The Acutely Confused Elderly Patient

Patients presenting to the ED with an Altered Mental Status (AMS) require a thorough history and an extensive work-up leading to time consuming evaluation, talking with families and caregivers, reviewing old records, labs and radiologic studies. Even after an broad work up, occasionally a diagnosis is not reached. It becomes a challenge for emergency physicians to work with limited history and examination findings. Therefore, adopting an organized approach to the evaluation of mental status would result in increased clinician comfort while taking care of elderly, better ability to communicate with other physicians, and improved patient and family satisfaction. 

Why do we need to learn about this?

ED visits for elderly patients are predicted to increase in future and at least 1/4 of all ED patients over age 65 years have some form of AMS. As the first responders, we need to be comfortable while evaluating the patients. 

What causes this acute confusional state?

A normal level of consciousness depends on an intact reticular activating system, cerebral cortex, and communication between the two. Various pathologies may disrupt optimal cortical functioning and result in confusion and the pathophysiology is not straightforward to understand. Widespread cortical dysfunction may result from substrate deficit, neurotransmitter dysfunction, or circulatory dysfunction. The magnitude of problem also depends on the reserve of central nervous system (CNS) function which varies from individual to individual; people with a pre-existing impairment may become confused after even minor changes in their normal state.

Delirium 

Delirium is an acute, fluctuating change in cognition, accompanied by impaired attention and consciousness. At times patient may be awake and distracted, then progress to a hyperalert state, and later may be lethargic. The mortality associated with delirium changes depending on whether or not the diagnosis is made in the ED (or in hospital). Although many patients recover fully, but they are prone have an increased likelihood of persistent cognitive deficits. 

Diagnosis of delirium

Delirium can present with:

1. Hypoactive i.e. lethargic
2. Hyperactive i.e. hyperalert
3. Mixed i.e. alterations between hyperactive and hypoactive.
4. Normal psychomotor activity

Delirium occurs abruptly and is usually apparent within hours to days of onset. Patients may have a prodrome of restlessness, impaired attention, and sleep disturbance that can last several days before the onset of frank delirium. It is this criterion that differentiates delirium from dementia.

Other symptoms of delirium 

• Altered sleep–wake patterns (daytime drowsiness and nighttime agitation and disorientation i.e. sundowning)
• Nonfocal neurologic deficits may occur, such as speech and language deficits (dysarthria, dysnomia, dysgraphia, or aphasia).
• Asterixis is associated with hepatic, renal disease or hypercarbia.
• Nystagmus and cerebellar abnormalities may suggest alcohol or drug intoxication.
• Pupillary abnormalities also can suggest drug intoxication (eg, miosis with narcotics).
• Alcohol or sedative–hypnotic withdrawal is associated with coarse tremors, tachycardia, and low-grade fever.
• Anticholinergic toxidrome (dry mouth, urinary retention, tachycardia, fever).

Differentiating Delirium from Dementia

Both delirium and dementia may cause impaired cognition. The key is finding out the onset of the symptoms; in delirium the symptoms are acute, whereas in dementia the onset is longer and more subtle. Determination of a single etiology causing delirium may be difficult, and often more than one etiology contributes to the delirium. Also remember that demented patients may presented with acute delirium with a long standing underlying dementia. 

Another possible cause for patients presenting with delirium includes primary psychiatric disorders, such as acute psychosis. This diagnosis, however, should be made only in patients without a prior history of psychiatric disease after extensive evaluation, rather than in the ED.

Etiology

Delirium is a manifestation of various medical disorders of cerebral metabolism or neurotransmission, and as such the etiologies are broad. 

1. Primary intracranial disease


• Cerebrovascular Accident

• Acute or Chronic Subdural hepatoma 
• Encephalitis
/ Meningitis

• Seizures (Convulsive or Non-Convulsive)
• Postictal state 
• Neoplasm
• Raised ICP

2. Systemic diseases secondarily affecting the central nervous system

• Hypertensive encephalopathy
• Infections (Pneumonia
/ UTIs/ Skin and soft tissue infections)
• Cardiopulmonary disorders (Acute myocardial infarction, CCF, Arrhythmia, Cardiogenic shock, 
Acute or chronic respiratory failure)
• Uremia
• Hepatic encephalopathy

