Physiological Effects of Continuous Negative External Pressure for Acute Hypoxemic Respiratory Failure

Sponsor

Columbia University (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT05675345

Collaborator

(none)

Enrollment

Location

Arms

21.6

Anticipated Duration (Months)

0.9

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

This study is being conducted to evaluate if wearing a non-invasive breathing support device over the chest/abdomen improves markers of breathing in patients with lung injury requiring high-flow oxygen. The breathing support device consists of a plastic shell that sits over the chest and abdomen and connects to a vacuum that helps the chest expand with breathing. This breathing support is known as continuous negative external pressure (CNEP). Study findings will help determine if this breathing support device might be useful for patients with acute hypoxemic respiratory failure (AHRF).

Condition or Disease	Intervention/Treatment	Phase
Acute Hypoxemic Respiratory Failure	Device: HFNC only Device: HFNC + CNEP10 Device: HFNC + CNEP20 Device: HFNC + CNEP30	N/A

Detailed Description

This study is a prospective randomized cross-over trial. Eligible, consenting participants will undergo 4 strategies of respiratory support: high-flow nasal cannula (HFNC) only, HFNC + continuous negative external pressure (CNEP) of 10 cmH2O, HFNC + CNEP of 20 cmH2O, HFNC + CNEP of 30 cmH2O. Throughout the study period, HFNC will be managed at a constant flow rate with fraction of inspired oxygen (FiO2) titrated to achieve goal oxygen saturation (SpO2) of 92-96%, measured via continuous pulse-oximetry. Each of the 4 strategies will be performed for 1 hour per strategy, interspersed with a 20-minute washout period of HFNC only. Participants will be randomized to the sequence of strategies for respiratory support.

A summary of the sequence of trial procedures is as follows:

Perform baseline measures.
Wait 5-10 minutes for recovery.
Initiate first random treatment assignment for up to 1 hour.
HFNC-only washout for 20 minutes
Initiate second random treatment assignment for up to 1 hour.
HFNC-only washout for 20 minutes
Initiate third random treatment assignment for up to 1 hour.
HFNC-only washout for 20 minutes
Initiate fourth random treatment assignment for up to 1 hour.
Return to usual care (HFNC only)

If a participant does not tolerate a given level of CNEP, the patient will be returned to HFNC for 5 minutes and then given the option to attempt that CNEP level again. If the patient declines reattempt or does not tolerate that CNEP level on reattempt, the HFNC-only washout will be instituted for 20 minutes before proceeding to the next protocol step.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

20 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Physiological Effects of Continuous Negative External Pressure for Acute Hypoxemic Respiratory Failure

Anticipated Study Start Date :

Mar 15, 2023

Anticipated Primary Completion Date :

Aug 31, 2024

Anticipated Study Completion Date :

Dec 30, 2024

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: HFNC only	Device: HFNC only HFNC for 1 hour, with FiO2 titrated to SpO2 of 92-96%
Experimental: HFNC + CNEP10	Device: HFNC + CNEP10 HFNC with CNEP of 10 cmH2O for 1 hour, with FiO2 titrated to SpO2 of 92-96%
Experimental: HFNC + CNEP20	Device: HFNC + CNEP20 HFNC with CNEP of 20 cmH2O for 1 hour, with FiO2 titrated to SpO2 of 92-96%
Experimental: HFNC + CNEP30	Device: HFNC + CNEP30 HFNC with CNEP of 30 cmH2O for 1 hour, with FiO2 titrated to SpO2 of 92-96%

Outcome Measures

Primary Outcome Measures

Change from baseline in SpO2/FiO2 [At the end of each treatment period, up to 1 hour]
The change in SpO2/FiO2 within each participant as measured at baseline and at the end of each treatment assignment period. The average SpO2/FiO2 over the last five minutes of the treatment period will be used.

