Delirium resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Pratik Bahekar, MBBS [2]

Overview

It is commonly associated with a disturbance of consciousness (e.g., reduced clarity of awareness of the environment). The change in cognition (memory deficit, disorientation, language disturbance) or the development of a perceptual disturbance, must be one that is not better accounted by a preexisting, established, or evolving dementia. Usually the rapidly fluctuating time course of delirium is used to help in the latter distinction.

Distressing symptoms of delirium are sometimes treated with antipsychotic, preferably those with minimal anticholinergic activity, such as haloperidol or risperidone, or else with benzodiazepine, which decrease the anxiety felt by a person who may also be disoriented, and has difficulty completing tasks. However, since these drug treatments do not address the underlying cause of delirium, and may mask changes in delirium which themselves may be helpful in assessing the patient's underlying changes in health, their use is difficult. Because delirium is a mere symptom of another problem that may be very subtle, the wisdom of treatment of the delirious patient with drugs must overcome natural skepticism, and requires a high degree of skill.

Definition

Delirium is an acute and relatively sudden (developing over hours to days), fluctuating decline in attention-focus, perception, and cognition.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Acute liver failure
• Acute renal failure
• Adrenal cortex insufficiency
• Brain infection
• Burns
• Carbon monoxide toxicity
• Cardiac failure
• Cerebral oedema
• Cerebrovascular accident
• Cyanide
• Diabetic ketoacidosis

• Drug overdose
• Drug withdrawal e.g. ethanol, benzodiazepines
• Epileptic seizures
• Head injury
• Heart failure
• Hypertensive encephalopathy
• Hypoglycemia
• Hypoxemia
• Raised intracranial pressure
• Sepsis
• Systemic organ failure
• Wernicke's encephalopathy

Common Causes

• Antihistamines
• Antipsychotics
• Chronic liver failure
• Chronic renal failure
• Folate deficiency

• Hyperthyroidism
• systemic inflammatory response syndrome
• Schizoaffective disorder
• Thiamine (Vitamin B1) deficiency
• Vitamin B12 deficiency

Management

Diagnosis

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Investigations

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Primary Prevention,

Characterize the symptoms: ❑ Impairment of sleep awake cycle ❑ Change in psychomotor activity ❑ Sensation of tightness, pressure, or squeezing ❑ Emotional disturbances with rapid and unpredictable shifts from one emotional state to another: anxiety, fear, depression,irritability, anger, euphoria, and apathy ❑ Nonspecific neurological abnormalities: tremor, myoclonus, asterixis, and reflex and muscle tone changes

Obtain detailed history: ❑ Collateral history from relatives, out patient care providers, case managers etc. is crucial in confused mental states. ❑ Baseline blood pressure ❑ Previous medical history including psychiatric diagnosis ❑ List of medications offending drugs (sedative, hypnotics, narcotics, anticholinergic drugs, corticosteroids, polypharmacy, withdrawal of alcohol or other drugs) Identify if patient is at high risk to develop delirium: ❑ Unnderlying cognitive impairment ❑ Older age (>65 years) ❑ History of delirium, stroke, neurological disease, falls or gait disorder ❑ Associating multiple medical aliments ❑ Male gender ❑ Sensory impairment (hearing or vision) ❑ Immobilization (catheters or restraints) ❑ Acute neurological pathology (for example, acute stroke [usually right parietal], intracranial hemorrhage, meningitis, enkephalitis) ❑ Intercurrent illness (for example, infections, iatrogenic complications, severe acute illness, anemia, dehydration, poor nutritional status, fracture or trauma, HIV infection) ❑ Metabolic impairment ❑ Surgery ❑ Stressful surroundings (for example, admission to an intensive care unit) ❑ Pain ❑ Emotional stress ❑ Lack of sleep

