History Delirium due to a General Medical Condition Etymology: - PDF document

Delirium Delirium by Other Names The Acute Syndrome of • Encephalopathy • Metabolic Encephalopathy Brain Insufficiency • Hepatic Encephalopathy David P. Kasick, M.D. • Acute Mental Status Change Assistant Professor of Clinical Psychiatry • ICU Psychosis/ICU Syndrome and • Acute Organic Brain Syndrome Nathan O’Dorisio, M.D. • Toxic Psychosis Assistant Professor of Internal Medicine • Febrile Insanity • Acute Confusional State Ohio State University Medical Center DSM-IV-TR Criteria History Delirium due to a General Medical Condition • Etymology: Latin, from delirare • Disturbance of consciousness � “Out of the furrow” (in plowing) � Reduced ability to focus, sustain or shift attention • Impairment of lucidity or other cognitive function or • Physicians have long recognized states of altered development of a perceptual disturbance behavior associated with: � Not better accounted for by a dementia � Fever, poisons, or other medical and • Distinctive clinical course neurological diseases � Develops over a short period of time and tends to fluctuate during the course of the day • Hippocrates provided the first written description • Evidence that the disturbance is caused by the direct of the syndrome physiologic effects of a general medical condition, substance use, or substance withdrawal 1

“Lucidity” “Consciousness” • “Clarity of thought” • “Paying attention” or “awareness” • Ability to mentally respond to sensory • Effective use of cognitive functions for experiences, including: interacting with the immediate environment: � Awareness of immediate environment and circumstances � Memory registration, storage, and retrieval � Ability to focus and sustain attention � Recognition, comprehension � Ability to shift attention � Concentration � Reasoning and judgment • Delirium always includes impairment of � Language skills, ability to communicate consciousness The Continuum of “Lucidity” Consciousness COMA EXTREME EXCITEMENT “NORMAL” CONSCIOUSNESS • “Impairment of consciousness can impair lucidity • Impairment of lucidity does not ALERT VIGILANT necessarily imply impairment of SOMNOLENT consciousness, nor vice versa RELAXED ATTENTIVE HYPERAROUSED STUPOROUS DISTRACTIBLE OBTUNDED HYPERVIGILANT HYPERSOMNOLENT 2

Delirium is frequently The Continuum of misdiagnosed Lucidity • Hypoactive symptoms: � “Dementia” IMPAIRED NORMAL LUCIDITY LUCIDITY � “Acute Onset Dementia” � “Acute Onset Depression” ACCURATELY AWARE • Hyperactive symptoms: COHERENT DISORIENTED TO TIME FLUENT � “Acute Onset Psychosis” CONFUSED ORGANIZED � “Acute Schizophrenic Break” DISORIENTED TO SELF • 23-42% of patients referred to C/L psychiatrists for depression were diagnosed with delirium DISORIENTED TO PLACE Subtypes of Delirium Delirium vs. Dementia • Hyperactive (~25%) • Hypoactive (~25%) DELIRIUM DEMENTIA � Sympathetic nervous � Lethargy and (acute onset) (gradual onset) system hyperactivity somnolence CONSCIOUSNESS Impaired, Fluctuating Normal � Psychomotor � Withdrawn, apathetic agitation � Decreased response � Verbal or physical to stimuli LUCIDITY Impaired, Fluctuating Impaired aggression � Psychomotor � Motor perseveration retardation COGNITIVE Impaired, Fluctuating Impaired � Wandering � Clouded FUNCTIONING consciousness, � Increased alertness to inattention stimuli PSYCHOPATHOLOGIC Any are possible Typically restricted � Slow speech SYMPTOMS (cognitive) � Mood lability, anger, euphoria Mixed (~35%) Signs and symptoms of both types 3

Clinical Features Suggesting Why is recognizing and treating delirium so important? Delirium in a Psychotic Patient • Morbidity and mortality of any serious disease are doubled with delirium • Altered level of consciousness � 3 month mortality rate is ~28% • Rapid onset of symptoms � 1 year mortality rate is ~50% • Recent onset of impairment of memory and • Harbinger of death or worsening medical illness other cognitive functions • 10% of hospitalized patients have delirium at any point in time • Disorientation for time and place (not caused by delusional thinking) � 20% with severe burns � 30% hospitalized with AIDS • Impaired awareness of the environment � 40% of elderly at some point during general hospital stay Prevalence of Delirium Clinical Features Suggesting Delirium in a Psychotic Patient in Specific Populations • Predominance of hallucinations in • Emergency Department 10-14% modalities other than auditory • Hospitalized medically ill patients 10-30% • Presence of a general medical condition • Hospitalized elderly patients 10-40% capable of altering metabolic support of • Cancer Patients 25% brain function • Intensive Care Unit 30% • Evidence of use of a psychoactive • Post-CABG 30% substance capable of causing delirium • Postoperative Patients 10-51% during intoxication or withdrawal • Patient with AIDS 30-40% • Onset of first psychotic episode after age 45 • Cardiac Surgery patients < 74% • Terminally ill patients < 80% • No history of mental illness or premorbid symptoms • Coexistent brain disease < 81% 4

