Download Breathlessness and oxygen therapy

Breathlessness and
oxygen therapy
Rosemary Moore
Physiotherapist
B App Sc (Physio) Grad Dip Physio (Cardiothoracic)
M Physio (Research) PhD
Take home messages
● Oxygen is a drug used to treat low
blood oxygen levels (hypoxaemia)
● Breathlessness does not always
indicate hypoxaemia
● Oxygen is not a treatment for
breathlessness
Why do we breathe?
Fuel:
oxygen
Waste: carbon dioxide
(Lavoisier 18th century)
“….. the body has practically
no storage capacity for
oxygen, but depends from
moment to moment for its
supply from the air”
(Haldane 1919)
Why might we feel breathless?
●demand and supply
●MANY possible causes of
excessive breathlessness
* excessive breathlessness not
always associated with
insufficient oxygen
The oxygen transport pathway
Respiratory Circulatory Muscles
System
(& organs)
System
Excessive Breathlessness:
some investigations
● Lungs
− Breathing tests (obstructive, restrictive lung
problem)
− Chest X-ray
− CT scan
● Heart
− ECG, angiogram, echocardiograph, 24 hour
monitor
● Exercise tests
● Blood tests
Dyspnoea
● perceived difficulty with breathing
● unpleasant urge to breathe (air hunger)
● breathing discomfort
● sensations of increased inspiratory work or
effort, chest tightness, unsatisfied
inspiration
* Dyspnoea is not always associated
with insufficient oxygen
Cycle of deconditioning
 SOB
on exercise
deconditioning
dyspnoea
avoidance of exercise
inactivity
Hypoxaemia: investigations
● Arterial blood gases
● Pulse oximetry
● Exercise tests – eg. 6 minute walk test
● Oxygen therapy is a drug prescribed to
treat hypoxaemia
− according to guidelines (Australasian)
− to achieve target oxygen saturation range
Acute / emergency oxygen therapy
● In hospital, emergency departments,
ambulance
● To correct hypoxaemia in severely ill
patients
● Target range:
− Australasian guidelines: SpO2 92% to 96%
− or 88–92% in COPD / risk of hypercapnea
(raised blood carbon dioxide level)
Home oxygen therapy
3 main categories
1. Continuous (“Long Term Oxygen Therapy”)
2. Nocturnal oxygen therapy
3. Intermittent oxygen therapy
− Exertional (ambulatory) oxygen therapy
− Air travel
− Palliative: terminal illness + severe dyspnoea
+ significant hypoxaemia
− Acute/life threatening asthma + isolated area
Home oxygen therapy
3 main categories
1. Continuous (“Long Term Oxygen Therapy”)
2. Nocturnal oxygen therapy
3. Intermittent oxygen therapy
− Exertional (ambulatory) oxygen therapy
− Air travel
− Palliative: terminal illness + severe dyspnoea
+ significant hypoxaemia
− Acute/life threatening asthma + isolated area
Continuous oxygen therapy
(LTOT)
● Indications: severe hypoxaemia at rest
− PaO2  55 mmHg
or
− PaO2 56–59 mmHg + hypoxic organ damage:
polycythaemia (blood test)
heart (echocardiograph)
● Aim: PaO2 > 60 mmHg
Continuous oxygen therapy
(LTOT)
● At least 15 hours per day
● Stationary concentrator
− +/- portable cylinders
− ? portable concentrator
● Evidence: in COPD
− improves survival
− alleviates hypoxic organ damage
Exertional (ambulatory)
oxygen therapy
● Indication:
− exercise induced hypoxaemia
● Australasian guidelines:
may be considered if
−  O2 sat:  88% during exercise
and
−  exercise tolerance or  dyspnoea
− Six minute walk tests
Exertional (ambulatory)
oxygen therapy
● For use during exertion
● Portable cylinders
● ? portable concentrator
● Evidence: not evidence based
Oxygen therapy –
Contraindications
● Normal oxygenation
● Sub-maximal therapy
● Current smoking
− fire risk
− reduced benefit
● Disinclination
Oxygen therapy – Risks
● Safety
− increased risk of falls
− burns
− death
● Incorrect flow
− hypercapnea (raised blood carbon dioxide)
● Nasal discomfort
Oxygen therapy – Barriers
● Difficulty with equipment
− lack of portability
− changing regulators
● Embarrassment
Take home messages
● Oxygen is a drug used to treat low
blood oxygen levels (hypoxaemia)
● Breathlessness does not always
indicate hypoxaemia
● Oxygen is not a treatment for
breathlessness
References
Getting started on home oxygen.
Lung Foundation Australia
HOME OXYGEN THERAPY GUIDELINES
Adult domiciliary oxygen therapy. Position statement of the
Thoracic Society of Australia and New Zealand.
McDonald et al. Medical Journal of Australia, 2005; 182(12): 621-626.
British Thoracic Society guidelines for home oxygen use in adults.
Hardinge et al. Thorax 2015;70:i1–i43.
ACUTE / EMERGENCY OXYGEN THERAPY GUIDELINES
TSANZ oxygen guidelines for acute oxygen use in adults.
“Swimming between the flags.”
Beasley et al. Respirology 2015; 20: 1182-1191.
BTS guidelines for emergency oxygen use in adult patients.
O’Driscoll et al. Thorax 2008;63(Suppl VI):vi1–vi68.
REVIEW ARTICLE
Dyspnoea and oxygen therapy in COPD.
Moore and Berlowitz. Physical Therapy Reviews, 2011; 16(1): 10-18.
When you can’t breathe,
nothing else matters