How Does Oral Care Prevent Aspiration Pneumonia?

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Answer

Aspiration, in and of itself, does not necessarily lead to pneumonia. Laryngeal aspiration only suggests that the larynx, as a valve, is inefficient in preventing secretions and food from entering the lower respiratory system. Laryngeal aspiration does not always mean tracheobronchial aspiration also occurs. Pneumonia from aspiration is the result of ingestion of a very large load of bacteria into the lower respiratory system where the infestation overwhelms the weakened immune system protection. Why would this happen and why don't all dysphagic patients develop pneumonia? First, for a patient to develop pneumonia from aspiration, he/she must be significantly ill-CVA, surgery, heart attack, etc. Any severe illness causes a stress response (via the hypothalamus) in the sick patient which lowers the body's immune system's ability to fight off bacteria. Pneumonia does not occur by itself; it occurs as a result of the serious illness and usually 3 to 7 days after the medical event.

Secondly, there has been much controversy about the source of the bacteria in dysphagic patients developing pneumonia. Some have said the mouth; others the stomach. But there is more than ample research, good research mainly in the dental literature, that documents the increase in gram-negative (anaerobic) bacteria in the oral cavity following the onset of a serious illness. What has been found is that the stress response (mediated by the hypothalamus) causes, among other responses, a decrease or cessation of saliva and oral mucous secretion in the oral cavity. One role of saliva and mucous is to fight bacteria through their immune properties. When they decrease their oral functions, this allows bacteria- already (and always) in the oral cavity-to multiply. Thus, more bacteria per cubic centimeter that normal, or increased bacterial load per aspiration.

Oral care has long been suspected as helping to keep the bacteria in the mouth at bay in sick people, but only recently have more research studies been published. The Japanese are producing a large volume of studies in this area. In fact, one study reported significant results in reducing aspiration-induced pneumonia when professional dental hygienists came to nursing facilities on a regular basis. There are also some nice studies in the critical care nursing areas (Garp et al) who have shown that the incidence of ventilator-dependent pneumonia is drastically decreased with aggressive oral care in intensive care patients.

Are there protocols, per se? Not standardized. Brushing once to three times per day has been shown to be effective. Intensive care nursing is now using toothbrushes with suction tubes attached to catch secretions while brushing and to help prevent dislodging and swallowing of bacteria by patients. The results have been very good. Some other findings have been that the green sponges often used in oral care are essentially worthless and may do more harm than good. Likewise, lemon-glycerine swabs. The glycerine swabs alone appear to moisten the mouth and do not clean it, but the lemon additive may, in fact, act to dry out the mucosa of the mouth-the opposite of what is desired.

In a nutshell, clean the mouth to prevent bacteria over-development in seriously ill patients, do it regularly and well, and prevent potential pneumonia from bacterial aspiration.

John R. Ashford, Ph.D., CCC-SP is a Professor at Tennessee State University and holds an Assistant Clinical Professorship at the Vanderbilt University School of Medicine. He retired from the VA Tennessee Valley Health Care System in 2005 after 28 years as a clinical Speech-Language Pathologist. He chaired the VA Best Practices in Dysphagia Treatment Taskforce. He is published and has presented nationally in the areas of dysphagia, voice disorders and evidence based practice. Dr. Ashford is the President-Elect of the Tennessee Association of Audiologists and Speech-Language Pathologists.