Comparison of Pressure Support and Pressure Control Ventilation in Chronic Respiratory Failure

Study Overview
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Brief Summary
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This study is looking at whether there is a difference in outcomes using two different types of breathing support in those patients who have chronic respiratory failure (patients who under-breathe). There is little data to demonstrate which mode of ventilation is better in terms of physiological outcomes and outcome data relating to patient symptoms. We hypothesize that one type of breathing support: pressure support ventilation would be more comfortable for patients as it more closely matches a patient's own respiratory pattern and and so leads to improved adherence and consequent improvement in quality of life. Patients with respiratory failure will be randomly assigned to receive either pressure support ventilation or pressure control ventilation for the first 6 weeks and then cross-over to receive the mode not previously used for a further 6 weeks. They will have baseline data recorded and then be followed up after each 6 week block.

Official Title
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A Pilot Study: Comparing Physiological Parameters and Outcome Variables Using Pressure Support Ventilation Versus Pressure Controlled Ventilation in Patients With Chronic Respiratory Failure

Conditions
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COPD, Chest Wall Disease, Neuromuscular Disease, Obesity Hypoventilation

Intervention / Treatment
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* Other: Pressure support ventilation
* Other: Pressure control ventilation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with chest wall deformity, neuromuscular disease or obesity hypoventilation syndrome with an FEV1/FVC ratio of >70% and VC <50% predicted or patients with COPD with a FEV1/FVC ratio of <70% an FEV1 <50% predicted Stable pH >7.35 ESS <18 Symptomatically stable with clinical resolution of intercurrent infection: normal C reactive protein, white cell count and afebrile Daytime symptoms compatible with nocturnal hypoventilation i.e. poor sleep, morning headache, daytime somnolence, shortness of breath Arterial carbon dioxide partial pressure (PaCO2) > 6.0kPa during day with evidence of nocturnal hypoventilation (TcCO2 >7.5KPa or a rise in TcCO2 of >1 KPa) No prior domiciliary ventilation use Patients with COPD must be established on optimal medical treatment prior to enrolment Exclusion Criteria: Psychological, social or geographical situation that would impair compliance with the schedule Patients who have underlying malignancy or severe cardiac dysfunction (ejection fraction <40%) Complex OSA

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Pressure support ventilation<br>Pressure support ventilation | Other: Pressure support ventilation<br>* Pressure support ventilation<br>|
| Active Comparator: Pressure control ventilation<br>Pressure control ventilation | Other: Pressure control ventilation<br>* Pressure control ventilation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Adherence to ventilation |  | 6 and 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial blood gases |  | 6 and 12 weeks | 
| Health related quality of life as measured by CRQ and SRI |  | 6 and 12 weeks | 
| Breathlessness (MRC dyspnoea score) |  | 6 and 12 weeks | 
| Assessment of daytime vigilance and fatigue by the Epworth sleepiness score,Oxford sleep resistance test and the fatigue severity score. |  | 6 and 12 weeks | 
| Sleep comfort as assessed by a visual analogue scale |  | 6 and 12 weeks | 
| Spirometry: forced expiratory volume in 1s and forced vital capacity |  | 6 and 12 weeks | 
| Respiratory muscle strength: maximum inspiratory pressure, maximum expiratory pressure and sniff nasal pressure |  | 6 and 12 weeks | 
| Sleep fragmentation as assessed by actigraphy |  | 2 week perids from 4 and 10 weeks | 
| Patient ventilator synchrony as measured by number of ineffective efforts |  | 6 and 12 weeks |