Asthma

Medical Meanderings 5 July 2006

Oxygen Addiction

I can feel you breathe / Just breathe… - Faith Hill, “Breathe”
Would somebody help me breathe? - Nickelback, “Breathe”
Everything is alright / if I just breathe… - Michelle Branch, “Breathe”
So cradle your head in your hands / And breathe, just breathe… - Anna Nalick, “Breathe”

Evidently, breathing is important to musicians. (Wonder why so many of them smoke?) While you read this article, I dare you to hold your breath and to find out it’s pretty important to you, too. Politicians are worried about our national addiction to oil, but what we’re really addicted to, as a species, is oxygen.

What does oxygen do for us? On a molecular level, oxygen is the molecule that is “the final electron acceptor at the end of our mitochondrial electron transport chain”. What?! Said more simply, we have to have oxygen for our cells and tissues to manufacture energy to keep all of our life processes going, from brain cell firing to toenail growing.

Oxygen is transported to our tissues in the blood, mostly attached to hemoglobin in our red blood cells. Hemoglobin has a crispy protein shell with a chewy iron center. (Hemoglobin is dark bluish red without oxygen, and a bright red with it.) The trick of hemoglobin is to be “sticky” to oxygen in the lungs, but not so “sticky” that it won’t let oxygen free in the tissues that need it. (Still holding your breath?)

Our red blood cells pick up oxygen (and drop of waste carbon dioxide) in the lungs, which do an efficient job of drawing in air through increasingly narrow pipes to tiny microscopic air sacs called “alveoli”. The alveoli sit at the end of the air pipes like grapes in a bunch. If the air pipes plug up (as in bronchitis and asthma) or spasm (as in asthma), it’s called “obstructive” lung disease, because as the person tries to exhale, the airways collapse and airflow out is blocked.

Asthma is a common and complicated problem caused by both inflammation (swelling and mucus production) and spasm of the air passages in the lungs. It is a disease partly caused by genetic (hereditary) factors that cause an over-active immune system and by outside factors that cause inflammation of our airway tissues. The narrowed airways cause wheezing and coughing, especially at night. The feeling of an asthma attack is like breathing through a tiny coffee stirrer; or like taking a breath in, only exhaling half of it, then trying to take another breath.

The airway spasm of asthma is treated with “bronchodilators” like albuterol (fast-acting but short-lasting) or salmeterol (slow-acting but long-lasting), which stimulate the muscle cells of the air tubes to relax and open. The inflammation of asthma is treated with steroid inhalers (all slow-acting and long-lasting) like fluticasone, which turn off the immune system’s attack on the airways. Asthmatics are also helped by avoiding “triggers” for their asthma such as cigarette smoke, cats, cold weather, exercise or strong emotion.

The American Lung Association’s motto is “when you can’t breathe, nothing else matters,” and they’re right. If you’ve held your breath while reading this, you know how right they are. Okay, you can breathe now.