Novel nasal high flow interface feasibility in the acute setting

The intervention is a new nasal high flow cannula for acutely-ill patients in intensive care unit (ICU) or high dependency unit (HDU). This nasal cannula is fitted to the patient in the same way as a standard Optiflow nasal cannula. Key changes to the novel cannula include: - A flexible hinge on the interface frame to maintain a comfortable placement on the patient face (as opposed to a fixed, continuous frame) - The manifold has the ability to rotate 360 degrees to swap the flexi-tube side. Current interfaces either are unable to swap sides or require disassembly and reassembly. - Introduction of modular prongs which can be removed from the interface and easily swap sizes. Current interfaces are a fixed size and require a full new interface to change sizes. The novel nasal cannula still provides nasal high flow therapy in the same way as prior cannula, and can deliver flows from 5-70 L/min. Eligible participants who are prescribed nasal high flow will be fitted with the new nasal cannula by a healthcare professional through which they will receive nasal high flow with room air, and oxygen if required, at their prescribed settings (same settings as for their standard care). Participants will be receiving this therapy for a minimum of 8 hours, up to a maximum of 7 days depending on their nasal high flow prescription. Participants will be asked to rate their level of comfort and tolerance every 12 hours, to determine adherence and comfort, and healthcare professionals will be asked to provide observations and rate the usability process.