10.3

• Delirium


  An acute confusional state, a major cause of morbidity and mortality, characterized by a relatively acute decline in cognition that fluctuates over hours or days
• Delirium


  • Defined by a deficit of attention, with all cognitive domains - including memory, executive function, visuospatial tasks, and language - variably involved
  • Associated symptoms may include altered sleep-wake cycles, perceptual disturbances, affect changes, and autonomic instability
• Subtypes of delirium


  • Hyperactive: Prominent hallucinations, agitation, and hyperarousal, often accompanied by life-threatening autonomic instability
  • Hypoactive: Patients are withdrawn and quiet, with prominent apathy and psychomotor slowing
• Hyperactive delirium


  The classic example is the cognitive syndrome associated with severe alcohol withdrawal, featuring prominent hallucinations, agitation, and hyperarousal, often accompanied by life-threatening autonomic instability
• Hypoactive delirium


  Exemplified by benzodiazepine intoxication, in which patients are withdrawn and quiet, with prominent apathy and psychomotor slowing
• Delirium is a clinical diagnosis that is made only at the bedside

  
• The reversibility of delirium is emphasized because many etiologies, such as infection and medication effects, can be treated easily
• Some episodes of delirium continue for weeks, months, or even years
• The persistence of delirium in some patients and its high recurrence rate may be due to inadequate initial treatment of the underlying etiology
• In some instances, delirium appears to cause permanent neuronal damage and cognitive decline
• Even if an episode of delirium completely resolves, there may be lingering effects of the disorder
• DSM-5-TR criteria for delirium

  • A. A disturbance in attention accompanied by reduced awareness of the environment
  • B. The disturbance develops over a short period of time, represents a change from baseline, and tends to fluctuate in severity
  • C. An additional disturbance in cognition
  • D. The disturbances are not better explained by another neurocognitive disorder and do not occur in the context of a severely reduced level of arousal
  • E. There is evidence that the disturbance is a direct physiological consequence of another medical condition, substance intoxication/withdrawal, or exposure to a toxin

  
• Specify if delirium is:

  • Acute: Lasting a few hours or days
  • Persistent: Lasting weeks or months

  
• Specify if delirium is:

  • Hyperactive: Hyperactive psychomotor activity, mood lability, agitation, refusal to cooperate
  • Hypoactive: Hypoactive psychomotor activity, sluggishness, lethargy approaching stupor
  • Mixed level of activity: Normal psychomotor activity with disturbed attention and awareness, or rapidly fluctuating activity level
• Substance intoxication delirium should be diagnosed instead of substance intoxication when the delirium symptoms predominate and are severe enough to warrant clinical attention

  
• Sensorium/Delirium


  Changes in level of consciousness
• Approach to a patient with changes in sensorium/delirium

  • Reversible causes
  • Life-threatening conditions
  • Streamlined approach: systematic diagnostic workup and appropriate management
• Hyperactive delirium


  The individual has a hyperactive level of psychomotor activity that may be accompanied by mood lability, agitation, and/or refusal to cooperate with medical care
• Ascending Reticular Activating System (ARAS)


  Upper 3rd of PONS up to diencephalon / thalamus, responsible for arousal
• Hypoactive delirium


  The individual has a hypoactive level of psychomotor activity that may be accompanied by sluggishness and lethargy that approaches stupor
• Cerebral cortex


  Responsible for content of consciousness, sensory processing, and awareness
• For coma to be present, there must be significant impairment of either the Reticular Activating System or both cerebral hemispheres
• Mixed level of activity delirium

  The individual has a normal level of psychomotor activity even though attention and awareness are disturbed. Also includes individuals whose activity level rapidly fluctuates
• Neurologic causes of changes in sensorium/delirium

