Elderly
Aging increases the risk of dysphagia. The prevalence of dysphagia in nursing homes is approximately 50%, and 30% of the elderly with dysphagia develop aspiration. For individuals older than 75, the risk of pneumonia due to dysphagia, is six times greater than those 65. Owing to multiple factors, such as frailty, impaired efficacy of swallowing, decreased cough reflex and neurological complications, dysphagia can be considered as a geriatric syndrome. Atypical presentation is common in the elderly. Older patients may have impaired T cell function and hence, they may be unable to mount a febrile response. The mucociliary clearance of older people is also impaired, resulting in diminished sputum production and cough. Therefore, they can present non-specifically with different geriatric syndromes. Microaspirations
In the elderly, dysphagia is a significant risk factor for the development of aspiration pneumonia. Aspiration pneumonia most often develops due to micro-aspiration of saliva, or bacteria carried on food and liquids, in combination with impaired host immune function. Chronic inflammation of the lungs is a key feature in aspiration pneumonia in elderly nursing home residents and presents as a sporadic fever (one day per week for several months). Radiological review shows chronic inflammation in the consolidated lung tissue, linking chronic micro-aspiration and chronic lung inflammation. Choking
After falls, choking on food presents as the second highest cause of preventable death in aged care. Although food choking risk is commonly associated with young children, data shows that individuals over 65 years of age have a choking incidence that is seven times higher than children aged 1–4 years.
Depending on the composition of the aspirate, three complications have been described:
Chemical pneumonitis may develop whose severity depends on the pH value and quantity of aspirate. The two lung changes after acid aspiration are:  a) direct toxic damage to the respiratory epithelium resulting in interstitial pulmonary edema and b) a few hours later, inflammatory response with production of cytokines, neutrophil infiltration, and macrophage activation. Oxygen-free radicals are generated which, in turn, lead to further lung damage. Patients may remain asymptomatic after acid aspiration. Others may develop dyspnea, pleuritic chest pain, cough, fever, bloody or frothy sputum, and respiratory failure. Aspiration pneumonia may develop. The third complication occurs after inhalation of particulate matter that obstructs airways. The patients will have sudden arterial hypoxemia with development of lung atelectasis. Location
The location is often gravity dependent, and depends on the persons position. Generally, the right middle and lower lung lobes are the most common sites affected, due to the larger caliber and more vertical orientation of the right mainstem bronchus. People who aspirate while standing can have bilateral lower lung lobe infiltrates. The right upper lobe is a common area of consolidation, where liquids accumulate in a particular region of the lung, in alcoholics who aspirate in the supine position. Diagnosis
Evaluation of aspiration is generally performed with a video fluoroscopic swallowing study involving radiologic evaluation of the swallowing mechanism via challenges with liquid and solid food consistencies.