Delirium in a Nursing Home Resident

We present a case of delirium in a nursing home resident who was ultimately determined to have suffered from a myocardial infarction. We review the diagnosis and mechanism of delirium. Atypical presentations of diseases commonly occur in the elderly population, and the underlying cause of delirium needs to be aggressively sought. Case Presentation Mrs. M is a 78-year-old female nursing home resident whose family was concerned that she was “not her usual self.” The nursing home staff had noticed episodic bouts of restlessness, agitation, and shortness of breath with spontaneous resolutions that began five days prior. Mrs. M’s past medical history was significant for stroke, bipolar disorder, cognitive impairment, chronic pain syndrome, osteoarthritis, and hypertension. Past surgeries included appendectomy and cesarian section. Her medications in the nursing home were valproic acid, lithium, acetaminophen with codeine, aspirin, and amlodipine and had not been changed recently. Her family history was significant for the unexpected death of a daughter two months earlier. She had no drug allergies and reported remote use of tobacco. Due to her osteoarthritis and chronic pain, she was mostly wheelchair-bound and required assistance with activities of daily living. Mrs. M’s only positive review of systems were feelings of sadness, decreased sleep, poor appetite, and increased urinary frequency. Assessment in the nursing home revealed an unremarkable physical exam with normal chest x-ray and laboratory test results (complete blood count [CBC], blood metabolic profile [BMP], urinalysis). A consulting psychiatrist initiated treatment with clonazepam. However, despite the clonazepam, the patient’s condition worsened, she became uncontrollable, and was sent to the Emergency Department. In the Emergency Department, she had a fluctuating level of consciousness consisting of lethargy with periods of agitation. Her vitals, including pulse oximetry, were normal. Mrs. M had bibasilar rales, with an otherwise unremarkable physical exam. A brain computed tomography scan showed no acute pathology, and CBC, BMP, serum lithium, and valproate levels were within range. Her chest x-ray revealed pulmonary vascular congestion and an electrocardiogram showed sinus rhythm and left bundle branch block (old), with slight upsloping of the ST segments. Cardiac enzymes revealed an elevated troponin of 3.9. Medical management for Mrs. M’s myocardial infarction was implemented including beta blockers, a statin, and aspirin. Her cardiac enzymes trended downwards and returned to normal. Mrs. M improved clinically with resolution of the delirium and her respiratory symptoms. A persantine thallium stress test study showed a large fixed inferior defect with no reversible features. Mrs. M was discharged back to nursing home after 2 weeks of hospitalization. The delirium resolved, but her baseline cognitive functioning had declined. She remained free of cardiac and respiratory symptoms with medical management of her coronary artery disease. Discussion Delirium Delirium is characterized by an acute change in cognition and a disturbance of consciousness, usually resulting from an underlying medical condition or from medication or drug withdrawal.¹ The term is derived from the Latin de lira, which means “off the path”² or “away from the furrow.” A standardized definition was not used until 1980 with publication of Diagnostic and Statistical Manual of Mental Disorders, third edition (DSM-III) and was updated in the DSM-IV (Table). Other terms that have been used include organic brain syndrome, metabolic encephelapathy, toxic psychosis, acute mental status change, exogenous psychosis, and sundowning. Delirium is a nonspecific manifestation of a widespread reduction in cerebral metabolism and derangement of neurotransmission. It is thought to be due to an imbalance among three neurotransmitters in the brain: acetylcholine, dopamine, and aminobutyric acid. Any disease process or medication that disrupts these neurotransmitters predisposes patients for delirium.³ Common causes include hypoxia, dehydration, acute brain injury, and the use of anticholinergic agents. Considerable morbidity and mortality have been associated with delirium. Patients with delirium have prolonged hospital stays, more medical complications, and higher rates of nursing home placement after hospitalization. Mortality is also higher in patients with delirium: The mortality rate among elderly hospitalized patients with delirium is estimated to range from 22% to 76%.⁴ Myocardial Infarction in the Elderly Atypical presentation of myocardial infarction is more common in elderly patients, with shortness of breath as the most frequent presentation.⁵ Furthermore, with increasing age, patients tend to exhibit more atypical presentations. In a prospective observational study of over 400,000 patients, 33% had no chest pain. Those without chest pain upon presentation to the hospital were, on average, seven years older than those with chest pain (74.2 vs 66.9 yr).⁶ Generally, frail elderly patients are more likely to have atypical disease presentation than well elderly (59% vs 25%; P 7 This case report demonstrates that atypical presentations of diseases should be considered in the elderly, especially in frail or institutionalized patients. Delirium is a common atypical presentation of disease and is prevalent across many clinical settings. It is imperative to determine the underlying cause of delirium and to treat accordingly. The authors report no relevant financial relationships.