And, considering about half of all breathing treatments I do are either for pneumonia or cardiac asthma, I am hereby convinced that even doctors have no clue what the difference between true asthma and cardiac asthma is.
According to the Mayoclinic.com, here is the definition of Cardiac Asthma:
The term "cardiac asthma" refers to wheezing associated with congestive heart failure. It isn't true asthma. As a result of congestive heart failure, fluid can build up in the lungs (pulmonary dema). This causes signs and symptoms — such as shortness of breath, coughing and wheezing — that may mimic asthma. True asthma is a chronic condition caused by inflammation of the airways, which can lead to breathing difficulties. The distinction is important because treatments for asthma and heart failure are very differentCardiac asthma is mainly caused due to increased pressure in the pulmonary vessels causing fluid to fill the air sacs, "preventing them from absorbing oxygen," and making the person feel extremely short-of-breath. This same increased pulmonary vessel pressure (increased pulmonary vascular resistance) in turn squeezes the bronchioles and causes the wheeze and other symptoms that mimic real asthma, and this is why this "problem" is quite often mistaken for asthma and treated with bronchodilators. Secretions sitting on the vocal cord may enhance the wheeze, often causing it to be audible. (Keep in mind that a true bronchospasm wheeze cannot be heard sans stethoscope).
When Cardiac Asthma is treated as bronchospasm, all we are doing is putting adding more fluid to lungs that are already filled with fluid. What we need to do is give these patients diuretics to get rid of some of the fluid, or other cardiac drugs to increase the force and contractility of the heart to reduce pulmonary pressure.
Another good strategy worth trialing is CPAP or BiPAP, as the incrased airway pressure has been shown to reduce preload and afterload to reduce the work the heart has to do to pump blood through the body. This can reduce the feeling of air hunger until the medicines take effect.
Other than the heart, there are other diseases that can cause pulmonary edema and cardiac asthma, and these include pneumonia, exposure to toxins, and high altitudes. It is the job of the nurse, the respiratory therapist, and doctor to determine the true cause of the symptoms. It is the doctors job to properly diagnose and treat.
We'll consider this RT Cave rule #26: Cardiac Asthma should not be treated as asthma. Throat wheezes, upper airway wheezes, and dyspnea on exertion are signs of cardiac asthma, and a wise medical specialist will not confuse the two.