High-flow nasal cannula therapy for initial oxygen administration in acute hypercapnic respiratory failure: study protocol of randomised controlled unblinded trial

Abstract

Introduction: Acute respiratory failure is a common clinical condition accounting for nearly 116 000 admissions in the UK hospitals. Acute type 2 respiratory failure is also called acute hypercapnic respiratory failure (AHRF) and characterised by an elevated arterial CO2 level of >6 kPa due to pump failure. Acute exacerbation of chronic obstructive pulmonary disease is the most common cause of AHRF. High-flow nasal therapy (HFNT) is a new oxygen delivery system that uses an oxygen-air blender to deliver flow rates of up to 60 L/min. The gas is delivered humidified and heated to the patient via wide-bore nasal cannula.

Methods and analysis: We hypothesised that HFNC as the initial oxygen administration method will reduce the number of patients with AHRF requiring non-invasive ventilation in patients at 6 hours post intervention when compared with low-flow nasal oxygen (LFO). A randomised single-centre unblinded controlled trial is designed to test our hypothesis. The trial will compare two oxygen administration methods, HFNT versus LFO. Patients will be randomised to one of the two arms if they fulfil the eligibility criteria. The sample size is 82 adult patients (41 HFNT and 41 LFO) presenting to the emergency department.

Ethics and dissemination: Ethical approval was obtained from the Office for Research Ethics Committees Northern Ireland (REC reference: 20/NI/0049). Dissemination will be achieved in several ways: (1) the findings will be presented at national and international meetings with open-access abstracts online and (2) in accordance with the open-access policies proposed by the leading research funding bodies we aim to publish the findings in high-quality peer-reviewed open-access journals.

Trial registration number: The trial was prospectively registered at the clinicaltrials.gov registry (NCT04640948) on 20 November 2020.

Keywords: COPD exacerbations.

Conflict of interest statement

Competing interests: None declared.

© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Study design summarising patient screening, randomisation and clinical care of a patient. Postrandomisation care will follow the current standard of care including peripheral oxygenation saturation target, 88%–92%. Continuation of treatment strategy is at the discretion of the treating clinician and established BTS guidelines of managing a patient with acute type 2 respiratory failure should guide clinical care. This includes symptom assessment, trends in Glasgow Coma Scale, respiratory rate, heart rate, monitoring of changes in pH, PaO2 and PaCO2. AHRF, acute hypercapnic respiratory failure; IMV, invasive mechanical ventilation; NIV, non-invasive ventilation; LFO, low-flow nasal oxygen.