to increase patient's survival.

Withdrawal of invasive mechanical ventilation remains a daily issue and traditionally requires the transition from fully controlled ventilation to pressure support ventilation. Among specific settings of the latter, the adjustment of the trigger value (or threshold for triggering the ventilator) has not been explored to date. The trigger threshold corresponds to the sensitivity of the ventilator to detect patient's inspiratory effort and then deliver the predefined pressure support to inflate the lungs and deliver a tidal volume. The lower (or more sensitive) the trigger threshold, the smallest patient's effort will be rewarded. On the other hand, the higher the threshold, the greater the inspiratory effort required from the patient. Usually, this value is set by default to the minimum level to avoid self-triggering of the ventilator. With the objective to optimize pulmonary aeration, the use of higher trigger levels could increase diaphragmatic work (with a potential re-training and reinforcement effect) and contribute to better alveolar recruitment in the postero-inferior territories that are traditionally the most impacted, following a higher diaphragmatic motion. The authors propose to explore the impact of different trigger levels on pulmonary aeration (evaluated by electrical impedance tomography) and ventilatory parameters, in order to validate our hypotheses and before considering a trial with the objective of defining individualized trigger levels, according to patient's respiratory mechanics and pulmonary parenchyma morphology, with potential benefits on ventilator weaning.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

30 participants

Allocation:

N/A

Intervention Model:

Single Group Assignment

Masking:

None (Open Label)

Masking Description:

Statistical analysis will be conducted by an independant statistician not involved in data collection

Primary Purpose:

Treatment

Official Title:

Pulmonary and Ventilatory Effects of Trigger Modulation in Intubated ICU Patients Spontaneously Breathing With Pressure Support Ventilation. A Physiopathology Exploratory Study.

Actual Study Start Date :

Apr 3, 2019

Anticipated Primary Completion Date :

Feb 3, 2022

Anticipated Study Completion Date :

Feb 3, 2022

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Trigger increasing steps Trigger variations will be performed following increasing steps of 2 L/min every 15 minutes. End expiratory lung volume and lung aeration will be conducted using elecrical impedance tomography. Diaphragmatic motion and thickening will be analyzed by ultrasonography. Work of breathing will be evaluated using gastric and oesophageal pressure measurements. Measurements will be conducted during the last minute of each step.	Other: Trigger setting of pressure support ventilation Trigger variations will be performed following increasing steps of 3 L/min every 15 minutes, from 0.2 to 15 L/min (0.2 - 3 - 6 - 9 - 12 - 15).

Arm

Intervention/Treatment

Experimental: Trigger increasing steps

Trigger variations will be performed following increasing steps of 2 L/min every 15 minutes. End expiratory lung volume and lung aeration will be conducted using elecrical impedance tomography. Diaphragmatic motion and thickening will be analyzed by ultrasonography. Work of breathing will be evaluated using gastric and oesophageal pressure measurements. Measurements will be conducted during the last minute of each step.

Other: Trigger setting of pressure support ventilation

Trigger variations will be performed following increasing steps of 3 L/min every 15 minutes, from 0.2 to 15 L/min (0.2 - 3 - 6 - 9 - 12 - 15).

Outcome Measures

Primary Outcome Measures

Lung volume (end expiratory lung volume, EELV) at each trigger level [T0 (before the first trigger step)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T15 minutes (last minute of the trigger step n°1)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T30 minutes (last minute of the trigger step n°2)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T45 minutes (last minute of the trigger step n°3)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T60 minutes (last minute of the trigger step n°4)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T75 minutes (last minute of the trigger step n°5)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T90 minutes (last minute of the trigger step n°6)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T105 minutes (last minute of the trigger step n°7)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T120 minutes (last minute of the trigger step n°8)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T135 minutes (last minute of the trigger step n°9)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol
Lung volume (end expiratory lung volume, EELV) at each trigger level [T150 minutes (last minute of the trigger step n°10)]
The main endpoint is the difference between the lung volume (EELV) measured by electroimpedancemetry by tomography (EIT) at the end of each trigger level (15th minute) and the basal value measured at the beginning of the protocol

Secondary Outcome Measures

Homogeneity of pulmonary aeration [Through study completion, 150 minutes]
Evaluation of homogeneity of pulmonary aeration with Center Of Ventilation by EIT
Homogeneity of pulmonary aeration [Through study completion, 150 minutes]
Evaluation of homogeneity of pulmonary aeration with Global Inhomogeneity index by EIT
Regional impedance variation [Through study completion, 150 minutes]
Evaluation of regional impedance variation (TIV: Tidal Impedance Variation) by EIT
Atelectrauma [Through study completion, 150 minutes]
Assessement of atelectrauma (RVD: Regional Ventilation Delay) by EIT
Lung volume variations [Through study completion, 150 minutes]
Evaluation of lung volume variations by EIT (EELI : End Expiratory Lung Impedance)
Transpulmonary pressure [Through study completion, 150 minutes]
Evaluation of maximum transpulmonary pressure (alveolar stress)
Alveolar strain defined as the ratio between tidal volume and Functional Residual Capacity [Through study completion, 150 minutes]
Alveolar strain defined as the ratio between tidal volume and Functional Residual Capacity
Transpulmonary driving pressure [Through study completion, 150 minutes]
Evaluation of transpulmonary driving pressure
Work of breathing [Through study completion, 150 minutes]
Evaluation of work of breathing (WOB) value (P01)
Work of breathing [Through study completion, 150 minutes]
Evaluation of inspiratory occlusion pressure values (P01)
Energy delivered [Measurement during the last minute of each trigger step]
Evaluation of energy delivered to lungs patient
Diaphragm thickening [Through study completion, 150 minutes]
Evaluation of the diaphragmatic thickening by ultrasound
Diaphragm motion [Through study completion, 150 minutes]
Evaluation of the diaphragmatic motion by ultrasound
Patient's weight [Through study completion, 150 minutes]
Study of the impact of patient's weight

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Age ≥18 years
Patient hospitalized in the Intensive Care Unit of Clermont-Ferrand's Hospital
Patients with mechanical invasive ventilation in spontaneous ventilation with inspiratory support (intubation or tracheostomy)
Trigger level set to minimum
Patient under sedation compatible with spontaneous ventilation (SV) with inspiratory support (AI) and positive end-expiratory pressure (PEP) Patient calm (RASS between -2 and 0) Consent for participation or consent from patient's next of kin or inclusion according to an emergency procedure Patient benefiting from the French social security scheme

Exclusion Criteria:

Refusal to participate in the proposed study
Contraindication to the installation of a nasogastric tube:
Severe disorder of uncorrected blood clotting
Known nasosinus lesion
Oesophageal varices recently ligated (<48h)
Contraindication to the use of the electro-impedancemetry technique by tomography
Thoracic lesions
Chest dressings
Pace-maker / Implantable Defibrillator
Known lesion of central respiratory centers, including patients with neurological injury
Patients with Acute Respiratory Distress Syndrome (according to Berlin criteria)
Patients with restrictive or obstructive pulmonary pathology
Patients admitted post-operatively for surgery that may affect the diaphragmatic function ( thoracic or abdominal supra-mesocolic)
Patients with abdominal distention (ileus, intra-abdominal hyperpressure)
Patient whose BMI is greater than 35 kg.m-2
Pregnant patient
Patient under guardianship,