Effects of Treatment With High Flow Nasal Cannulas on Respiratory Pattern and Work of Breathing Among Patients. (HDWOBPT)

Laval University

Status: Unknown

Conditions: Respiratory Failure

Treatments: Device: Oxygen delivery via conventional nasal mask; Device: Airvo 2; Ficher and Paykel HealthCare

Study type: Interventional

Funder types: Other

Identifiers

NCT02494154

IUCPQ-HDWOBPT

Details and patient eligibility

About

This study evaluates the work of breathing among patients under various conditions of treatment with high flow nasal cannulas. Sixteen spontaneously breathing patients with respiratory failure (hypercapnic or hypoxemic) will be included. The design of this study is a cross over of four treatment periods with different flow settings.

Full description

High flow oxygen therapy (HFOT) is a promising technique increasingly used in the management of acute respiratory failure. In hospitalised hypoxemic patients, recent clinical evidence showed that HFOT can reduce endotracheal intubation and reduce mortality. Physiologically, the HFOT causes a decrease in respiratory rate and minute-ventilation and may be associated with a decrease in PaCO2. It is possible that these effects are associated with decreased work of breathing, which could explain some of the benefits in terms of comfort and efficiency.

The objective of this research is to evaluate the impact of a wash-out of anatomical dead space by high flow nasal cannulas on respiratory parameters and on the work of breathing.

The investigators will evaluate the baseline status with conventional oxygen therapy methods (low flows), and then compare it with three different levels of high flow oxygen therapy in a randomised order. The primary endpoint will be the work of breathing.

Enrollment: 16 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

Spontaneously breathing patients exhibiting a respiratory distress defined by a respiratory rate ≥ 20 breaths/min associated with

• either hypoxemia (SpO2<90% with O2≥3L/min) ;
• or hypercapnia (PaCO2>45 mmHg with a respiratory acidosis (pH<7,38).

Exclusion criteria

• Patients below 18yo, pregnant or breastfeeding women;
• Patients enrolled in another study excluding co-enrolment;
• History of ear nose and throat disease (i.e. surgery, epistaxis, trauma), eso-gastric disease (i.e. esophageal varices, digestive haemorrhage), rheumatologic or neurologic disease possibly interfering with the design of the study;
• Acute respiratory or cardiovascular disease contra-indicating the enrolment in the study protocol (i.e. acute coronary syndrome, pulmonary embolism, pneumothorax);
• Need for immediate intubation or for continuous noninvasive ventilation and/or recent (<6h) arterial blood gases showing a respiratory acidosis with a pH<7.30;
• Patient feeling nauseous or under recent fed condition (<1h).

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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16 participants in 4 patient groups

Conventional flow via nasal prongs

Active Comparator group

Description:

Oxygen delivery via conventional nasal interface with flow adjusted to reach a target SpO2 according to the patient's condition.

Treatment:

Device: Oxygen delivery via conventional nasal mask

High flow nasal cannulas 20L/min

Experimental group

Description:

Oxygen delivery via high flow nasal cannulas (20L/min) with fraction of inspired oxygen (FiO2) adjusted to reach a target SpO2 according to the patient's condition.

Treatment:

Device: Airvo 2; Ficher and Paykel HealthCare

High flow nasal cannulas 40L/min

Experimental group

Description:

Oxygen delivery via high flow nasal cannulas (40L/min) with FiO2 adjusted to reach a target SpO2 according to the patient's condition.

Treatment:

Device: Airvo 2; Ficher and Paykel HealthCare

High flow nasal cannulas 60L/min

Experimental group

Description:

Oxygen delivery via high flow nasal cannulas (60L/min) with FiO2 adjusted to reach a target SpO2 according to the patient's condition.

Treatment:

Device: Airvo 2; Ficher and Paykel HealthCare