None listed
Conditions
Brief summary
In medical practice and published research, it is well documented that in some patients with respiratory failure due to chronic lung disease, breathing high concentrations of oxygen can cause carbon dioxide levels to increase, sometimes to potentially harmful levels. The effect of oxygen on patients who have chronic respiratory failure from other causes such as obesity hypoventilation syndrome is less clear. We would like to test the effect of two concentrations of oxygen on breathing pattern and carbon dioxide levels in patients who have chronic respiratory failure due to obesity hypoventilation syndrome. We expect that breathing high concentration oxygen will cause an increase in carbon dioxide levels and alter breathing pattern in this group. It has also been proposed that this group, treating (and reversing) hypercapnia through the use of nocturnal positive airway pressure therapy may improve responsiveness to carbon dioxide, thereby minimising the potentially harmful effects of supplemental oxygen. We hypothesised that three months of treatment with nocturnal positive airway pressure would lessen any adverse responses to supplemental oxygen observed during testing at initial presentation.
Interventions
During a testing session, participants will breathe supplemental oxygen at 2 concentrations (fraction of inspired oxygen 28% and 50%) for 20 minutes each. There will be a one-hour washout period between interventions. A group of healthy control participants will be tested on only one occasion to allow us to document the normal response to 28% and 50% oxygen. Participants with hypercapnic respiratory failure will perform testing on two occasions: once at initial presentation with untreated hyperc
During a testing session, participants will breathe supplemental oxygen at 2 concentrations (fraction of inspired oxygen 28% and 50%) for 20 minutes each. There will be a one-hour washout period between interventions. A group of healthy control participants will be tested on only one occasion to allow us to document the normal response to 28% and 50% oxygen. Participants with hypercapnic respiratory failure will perform testing on two occasions: once at initial presentation with untreated hypercapnic respiratory failure; and once after three months of treatment with nocturnal positive airway pressure therapy. Nocturnal positive airway pressure will be prescribed and implemented in accordance with usual clinical practice at our centre. Some data collected as part of this study will also be used for two measurement validation studies. The first study is investigating the validity of arterialised venous blood gases against gold standard acid-base measures obtained from arterial blood gases. A single pair of simultaneously taken arterialised venous and arterial blood samples taken during each testing session will used for this validation. The second study is investigating the validity of respiratory inductive plethysmography in people with obesity hypoventilation syndrome and healthy controls. Simultaneous repeated measurements of tidal volume, minute ventilation, and respiratory rate measured by the air/oxygen breathing circuit and a non-invasive respiratory inductance vest will be compared for this validation study.
Sponsors
Royal Prince Alfred Hospital
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
18 Years to 90 Years
Healthy volunteers
No
Inclusion criteria
Chronic hypercapnic respiratory failure due to obesity hypoventilation syndrome or neuromuscular disease
Exclusion criteria
Acute respiratory failure or recent respiratory illness, Obstructive pulmonary disease, Pregnancy, Unstable cardiac condition, Psychiatric illness, Non-english speaking
Outcome results
None listed