Your Best Friend During a Respiratory Tract Infection
This is the time of year that we celebrate the traditional Holiday season. Unfortunately, this is also the beginning of the high season for respiratory tract infections that include influenza (the flu), nasopharyngitis, (the common cold), sinusitis, and bronchitis (lung infection). These illnesses can certainly dampen the Holiday spirit and interfere with associated celebrations.
Our best friend during these illnesses is respiratory mucus.
The respiratory system, the nose, throat, sinuses, and lungs, are lined with a thin sheet of tissue called a membrane. This membrane acts a partition/barrier that protects the underlying structures from harmful external agents. The largest organ in the body, the skin, functions in a similar manner. This membrane contains glands that manufacture and secrete a substance known as mucus. Mucus is a gel-like material that, under normal circumstances, is constantly produced in small amounts that is not noticeable (about 4 cups/day). Thus, the lining of the respiratory tract is called a mucous membrane. The mucus that it produces has lubricating and protective properties that keeps the lining of the respiratory tract moist and acts as a defense against noxious environmental agents such as smoke, pollen, and microorganisms (bacteria and viruses). If inhaled, particles from these agents are trapped in the mucus and expelled by nose-blowing, sneezing, and coughing. Swallowing not only eliminates saliva but also mucus produced in the upper respiratory tract that accumulates in the throat.
The mucus membrane also contains millions of hair-like microscopic structures, called cilia, that vibrate in a rhythmic waving or beating motion to propel mucus out of the respiratory tract. These cilia are most important in the lung’s bronchial tubes because they move foreign material up and out of the airways. They are very effective in removing mucus that is thin and not viscous (thick and sticky).
When respiratory tract infections occur, mucus production increases as a major defense mechanism against these bugs which become trapped in the mucus. During an infection, the mucous thickens due to the accumulation of the immune system’s white blood cells in the mucus that trap and kill the invading organisms. To overcome the infection, this infected mucus must be expelled from the structures of the respiratory tract. If it remains stagnant, the bacteria or viruses that caused the infection can continue to proliferate despite the efforts of the white blood cells to engulf and kill them. The immobilized stuck mucus obstructs airflow through the nose and lungs and tends to dry out the mucous membrane. The cilia’s ability to remove this mucous is also compromised. It is well known that a viral respiratory infection increases a person’s susceptibility to a ‘super infection’ with a bacterium. A patient may be recovering from a viral illness and then suddenly worsen because of this bacterial invasion. This is more likely to occur if mucus is not cleared during the acute viral illness.
Our immune system fights the infection by increasing mucus production and this causes the aggravating symptoms of excessive nasal drainage and cough. Additionally, the immune response increases blood flow to the respiratory tract resulting in swelling of the mucus membrane and congestion in the nose, sinuses and chest. These symptoms are aggravating to ill patients and to alleviate the misery, they turn to one of the many OTC products that are advertised as treatment for colds and the flu.
These medications can provide relief from the congestion and drainage but can actually prolong the illness by drying the mucous membrane and the mucus. The invading bugs enjoy this environment as do environmental bacteria that are waiting to ‘join the party’. This drying effect is particularly problematic if there is mucus in the chest. Cough will be ineffective in expelling the mucus and when the mucus gets thick and tenacious, mucus plugs can form and obstruct the bronchial tubes.
So, which cold preparations should you avoid? The answer is ALL OF THEM! They all contain antihistamines and decongestants, both of which are very drying. Examples of those that are inappropriately and commonly used include: Nyquil, Dayquil, and Advil PM. Be aware that almost all OTC sleep aids contain antihistamines.
Patients who take antihistamines for allergies should discontinue these until the infection resolves.
To liquefy the mucus, hydration is very important. This thins mucus so that it is more easily expectorated. What about grandma’s chicken soup? It is likely effective because the warm, salty broth is a very effective mucus hydrating agent.
The only OTC product that is helpful is guaifenesin. One effective brand is plain Mucinex tablets. If cough is interfering with sleep, dextromethorphan can help (Mucinex DM). Drugs that are effective in treating fever, headache, and other aches and pains are acetaminophen (Tylenol) and ibuprofen (Advil).
Remember, during a respiratory tract infection, mucus causes aggravating symptoms but allowing it to work and then expectorating it is the ticket to recovering from the infection.
Dr. Tippett is the founder of Comprehensive Quality Healthcare Providers, a concierge internal medicine practice, located at 1210 Commerce Dr. Suite 106 Greensboro, Ga. 30642. He can be reached at 706-510-3659. Visit his webpage at www.drtippett.com