Oxygen

Question 1

Oxygen - Contraindications (1)

Precautions (4)

Answer 1

Contraindications:
* patients with normal SpO2 (>92%ra) including those presenting with stroke, ACS, or cardiac arrythmias

Precautions:
# no effect on breathlessness in non-hypoxaemic patients
# in acute SOB, administer O2 before obtaining SpO2 - O2 can later be titrated
# if pulse oximetry unavailable, provide an initial dose of 2-6L via nasal cannulae or 5-10L via Hudson mask until SpO2 can be obtained or symptoms resolve
# in setting of paraquat or bleomycin poisoning, prophylactic hypoxaemia (SpO2 88-92%) is recommended
# chronic hypoxaemia patients (COPD, neuromuscular disorders, obesity) require O2 titrated to achieve SpO2 88-92%, provided no critical illnesses exist
# COPD should be suspected in any patient: >40 years, who is a smoker/ex-smoker, experiencing dyspnoea that is progressive, persistent and worse with exercise, has a chronic cough or sputum production, and a family history of COPD.

Question 2

Oxygen - Side Effects

Answer 2

> can increase stroke severity

Question 3

Oxygen - Actions

Answer 3

Treatment aims to achieve normal or near-normal SpO2 in acutely ill patients.

Early, aggressive O2 administration with 10-15L, considering BVM where tidal volume inadequate (to achieve SpO2 of 100%) may benefit patients with critical illnesses who are haemodynamically unstable, including:
85 AT DE PASS:
- 85: SpO2 less than 85%
- A: arrest / resuscitation
- T: trauma (major) / head injury 
- D: diving emergencies (decompression)
- E: epilepsy (status epilepticus)
- *P: poisoning (with carbon monoxide) / pneumothorax 
- A: anaphylaxis
- S: shock
- S: severe sepsis
*Once the patient is haemodynamically stable, O2 can be titrated to 94-98% except in the case of the "P" as these patients receive high-flow O2 until arrival at hospital.