Assessing Ventilator Safety in Patients on Pressure-Support Ventilation

Study Overview
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Brief Summary
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ASOP is a prospective cohort study comparing three methods for assessing risk of self-induced lung injury in patients with acute respiratory failure being managed with pressure-support ventilation. We will describe the relationship between three different assessment methods for risk of self-induced lung injury and compare them to a gold standard measurement.

Detailed Description
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Ventilator-induced lung injury (VILI) is known to cause significant morbidity and mortality in patients with acute respiratory failure. Most studies on VILI have involved the effects of inappropriate (often excessive) mechanical ventilator settings. More recently, it has been noted that similar lung damage can be caused by large, patient generated, uncontrolled tidal volumes and driving pressures, which has been termed self-induced lung injury, or SILI. Pressure-support ventilation (PSV) is a common mechanical ventilation mode often used in patients with active inspiratory efforts to help reduce patient inspiratory work and improve comfort. PSV effectively allows spontaneously breathing patients to determine their breath flow-rate and breath duration, eliminating flow and cycle dyssynchrony. However, pressure support ventilation does not allow for physicians to control tidal volume or driving pressure. The risk of SILI may thus be increased with PSV. Several different methods have been proposed to address these challenges. However, to date none of these methods have been compared to assess for concordance in their ability to indicate an increased risk of self-induced lung injury. ASOP is a prospective cohort study comparing three methods for assessing risk of self-induced lung injury in patients with acute respiratory failure being managed with pressure-support ventilation.

Official Title
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Assessing Ventilator Safety in Patients on Pressure-Support Ventilation

Conditions
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Acute Respiratory Failure, Mechanical Ventilation Complication, Ventilator-Induced Lung Injury

Intervention / Treatment
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* Device: Viasys Avea Ventilator
* Device: Philips Respironics NM3 device
* Device: Servo U ventilator
* Device: Vyaire SmartCath adult nasogastric tube with Esophageal balloon


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients age ≥18 years with acute respiratory failure receiving invasive mechanical ventilation Managed in pressure-support mode of ventilation Exclusion Criteria: Actively undergoing a spontaneously awakening trial or SAT Patient or surrogate is unable to provide informed consent Currently pregnant Currently incarcerated Acute exacerbation of an obstructive lung disease Known esophageal varices or any other condition for which the attending physician deems an orogastric catheter to be unsafe Esophageal, gastric or duodenal surgical procedures within the last 6 months

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Acute Respiratory Failure<br>Patients with acute respiratory failure managed with pressure-support ventilation. | Device: Viasys Avea Ventilator<br>* Measuring dynamic airway driving pressure and static airway driving pressure during pressure support breath, and static airway driving pressure during a volume control breath. Measuring airway occlusion pressure during pressure support breath.<br>Device: Philips Respironics NM3 device<br>* Measuring static airway driving pressure during pressure support breath<br>Device: Servo U ventilator<br>* Measuring static airway driving pressure and p0.1 during pressure support breath.<br>Device: Vyaire SmartCath adult nasogastric tube with Esophageal balloon<br>* Measuring static and dynamic esophageal driving pressure during pressure support breath, and esophogeal pressure change during airway occlusion maneuver.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory System Driving Pressure measure by Servo Ventilator (DPrs-servo) | Driving pressure in centimeters of water measured with inspiratory hold on Servo Ventilator in pressure-support ventilation. | Study day 1 | 
| Respiratory System Driving Pressure measure by Respironics NM3 device (DPrs-NM3) | Driving pressure in centimeters of water measured with Phillips Respironics NM3 device in pressure-support ventilation. | Study day 1 | 
| Airway Occlusion Test (AOC) | Maximum negative airway pressure in centimeters of water during an airway occlusion maneuver. | Study day 1 | 
| Respiratory System Driving Pressure measured during volume control breath. | Airway driving pressure in centimeters of water measured with inspiratory hold in volume control/assist control. | Study day 1 | 
| Transpulmonary Driving pressure measured during volume control breath. | Transpulmonary driving pressure in centimeters of water measured via esophageal balloon with inspiratory hold in volume control/assist control. | Study day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of mechanical ventilation | Number of days receiving mechanical ventilation | Index hospitalization (up to 28 days) | 
| Duration of intensive care unit admission | Number of days admitted to intensive care unit | Index hospitalization (up to 28 days) | 
| Duration of hospital admission | Number of days admitted to hospital | Index hospitalization (up to 28 days) | 
| Ventilator Free Days | Number of days free from mechanical ventilation | Index hospitalization (up to 28 days) | 
| In-hospital survival | Survival to discharge | Index hospitalization (up to 28 days) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Self-induced lung injury, Pressure-support ventilation