High-flow Nasal Cannula vs. Helmet PSV vs. Helmet CPAP During Respiratory Failure (HIGHFLOWHELMET)

Physiological Comparison of High-flow Nasal Cannula, Helmet Pressure Support Ventilation and Continuous Positive Airway Pressure During Acute Hypoxemic Respiratory Failure: a Randomized Cross-over Study

The investigators designed a cross-over, randomized trial to assess the physiological effects of helmet pressure support ventilation (PSV) and continuous positive airway pressure (CPAP) as compared to high-flow nasal cannula during the early phase of acute hypoxemic respiratory failure

Study Overview

Detailed Description

Setting: 21-bed general ICU, emergency room of the Emergency department (ED), Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy..

Patients: adult hypoxemic non-hypercapnic patients admitted to the emergency department or the ICU with de novo acute respiratory failure will be assessed for the enrolment.

Each eligible patient, in the absence of exclusion criteria, will receive 15 minutes of heated and humidified 60% oxygen at a rate of 50 l/min via a non-rebreathing face mask. An ABG will be then collected and PaO2/FiO2 ratio computed: given the high flows used, actual FiO2 will be approximated to the set one.

Nonhypercapnic patients with a PaO2/FiO2≤200 mmHg will be enrolled. In the absence of exclusion criteria and if all other inclusion in criteria are met, patients showing PaO2/FiO2≤300 and >200 mmHg will be treated according to the clinical practice eventually reassessed for the presence of oxygenation criterion subsequently.

Enrolled patients will receive all the interventions (helmet CPAP, PSV and high-flow nasal cannula) in a randomized, cross-over fashion, for 40 minutes each.

At the end of the study, the patient will receive the treatment that will be shown as more appropriate for the patient, according to the attending physician, who will be informed about the results of the study on the individual patient.

Study Type

Interventional

Enrollment (Actual)

15

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 Locations

      • Rome, Italy
        • Fondazione Policlinico Universitaro A. Gemelli IRCCS

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

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

Patients: adult hypoxemic non-hypercapnic patients admitted to the emergency department or the ICU with de novo acute respiratory failure will be assessed for the enrolment.

Patients will be considered eligible whether all the following inclusion criteria are met:

  1. Respiratory rate>25 bpm.
  2. PaO2/FiO2 ≤200 in the supine position, measured after 15 minutes of high flow treatment with face mask (60 l/min, temperature of the humidification chamber set at 37°C, FiO2 set to achieve a SpO2 >92% and <98%). Given the use of the high flows, nominal FiO2 will be considered a reliable estimate of the actual one.
  3. PaCO2 <45mmHg
  4. Absence of history of chronic respiratory failure or moderate to severe cardiac insufficiency.
  5. Written informed consent

Exclusion Criteria:

  • Exacerbation of asthma or chronic obstructive pulmonary disease;
  • Cardiogenic pulmonary oedema;
  • Haemodynamic instability (Systolic blood pressure <90 mmHg or mean arterial pressure <65 mmHg) and/or lactic acidosis (lactate >5 mmol/L) and/or clinically diagnosed Shock
  • Metabolic Acidosis (pH <7.30 with normal- or hypo-carbia);
  • Glasgow coma scale <13;
  • Recent head surgery or anatomy that prevent the application of helmet or nasal cannula to patient's face.

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: RANDOMIZED
  • Interventional Model: CROSSOVER
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: High-flow oxygen therapy
Nasal high flow oxygen therapy will be delivered with the Optiflow system. Initial set flow will be ≥ 50 /min and flows will be decreased in case of intolerance and/or according to patients' requirements: flows≥30 L/min will be mandatory in all enrolled patients. Humidification chamber (MR860, Fisher and Paykel healthcare, New Zealand) will be set at 37 °C or 34 °C according to patient's comfort33. FiO2 will be titrated to obtain an SpO2≥92% and ≤98%.
Noninvasive respiratory support respiratory support
EXPERIMENTAL: Helmet PSV

Dedicated helmets for noninvasive ventilation will be used and size will be chosen according to neck circumference or according to manufacturer recommendations.

Each patient will be connected to a compressed-gas based ventilator through a bitube circuit with no humidification.

