A novel ward-based weaning protocol for High-Flow Nasal Oxygen in an adult population

The intervention is a protocol for weaning hospital admitted patients from high flow nasal oxygen (HFNO) to low flow nasal oxygen (LFNO) or room air (RA). The protocol is medically supervised and performed by medical or nursing staff with careful and monitored step-by-step guidance. It will be applied to patients recovering from acute respiratory illness who were commenced on HFNO for an acute respiratory illness. The protocol will have three stages: the order to wean, the weaning period, and the post-wean assessment. ORDER TO WEAN A doctor from the treating team will assess the patient on HFNO (e.g. during ward round, but can also occur ad hoc) for the following “criteria to wean”: - No signs of respiratory distress/"Looks comfortable" - Clinical judgement of the patient being past the peak of their illness and recovering i.e. clinically ready to wean - SpO2 92-96% (Alternative SpO2 aims acceptable where clinically appropriate for the individual patient) - RR =< 25 If the patient meets all criteria, then the doctor initiates an order to wean HFNO. The order will be documented in EMR as a specific note and communicated verbally to nursing staff to commence the weaning period. WEANING PERIOD Part 1: Decreasing settings 1. Nurse or doctor decreases both the FiO2 by 10% and flow by 10 L/min simultaneously (to a minimum flow of 30 L/min) 2. Within 30 minutes after the setting reduction, nurse check SpO2, RR, HR, and BP -> if stable continue at the new settings 3. 2 hours after the vital sign check from step 2, nurse check SpO2, RR, HR, and BP -> if stable wean both the FiO2 by 10% and flow by 10L/min 4. Repeat steps 1) to 3) until FiO2 30% is reached 5. 2 hours after being at FiO2 30%, nurse check SpO2, RR, HR, and BP -> if stable move to “Part 2” below 6. At each vital sign check, if any parameters worsen (i.e. deterioration in SpO2, RR, HR, BP) or any of the above “criteria to wean” are lost, or if there are any other clinical concerns -> return to the previous setting and contact a doctor from the treating team for a medical review a. Doctor will determine if patient still appropriate to continue weaning via protocol (or whether other clinical factors necessitate an separate individualised weaning plan) Part 2: Separation from HFNO Once vital signs have been stable for 2 hours on FiO2 30%: 1. Nursing staff contact doctor from treating team OR perform a nursing lead assessment of the patient for the “criteria to wean” (at nursing discretion) then contact a doctor from the treating team for a medical review for formal HFNO separation 2. Doctor assesses patient against the original “criteria to wean” – can be done in person or via chart review at doctor’s discretion as clinically appropriate 3. Doctor calculates the ROX score: (SpO2/FiO2) / RR 4. If all the “criteria to wean” are met and the ROX score is >= 9.2 -> switch patient to LFNO 2 L/min and this to be documented by the doctor on EMR 5. Within 30 minutes after changing to LFNO, nurse checks SpO2, RR, HR, and BP 6. If any vital signs worsen or any “criteria to wean” are lost, or if there are any other clinical concerns, return to HFNO at the last setting 7. HFNO apparatus will remain at the patient’s bedside for at least 4 hours post change to LFNO POST WEAN ASSESSMENT: As a secondary outcome a patient will be considered successfully weaned from HFNO if remaining on LFNO/absence or re-escalation to HFNO after 24 hours. At this stage (or earlier), a doctor from the medical team can elect to trial a wean from LFNO to room air as per standard clinical practice. PATIENT SELECTION AND ALLOCATION: Included patients in the intervention group (weaning protocol applied) will be those who have been commenced on HFNO for an acute respiratory illness admitted under the Respiratory bed card. Patients in the non-interventional group (weaning protocol not applied) will be those commenced on HFNO for an acute respiratory illness to a General Medicine ward. Screening of ward admission lists and electronic medical records will be conducted by authorised members of the research team to identify patients who meet the inclusion criteria.