Diagnosis is made by DSM V criteria or CAM-ICU scale ❑ DSM V Diagnostic Criteria Diminished focus or concentration and lack of knowledge or perception of the surroundings Developing in a brief period of time accounting to hours to days, a shift from a baseline which change in severity in it’s course Also, interference in faculties of cognition like, memory, orientation, visuospatial ability, or language 1st and 3rd criteria are not a result of any previous, current, or developing neurocognitive disorder and is not related to a shift in arousal status e.g. coma The manifestation of the disturbances resulting as a, Physiological sequel of a medical condition Intoxication or Withdrawal of substance(s)/ medicine(s)/ toxin(s) Is due to multiple etiologies As explained by the history, physical examination, or laboratory findings Specify if, Substance intoxication delirium Substance withdrawal delirium Delirium caused by another medical condition Delirium caused by multiple etiologies Specify if delirium is, Acute Persistent Specify if delirium is, Hyperactive Hypoactive Mixed level of activity Or, ❑ Confusion Assessment Method for the ICU (CAM-ICU) Diagnostic Criteria Diagnosed if, feature 1 and 2 are present along with 3 or 4 Onset of symptoms, is acute(change from baseline) or fluctuating as calibrated by Richmond Agitation Sedation Scale or Glasgow Coma Scale Inability to focus as measured by Attention Screening Examination Thinking is not organized Altered level of consciousness if Vigilant, Lethargic, Stupor, Coma

If delirium is diagnosed, do focused examination to find out underlying etiology: Vital signs ❑ Blood pressure ❑ If lower than baseline: Shock, drug overdose e.g. opiates ❑ If higher than baseline: Increased intracranial pressure, drug overdose e.g. cocaine, hypertensive crisis Pulse ❑ Tachycardia:Shock, drug overdose eg. cocaine ❑ Bradycardia:Increased intracranial pressure Respiratory rate ❑ If lower: drug overdose e.g. opiates ❑ If higher: Pulmonary pathology like pneumonia, asthma, COPD Raised temperature ❑ Suspect cholinergic drug overdose ❑ Underlying infection Skin ❑ Jaundice: Liver and biliary pathology ❑ Cherry red appearance: CO poisoning ❑ Edema: Heart failure, liver failure, renal failure, malnutrition ❑ Cyanosis:Heart failure, lung pathology, drug overdose ❑ Needle marks: drug overdose Appearance ❑ Cherry red tongue, lip fissure etc suggestive of malnutrition ❑ Unkempt and unhyginic: Scrizophrenia Nurological examination ❑ Emergence of new focal neurological signs: Cerebrovascular event ❑ Trauma to head: hemorrhage and increased intracranial pressure ❑ Meningeal signs: Meningitis ❑ Neurodegenerative diseases: parkinsonism, alzhimers etc. ❑ Mental status examination: Dementia Cardiovascular examination ❑ New onset murmur: myocardial infarction ❑ S3 and S4: Heart failure ❑ Murmur: underlying shunts and cardiac valve pathology Pulmonary examination ❑ Basal rales: Suggestive of congestive heart failure ❑ Wheeze may be because of asthma or COPD ❑ Increased tactile vocal fermitus, egophony and dull on percussion may indicate underlying pneumonia Abdominal examination ❑ Ascitis: Liver failure, heart failure, kidney failure ❑ Organomegaly: Liver failure, portal hypertension, hepatic encephalopathy ❑ Distended bladder: urinary obstruction leading urinary track infection.

If delirium is not diagnosed, ❑ Re-access patient multiple times a day, diagnosis of delirium may be missed because of it's fluctuating course ❑ Consider following differential diagnosis, Psychiatric illness: Psychotic disorders like, brief psychotic disorder, schizophrenia, schizophreniform disorder, bipolar etc. Acute stress disorder Malingering and factitious disorder Confusional states Other neurocognitive disorders. Neurological Disorders: Frontal lobe disorders such as tumor Cerebral contusion Bacterial Meningitis Parital lobe disorders like Wernicke's aphasia Nonconvulsive epileptic episodes Hepatic encephalopathy Sundowning Viral encephalitis

Do's

Dont's

References

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