I am often surprised to learn that terms and concepts I use on a regular basis are different than
I thought. A common term that I have misunderstood for many years is “aspiration pneumonia.”
Recent reading has led me to a new understanding of this term.
I have found there is no uniform definition or gold standard test for “aspiration pneumonia.”
The pathophysiology of both aspiration pneumonia and other pneumonias is identical. That is,
micro-organisms colonize the oropharynx and nasopharynx and are either micro or macro aspirated.¹
The reality is that most common consequence of aspiration is no consequence. DiBardino goes as far as to state that aspiration may lie within the spectrum of normal physiology.² Butler added credence to this idea when 18% of her research subjects, a large cohort of normal healthy adults, aspirated.³
A host of literature, primarily focused on elderly stroke survivors and nursing home residents, associates documented dysphagia with pneumonia. However, the data generated in these studies does not discriminate between aspiration pneumonia and traditional community acquired pneumonia.² Standard thought has been that the lower respiratory tract is sterile below the larynx so that specimens collected in such a way as to avoid contaminants from above that level (via aspiration) define pathology. However, more recent studies using culture-independent techniques have shown that there is a respiratory tract microbiome that extends from the nasal passages to the alveoli.
Based on a review of ICD-9 coding patterns, DiBardiono reports “aspiration pneumonia” is the second most common diagnosis given to hospitalized Medicare patients. He proposes the reason may be a higher reimbursement rate for this diagnosis.²
In this journey, I found another jewel comparing three dysphagia interventions. All participants had imaging to verify their dysphagia. All of them aspirated. The cohort was divided into three groups: Group 1 - Patient selected their own diet and had one educational session concerning compensatory strategies. Group 2 - Therapists prescribed a diet and provided an educational session concerning compensatory strategies. Group 3 - Therapists prescribed a diet and joined patients at meal times enforcing adherence and use of compensatory strategies. There was no statistically significant difference in the outcomes of the three groups.4
Perhaps the takeaway for us is that the term “aspiration pneumonia” is not so scary, considering there is not a consistent definition. Good oral care may prevent recurrent episodes of pneumonia more than altering diets.¹ If Speech and Lanuage Pathologists shifted the goal of dysphagia therapy away from a focus on aspiration to a focus on positive nutrition and hydration, both the value of our professional services and patient quality of life could be increased.
References:
1. Ferguson, J., Ravert, B., Gailey, M. Aspiration: /asp’rāSH()n/: Noun: An ambiguous term used for a diagnosis of uncertainty. Clinical Pulmonary Medicine 25(5), 177-183, 2018
2. DiBardino, D. M., & Wunderink, R. G. Aspiration pneumonia: a review of modern trends. J Crit Care, 30(1), 40-48, 2015
3. Butler, S. G., Stuart, A., Markley, L., Feng, X., & Kritchevsky, S. B. Aspiration as a function of age, sex, liquid type, bolus volume, and bolus delivery across the healthy adult life span. Ann Otol Rhinol Laryngol, 127(1), 21-32, 2018
4. DePippo, K. L., Holas, M. A., Reding, M. J., Mandel, F. S., & Lesser, M. L. (1994). Dysphagia therapy following stroke: a controlled trial. Neurology, 44(9), 1655-1660, 1994