Best End-Expiratory and Driving-pressure for Individualized Flow Controlled Ventilation in Patients With COPD

Study Overview
=================
Brief Summary
-----------------
Patients with chronic obstructive pulmonary disease (COPD) have a significantly increased risk of postoperative pulmonary complications (PPC). Protective ventilation of the lungs could reduce the rate of PPC in patients with COPD. It has been suggested that flow controlled ventilation (FCV) may be less invasive and more protective to the lungs than conventional ventilation in patients with COPD. The primary aim of this study is to determine a optimal individual ventilation setting for FCV in ten participants with COPD.

Detailed Description
-----------------
The estimated worldwide chronic obstructive pulmonary disease (COPD) mean prevalence is 13.1%. In 2015, 3.2 million people died from COPD worldwide, and estimates show that COPD will be the third leading cause of death in 2030. Patients with COPD are at high risk for postoperative pulmonary complications (PPC). It has been proposed that FCV might be less-invasive and more protective for the lungs than conventional ventilation in patients with COPD. The pathophysiology of COPD is multifactorial, with the collapse of the central airways having a major impact on the symptoms. Minimizing the expiratory flow could prevent this airway pathology, and thus be beneficial in the ventilation of patients with COPD. In the operation theater participants will be ventilated with flow controlled ventilation (FCV). Arterial blood gas analysis and electrical impedance tomography (EIT) will be measured. The aim of the study is to determine the best end-expiratory pressure and driving pressure (assessed after anesthesia induction based on compliance and EIT parameters).

Official Title
-----------------
Best End-Expiratory and Driving-Pressure for Individualized Flow Controlled Ventilation in Patients With COPD - an Observational Study.

Conditions
-----------------
COPD, Ventilator Lung, Anesthesia

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients undergoing surgery with endotracheal intubation Age ≥ 18 Verified COPD (preoperative spirometry) Exclusion Criteria: Pregnant woman Laparoscopic surgery Surgery that might interfere with EIT measurement Cardiac Implantable Electronic Devices

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------
What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best end-expiratory pressure | Best end-expiratory pressure (mbar), defined as the end-expiratory pressure associated with the best compliance, best tradeoff between alveolar collapse and hyper distension (EIT) | 1 hour after tracheal Intubation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best driving pressure | Best driving pressure (peek pressure - end-expiratory pressure in mbar) associated with the best compliance, best tradeoff between alveolar collapse and hyper distension (EIT) | 1 hour after tracheal intubation | 
| Dissipated energy | Calculated dissipated energy per liter of gas ventilated (J) during ventilation. | 1 hour after tracheal intubation | 
| Required minute volume to maintain carbon dioxide partial pressure (pCO2) level | The minute volume (L/min) of the ventilator will be adjusted to maintain the preoperative baseline pCO2 level (blood gas analysis). | 1 hour after tracheal intubation | 
| Applied mechanical power | Calculated applied mechanical power during ventilation (J/min) | 1 hour after tracheal intubation | 
| Ventilation distribution | Expressed as the percentage of total pulmonary ventilation through each of the regions-of-interest, total 100%. | 1 hour after tracheal intubation | 
| Delta Z | Measured variation of impedance (arbitrary units) by electrical impedance tomography. | 1 hour after tracheal intubation | 
| Delta end-expiratory lung impedance | Variation of impedance plethysmography at end-expiration measured by electrical impedance tomography. | 1 hour after tracheal intubation | 
| Distribution of regional tidal ventilation | Distribution of regional tidal ventilation will be determined as the relation of regional ΔZ/total ΔZ (expressed in percentage), measured by electrical impedance tomography. | 1 hour after tracheal intubation | 
| Regional lung compliance | Calculated by electrical impedance tomography (ml/cm H2O) | 1 hour after tracheal intubation | 
| Center of Ventilation | Variations of the pulmonary ventilation distribution in the ventral-dorsal and left-right direction measured by electrical impedance tomography. | 1 hour after tracheal intubation | 
| Global inhomogeneity index | Impedance variations of each pixel between the end of inspiration and expiration measured by electrical impedance tomography. | 1 hour after tracheal intubation | 
| arterial oxygen partial pressure (paO2) | Measured by blood gas analysis (mmHg) | 1 hour after tracheal intubation | 
| carbon dioxide partial pressure (pCO2) | Measured by blood gas analysis (mmHg) | 1 hour after tracheal intubation | 
| Horovitz quotient | Ratio of PaO2 (mmHg) and the fraction of oxygen of the inhaled air (FiO2). | 1 hour after tracheal intubation | 
| Base excess | Measured by blood gas analysis (mmol/l) | 1 hour after tracheal intubation | 
| potential of hydrogen (pH) | Measured by blood gas analysis | 1 hour after tracheal intubation | 
| Resistance | Pressure change per flow change measured by the ventilator (kPa*s/l). | 1 hour after tracheal intubation | 
| tidal volume | Measure by ventilator (ml) | 1 hour after tracheal intubation | 
| Peak inspiratory pressure | Maximum pressure during the inspiration measured by the ventilator (mbar). | 1 hour after tracheal intubation | 
| Respiratory rate | Measured by the ventilator (1/min) | 1 hour after tracheal intubation | 
| End-tidal carbon dioxide (etCO2) | End-tidal carbon dioxide level measured by the ventilator (mmHg). | 1 hour after tracheal intubation |