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

Delirium is an acute (developing over hours to days), fluctuating decline in attention-focus, perception, and cognition. 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. The differentiation of delirium from dementia is based upon the rapidly fluctuating time course of delirium.

Distressing symptoms of delirium are sometimes treated with an antipsychotic, preferably those with minimal anticholinergic activity, such as haloperidol or risperidone, or with a benzodiazepine, which decrease the anxiety felt by a person who may also be disoriented, and may have 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), they should be used judiciously.

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

Characterize the symptoms: ❑ Impairment of sleep awake cycle ❑ Change in psychomotor activity ❑ 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, narcotic, anticholinergic, corticosteroid, 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, encephalitis) ❑ 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, 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. opiate ❑ 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 unhygienic: Schizophrenia Neurological examination ❑ Emergence of new focal neurological signs: Cerebrovascular event ❑ Trauma to head: hemorrhage and increased intracranial pressure ❑ Meningeal signs: Meningitis ❑ Neurodegenerative diseases: Parkinsonism, alzheimer's disease 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 ❑ Inspiratory crackles: 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 ❑ Ascites: Liver failure, heart failure, kidney failure ❑ Organomegaly: Liver failure, portal hypertension, hepatic encephalopathy ❑ Distended bladder: Urinary obstruction leading urinary tract 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 disorder etc. Acute stress disorder Malingering and factitious disorder [states] Other neurocognitive disorders e.g. dementia 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

Investigations ❑ Delirium is a clinical diagnosis, investigations are aimed to reveal underlying etiology. Lab investigations: Complete blood count (CBC) Glucose Calcium Urinalysis Magnesium Blood urea nitrogen (BUN) / creatinine Arterial blood gases Pulse oximetry Vitamin B12 Folate levels Thyroid function test Urine culture Blood culture. If indicated Arterial blood gas Specific cultures e.g. sputum CT scan of the brain: Focal neurological signs Head injury Increased intracranial pressure. MRI of brain: Intracranial bleed Brain tumor Dementia etc.

Primary Prevention ❑ Targeted symptomatic intervention can help prevent the emergence of delirium Curtailing cognitive decline Write names of care providers, the day’s schedule on board Constantly reorient patients to surroundings Activities to stimulate cognitive unctions like discussion of current events, structured reminiscence, or word games Curtail sleep impairment Reduce environmental noise Relaxing activities such as music, back massage Reduce immobility Minimal use of catheter or other aids which promotes immobility Early mobilization Incorporation of an exercise regiment Manage difficulties in sight Use of visual aids Use of large fluorescent tapes or objects with illuminations to help in vision Manage difficulties in hearing Use of aids Ear care Avoid dehydration Regular hydration Early recognition and prompt treatment ❑ Delirium in ICU can be predicted by [PREDELIRIC] model

Treatment: ❑ Treatment of underlying etiology is important in the management of delirium. ❑ Non-pharmacological treatments Avoid unnecessary movement of the patient Maintain continuity of care from caring staff Avoid physical restraints Involve family members in care Having recognizable faces at the bedside Sensory aids should be available and working where necessary Maintenance or restoration of normal sleep patterns Avoid sudden and irritating noise (e.g. Pump alarms) Careful management of bowel and bladder elimination Having a means of orientation available (such as a clock and a calendar) Reassurance and explanation to the patient Verbal and non-verbal de-escalation techniques to calm the patient. ❑ T-A-DA Method (Tolerate, Anticipate, Don't Agitate) Tolerate patient behavior, as long as the patient or other people are not in danger Provide greater mobility by removing unnecessary attachments like catheter Reduce agitation, do not reorient if reorientation causes agitation Provide supervision, anticipate behavior to keep the patient safe. ❑ Wandering and Rambling Speech Closely observe wandering patients Distract agitated wandering patient, if required, seek help from relatives Rule out common stressors causing agitation, such as pain, thirst, need for toilet Do not agree with rambling talk, acknowledge the feelings expressed and ignore the content, or change the subject, tactfully disagree, if the topic is not sensitive. ❑ If non pharmacological techniques fail, or if de-escalation techniques are inappropriate, use pharmacological treatment to tackle delirium.

Medical Management: ❑ Antipsychotics Haloperidol is a gold standard IV route can reduce extrapyramidal side effects Droperidol can be given alone or after haloperidol, if quicker results are desired ❑ Sedative such as Benzodiazepines To conduct required diagnostic procedures or to deliver treatment If patient is danger to others or themselves Highly agitated or hallucinating patient Alcholol withdrawal Benzodiazepine withdrawal When antipsychotics are contraindicated, Parkinson's disease, neuroleptic malignant syndrome, dementia with Lewy bodies ❑ Cholinergic: Physostygmine is used if caused by anticholinergic medications ❑ Morphine and paralysis: Used in extremely agitated patients, unresponsive to other treatment, who may need sedation and ventilatory support It increases oxygenation and skeletal muscle exertion Morphine is useful when pain is an important aggravating factor. But, opiates etc. can exacerbate delirium because of anticholinergic properties

Restrains: Used as a last resort in a severe delirium Must be avoided as it can increase agitation and risk of injury Local laws on restrains must be well known to care providers.

Dose of Haloperidol

Geriatric population, and seriously ill patients	0.25 - 0.50mg four hourly
Healthier patients	2mg - 3mg per day
Very agitated patients	5mg - 10mg per hour iv

Offending Drugs causing Delirium

Antiarrhythmic
Antihistamine]
Antiparkinsonian drugs such as benzatropine
Antispasmodic
Benzodiazepine
Diuretic e.g. Furosemide
Incontinence medicines e.g. Oxybutynin
Opioid Analgesics]]
Tricyclic antidepressant

Do's

Always start with the lowest possible dose and titrate according to symptoms. Antipsychotics are usually given for a short period of time - approximately 1 week. Antipsychotics:ECG monitoring is required to calibrate QTc interval. Cardiology consult should be done if QTc interval is more than 450msec or it is greater than 25% baseline. Dose adjustment or discontinuation of antipsychotic medication may be warranted. Haloperidol has can cause sedation and hypotension. Lowering of the seizure threshold, galactorrhea, elevations in liver enzyme levels, inhibition of leukopoiesis, neuroleptic malignant syndrome, and withdrawal movement disorders are rare side effects of antipsychotic medication.

Dont's

Elderly patients and delirium with hypoactive features do not require sedation. All sedatives can cause delirium, especially if drugs like thioridazine, chlorpromazine which have anticholinergic effects. Sedatives must be used with caution with minimum possible dosage and should be discontinued if they are no longer required. Benzodiazepines are contraindicated in hepatic encephalopathy, respiratory depression or compromised lung functons. They must be used with caution if liver functions are compromised. Can cause behavioral dis-inhibition, amnesia, ataxia, respiratory depression, physical dependence, rebound insomnia, withdrawal reactions, and delirium. Adolescents and pediatric may suffer from disinhibition reactions, emotional lability, increased anxiety, hallucinations, aggression, insomnia, euphoria, and in-coordination.

Anticholinergics Causes bradycardia, nausea, vomiting, salivation, and increased gastrointestinal acid. Physostigmine can cause seizures.

References

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