Assessing Ventilator Safety in Patients on Pressure-Support Ventilation (ASOP)

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.

Study Overview

• Status: Completed
• Conditions: Ventilator-Induced Lung Injury; Mechanical Ventilation Complication; Acute Respiratory Failure
• Intervention / Treatment: Device: Viasys Avea Ventilator; Device: Philips Respironics NM3 device; Device: Servo U ventilator; Device: Vyaire SmartCath adult nasogastric tube with Esophageal balloon

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 16
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Duke University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Acute Respiratory Failure; Patients with acute respiratory failure managed with pressure-support ventilation.

Device: Viasys Avea Ventilator; 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.; Device: Philips Respironics NM3 device; Measuring static airway driving pressure during pressure support breath; Device: Servo U ventilator; Measuring static airway driving pressure and p0.1 during pressure support breath.; Device: Vyaire SmartCath adult nasogastric tube with Esophageal balloon; Measuring static and dynamic esophageal driving pressure during pressure support breath, and esophogeal pressure change during airway occlusion maneuver.

What is the study measuring?

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. The Vyaire SmartCath adult nasogastric tube with esophageal balloon was used to measure esophogeal pressure change during 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
Ventilator Free Days	Number of days free from mechanical ventilation	Index hospitalization (up to 28 days)
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)
In-hospital Survival	Survival to discharge	Index hospitalization (up to 28 days)

Collaborators and Investigators

• Sponsor: Duke University
• Investigators: Principal Investigator: Neil R MacIntyre, MD, Professor of Medicine

Publications and helpful links

General Publications

• Hess DR. Ventilator waveforms and the physiology of pressure support ventilation. Respir Care. 2005 Feb;50(2):166-86; discussion 183-6.
• Grieco DL, Menga LS, Eleuteri D, Antonelli M. Patient self-inflicted lung injury: implications for acute hypoxemic respiratory failure and ARDS patients on non-invasive support. Minerva Anestesiol. 2019 Sep;85(9):1014-1023. doi: 10.23736/S0375-9393.19.13418-9. Epub 2019 Mar 12.
• Mauri T, Yoshida T, Bellani G, Goligher EC, Carteaux G, Rittayamai N, Mojoli F, Chiumello D, Piquilloud L, Grasso S, Jubran A, Laghi F, Magder S, Pesenti A, Loring S, Gattinoni L, Talmor D, Blanch L, Amato M, Chen L, Brochard L, Mancebo J; PLeUral pressure working Group (PLUG-Acute Respiratory Failure section of the European Society of Intensive Care Medicine). Esophageal and transpulmonary pressure in the clinical setting: meaning, usefulness and perspectives. Intensive Care Med. 2016 Sep;42(9):1360-73. doi: 10.1007/s00134-016-4400-x. Epub 2016 Jun 22.
• Sottile PD, Albers D, Smith BJ, Moss MM. Ventilator dyssynchrony - Detection, pathophysiology, and clinical relevance: A Narrative review. Ann Thorac Med. 2020 Oct-Dec;15(4):190-198. doi: 10.4103/atm.ATM_63_20. Epub 2020 Oct 10.
• Beitler JR, Malhotra A, Thompson BT. Ventilator-induced Lung Injury. Clin Chest Med. 2016 Dec;37(4):633-646. doi: 10.1016/j.ccm.2016.07.004. Epub 2016 Oct 14.
• Slutsky AS, Ranieri VM. Ventilator-induced lung injury. N Engl J Med. 2013 Nov 28;369(22):2126-36. doi: 10.1056/NEJMra1208707. No abstract available.

Study record dates

Study Major Dates

• Study Start (Actual): February 8, 2022
• Primary Completion (Actual): November 21, 2023
• Study Completion (Actual): December 21, 2023

Study Registration Dates

• First Submitted: November 8, 2021
• First Submitted That Met QC Criteria: November 8, 2021
• First Posted (Actual): November 18, 2021

Study Record Updates

• Last Update Posted (Estimated): October 15, 2025
• Last Update Submitted That Met QC Criteria: September 25, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Self-induced lung injury; Pressure-support ventilation
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Lung Diseases; Lung Injury; Ventilator-Induced Lung Injury
• Other Study ID Numbers: Pro00106860

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes