Study of the Efficacy of Home Mechanical Ventilation Post Acute Hypercapnic Exacerbation of Chronic Obstructive Pulmonary Disease (COPD)

• Days from trial intervention to either hospital admission or death [ Time Frame: 1 year ] [ Designated as safety issue: No ]
  

• Spirometry - specifically FEV1 & FVC change from trial intervention to follow up. [ Time Frame: 1 year ] [ Designated as safety issue: No ]
  
• Changes Health related quality of life from pre-intervention to follow up - specifically outcomes of severe respiratory insufficiency questionnaire, chronic respiratory disease questionnaire & MRC dyspnoea score [ Time Frame: 1 year ] [ Designated as safety issue: No ]
  
• Change in arterial PaCO2 from pre-intervention to follow up [ Time Frame: 1 year ] [ Designated as safety issue: No ]
  
• Change in the incremental shuttle walk test from pre-intervention to follow up [ Time Frame: 1 year ] [ Designated as safety issue: No ]
  
• Frequency of acute exacerbations of COPD requiring addition of antibiotics and or steroids and or hospital admission [ Time Frame: 1 year ] [ Designated as safety issue: No ]
  

Although HMV has been shown to improve physiological parameters as well as have clinical benefits in terms of dyspnoea and exercise capacity in severe COPD, the published randomised controlled trials have been less positive. The Steering Committee are committed to design a robust clinical trial that will answer this clinical question. Therefore, a multi-centre randomised controlled trial has been designed with recruitment and power calculations based on the applicants own data.

We will recruit from 8 UK university centres with expertise in HMV, 116 hypercapnic patients (58 in each arm) with persistent hypercapnia following an episode of acute hypercapnic respiratory failure. During the acute hypercapnic episode the patient would have be eligible for non-invasive ventilation with a pH <7.35 and a partial pressure of carbon dioxide (PaCO2) > 7.0kPa. They will be randomised, for a 12 months, to either

1. HMV and LTOT (Treatment Group)

2. LTOT alone (Control Group) This study would allow the investigators to answer a number of questions pertaining to clinical efficacy of HMV in COPD as well as the mechanism of action of HMV in COPD

   • Does HMV effect admission-free survival?
   • Does HMV reduce exacerbation frequency?
   • Does HMV impact on disease progression?
   • Does HMV improve health-related quality of life?
   • Does HMV improve exercise capacity?
   • Is there a dose-response between hours of ventilator compliance and daytime PaO2 and PaCO2?
   • Do patients increase hours of ventilator use during acute exacerbations?
   • Is ventilator compliance with HMV and LTOT acceptable?
   • Does HMV reduce healthcare utilisation? Follow-up assessments will be performed at 6 weeks, 3, 6 and 12 months. These data collected will include admission-free survival (primary outcome), hours of compliance with HMV, HRQL, gas exchange, lung function, body composition, exercise capacity, exacerbation frequency primary care consultations and compliance with LTOT, time to withdrawal of LTOT/night-time oxygen therapy based on daytime PaO2 and overnight SaO2 (secondary outcome measures). The relation of any changes to factors predicting severity of COPD will be studied. The cost effectiveness and cost-utility analysis of HMV will be studied.