The use of nebulised salbutamol while treating a person with acute pulmonary oedema has been debated over the past decade in both pre-hospital care and emergency departments. In Australia, the current understanding of nebulised salbutamol and acute pulmonary oedema (APO) is that the salbutamol will worsen the patient’s condition.
The following identifies current understandings about acute pulmonary oedema and salbutamol:
Pulmonary Oedema is caused by anything that results in fluid crossing from the pulmonary artery into the alveoli and lungs. The most common cause is left sided cardiac failure, in which the left ventricle is working poorly, leading to a backlog of blood within the pulmonary artery. When the right side of the ventricles contract properly, they increase the hydrostatic pressure in the pulmonary artery, and this can force blood through the selectively permeable membrane of the alveoli and into the lungs.
Salbutamol stimulates the beta II receptors within the lungs. This causes bronchial- dilation and makes it easier for the fluid to flow into the lungs. It also increases the heart rate of the already weakened cardiac pump.
Examples of APO and Salbutamol Problems
If a patient is trying to shift fluid through a straw it will take much longer than a large hose pipe. In an example of APO and Salbutamol, the patient without salbutamol on board will have the fluid entering the lungs through a straw, whereas the person with salbutamol on board will have fluid entering through the large hose pipe.
Another example would be if you increase the heart rate while the person is in APO (which is a natural secondary effect of salbutamol on the heart), it is the same as trying to increase the RPM of an engine that is about to fail, all you do is cause it to stop completely.