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

Not Applicable

• Conditions: Respiratory Failure

• Registration Number: NCT02494154
• Lead Sponsor: Laval University

Brief Summary

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.

Detailed 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.

Study Timeline

• Study Start: 2015-05
• Study First Submitted: 2015-06-04
• Status Verified: 2015-07
• Study First Submitted QC: 2015-07-09
• Last Update Submitted: 2015-07-09
• Study First Posted: 2015-07-10
• Last Update Posted: 2015-07-10
• Primary Completion: 2015-10

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 16

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).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Work of breathing	15 minutes	Work of breathing at the end of each period is calculated from the measurement of esophageal pressure and tidal volume (composite outcome)

Secondary Outcome Measures

Name	Time	Method
Esophageal pressure-time product	15 minutes	Measured at the end of each period
Comfort of breathing	15 minutes	Subjective evaluation at the end of each period
End-tidal carbon dioxide	15 minutes	Measured at the end of each period
Blood gases	15 minutes	Arterial or capillary blood gases at the end of each period
Tidal volume	15 minutes	Measured at the end of each period
Respiratory rate	15 minutes	Measured at the end of each period
Dyspnea	15 minutes	Evaluation on a borg scale at the end of each period
Heart rate	15 minutes	Measured at the end of each period
Oxygen saturation	15 minutes	Measured at the end of each period

Trial Locations

Locations (1)

IUCPQ; 🇨🇦 Québec, Quebec, Canada