Medical Emergency in the Dental Surgery 2026 -Part 3 – Oxygen update

There is one word that sums up medical emergency treatment:

PERFUSION

Perfusion is defined as the passage of fluid through the lymphatic system or blood vessels to an organ or a tissue.

In emergency medicine that fluid is BLOOD,

and preferably carrying OXYGEN.

The organ is the BRAIN,

via the pump of the body – the HEART.

The faster the better!

The ideal percentage of oxygen is best.

This takes us to the following assessment guide: SCRAP

Skin – Pale cold sweaty.

Conscious State – Unconscious, Agitation, Confused.

Respiration Rate – above 25 or less than 10 breathes per minute for adults.

Airway – impaired by foreign material or body swelling or inflammation.

Perfusion of Oxygen – Saturation percentage of oxygen in the blood. Below 93 % oxygen should be given. Do not give more oxygen above 96%, as this damages the body. We want the ideal concentration.

This is determined by a Pulsimeter. Its best placed on the thumb facing up, in order to see it the screen.

Too much oxygen in the lungs overwhelms the blood’s ability to carry the oxygen away. The results in the excess oxygen forming free radicals that binds to the surface proteins of the lungs. Theses free radicals interfere with the central nervous system and attack the retina in the eye. Effectively it’s a form of chemical burning of tissue.

Oxygen administration is now viewed as giving a drug, and therefore needs to be recorded. In the past we gave 100% oxygen for long periods of time and thought it was safe. Now we have found that this unregulated use has led to permanent damage of parts of the body.

This means we need to give oxygen with a finger pulse oximeter. The oximeter is a portable non-invasive, spot check of oxygen saturation via a finger of arterial haemoglobin and pulse rate of an adult and paediatric patients at home and in hospital. Tip-if the patient has false nails, then turn the finger side on for accurate readings.

A healthy patient: Pulse rate should sit between 60-100 per minute for an adult, and a child between (9-15 years) should be 80-100 per min.

A healthy patient: SpO2 (oxygen saturation) for an adult, and a child from (9-15years), should be also 95%-98%.

Oxygen Administration – Adult

SpO2 below 92%

• Oxygen via nasal prongs at 2-4 litres/minute, until target 92-96% is reached.
• If target not reached then use a mask and increase flow to 8 litres/minute, until target 92-94% is reached.

Keep SpO2 below 96% – turn down or stop oxygen if target exceeded.

Oxygen Administration – Children

SpO2 below 92%

• Oxygen, via nasal prongs, at 2-4 litres/minute until target 94-98% is reached.
• If target not reached then use a mask and increase flow to 8 litres/minute until target 94-98% is reached.

Keep SpO2 below 98% – turn down or stop oxygen if target exceeded

There are other conditions where the oxygen saturations need to be lower, than above, as it may cause respiratory arrest. Additional measures such as a bronchodilator may be needed.

The updated assessment of the need to start CPR is a breath assessment. If the person is not responding to stimuli and there is ONE OR LESS BREATHES PER 10 SECONDS then compressions should be started.  Compression of the heart causes blood to flow to the brain carrying with it oxygen to perfuse the brain tissue.

Checking for a pulse is often difficult and takes too much time. If the person is OK, they will soon become conscious very quickly with compressions.