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

Not Applicable

Completed

• Conditions: Respiratory Failure; Hypoxemia

• Registration Number: NCT04241861
• Lead Sponsor: Fondazione Policlinico Universitario Agostino Gemelli IRCCS

Brief Summary

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

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 Timeline

• Status Verified: 2020-01
• Study Start: 2020-01-22
• Study First Submitted: 2020-01-22
• Study First Submitted QC: 2020-01-24
• Study First Posted: 2020-01-27
• Primary Completion: 2021-01-27
• Study Completion: 2021-01-27
• Last Update Submitted: 2021-02-04
• Last Update Posted: 2021-02-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 15

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Inspiratory effort	40 minutes	The negative deflection in esophageal pressure during inspiration
Tidal volume	40 minutes	The tidal change in lung impedance, assessed by electrical impedance tomography

Secondary Outcome Measures

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

Trial Locations

Locations (1)

Fondazione Policlinico Universitaro A. Gemelli IRCCS; 🇮🇹 Rome, Italy