Mechanical Ventilator Adjustments and Patient Dyspnea

July 8, 2026 updated by: Elias Baedorf Kassis, Beth Israel Deaconess Medical Center

The Influence of Standard Ventilator Setting Adjustments on Dyspnea Experienced in Awake Mechanically-ventilated Patients: A Pilot Study

In the past 5 years, there are increasing data suggesting that patients treated with mechanical ventilation experience shortness of breath, despite appropriate sedation. This adverse experience is believed to contribute to the finding that up to 25% of patients who survive severe respiratory diseases experience mental health problems including post traumatic distress syndrome (PTSD). The purpose of this study is to evaluate if/how sequential changes in the delivery of mechanical ventilation affect shortness of breath sensation in awake patients requiring mechanical ventilation. Improving the knowledge of the impact of the patient-ventilator interaction on shortness of breath sensation may lead to strategies to improve the comfort of non-sedated and sedated ventilated patients, and thereby reduce mental health sequelae in survivors of acute severe respiratory diseases The investigators hypothesize that current ventilator strategies, particularly reduced tidal volume (size of breath given by the ventilator) utilized in managing patients with severe respiratory diseases, contribute to shortness of breath in patients with increased drive to breathe. In this setting, some safe ventilator changes may improve or worsen the shortness of breath sensation in awake patients on mechanical ventilation.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

For patients who develop acute respiratory failure, endotracheal tube (ETT) intubation and mechanical ventilation represent a potentially life-saving intervention to provide support for breathing and allow the opportunity for lungs to recover from critical illness. Current standard practice for mechanical ventilation varies, and includes selecting mechanical ventilator mode (including volume-cycled or pressure-cycled), and routine adjustments of ventilator settings [including settings such as flow rate, tidal volume (Vt), positive end-expiratory pressure (PEEP)].

To assess and confirm the choice of mechanical ventilator settings for each patient, current standard practice includes monitoring vital signs, lung mechanics, observed use of accessory respiratory/breathing muscles by the patient, non-invasive measurement of percent oxygen saturation of the blood (SpO2), and direct blood sample analysis (including arterial or venous blood gas tests). However, direct assessment of patient breathing comfort, or the presence of breathing discomfort (i.e. dyspnea), is not routinely performed in mechanically ventilated patients, and represents a significant knowledge gap.

Dyspnea is a common symptom in hospitalized patients, but the incidence, prevalence and severity of dyspnea in mechanically ventilated ICU patients is incompletely understood. Dyspnea is a common symptom among hospitalized patients. It is defined by American Thoracic Society as "a term used to characterize a subjective experience of breathing discomfort that consists of qualitative distinct sensations that may vary in intensity. The experience derives from interaction among multiple physiological, psychological, social and environmental factors, and may induce secondary physiological and behavioral responses".

Limited publications suggest that up to 50% of intubated patients experience moderate-to-severe dyspnea during ICU admission (data limited to patients who are able to communicate), and survivors of critical illness acute respiratory failure report post-traumatic stress disorder (PTSD), and dyspnea symptoms other mental health problems commonly associated with including nightmares and flashbacks.

Dyspnea assessment in intubated and mechanically ventilated patients represents a substantial challenge. For patients with acute critical illness requiring intubation and mechanical ventilation, treatment often also requires a heavy significant level of analgosedation to provide patient comfort, but while rendering the patient non-communicative.

The purpose of this protocol is to perform a pilot investigation, a prospective, single center, multiple ICU, randomized, blinded, clinical study to assess the impact of standard ventilator setting adjustments on breathing discomfort experienced by intubated patients recovering from acute respiratory failure. This study will focus on adults who remain intubated (endotracheal tube; ETT), mechanically ventilated, but are awake and can effectively communicate by non-verbal means.

Data collection will focus on assessment for the presence or absence of patient-reported dyspnea at baseline, and following transitioning to a standard mechanical ventilator mode (VC/AC), and then during various standard adjustments of mechanical ventilator settings (including tidal volume, PEEP, and oxygen flow rate). Adjustments for each setting will include a specified pre-determined number of adjustments that reflect standard-of-care, followed by an assessment of patient-reported dyspnea over the course of 3 minutes at each setting adjustment.

For the purposes of this study, randomization refers to the sequence of changes in ventilator settings for each patient. All ventilator adjustments will be performed in the presence of a physician and respiratory therapist. Dyspnea will be assessed using standard validated tools (including Dyspnea modified multidimensional scale, and Dyspnea Quality Scale). Data will be collected on standardized form. The pilot study plan to enroll a total of 20 patients over a period of 6 months, including patients receiving care in any one of the BIDMC intensive care units, and each patients will be evaluated over the course of "30 minutes to 2 hours" for the purposes of this protocol.

Data from this pilot study will improve understanding of dyspnea associated with intubation and mechanical ventilation, and inform on design of future studies focusing on the management of patients with acute respiratory failure and requiring intubation and mechanical ventilation.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02215
        • Beth Israel Deaconess Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Admitted to a participating ICU at BIDMC
  • Requiring mechanical ventilation
  • Awake by both of the following criteria
  • RASS -2 to +2*
  • CAM-ICU negative‡

  • Able to communicate/answer dyspnea questionnaire

    • RASS (Richmond Agitation-Sedation Scale) is a validated scale commonly used in the ICU to assess patient's level of sedation and agitation. It ranges from -5 to +4. While -5 means an unarousable coma, +4 means violent patient with immediate self danger. The scale from -2 to +2 ranges from light sedation to agitated.