Secondary Outcome Measures

Change from baseline in Respiratory Rate [At the end of each treatment period, up to 1 hour]
The change in Respiratory Rate within each participant as measured at baseline and at the end of each treatment assignment period. The average Respiratory Rate over the last five minutes of the treatment period will be used.
Change from baseline in ROX Index [At the end of each treatment period, up to 1 hour]
The change in ROX index within each participant as measured at baseline and at the end of each treatment assignment period. ROX index is calculated as SpO2/FiO2 divided by the Respiratory Rate. The average ROX index over the last five minutes of the treatment period will be used.
Change from baseline in Transcutaneous Carbon Dioxide (CO2) [At the end of each treatment period, up to 1 hour]
The change in Transcutaneous Carbon Dioxide within each participant as measured at baseline and at the end of each treatment assignment period. The average Transcutaneous Carbon Dioxide over the last five minutes of the treatment period will be used.
Change from baseline in Minute Ventilation [At the end of each treatment period, up to 1 hour]
The change in Minute Ventilation within each participant as measured at baseline and at the end of each treatment assignment period, estimated from lung electrical impedance tomography. The average Minute Ventilation over the last five minutes of the treatment period will be used.
Change from baseline in Tidal Volume [At the end of each treatment period, up to 1 hour]
The change in Tidal Volume within each participant as measured at baseline and at the end of each treatment assignment period, estimated from lung electrical impedance tomography. The average Tidal Volume over the last five minutes of the treatment period will be used.
Change from baseline in Anteroposterior Ventilation Ratio [At the end of each treatment period, up to 1 hour]
The change in Anteroposterior Ventilation Ratio within each participant as measured at baseline and at the end of each treatment assignment period, estimated from lung electrical impedance tomography. The average Anteroposterior Ventilation Ratio over the last five minutes of the treatment period will be used.
Change from baseline in End-Expiratory Lung Volume [At the end of each treatment period, up to 1 hour]
The change in End-Expiratory Lung Volume within each participant as estimated from end-expiratory lung impedance measured at baseline and at the end of each treatment assignment period. The average End-Expiratory Lung Impedance over the last five minutes of the treatment period will be used to derive change in end-expiratory lung volume.
Change from baseline in Heart Rate [At the end of each treatment period, up to 1 hour]
The change in Heart Rate within each participant as measured at baseline and at the end of each treatment assignment period. The average Heart Rate over the last five minutes of the treatment period will be used.
Change from baseline in Blood Pressure [At the end of each treatment period, up to 1 hour]
The change in Blood Pressure within each participant as measured at baseline and at the end of each treatment assignment period. The average Blood Pressure over the last five minutes of the treatment period will be used.
Change from baseline in Breathing Discomfort [At the end of each treatment period, up to 1 hour]
The change in Breathing Discomfort within each participant as measured at baseline and at the end of each treatment assignment period. Breathing Discomfort will be measured with component A1 of the Multidimensional Dyspnea Profile.
Change from baseline in Anxiety [At the end of each treatment period, up to 1 hour]
The change in Anxiety within each participant as measured at baseline and at the end of each treatment assignment period. Anxiety will be measured with a subcomponent of A2 of the Multidimensional Dyspnea Profile.
Change from baseline in Lightheadedness [At the end of each treatment period, up to 1 hour]
The change in Lightheadedness within each participant as measured at baseline and at the end of each treatment assignment period. Lightheadedness will be measured with an ordinal scale ranging from 0 to 10.
Change from baseline in Nausea [At the end of each treatment period, up to 1 hour]
The change in Nausea within each participant as measured at baseline and at the end of each treatment assignment period. Nausea will be measured with an ordinal scale ranging from 0 to 10.
Change from baseline in Skin Discomfort [At the end of each treatment period, up to 1 hour]
The change in patient-reported Skin Discomfort as measured at baseline and at the end of each treatment assignment period. Skin Discomfort will be measured with an ordinal scale ranging from 0 to 10.
Change from baseline in Skin Erythema [At the end of each treatment period, up to 1 hour]
The change in Skin Erythema within each participant as measured at baseline and at the end of each treatment assignment period. Skin erythema will be measured by investigator visual assessment using a five-point scale.

Other Outcome Measures

Change from baseline in other components of the Multidimensional Dyspnea Profile [At the end of each treatment period, up to 1 hour]
The change in other components of the Multidimensional Dyspnea Profile within each participant as measured at baseline and at the end of each treatment assignment period.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Acute hypoxemic respiratory failure
Non-cardiogenic airspace opacities on chest radiograph or computed tomography (CT) scan
High-flow nasal cannula (flow ≥ 30 LPM) initiated within last 96 hours (4 days)
FiO2 ≥ 40%
SpO2 ≥ 92%

Exclusion Criteria:

Age < 18 years
Do-not-intubate order
Anatomical factor predisposing to poor fit of cuirass (e.g. severe kyphosis or scoliosis)
Use of cuirass precluded, e.g. due to:
Clinically prescribed prone positioning
Tense ascites
Severe abdominal pain
Abdominal wound or surgery
Pregnancy
Agitated delirium
Prior intubation during hospital stay
Cardiogenic pulmonary edema
Exacerbation of asthma or COPD
Chronic lung disease, including:
Interstitial lung disease
Cystic fibrosis
Lung mass, lung cancer, or metastasis to the lung
Lung transplant recipient
Any disease that requires home oxygen
Glasgow coma score < 15
Chest tube, pneumothorax, or pneumomediastinum
Implantable electrical device (e.g. pacemaker, defibrillator, neurostimulator)
Unreliable pulse-oximetry tracing
Imminent intubation
Anticipated lack of patient availability to complete study procedures (e.g. due to planned clinical procedure such as CT scan or dialysis during potential time of study)
Attending physician refusal