• Fluid or electrolyte abnormalities (Dehydration. Hyper/HypoNa, Hypo/Hyperglycemia
, Hyper/HypoCa)
• Nutritional (Severe Anemia)
• Thyroid/Adrenal Disorders
• Paraneoplastic Syndromes

3. Exogenous toxins and Drug withdrawal

• Anticholinergic medications - Antihistamines, 
Antiemetics, 
Antiparkinsonian medications 
• Antispasmodics (gastrointestinal) Alcohol
• Sedative–hypnotics

Common etiologies in elderly patients include infections, medications, and primary CNS disorders. Focus of an infection can be urine, respiratory tract, intrabdominal pathology, skin and soft tissues or CNS. If they look unwell, administer broad spectrum antibiotics and obtain relevant cultures. 

Don’t miss on the drug history including over the counter medications. The most common category of medications to cause delirium is drugs with anticholinergic properties: antihistamines, antiemetics, antipsychotics, antiparkinsonian drugs, antidepressants, gastrointestinal antispasmodics and fentanyl patches. It is imperative to review the side-effect profile of any new medication and to assume that a new medication as culprit if alternative explanations are not available.

What kind of work up do they need in the ED?

The workup of an older patient who has delirium can be extensive unless a clear cause is determined from the history and physical examination. This may be difficult and frustrating, if a history from a surrogate is not available and the patient is unable to cooperate with the examination. The mortality associated with delirium is high, especially if unrecognized. 

• CBC (infections are a common cause of delirium in elderly and they may present without fever or leukocytosis!
• Electrolytes (Hypo/HyperNa, Hyper/HypoCa)
• BUN, Creatinine (Uremia)
• Glucose (Hypoglycemia)
• EKG (ACS may present with confusion in elderly)
• Pulse Oximetry (Hypoxia)
• ABG (Hypercarbia, Hypoxia)
• CXR (Pneumonia, CHF)
• UA (UTI)
• CT Head/LP (Stroke, Meningitis)
• Serum Ammonia (if they have a h/o liver issues)
• Urine Dug Screen
• Thyroid Function
• Bedside USG (Look for urinary retention, cardiac function, consolidation)

The yield use of computed tomography (CT) of the brain in patients who have delirium is not great unless you have focal new neurological findings.

Role of Family and Caregivers

It is pivotal to understand the family’s position and perspective here, as they are the ones who take care of the patient. Avoid medical jargon when explaining the prognosis, be realistic about the outcome and arrange support for them if needed. Also get a sense of a patient’s baseline status before you begin your evaluation. Live-in family may be able to provide a clearer history of the duration of symptoms than others who haven’t seen the patient for long. In nursing home patients, it is helpful to contact the nurse who sent the patient to fill in the gaps in the history.

Determinations of the level of consciousness can be made by simple observation of the patient during routine history and examination. A thorough history including, dietary habits, symptoms of thyroid disease, alcohol, medications etc. goes a long way.

Emergency Management of an Acutely Confused Patient

Treatment of delirium usually is directed at the underlying cause of the delirium. Identify and treat the life threatening causes such as STEMI, Seizures, Hypoxia quickly. If a cause is not identified in the ED, then admit them and do the additional work up. Minimise environmental interventions, such as turning off the lights, bringing families to the bed-side. Avoid physical restraints if possible as they increase the patient’s agitation and the severity of the delirium. 
They might require some fluids, antibiotics and other medications to allay the agitation. 

Haloperidol is recommended most frequently in low doses i.e. 0.5 to 1.0 mg orally, IM, or IV to control the agitation (Repeat every 30 minutes until the desired effect is achieved). Other options include risperidone or olanzapine. Use benzodiazepines only for specific conditions, like alcohol or sedative hypnotic withdrawal or seizures. Beware of paradoxic CNS reactions that may worsen the patient’s condition.

Disposition

Older ED patients should be admitted to the hospital for evaluation unless there is a single, clear, and reversible etiology of the delirium, such as intoxication from a short-acting medication. 

Take Home:

• When evaluating delirium, do a through history and physical and ask for medications and also over the counter prescriptions.
• Identify and treat life threats first.
• Do not underestimate the role of family or nursing home staff who can better detect a change in the patient’s cognition. Be extremely sensitive while dealing with the family.

Author:

              

     Lakshay Chanana
     
     Speciality Doctor
     Northwick Park Hospital
     Department of Emergency Medicine
     England

     @EMDidactic