  • Trauma – hematoma, DAI
  • Tumors – primary or metastatic
  • Vascular – stroke syndrome, HIE
  • Infections – CNS infections
  • Seizures – postictal/ nonconvulsive status epilepticus
  • Hydrocephalus – any cause
  • Autoimmune – autoimmune encephalitis
  • PRES – posterior reversible encephalopathy syndrome
  • Osmotic demyelination syndrome

  
• Substance intoxication delirium


  This diagnosis should be made instead of substance intoxication when the symptoms in Criteria A and C predominate in the clinical picture and when they are sufficiently severe to warrant clinical attention

  
• Toxic-metabolic causes of changes in sensorium/delirium

  • Toxic – drug overuse: narcotics, sedative-hypnotics, drugs of abuse, medication overuse
  • Environmental causes: hypo or hyperthermia, CO poisoning
  • Metabolic encephalopathy: hypoxia/ hypercapnia, hypo/hyperglycemia, sepsis, shock states/ hypoperfusion, hypo/hypernatremia, hepatic encephalopathy, uremia, Wernicke's encephalopathy, endocrine etiology: myxedema, adrenal insufficiency, hypercalcemia
• The ICD-10-CM codes for the [specific substance] intoxication delirium are indicated in the table below. Note that the ICD-10-CM code depends on whether or not there is a comorbid substance use disorder present for the same class of substance

  
• Substance withdrawal delirium


  This diagnosis should be made instead of substance withdrawal when the symptoms in Criteria A and C predominate in the clinical picture and when they are sufficiently severe to warrant clinical attention

  
• The ICD-10-CM codes for the [specific substance] withdrawal delirium are indicated in the table below. Note that the ICD-10-CM code depends on whether or not there is a comorbid substance use disorder present for the same class of substance

  
• Glasgow Coma Scale (GCS)


  Assesses eyes, verbal, and motor responses
• Approach to patients with disordered consciousness

  1. Primary survey: ABCDE approach

  2. GCS assessment

  3. Vital signs monitoring

  4. History taking

  5. Diagnostics: blood tests, CBG
• Medication-induced delirium


  This diagnosis applies when the symptoms in Criteria A and C arise as a side effect of a medication taken as prescribed

  
• History of present illness

  Establishes the time course of the disorder and provides clues to its nature and cause
• F05 Delirium due to another medical condition: There is evidence from the history, physical examination, or laboratory findings that the disturbance is attributable to the physiological consequences of another medical condition

  
• Past medical history factors

  • Alcoholism
  • Other drug abuse
  • Infection (HIV)
  • Diabetes
  • Heart disease
  • Epilepsy
  • Head trauma
• F05 Delirium due to multiple etiologies: There is evidence from the history, physical examination, or laboratory findings that the delirium has more than one etiology (e.g., more than one etiological medical condition; another medical condition plus substance intoxication or medication side effect)

  
• Vital sign abnormalities


  • Bradycardia
  • Tachycardia
  • Hypotension
  • Hypertension
  • Bradypnea
  • Tachypnea
  • Hyperthermia
  • Hypothermia
• Risk factors for delirium

  • Older age
  • Baseline cognitive dysfunction
  • Sensory deprivation (preexisting hearing and visual impairment)
  • Poor overall health (baseline immobility, malnutrition, underlying medical or neurologic illness)
  • Use of bladder catheterization, physical restraints, sleep and sensory deprivation, and the addition of three or more new medications
  • Surgical and anesthetic risk factors (procedures involving cardiopulmonary bypass, inadequate or excessive treatment of pain in the immediate postoperative period, and perhaps specific agents such as inhalational anesthetics)
• Physical exam findings in confusional state

  • Neck stiffness
  • Battle sign or raccoon eyes
  • Hemotympanum
  • CSF oto- or rhinorrhea
  • Jaundice
  • Petechial rash
  • Heart murmur
  • Ascites
  • Rectal bleeding
• Delirium is common, with estimates of delirium in hospitalized patients ranging from 10 to >50%, with higher rates reported for elderly patients and patients undergoing hip surgery