The ventilator will be set in PSV, with the following suggested settings 34-38:

  1. initial pressure support≥8-10 cmH2O and adequate to permit of a peak in the inspiratory flow of 100 l/min;
  2. positive end-expiratory pressure=10-12 cmH2O and increased to achieve the oxygenation target according to the choice of the attending physician.
  3. FiO2 will be titrated to obtain an SpO2≥92% and ≤98%.
  4. Inspiratory flow trigger = 1 l/min or according to the practice of each institution;
  5. fastest pressurization time;
  6. expiratory trigger: 10-50% of the maximum inspiratory flow;
  7. maximum inspiratory time 1.2 second.
Noninvasive respiratory support respiratory support
EXPERIMENTAL: Helmet CPAP

Dedicated helmets for noninvasive ventilation will be uses and size will be chosen according to neck circumference or according to manufacturer recommendations.

Treatment will be delivered through a high-flow generator. The following settings will be applied:

  1. Continuous air flow=50-60 L/min.
  2. Expiratory positive end-expiratory pressure valve set to achieve a PEEP==10-12 cmH2O and eventually increased to achieve the oxygenation target according to the choice of the attending physician.
  3. FiO2 will be titrated to obtain an SpO2≥92% and ≤98%. Pressure inside the helmet will be monitored with a manometer in order to maintain the set PEEP.
Noninvasive respiratory support respiratory support

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Inspiratory effort
Time Frame: 40 minutes
The negative deflection in esophageal pressure during inspiration
40 minutes
Tidal volume
Time Frame: 40 minutes
The tidal change in lung impedance, assessed by electrical impedance tomography
40 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Oxygenation
Time Frame: 40 minutes
Ratio of PaO2 to FiO2
40 minutes
Tidal volume distribution
Time Frame: 40 minutes
Distribution of tidal volume within the lung regions, assessed by electrical impedance tomography
40 minutes
Carbon dioxide
Time Frame: 40 minutes
Blood carbon dioxide, measured with the arterial blood gas analysis
40 minutes
Respiratory rate
Time Frame: 40 minutes
Respiratory rate/minute, assessed with the esophageal pressure
40 minutes
Dyspnea
Time Frame: 40 minutes
Dyspnea assessed with the visual analog scale, 0-10 scale where the highest value corresponds to the highest degree of dyspnea
40 minutes
Comfort
Time Frame: 40 minutes
Comfort assessed with the visual analog scale, 0-10 scale where the highest value corresponds to the highest degree of discomfort
40 minutes
Global impedance-derived End-expiratory lung volume
Time Frame: 40 minutes
End-expiratory lung volume, measured with electrical impedance tomography
40 minutes
Regional impedance-derived End-expiratory lung volume
Time Frame: 40 minutes
End-expiratory lung impedance in the four regions of the lungs (ventral, mid-ventral, mid-dorsal, dorsal), measured with electrical impedance tomography
40 minutes
Dynamic transpulmonary driving pressure
Time Frame: 40 minutes
The tidal change in transpulmonary pressure
40 minutes
Global impedance-derived lung dynamic strain
Time Frame: 40 minutes
Change in impedance due to tidal volume / end expiratory lung impedance, both measured with electrical impedance tomography
40 minutes
Regional impedance-derived lung dynamic strain
Time Frame: 40 minutes
Change in impedance due to tidal volume / end expiratory lung impedance in the four regions of the lungs (ventral, mid-ventral, mid-dorsal, dorsal), measured with electrical impedance tomography
40 minutes
Respiratory system dynamic compliance
Time Frame: 40 minutes
Ratio of the tidal change in lung impedance to dynamic transpulmonary driving pressure
40 minutes
Pendelluft
Time Frame: 40 minutes
Occurrence of intra-tidal shift of gas within different lung regions at beginning of inspiration
40 minutes
Work of breathing
Time Frame: 40 minutes
Esophageal pressure simplified pressure time product per minute
40 minutes

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Massimo Antonelli, MD, Fondazione Policlinico Universitario A. Gemelli, IRCCS
  • Principal Investigator: Domenico L Grieco, MD, Fondazione Policlinico Universitario A. Gemelli, IRCCS

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.

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 (ACTUAL)

January 22, 2020

Primary Completion (ACTUAL)

January 27, 2021

Study Completion (ACTUAL)

January 27, 2021

Study Registration Dates

First Submitted

January 22, 2020

First Submitted That Met QC Criteria

January 24, 2020

First Posted (ACTUAL)

January 27, 2020

Study Record Updates

Last Update Posted (ACTUAL)

February 8, 2021

Last Update Submitted That Met QC Criteria

February 4, 2021

Last Verified

January 1, 2020

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Data will be made available upon a reasonable request

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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