Clinical trial NCT02983565: Intelligent Oxygen Therapy During Sleep
Official title: The Assessment of Intelligent Oxygen Therapy (iO2T) in Patients With Respiratory Failure on Long-term Oxygen Therapy During Sleep
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Respiration Failure
Keywords: Long-term oxygen therapy
Intelligent oxygen therapy system
Auto-titrating oxygen system
Lead sponsor: Imperial College London
Sponsor class: OTHER
First posted: 2016-12-06
Enrollment: 6
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: The percentage of time spent with SpO2 <90% during sleep (%)
timeFrame: 10 hours in bed
Secondary outcomes:
measure: The percentage of time spent with SpO2 >96% during sleep (%)
timeFrame: 10 hours in bed
measure: The mean transcutaneous carbon dioxide level during sleep (measured in kPa)
timeFrame: 10 hours in bed
measure: The peak transcutaneous carbon dioxide level during sleep measures in kPa
timeFrame: 10 hours in bed
measure: The mean sleep SpO2
timeFrame: 10 hours during sleep
measure: Sleep quality as measured on a visual analogue scale (0 - 100mm).
timeFrame: 10 hours in bed
measure: Total Sleep time
timeFrame: 10 hours during sleep
measure: Sleep efficiency
timeFrame: 10 hours in bed
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: Royal Brompton and Harefield NHS Foundation Trust
Study officials:
affiliation: Imperial College London
name: Anita K Simonds
role: PRINCIPAL_INVESTIGATOR
References: