Oxygen for IPFSimon Johnson

What is oxygen for?

• Oxygen is needed to generate energy for all body functions– Muscles

• walking, lifting, dressing etc.– Brain

• consciousness, thinking

• Normally oxygen levels are stable no matter how much exercise you do

• Symptoms of low oxygen – Breathlessness– Fatigue– Cyanosis – Fluid retention

Oxygen uptake from the lungs

Exercise increases oxygen extraction from the blood

musclesO2

muscles

comfortable‘normal’

breathlessfaint

cyanosed

How is this related to IPF?

• IPF reduces transfer of O2 from the lungs to the blood

• Desaturation to <88% during 6 min walk predicts outcome– independent of age, sex, smoking, lung

function and CT scores• Decreased overnight saturation associated

with reduced daytime energy and social functioning

• A low O2 causes frightening symptoms

Who needs oxygen therapy?

• Not everyone with IPF

• Not everyone who gets breathless

• Those limited by low blood oxygen– walking outside / gardening – around the house– at night– all or most of the time

British Thoracic Society guidelines

• In the absence of suitable controlled studies……………..• …. patients with persistent resting hypoxaemia and who are breathless

should be considered for oxygen at home delivered by oxygen concentrator.

• …… may also benefit form ambulatory oxygen if they remain active outside the home.

• Patients who are not chronically hypoxic but who are breathless, mobile and exhibit desaturation on exercise (90%) should be considered for ambulatory oxygen if improvement in exercise capacity and/or less breathlessness can be demonstrated by formal ambulatory oxygen assessment.

• Intermittent supplemental oxygen for periods of 10–20 min may relieve breathlessness associated with hypoxaemia in patients with ILD who do not require oxygen concentrator or ambulatory oxygen.

• When prescribing oxygen, individually titrate oxygen therapy according to oxygen saturations measured during normal activity.

• Nocturnal hypoxaemia is common in patients with IPF and may be associated with daytime impairment of quality of life, but there is no evidence that supplemental oxygen is useful in this setting.

• Clinical trials are required ……………….

How can you tell who needs oxygen?

• Blood gas test– gives information on O2 and CO2

– usually done at rest – doesn’t predict what happens on exertion

• Six minute walk test– gives information on O2 and exercise capacity– well validated and predicts prognosis– time consuming and hard work

• Corridor walk test– easy and predicts need for ambulatory O2

Corridor walk test

pre walk minimum

100

95

90

85

80

75

70

65

SaO2

24 hour O2 saturation

O2

pulse

7am 7pm 7am

awake asleep

Patient diary

Summary data

• Only 20 minutes with saturation in ‘red zone’

• Good values overnight

• Discuss need for ambulatory O2

• Long term O2 – >15 hours / day

• Overnight O2

• Short burst

• Ambulatory

Different types of O2 therapy

• Conserving devices–double duration of cylinder use

• Portable concentrators–small, – fewer features,

• usually 2l only

Longer lasting systems

Issues with O2 therapy for IPF

• Most evidence for O2 therapy comes from COPD– Gas exchange and O2 requirements are

different– Prescribing O2 in IPF is different

• Not always practical around the home • ‘I don’t want to get addicted to it’• Feeling self conscious about using O2 in

public

Conclusions

• Need for O2 is independent of lung function– more likely in patients with advanced

disease• O2 best prescribed after assessment on

exertion and at night• O2 can improve social functioning• Various systems are available according

to need and lifestyle

Any questions?

Travel

• >95% : fine• <92% : supplementary in-flight oxygen• 92-95% : flight assessment

– 15 mins of 15% oxygen