Increased Risk for Delirium Some Characteristics in Patients with: of Delirium • CNS disorders • Acute onset and fluctuating course are strongly � HIV, Parkinson’s, CVA, etc. suggestive • Postoperative states � “Waxing and waning” • Very young or old age � Change from baseline • Dependence on alcohol or sedative hypnotics � Often obtained from nursing staff or family • Underlying dementia • Altered consciousness • Mental retardation • Inattention, difficulty with focus, easily • Severe burns distractible • Sensory deprivation � Problems keeping track of what is being said • Undertreated pain • Impairment of lucidity or other cognitive function • Polypharmacy Some Characteristics Impact of Delirium of Delirium • Delirium may include any psychiatric symptom: • Utilization of greater amounts of hospital resources � Psychotic symptoms • Delusions, hallucinations, thought disorder, • Increased rates of ECF placement and paranoia, fearfulness length of hospital stays • Disorganized speech and thinking • More frequent major postoperative – Rambling or irrelevant conversation complications – Unclear or illogical flow of ideas • Experience poor functional recovery – Unpredictable switching from subject to subject 5

Some Characteristics Some Characteristics of Delirium of Delirium � Mood symptoms � Psychomotor increase or decrease • Emotional lability � Nonspecific, nonlocalizing neurological abnormalities • Depression to Euphoria • Irritability, agitation • Tremor, asterixis, myoclonus, change in muscle tone � Anxiety Some Characteristics Clinical Course of Delirium of Delirium • Onset: � Typically acute (hours to days) � Occasionally subacute (days to weeks) � Memory deficits � May be abrupt � Disorientation • Diurnal variation: � FLUCTUATION is characteristic and highly � Visual-constructional impairment suggestive � Language disturbance � Lucidity is typically best in morning � Confusion is typically greatest at night � Sleep-wake cycle disturbance • Environmental interaction: � Worsened by excessive sensory stimulation or marked sensory deprivation 6

Pathophysiology Clinical Course of Delirium • Duration: • Causes are often multiple and additive � Typically hours to days � Each cause alone may or may not be � Sometimes weeks to months able to cause delirium by itself • Outcome: • 56% of elderly patients with delirium had a � Many have full recovery single cause • Often not by the time of discharge • Remaining 44% had an average of 2.8 � Persistent cognitive deficits are common etiologies • Dementia, amnestic syndromes � Beware: “Their basic labs look normal” • New, lower cognitive baseline � Progression to other injuries and death Pathophysiology Pathophysiology / Etiology • The entire neuronal population of the brain is affected • Several theories exist: • Current understanding is limited � Dysfunction of the Reticular Activating System • Results from disturbances of metabolic (RAS) function of the brain • Arousal and motivation centers in brainstem � Dysfunction of neurochemical systems • A large number of different abnormalities may alter brain metabolism • Noradrenergic, GABAergic, dopamine, and serotonin systems � Hence the large list of potential etiologies � Hypofunction of cholinergic system • Classic model of anticholinergic drug toxicity – "Hot as a Hare, Dry as a Bone, Red as a Beet, Mad as a Hatter, Blind as a Bat 7

Delirium: Differential Delirium: Identifying the (“ I WATCH DEATH” ) Underlying Problem • The primary treatment of delirium: • I nfection � Sepsis, encephalitis, meningitis, � Diagnose and correct the syphilis, HIV, etc. underlying medical cause(s) • W ithdrawal � Alcohol, benzodiazepines, barbiturates Delirium: Differential Delirium: Emergent Differential (“ WHHHHIMP” ) (“ I WATCH DEATH” ) • W ernicke’s or W ithdrawal • A cute Metabolic � Electrolyte disturbance (especially Na+) • H ypoxia • H ypoglycemia � Renal Failure • H ypoperfusion � Hepatic Failure • H ypertension � Acidosis or alkalosis • I nfection or I ntracranial bleed • T rauma • M eningitis � Closed head injury, postoperative • P oisons or Medications states, heat stroke, severe burns 8