Re: How bad is it to inject air bubbles into a muscle along with the medicine?

Devin,

The reason that injecting air into the blood stream is a problem is that 
the bubbles will travel to the capillaries in the lung and plug them up. 
This is called an air embolism. If gas exchange in the capillaries in the 
lungs is so impeded that the there is insufficient oxygen in the arterial 
blood then the tissues of the body will not function properly. This can be 
fatal. It also takes more than just a few small bubbles to cause a 
problem. Blood clots that travel to the lungs can also be fatal. This is 
also the reason for "bends" in divers. The nitrogen from the air is forced 
into solution in the blood under pressure and at decompression bubbles out 
of the blood.

Injecting air into the muscle or fat would not find its way into the blood 
stream very easily and would not cause problems with pulmonary embolism. 
If a lot of air was injected into muscle or fat it would dissect into the 
tissue and form a pocket until it was absorbed into the tissue. The 
dissection may cause some discomfort and broken blood vessels, but that 
would be the most that would happen.