Stimulating oral and nasal chemoreceptors for preventing aspiration pneumonia in the elderly

Aspiration pneumonia remains a major cause of death in the elderly. However, fundamental and effective treatment has not been established yet. Onset of aspiration pneumonia is based on the presence of dysphagia, such as delayed triggering of the swallowing reflex. The swallowing reflex in the elderly is temperature sensitive, even if it is impaired. Swallowing reflex was delayed when the temperature of the food was close to body temperature. The actual swallowing time shortened when the temperature difference increases. The improvement of swallowing reflex by temperature stimuli could be mediated by the temperature-sensitive TRP channel. Administration of the TRPV1 agonists improves the delay of the swallowing reflex. Red wine polyphenols have been suggested to improve the swallowing reflex by increasing TRPV1 response. Food with menthol, an agonist of TRPM8 which is a cold temperature receptor, also decreased the delay in swallowing reflex. Olfactory stimuli, such as black pepper, can be a useful tool to improve swallowing reflex in people with lower ADL and consciousness levels. By combining these various sensory stimuli, we developed a protocol to start oral intake in patients with aspiration pneumonia This protocol shall continue to contribute to the ingestion of many older people.