Oxygen Use in Emergency Presentations (Adult)

Oxygen Use in Emergency Presentations

Status

Assess

Acute or chronic
Respiratory status
Assess and monitor SpO2 continuously
Consider causes of hypoxia


Normal Oxygen Saturation
No O2 required, Reassure Pt


Mild-Moderate Hypoxaemia SpO2: 85-93%
Titrate O2 flow to SpO2 of 94-98% if no clinical illness present - Initial dose of 2-6 l/min via nasal cannulae - Consider simple face mask at 5-10 l/min


Moderate-Severe Hypoxaemia SpO2: <85%
	Or
Critical Illnesses - Cardiac Arrest or Resuscitation - Major Trauma / Head Injury - Carbon Monoxide Poisoning - Shock - Severe Sepsis - Anaphylaxis
Initial management - Initial dose nonrebreather mask of 10-15 l/min - If inadequate Tidal Volume or Residual Volume, consider BVM ventilation with 100% O2
Once Pt stable Titrate O2 flow to SpO2 of 94 -98%
If Pt deteriorates or SpO2 remains < 85% - BVM ventilation with 100% O2 - Consider LMA
Consider ETT


Chronic Hypoxaemia - COPD/Pulmonary Disease - Neuromuscular Disorder - Morbid Obesity
Stop
High-concentration O2 may be harmful in the COPD Pt at risk of hypercapnic respiratory failure
Titrate O2 flow to SpO2 of 88-92% if no clinical illness present - Initial dose of 2-6 l/min via bi-nasal cannulae - Consider simple face mask at 5-10 l/min
If Pt deteriorates or SpO2 remains <88% - Treat as Moderate-Severe Hypoxaemia

Introduction

- The Oxygen Use in Emergency Presentations guideline has been introduced after a comprehensive and thorough review of evidence-based medical literature investigating oxygen therapy in emergency settings. **

- This guideline is intended for use in Ambulance and MICA Paramedics where a reliable oxygen saturation reading (or pulse oximetry reading SpO2) is available.

- This guideline should only be applied to patients 16 years or older.

** O'Driscoll BR, Howard LS, Davison AG, BTS guideline for emergency oxygen use in adult patients. Thorax. 2008;63(SUPPL. 6):vi168

Management Principles

- Oxygen is a treatment for hypoxaemia, not breathlessness. Oxygen has not been shown to have any effect on the sensation of breathlessness in non-hypoxaemic patients.

- This guideline aims to achieve normal or near normal oxygen saturations in acutely ill patients. Oxygen should be prescribed to achieve a target

oxygen saturation reading, while continuously monitoring the patient for any changes in condition.

- Oxygen should not be administered routinely to patients with normal oxygen saturations. This includes those with stroke, acute coronary syndromes and arrhythmias.

- In patients who are acutely short of breath, the administration of oxygen should be prioritised before by obtaining an oxygen saturation reading. Oxygen can later be titrated to reach a desired target saturation range.

- If pulse oximetry is not available or unreliable, provide an initial dose of 2-6 l/min via nasal cannulae or 5-10 l/min via face mask until a reliable oxygen saturation reading can be obtained.

Special Circumstances

Early aggressive oxygen administration may benefit patients who develop critical illnesses and are haemodynamically unstable, such as (1) Cardiac Arrest or Resuscitation, (2) Major Trauma / Head Injury, (3) Carbon Monoxide Poisoning, (4) Shock, (5) Severe Sepsis, and (6) Anaphylaxis. In the first instance, oxygen should be administered with the aim of achieving an SpO2 of 100%. Once the patient is haemodynamically stable, oxygen dose should be titrated to normal levels.

Patients with chronic hypoxaemia (e.g. COPD, neuromuscular disorders, morbid obesity etc.) who develop critical illnesses as above, should have the same aggressive oxygen administration, pending the results of blood gas measurements.

If a diagnosis of COPD is unknown, it should be assumed in any patient who is >50 years of age who are long-term smokers or ex-smokers with a history of longstanding breathlessness on minor exertion. Patients with COPD may also use the terms "Chronic Bronchitis" or "Emphysema" to describe their condition, but sometimes mistakenly use "Asthma".

General Care

Oxygen exchange is at its greatest in the upright position. Unless other clinical problems determine otherwise, the upright position is the preferred position when administering oxygen.

Ensure the patients fingertips are clean of soil or nail polish. Both may affect the reliability of the pulse oximetry reading. The presence of onychomycosis may also cause a falsely low reading.

Take due care with pts who show evidence of anxiety/panic disorders (e.g Hyperventilation Syndrome). Oxygen is not required, however no attempt should be made to retain carbon dioxide (e.g. paper bag breathing).

All women with evidence of hypoxaemia who are more than 20 weeks pregnant should be managed with left lateal tilt to improve cardiac output.

Some pts may experience dryness of nasal mucosa if oxygen flow exceeds 4 l/min via nasal cannulae.

Face masks should not be used for flow rates <5 l/min, due to the risk of carbon dioxide retention.

Nasal cannulae are likely to be just as effective with mouth-breathers. However, where nasal passages are congested or blocked, face masks should be used to deliver oxygen therapy.

Special Notes

Pulse oximetry may be particularly unreliable in Pts with peripheral vascular disease, severe asthma, severe anaemia, hypotension and carbon dioxide poisoning.

Pulse oximetry can be unreliable in the setting of severe hypoxaemia. An oxygen saturation reading below 80% increases the chance of being inaccurate.

All patients with suspected carbon monoxide poisoning or pneumothorax should be given high dose oxygen until arrival at hospital. Pts who show no clinical evidence of breathlessness or hypoxaemia may still benefit from this practice.

Poisoning with substances other than carbon monoxide should be given oxygen to maintain an SpO2 of 94-98&. Special circumstances occur in the setting of paraquat and bleomycin poisoning where the use of oxygen therapy may prove detrimental to the patient. The maintenance of prophylactic hypoxaemia in these patients (Sp02 of 88-92%) is recommended.