Delirium Risk Prediction (v1.1)

Dec 4, 2022 | Projects

The Delirium Risk Prediction tool was developed to predict which patients who have not yet been discharged, might have a delirium episode. Delirium can be defined as a serious change in mental abilities. This project was deployed at Mount Sinai Morningside in December 2022.

Definition

Confusion

  • A mental and behavioral state 8
  • Reduced comprehension, coherence, and capacity to reason 8
  • Most common problem in medicine 8
  • Accounting for a large number of emergency visits, hospital admissions and inpatient consultations 8

Delirium

  • Acute confusional state 8
  • Potentially reversible cognitive disturbance 8
  • Acute onset of an altered level of consciousness with fluctuating levels of orientation , memory, thought , and/or behavior.1
  • Major cause of morbidity and mortality
  • Costing over  150$ billion dollars annually in health care costs in US alone

Diagnosis

  • acute onset and fluctuating course
  • Inattention accompanied by
    • Disorganized thinking
    • An altered level of consciousness
    • May worsen at night (Sundowning) is not essential for diagnosis

Epidemiology

  • Common in the early stages of hospitalization for a variety of acute and chronic diseases 1
  • Commonly observed with an acute medical condition in internal medicine ,neurology, psychiatry, and geriatric wards 1
  • Co-morbidities :
    • Dementia with Parkinsonism —> dementia with levy bodies 8
  • Estimates  of delirium in hospitalized patients range from 18% to 64% —> max in Hip surgery
    • Old ICU patients have high rates that approach 75%
  • Until recently, an episode of delirium was viewed as transient condition that carried a benign prognosis
  • Now it’s recognized as disorder with substantial morbidity rate and increased mortality rate and often represent first manifestation of a serious underlying illness.
    • Recent estimates of inpatient mortality rate of delirious patients have ranged from 25-33% same as sepsis

Pathophysiology

Clinical Features 8

  • Terms used to describe the delirium patients:
    • encephalopathy
    • Acute brain failure\
    • Acute confusional state
    • Post-operative or ICU psychosis
  • Acute decline in cognition  that fluctuates over hours pr days
    • Hallmark —> attention deficit
    • Diffuse localization within brain stem, thalamus, prefrontal cortex ,and parietal lobe
    • memory
    • Executive function
    • Visuospatial tasks
    • Language
  • Associated symptoms \
    • Altered sleep-wake cycles
    • Perceptual disturbances such as hallucinations
    • Affect changes
    • Autonomic findings  including Heart rate and blood pressure instability

Clinical Subtype

  • Based on psychomotor features
    • Hyperactive (easily recognizable )
      • Cognitive symptoms associated with sever alcohol withdrawal (Delirium Tremens)
        • Hallucination
        • agitation
        • Tremor
        • hyperarousal
        • Life-threatening autonomic instability
    • Hypoactive
      • Benzodiazepine intoxication
        • apathy
        • Psychomotor slowing
    • Patient often falls between subtypes and sometimes fluctuating from one to the other —> makes diagnosis very hard (gray area) because clinicians should recognize the broad range of presentations
  • Some episodes of delirium continue for weeks , months or even years
  • Delirium may cause permanent neural damage and cognitive decline
  • Patient’s recall of events after delirium varies widely ranging from complete amnesia to repeated re-experiencing of frightening period of confusion same as PTSD patients

Risk factors 8

  • Older age —> age >65 yrs.
  • Baseline cognitive dysfunction
  • Sensory deprivation such as
    • Pre-existing hearing and visual impairment
    • Poor overall health including
      • Immobility
      • malnutrition
      • Underlying medical or neurologic illness
  • Bladder catheterization
  • Physical restraints
  • Sleep and sensory deprivation
  • Addition of three or more medications
  • Surgical and anesthetic risk factors:
    • Procedures such as cardiopulmonary bypass
    • Inadequate or excessive treatment of pain in the immediate postoperative period
    • Inhalation anesthetics

Pathogenesis

  • Right parietal and medial dorsal thalamic lesions have been reported most commonly
  • In most cases delirium results from widespread disturbances in cortical and subcortical regions rather than a focal neuroanatomic cause
  • EEG shows symmetric slowing  —> nonspecific cerebral dysfunction
  • Deficiency of ACh and medication with anti-Cholinergic properties
  • Increases in dopamine can also lead to delirium

Treatment

  • Sensory isolation should be prevented
  • Sleep-wake cycle interventions particularly in ICU
  • Very low dose typical or atypical antipsychotics

Morbidities/Complications

  • High mortality
  • Long hospitalization
  • Greater degree of dependence after discharge 3

