by Dr Pandula Siribaddana

Created on: November 29, 2010

CPAP stands for continuous positive airway pressure and in based on the principle that, a positive air pressure maintained throughout the breathing cycle will cause higher volume of oxygen within the lungs after an expiration therefore allowing the lungs to work at ease, the heart to pump efficiently as well as for the tissues to be well oxygenated. When considering the complexities associated with determining the right candidate, this is a procedure that needs to be prescribed only by well trained health care professionals.

How is it given?

The CPAP system is a completely enclosed system in which an oxygen flow is delivered to the lungs via a tightly fitting mask or an inhalation device which also allows expiration to take place through a low resistance valve. The flow rate of air should be adjusted according to the need and other treatment modalities should continue while CPAP is in progress.

What are the indications for giving CPAP?

CPAP is able to prevent atelectasis in susceptible individuals and is useful to reduce work of breathing which will improve the oxygenation of body tissues. It has also been used to reduce the cardiac output in patients with pulmonary edema and had often been helpful to regain lung function in patients whom are weaned off from the ventilator in certain instances.

What are the contradictions to use continuous positive airway pressure?

As the process includes maintaining a positive pressure throughout the respiratory cycle, it may be a risky procedure for susceptible individuals whom can suffer barotrauma, abnormal heart functioning or develop certain other complications. Let us now take a look at these contraindications one by one.

-The susceptibility of developing barotrauma will be more when a person is diagnosed of having recurrent pneumothorax or if a pneumotorax is untreated. Therefore, such patients are contraindicated from receiving CPAP treatment.

-When there is an air leak in the lungs, it can also be a contraindication.

-When a person is apnoeic they should not receive CPAP.

-Bleeding from the nose is another contraindication as it can increase the risk of aspiration of blood.

-In instances where the patient is suffering from significant lung over distension such as in the case of emphysema and asthma.

-Facial injuries such as fractures, lacerations, burns…etc as it will not permit the tightly fitting masks or other breathing devices to be attached.

-Recent surgical measures undertaken in the ear, nose or throat.

-In instances where a rise in the intracranial pressure could be detrimental to life and application of CPAP leads to a significant reduction in blood flow towards the brain.

At the same time, basal skull fractures are also looked at as a contraindication because it can give rise to a pneumocephalus which may be a risk to life.

Apart from the above manifestations, there are several relative contraindications and therefore it is a procedure which should be monitored closely following it implementation among patients whom it is indicated.

Reference:

Royal United Hospital Bath NHS Trust, Guidelines For The Use Of Continuous Positive Airway Pressure (CPAP) Systems In Adults

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