Respiration Failure
Conditions
Keywords
Long-term oxygen therapy, Intelligent oxygen therapy system, Auto-titrating oxygen system
Brief summary
Long-term oxygen therapy improves survival in patients with severe hypoxia. However, some patients despite this oxygen, experience episodes of low oxygen levels (intermittent hypoxia) especially during sleep which may be harmful. In order to overcome this, the investigators have designed an auto-titrating oxygen system (called intelligent oxygen therapy) which automatically adjusts oxygen flow rates to maintain oxygen levels in patients already on oxygen. This study will investigate whether the intelligent oxygen therapy system can prevent intermittent hypoxia during sleep in patients already on long-term oxygen.
Detailed description
Long-term oxygen therapy (LTOT) improves survival in patients with chronic obstructive pulmonary disease (COPD) and severe persistent hypoxia. LTOT is prescribed at a fixed-flow rate with the aim of maintaining a partial pressure of oxygen greater than or equal to 8 kilopascals (kPa). However, a number of studies have demonstrated that patients on home LTOT experience episodes of intermittent hypoxia during rest, activities and especially sleep. Simply increasing the oxygen flow rate at night can relieve this hypoxia but at the expense of hyperoxia with its detrimental effects of hypercapnia and respiratory acidosis. Therefore, a more targeted approach is needed to oxygen delivery. The investigators have devised an auto-titrating oxygen system (intelligent oxygen therapy \[iO2Ts\]) which delivers variable flow oxygen to maintain a pre-set specific oxygen saturation ( SpO2) target. The system can avoid the dual hazards of hypoxia and hyperoxia and potentially optimise LTOT. This study will be investigating whether the iO2Ts can reduce intermittent hypoxia during sleep compared to usual fixed flow oxygen in patients on LTOT. Nineteen patients will be recruited to undergo two sleep studies each on two different nights; one on their usual LTOT flow rate and one of the iO2Ts. During both sleep studies, all participants will have full polysomnography, oxygen and transcutaneous carbon dioxide monitoring. The primary outcome will the percentage of time spent with SpO2 \< 90% during sleep.
Interventions
DEVICEIntelligent oxygen therapy system (iO2Ts)
Sponsors
Imperial College London
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
Participant not aware using iO2T or Fixed flow oxygen
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* On or eligible for long-term oxygen therapy
Exclusion criteria
1. Nocturnal use of non-invasive ventilation (NIV) or continuous positive airways pressure (CPAP) 2. A diagnosis of obstructive sleep apnoea 3. A diagnosis of a neuromuscular disease 4. Daytime partial pressure of carbon dioxide \> 8.0 kPa 5. Inability to consent for the study 6. Exacerbation of the underlying lung disease or chest infection in the previous 4 weeks 7. Pregnancy 8. Severe co-morbidities 9. Patients with a tracheostomy 10. Long-term oxygen therapy flow rate ≥ 4 litre per minute 11. Inability to understand the English language
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The percentage of time spent with SpO2 <90% during sleep (%) | 10 hours in bed | The difference in percentage time spent at SpO2 less than 90% during sleeping usual LTOT and iO2T (measured as %) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The mean transcutaneous carbon dioxide level during sleep (measured in kPa) | 10 hours in bed | Mean level of transcutaneous carbon dioxide level during sleep (measured in kPa) |
| The peak transcutaneous carbon dioxide level during sleep measures in kPa | 10 hours in bed | The maximum level of transcutaneous carbon dioxide during sleep (measured in kPa) |
| The mean sleep SpO2 | 10 hours during sleep | The mean level of SpO2 during sleep (measured in SpO2 %) |
| The percentage of time spent with SpO2 >96% during sleep (%) | 10 hours in bed | The percentage of time during sleep with an SpO2 value \>96% (measured as %) |
| Total Sleep time | 10 hours during sleep | The total amount of time spent in sleep confirmed by polysomnography (measured in minutes) |
| Sleep efficiency | 10 hours in bed | This is the total amount of time the patients actually slept divided by the total time they were in bed (measured as a percentage). |
| Sleep quality as measured on a visual analogue scale (0 - 100mm). | 10 hours in bed | The morning after the sleep study, participants will complete a visual analogue scale of their sleep quality. The visual analogue scale is on a A4 paper, it is a straight line of 100mm. |
Countries
United Kingdom
Outcome results
None listed