Divers should always be carefully monitored by their colleagues and supervisors so that if an air embolism occurs, it can be immediately identified and treated.
The symptoms, such as dizziness and blurred vision, usually appear a few minutes after surfacing (see Air embolism - symptoms for more information).
A physical examination and tests, such as chest X-rays, may be carried out by a doctor to check that the symptoms are not caused by another condition.
If a scuba diver loses consciousness within 10 minutes of surfacing, they probably have an air embolism and should be treated immediately (see Air embolism - treatment for more information).
Monitoring patients during surgery
There are several ways to monitor a person during surgery if they are thought to be at risk of developing an air embolism.
Transesophageal echocardiography
A tiny scanner on the end of a thin tube is inserted into the body, through the mouth and down the airway, to monitor the heart with ultrasound. This can detect relatively small air bubbles. However, it is invasive (medical instruments enter the body) and cannot locate where the bubble is in the body.
Doppler ultrasound
An ultrasound scanner is placed over the right side of the heart to measure the speed of bloodflow and changes in blood density. It is quite sensitive and is commonly used during surgical procedures to the nervous system.
However, it cannot determine the size of the embolus or distinguish between life-threatening and minor air bubbles. It can sometimes be difficult to place the equipment on the person, especially if they are obese.
Pulmonary artery catheter
A tiny tube is inserted into the artery connecting the heart to the lungs and blood pressure is monitored. A change in blood pressure shows that an air embolism may be present.
However, a change in blood pressure could have another cause, so this is not a routine method of monitoring.
