Cost Effectiveness of Outpatient Set-up of Automated NIV in Obese Patients With Chronic Respiratory Failure

Intervention set ups will follow a standard protocol for the automated device (A40 AVAPS-AE machine;Manufactured by Philips-Respironics, Murraysville, Pittsburgh, US) and patients will be discharged with the machine and a full face mask or nasal interface. Patients will then undergo a 1-2 night home oximetry study to ensure adequate control of overnight oxygenation. Patients will be reviewed clinically as an outpatient at 6 weeks and adherence to non-invasive ventilation will be evaluated and an arterial blood gas measurement will be undertaken. A full clinical review and optimisation of NIV and interface will be performed at this visit. Patients will be reviewed at 3 months as an inpatient where overnight transcutaneous carbon dioxide level and SpO2 studies will be performed. All other patient-centred, physician-centred and healthcare utilisation measurements will be assessed at baseline, 6 weeks and 3 months.

The patient will follow a specialist nurse-led protocolised set up of spontaneous/timed (S/T) mode pressure support ventilation (A40 AVAPS-AE machine; Manufactured by Philips-Respironics, Murraysville, Pittsburgh, US) using limited respiratory polygraphy, including overnight TcCO2 (Trascutaneous Carbon Dioxide) and SpO2 (Oxygen Saturation) studies. Following the inpatient set-up, patients will be reviewed as an outpatient at 6 weeks and adherence with non-invasive ventilation will be evaluated and arterial blood gas measurements will be performed. Patients will then be reviewed at 3 months as an inpatient where overnight respiratory polygraphy, TcCO2 and SpO2 studies will be repeated. All other patient-centred, physician-centred measurements and healthcare utilisation measurements will be assessed at baseline, 6 weeks and 3 months.