Cough in the elderly: a novel strategy for preventing aspiration pneumonia.

Management of cough in the elderly with a deteriorated physical and mental status has received little focus. Since an aged population is rapidly increasing in developed countries, the research in this population are warranted. Cough reflex sensitivity in the elderly was shown to be hypersensitive, normosensitive and hyposensitive. The hypersensitive cough reflex is mostly due to gastro-esophageal reflux in nursing home patients. Impaired cough reflex sensitivity is assumed to play a crucial role in the development of pneumonia in the elderly. A marked depression of cough reflex sensitivity is reported in elderly patients with aspiration pneumonia. The impairment of the cough reflex in patients with aspiration pneumonia can involve both cortical facilitatory pathways for cough and medullary reflex pathways. We found the urge-to-cough in patients with aspiration pneumonia was also down-regulated, suggesting the involvement of supramedullary dysfunction in the etiology of aspiration pneumonia in the elderly. In order to prevent aspiration pneumonia in the elderly, restoration of cough reflex sensitivity is essential. We found several methods to restore cough reflex sensitivity in the elderly. They also improved the swallowing reflex, another important airway protective reflex, in the elderly. In the treatment of aspiration pneumonia, one of the most challenging steps is the start of eating for patients who usually fast at the time of hospitalization. By combining the methods to restore the cough reflex sensitivity and swallowing reflex, we developed a protocol to start eating in the elderly patients with aspiration pneumonia. Using the protocol, we reduced the incidence of re-aspiration due to start of eating in patients with aspiration pneumonia to one third of the patients without the protocol.