Researchers Explore Connection Between Oral Health and Stroke-Associated Pneumonia

When a patient dies after surviving the acute phase of stroke, stroke-associated pneumonia is often cited as the cause. In fact, pneumonia is thought to be a primary reason for poor outcomes overall, including expanded lengths of hospital stays and attendant costs.

Numerous studies indicate that microaspiration, which involves the inhalation of small amounts of oropharyngeal or gastric contents from reflux—along with any oral bacteria that is present—is a major risk factor for pneumonia overall. Patients experiencing dysphagia (difficulty swallowing), a common stroke-related condition, are at an increased risk for this. Other risk factors include weakened buccal musculature, oral stereognosis, hypotonic lip musculature, and oral apraxia. All of these may lead to oral hygiene issues. The link between poor oral hygiene and aspiration pneumonia is well supported.

INVESTINGATING THE LINK

A recently published observational study investigated the connection between oral health, oral microbiota, neurological and immunological factors, and the incidence of pneumonia in 99 patients admitted to the stroke unit, at the Department of Neurology, Bezirksklinikum Regensburg & University of Regensburg, Regensburg, Germany.¹

Data were collected over 5 months at three different points in time: within 24 hours of admission (baseline); and 48 and 120 hours after the baseline collection. The baseline investigation involved dental exams; collection of demographic, neurological, and immunological data; and the collection and analysis of microbiological samples involving saliva and subgingival plaque. Subsequent time points continued the collection of immunological data and microbiological samples.

Out of the 99 patients included in the study, 57 were diagnosed with stroke and 42 were “stroke mimics,” or patients with stroke-like symptoms not actually diagnosed with stroke. Eight of the 57 patients developed pneumonia. Researchers report that factors such as higher age, greater severity of stroke, embolectomy, nasogastric tube, and higher baseline C-reactive protein also appeared to strongly factor into stroke-associated pneumonia.

SUGGESTIVE RESULTS

Though the study revealed no significant differences between groups regarding numbers of decayed teeth, root remnants, and restored teeth, results do however suggest that patients with missing teeth—probably indicative of periodontal diseases—and whose oral hygiene was poor tended to have a higher incidence of pneumonia. In fact, while there appeared to be no relevant differences in microbial composition between groups, a certain number of bacterial species within the genera Neisseria, Porphyromonas, and Prevotella could be associated with pneumonia patients.

Although studies have shown that poor oral health in stroke survivors can elevate the potential for aspiration pneumonia, there is also evidence that with improved oral care in stroke patients, the risk of this type of pneumonia is reduced. So, while the researchers suggest the undertaking of further investigations with larger patient cohorts, they also encourage the implementation of oral hygiene programs in stroke units, which may be beneficial in limiting incidence of stroke-associated pneumonia.

REFERENCE

1. Cieplik F, Wiedenhofer AM, Pietsch V, et al. Oral health, oral microbiota, and incidence of stroke-associated pneumonia—a prospective observational study. Front Neurol. 2020;11:528056.