Current Prediction tools

  • Confusion Assessment Method (CAM) and CAM-ICU 4
    • Developed based on DSMIII
    • To enable non psychiatric trained clinicians to identify delirium
    • CAM-ICU has been designed to assess nonverbal patients based on the cam algorithm
  • Delirium Rating Scale 5
  • Intensive Care Delirium Screening Checklist 6
  • Nursing Delirium Screening Scale 7
  • Organic Brain Syndrome scale
  • Delirium detection syndrome

Potential solutions

Non verbal/ language based tool

Potential Predictors

  • PE
    • Signs of infection
      • Fever
      • Tachypnea
      • Pulmonary  consolidation
      • Heart murmur
      • Stiff neck
    • Patient’s fluid status
      • Dehydration and fluid overload with hypoxemia
    • Appearance of skin
      •  Jaundice in hepatic encephalopathy
      • Cyanosis in hypoxemia
      • Needle tracks
    • Neurologic examination
      • Altered level of consciousness (hyper arousal to lethargy to coma)
        • Tangenital speech
        • A fragmentary flow of ideas
        • Inability to follow complex commands
        • Test of digit span forward  —> digit span of 4 or less
        • MMSE
        • Pattern of sundowning
  • CBC
  • Electrolyte panel
    • Ca
    • Mg
    • Phosphorus
  • ECG
  • ABG
  • Serum Ammonia
  • ESR
  • ANA
  • p-ANCA
  • C-ANCA
  • Serum / Urine toxicology
    • Anti-cholinergic
    • narcotic
    • Benzodiazepines
    • Drug Abuse
      • Alcohol
      • Opiates
      • ecstasy
      • LSD
      • GHB
      • PCP
      • Ketamine
      • Cocaine
      • Bath salts
      • Marijuana
    • Carbon monoxide
    • Ethylene Glycol
    • Pesticides
  • Metabolic conditions
    • Electrolyte disturbances
      • TSH and T4
        • Hypo/hyperglycemia
        • Hypo/Hypernatremia
      • Hypo/Hypercalcemia
      • Hypomagnesemia
      • Hypo/hyperthermia
      • Liver failure/Hepatic encephalopathy
      • Renal failure/uremia
      • Cardiac failure
      • Vitamine deficiencies:
        • B12
        • Thiamine
        • Folate
        • Niacin
      • Dehydration
      • Malnutrition
      • Anemia
    • Chest x ray
    • UA/UC
    • Blood culture
  • Infection
    • Systemic infection
      • UTI
      • pneumonia
      • Skin and soft tissue infection
      • sepsis
  • Endocrine conditions
    • Hypo/Hyperthyroidism
    • Hyperparathyroidsm
    • Adrenal insufficiency
  • Cerebrovascular disorder
    • Global hypo perfusion states
    • Hyper tensive encephalopathy
    • Focal ischemic strokes and hemorrhages: non dominate parietal and thalamic lesions
  • Autoimmune disorders
    • CNS vasculitis
    • Cerebral lupus
  • Seizure -related disorders
    • Non convulsive status epilepticus
    • Intermittent seizures with prolonged poetical states
  • Neoplastic disorders
    •  Diffuse metastasis of the brain
    • Gliomatosis cerebri
    • Carcinomatous meningitis
    • CNS Lymphoma

References

  1. Lipowski Z. Delirium in geriatric patients. In: Delirium: Acute Confusional States. New York: Oxford University Press; 1990.
  2. Confusion assessment method: A systematic review and meta-analysis of diagnostic accuracy
  3. Shi Q, Presutti R, Selchen D, Saposnik G. Delirium in acute stroke: a systematic review and meta-analysis. Stroke. 2012;43(3):645–649.
  4. Inouye SK, van Dyck CH, Alessi CA, Balkin S, Siegal AP, Horwitz RI. Clarifying confusion: the confusion assessment method. A new method for detection of delirium. Ann Intern Med. 1990;113(12): 941–948.
  5. Trzepacz PT, Baker RW, Greenhouse J. A symptom rating scale for delirium. Psychiatry Res. 1988;23(1):89–97.
  6. Radtke FM, Franck M, Oppermann S, et al. [The Intensive Care Delirium Screening Checklist (ICDSC) – translation and validation of intensive care delirium checklist in accordance with guidelines.] Anasthesiol Intensivmed Notfallmed Schmerzther. 2009;44(2):80–86.
  7. Luetz A, Heymann A, Radtke FM, et al. Different assessment tools for intensive care unit delirium: which score to use? Crit Care Med. 2010; 38(2):409–418
  8. Harrison’s principles of medicine 19th edition