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Monday, March 6, 2017

Here's what Albuterol really does, and does not do

Albuterol is the world's most abused medicine. Listed here are some of the medical conditions it is so often prescribed for in the hospital setting. This is followed by a pithy explanation of why it does or does not work for that particular diagnosis.

Asthma. Bronchial airways are chronically inflamed and hypersensitive (twitchy) to asthma triggers. Exposure to which causes an abnormal immune response that causes worsening airway inflammation. This irritates bronchial smooth muscles that spasm and constrict (bronchial constriction). This is responsive to bronchial dilators (beta adrenergic medicines) like Albuterol. This is because they are lined with beta 2 adrenergic receptors. Albuterol attaches to them and causes bronchial smooth muscles to relax, thereby opening airways and relieving asthma symptoms. This same type of bronchial constriction occurs with cystic fibrosis and in patients with chronic bronchitis, so it works for them too.

Pulmonary Edema. Heart failure. It causes an audible upper airway wheeze. It causes orthopnea. It causes severe dyspnea. It also causes increased intrathoracic pressure, and this squeezes airways, causing bronchoconstriction. This is not responsive to bronchodilators. Yet, because these patients wheeze and have dyspnea, the "feel good" solution here is to order a bunch of albuterol treatments, none of which do any good.

Pneumonia. I explained this in my post "Links between pneumonia and COPD."  I wrote, "It’s an infection of the air exchange units in your lungs, mainly the respiratory bronchioles and alveoli. An immune response causes this area to become inflamed. White blood cells (WBCs) are sent to the area of infection. The purpose of this response is to trap, kill, and remove the pathogens. As the disease progresses, the accumulation of WBCs cause pus to fill these areas, making them poor air exchange units. This means they become poor at allowing blood to cross into the bloodstream, resulting in a drop in blood oxygen levels."

A natural response to this by physicians is to order bronchodilators. However, unless a person has asthma, pneumonia does not cause bronchospasm. Bronchodilators are 0.5 microns, ideal for impacting bronchial walls. Terminal airways, respiratory airways, and alveoli are less than 0.2 microns, so bronchodilators don't even get that far. And, even if they did, there are not beta 2 adrenergic receptors there, so they do not good. Bronchodilators are not anti inflammatory medicines, and therefore are useless for pneumonia. However, despite this fact, a common criteria or admission to the hospital is three failed breathing treatments. This is a good criteria, considering (as you now know) albuterol is useless for pneumonia. The treatments will fail no matter how many you give because pneumonia is not bronchospasm.

Some doctors have sited studies showing albuterol increases sputum production as evidence it helps with pneumonia. However, what the hell does increased sputum production do with treating pneumonia? For more on this, check out Rick's post, "A World of Bronchodilator Lies." Also check out his post called, "Does Albuterol Treat Pneumonia?"

Emphysema. I explained this in my post "Bullous Emphysema." It's caused by the destruction of elastic tissue. This results in inflammation and breakdown of alveolar walls. Alveoli lose their elasticity, or ability to regain their normal shape after normal inhalation. "They eventually rupture, creating air spaces. Lacking elastic tissue, alveoli lose their ability to contract during exhalation. When the elastic tissue of enough alveoli are destroyed, these portions of the lungs expand all the way to the rib cage, giving the person the appearance of a barrel chest.  As the lungs are pulled outward, this causes bronchial airways to become stretched, thereby making them narrow (bronchial constriction). This causes increased resistance to air flowing through airways during both inspiration and expiration, slowing the flow of air. This is airway obstruction that does not respond to rescue medicine."

But we give bronchodilators to these patients anyway. However, despite this, most emphysema patients (a.k.a. pink puffers) claim they do not notice any difference afterwords.

Lung Cancer. Lung cancer takes up space in the lungs and prevents gas exchange from occurring. It results in wheezing and dyspnea. Albuterol is often given to these patients, but it will not make the cancer go away, and will not help these patients unless asthmatic bronchospasm is occurring, which is more than likely not the case unless there is also a diagnosis of asthma or chronic bronchitis.

Pleural Effuston. This is where you have excessive fluid buildup around the lungs. Because it can cause shortness of breath, the logical solution by physicians is to order Albuterol. However, albuterol does not suck fluid out of lungs, and therefore will not benefit this medical condition. It doesn't matter, because it will be ordered anyway.

Pneumothorax.  This is also called a collapsed lung. The belief among the medical community is that albuterol will re-inflate airways. The reality is that this is not going to happen. What is needed is a chest tube. The use of a chest tube in and of itself is often an indicator of the need for albuterol. However, Albuterol does not speed up time from chest tube insertion to complete recovery, at least not since the last time I checked.

Rickets. It is the softening of the bones in children. Albuterol will not help. However, and unfortunately already busy respiratory therapists, Albuterol will probably still be ordered for these patients.

Audible wheezes. If it's audible, it cannot be bronchospasm. It's audible because secretions are sitting on the vocal cords. This is very common when a person has pulmonary edema, such as what occurs in heart failure. What I say here makes sense, because true bronchospasm can only be heard by auscultation; it cannot be heard by the unaided ear. However, despite this fact, bronchodilators are so often prescribed for audible wheezes. I would go as far to say that about 80% of breathing treatments in the emergency room are for heart failure, which is the most common cause of audible wheezes. Another cause is dehydration, something that occurs in the aging and in ETOH and detox patients.

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