      • CAM-ICU (Confusion Assessment Method) is an ICU validated scale used to assess the presence of delirium. A negative CAM-ICU scale has good positive and negative predictive value to diagnose or exclude delirium.

Physicians and nurses are trained to evaluate patients using both scales

Exclusion Criteria:

  • Age < 18 years old
  • Comfort measures only
  • Hemodynamic instability (MAP < 65 mmHg) or increasing requirement of vasopressor
  • PEEP > 10 cmH2O
  • FiO2 > 0.6
  • Current Prone position
  • Current Pneumothorax
  • Bronchopleural fistula
  • Neuromuscular conditions that impair responding to the dyspnea scale or expression
  • Dementia
  • Prisoners
  • Pregnant women
  • Patients intubated and ventilated for less than 12 hours during the current ventilation episode
  • pH < 7.20 or > 7.55
  • Presence of chest tube
  • Status post thoracotomy
  • Treating clinician refusal

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Mechanical Ventilator Changes

The intervention consists of changes in ventilator with evaluation of associated patient dyspnea.

The sequence of interventions will include:

  • After consenting and explaining the procedures in details, baseline dyspnea will be obtained
  • All patients will be set on volume control/assist control (VC/AC) with flow at ramp and appropriate settings to approximate their initial tidal volume, minute ventilation, respiratory rate, FiO2 and PEEP. This change is routinely performed in the ICU. Patients already on VC/AC will be kept on same settings. The investigators will check dyspnea after this initial change.

  • The following series of changes in mechanical ventilation will be instituted in a randomized sequence, lasting 3 minutes each:

    • Change in tidal volume
    • Change in inspiratory flow
    • Change in PEEP
    • Change to PSV to match their initial settings.
  • After every change the patient will rate dyspnea with an ordinal scale and Pocc and P01 will be assessed
Other: Change to VC/AC
All patients will be set on volume control/assist control (VC/AC) with flow at ramp and appropriate settings to approximate their initial tidal volume, minute ventilation, respiratory rate, FiO2 and PEEP. This change is routinely performed in the ICU. Patients already on VC/AC will be kept on same settings. The investigators will check dyspnea after this initial change.
Other: Change in Tidal Volume
Change in 2mL/kg (increase and/or decrease) for 3 minutes. After every change the patient will rate dyspnea with an ordinal scale and The investigators will assess occlusion pressure at the mouth at the onset of inspiration (P0.1 and Pocc).
Other: Change in inspiratory flow
Increase in 25% of baseline flow for 3 minutes Decrease in 25% of baseline flow for 3 minutes After every change the patient will rate dyspnea with an ordinal scale and the investigators will assess occlusion pressure at the mouth at the onset of inspiration (P0.1 and Pocc).
Other: Change in PEEP
Change in PEEP by 5 cmH2O After every change the patient will rate dyspnea with an ordinal scale and the investigators will assess occlusion pressure at the mouth at the onset of inspiration (P0.1 and Pocc).
Other: Change to PSV
Change to PSV to match their initial settings. After every change the patient will rate dyspnea with an ordinal scale and The investigators will assess occlusion pressure at the mouth at the onset of inspiration (P0.1 and Pocc).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in dyspnea scale from baseline
Time Frame: 3 minutes after the change

Change in dyspnea scale when changing the following settings Increase and decrease in tidal volume Increase, decrease in flow and change in flow curve Changes in PEEP Change to PSV to match their initial settings.

We will use a modified multidimensional dyspnea scale, which includes from pleasant, neutral, slight sensation, annoying, distressing and unbearable. It also includes sensory qualities which ranges from 1 to 5 (5 being worse)
3 minutes after the change

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in dyspnea scales with change to VC/AC
Time Frame: 3 minutes after change

Changes in dyspnea scales with change to VC/AC from original mode

We will use a modified multidimensional dyspnea scale, which includes from pleasant, neutral, slight sensation, annoying, distressing and unbearable. It also includes sensory qualities which ranges from 1 to 5 (5 being worse)
3 minutes after change
Change in respiratory drive measured by P0.1
Time Frame: 3 minutes after each change

Changes in P0.1 in cmH2O with each intervention/change in ventilator setting:

Change in tidal volume Change in inspiratory flow Change in PEEP Change to PSV to match their initial settings. Original mode to VC/AC with equivalent parameters
3 minutes after each change
Change in respiratory effort measured by Pocc
Time Frame: 3 minutes after every change

Changes in Pocc in cmH2O with each intervention/change in ventilator setting:

Change in tidal volume Change in inspiratory flow Change in PEEP Change to PSV to match their initial settings. Original mode to VC/AC with equivalent parameters
3 minutes after every change
Changes in P0.1/Pocc ratio
Time Frame: 3 minutes after every change

Changes in P0.1/Pocc with each intervention/change in ventilator setting:

Change in tidal volume Change in inspiratory flow Change in PEEP Change to PSV to match their initial settings. Original mode to VC/AC with equivalent parameters
3 minutes after every change

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Beth Israel Deaconess Medical Center

Investigators

  • Principal Investigator: Elias Baedorf-Kassis, MD, Beth Israel Deaconess Medical Center
  • Study Director: Richard Schwartzstein, MD, Beth Israel Deaconess Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 1, 2026

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

July 1, 2027

Study Registration Dates

First Submitted

June 10, 2026

First Submitted That Met QC Criteria

July 8, 2026

First Posted (Actual)

July 14, 2026

Study Record Updates

Last Update Posted (Actual)

July 14, 2026

Last Update Submitted That Met QC Criteria

July 8, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2026P000159

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data may be shared upon reasonable request and after approval by the study investigators and institutional review board, in accordance with institutional policies and participant privacy protections.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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