Are physiotherapy treatments feasible for patients with low oxygen levels after surgery?

Brief name: “Talk, Walk, Breathe” and Non Invasive Ventilation (NIV) Therapy will be delivered as individual sessions, face to face within the participants hospital bedspace or ward by qualified and registered physiotherapists of varying experience level, trained in physiotherapy-led NIV and all trial processes. The protocolised therapy will be delivered following trial recruitment, up to and including the 7th postoperative days unless a threshold for discharge from physiotherapy is reached earlier. Talk: a minimum of once, duration 10-minutes Walk: daily up to and including the seventh postoperative day, 10-15mins Breathe: a minimum of 4 sessions over two days. 1 session includes 20 deep breaths and 6 coughs. Duration of one session = 5-10 minutes. NIV: a minimum of 4 supervised 30-minute sessions over two days following trial recruitment For all therapy components (Talk, Walk, Breathe, NIV) adherence will be recorded on a case report form by the treating physiotherapist. The intervention group will receive “Talk, Walk, Breathe” as described for the control group with the following exceptions/additions. TALK: A minimum of once, for 10 mins (5 minutes as the control group + 5 minutes for additional NIV information) Participants will be verbally orientated to the NIV machine, circuit and interface after the first DB&C session. Participants will be educated on the potential benefit of positive pressure delivered with NIV to improve oxygen levels, increase lung volumes and sputum clearance. The booklet provided during "Talk" will be the same as the control group and not contain information about NIV. In addition to “Talk, Walk, Breathe”, the intervention group will receive NIV. NIV: Supervised NIV (bilevel or CPAP) for a minimum of 4x 30 mins sessions over 2 days. Prior to each NIV session the physiotherapist will confirm the absence of any contraindication to NIV using a standardised checklist. NIV will be delivered through a face mask by a ResMed VPAP S9 machine while the patient is either sitting up in a supportive chair, or in bed with head raise elevated 45-90 degrees. For bilevel NIV application: Mode- Spontaneous/timed, Settings: Expiratory positive airway pressure (EPAP) will start then progress from 5 to 10cm of water and inspiratory positive airway pressure (IPAP) 10 to 15cm of water. The difference between IPAP and EPAP will be a minimum of 4 cm of water and back up rate of 6 breaths/minute with pressure rise time initially set at the slowest speed (900ms) and the inspiratory trigger at the minimum value. Continuous positive airway pressure (CPAP) breathing mode may be selected in place of bilevel at clinician discretion following assessment, with pressure settings 5 to 10 cm of water. Machine settings and entrained oxygen will be titrated to breathing pattern and frequency (goal <25 breaths/minute), comfort, tidal volume, and goal oxygen saturations of 92-96% unless an alternate goal oxygen saturation range is specified by the medical team. NIV machine settings and levels of oxygen entrainment will be recorded. Correct mask size and careful fitting will be used to reduce air-leak, in addition to air-leaks being monitored and recorded. The participant may remove, or request assistance to remove the NIV mask at any time for any reason. Temporary mask removal will be encouraged should coughing result in sputum expectoration which is not immediately swallowed. If the participant is unable or unwilling to continue NIV therapy within 5 mins of a break, the session will be terminated, and the reason documented. If the participant remains unable to tolerate the therapy despite titration and reassurance, cessation of NIV therapy will occur for that session and be reported. Order of therapies: 1. TALK - as control group 2. WALK - as control group 2. BREATHE - as the control group 3. TALK - NIV specific information 4. NIV As the control group: High flow oxygen therapy (HFOT) use may be prescribed at any time by the medical team in line with local practise. Timing of initiation and duration of HFOT will be recorded but not protocolised.