Oxygen Therapy

Question 1

Aims of O2 Therapy

Answer 1

correct hypoxaemia and therefore reduce tissue hypoxia decrease effort placed on myocardial tissue and WOB
for relieving hypoxaemia NOT breathlessness

Question 2

What patients need O2 therapy?

Answer 2

critically ill patients with cardiorespiratory of metabolic dysfunction
patients with SpO2 <92%
deteriorating SpO2
risk of hypercapnia
breathless patients if can’t obtain reliable oximetry signal

Question 3

Parameters to Aim for Medical Conditions

Answer 3

COPD

• administor if SpO2 <88%
• aim for SpO2 88-92%

Acute Medical Conditions

• administer if SpO2 <92%
• aim for SpO2 92-96%

Question 4

Potential Adverse Effects

Answer 4

not as important as ensuring they are adequately oxygenated
oxygen induced hypercapnia
- result of VQ mismatch due to loss of hypoxic vasoconstriction
CO2 rebreathing
depression of ciliary function
absorption atlectasis
oxygen toxicity

Question 5

Role of Physio

Answer 5

titrate oxygen to within prescribed and documented aims for O2 sats or ABG measurements
recommendations for correct delivery service
ensure correct fit and flow rate
observe improvements/deterioration and titrate accordingle
consider mobilisation requirements
minimise adverse effects O2 therapy

Question 6

Long Term Oxygen Therapy Aims

Answer 6

provision of O2 therapy for 15-25 hours per day
for patients with chronic but stable hypoxaemia
improve QoL and potential length of life

Question 7

Long Term Oxygen Therapy Recommendations

Answer 7

patient has stable daytime PaO2 <55,,Hg or 56-59mmHg with evidence of hypoxic organ damage
desaturate to SpO2 88% for more than 1/3 of night
when pt wants to increased amount of O2 they recieve throughout a 24 hours period
where would benefit a chronic lung disease patient
palliative care
chronic heart failure
during air travel

Question 8

Long Term Oxygen Therapy Contraindications

Answer 8

severe airflow limitation 
complain of dyspnoea but PaO2 >60
continued smoker 
not reqceived adequate therapy for underlying medication conditions 
not sufficiently motivated

Question 9

Nasal Prongs

Answer 9

low flow rate
2-5L/min
max 5L/min
for every L of O2 added, increases the FiO2 by 2%
can’t use humidifier
for patient with low O2 requirements
oxygen delivery dependent on their minute ventilation

Question 10

Hudson Mask

Answer 10

delivers higher flows
4-10L/min
comfortable
need to add humidification at flows from 5L/min to prevent airway drying out

Question 11

Venturi Mask

Answer 11

doesn’t depend on patient’s minute ventilation
able to titrate FiO2 to be very exact, helps to reach target SpO2
good for COPD patients

Question 12

Non-Rebreather Mask

Answer 12

provides up to 15L/min
emergency situations where oxygen delivery is a priority
only breathe in O2 - exhaled air filtered out via vents
needs humidifier
uncomfortable for patients

Question 13

High Flow Nasal Prongs

Answer 13

high flow rates 35-55L/min
can deliver 100% oxygen
oxygen heated and humidified already

Question 14

Indications for humidification

Answer 14

High flows of supplemental oxygen
Acute infection
increased sputum load

Question 15

Potential hazards of humidification

Answer 15

Infection
Aspiration of water droplets
Condensation may trigger bronchospasm