Delirium in ICU

Dr.Tinku JosephDM Resident

Department of Pulmonary MedicineAIMS, Kochi.

Email: tinkujoseph2010@gmail.com

Overview

What is delerium ?

How is it categorised?

Why does it matter?

Why does it happen?

How do we diagnose/monitor it?

How do we prevent and treat it?

What is Delirium?

An acute confusional state with:

Fluctuating mental statusDisordered attentionDisorganised thinking or altered consciousness

DSM –IV definition: “A disturbance of consciousness with

inattention accompanied by a change in cognition or perceptual disturbance that develops over a short period (hours to days) and fluctuates with time”

What is Delirium?

Synonyms:ICU psychosis, septic encephalopathy, ICU syndrome, acute brain failure, acute confusional state

Delirium develops over a short period of time (usually hours to days) and tends to fluctuate during the course of the day.

Delirium is typically caused by a:

Medical condition

Substance intoxication

Medication side effect.

What is Delirium?

How is Delirium Categorized?

Hyperactive

Hypoactive

Mixed

1.6% of cases, “ICU psychosis”, agitation, restlessness, pulling lines and tubes emotional lability

54.1% % of cases43.5% of cases, “encephalopathy”, often unrecognized, withdrawal, apathy, lethargy, decreased responsiveness, may be misdiagnosed as depression. Far more common, likely due to sedating medications

Why does delirium matter?

Increased reintubation risk (OR=3) Increased ICU & hospital stay* (up to 10 days extra)

Each day in delirium increases risk of longer stay by 20% Increased mortality in ICU & out to 6 months** (OR=3)

Each day spent in delirium increases risk of death by 10% Increased ICU & hospital costs*** 10-24% risk of long-term cognitive impairment Increased dementia risk Reduced functional status at 3 & 6 months

* Ely et al, Intensive Care Med 2001; 27: 1892-1900** Ely et al, JAMA 2004; 291: 1753-62*** Milbrandt et al, CCM 2004; 32: 955-62

Why does delirium happen? Higher cortical dysfunction (on functional neuroimaging)

Pre-frontal cortex, non-dominant posterior parietal regions, anterior thalamus, basal ganglia, temporal-occipital cortex

Neurotransmitter dysfunction Reduced acetylcholine levels – blockade or deficiency

Endogenous anticholinergic substances Opiates/hypoxia/inflammation

Serotonin fluctuation Dopamine excess Glutamate excess (2o to IFN-, LPS, hypoxia, hypoglycaemia)

Predisposition (baseline vulnerability) Precipitants (clinical, iatrogenic, organisational risk factors)

Why does delirium happen?

SerotoninAcetylchol

ineDopamine

Opioids & benzo’s

2o cerebral infection

Decreased cerebral

metabolism

1o intracranial disease

Systemic disease

Hypoxia

Metabolic derangement

Withdrawal syndromes

Toxins

Predisposing factors (host factors)

Present before ICU admission1. Age2. Alcoholism3. Smoking4. Hypertension 5. Apolipoprotein 4 polymorphism6. Cognitive impairment7. Hearing/visual impairment8. Depression

Risk factors

Precipitating factors.

Occur during course of critical illness

May involve factors of acute illness or be iatrogenic;

Factors of critical illness

1. Acidosis2. Anemia3. Infection/sepsis4. Hypotension5. Metabolic

disturbances6. Respiratory disease7. High severity of

illness

Iatrogenic factors1. Immobilization2. Medication (opoids,

BDZ)3. Sleep disturbances

Modifiable Risk factors

Age

Severity

Benzo’sPun & Ely, Chest 2007; 132: 624–636Pandharipande et al, Anesthesiology 2006; 104: 21-26

DELIRIUM(S) - causes DD Drugs, dementia E Eyes & ears (poor vision and hearing) L Low O2 states (CHF, COPD, ARDS, MI,

PE) I Infection R Retention (urine and stool) I Ictal states U Underhydration/undernutrition M Metabolic upset (S) Subdural, sleep deprivation

I WATCH DEATH I Infection W Withdrawal (alcohol, sedatives, barbiturates etc.) A Acute metabolic (acidosis, alkalosis, electrolytes) T Trauma (closed head injury, haematoma etc.) C CNS pathology (seizures, stroke, encephalitis) H Hypoxia D Deficiencies (thiamine, niacin, B12, folate) E Endocrinopathies (thyroid, glucose, adrenal) A Acute vascular (hypertensive crisis, arrhythmia) T Toxins/drugs H Heavy metals

Diagnosis & monitoring

Intensive Care Delirium Screening Checklist (ICDSC) and the Confusion Assessment Method for the ICU (CAM-ICU)

Using ICDSC, each patient is assigned a score from 0 to 8; a cut-off score of 4 has sensitivity 99% and specificity 64% for identifying delirium

CAM-ICU has a more modest sensitivity ranging from 64% to 81%, high specificity from 88% to 98%.

Diagnosis & monitoring

S100B protein indicator of glial activation and/or death. Shown to be elevated in patients with delirium.

Higher baseline levels of procalcitonin or C-reactive protein were associated with more days with delirium.

Other biomarkers elevated-brain-derived neurotrophic factor, neuron-specific enolase, interleukins, cortisol.

Biomarkers

What should we do to What should we do to prevent/treat delerium in ICU prevent/treat delerium in ICU

patientspatients

Treating/Preventing delirium

Monitoring Non-pharmacological

interventions Reduction in deliriogenic

medications Pharmacological

interventions

Environmental factors

Extremes in sensory impairment Extremes in sensory impairment eg: hypothermia.eg: hypothermia.

Deficits in vision or hearingDeficits in vision or hearing

Immobility or decreased activityImmobility or decreased activity

Social isolationSocial isolation

Novel environmentNovel environment

stressstress

A bundle for delirium prevention ??

Family support (all levels, kids, children)

Allow family at bed side when ever possible

Orientation improvements: Day lights, wall clocks, exterior view from ICU.

Privacy for patients.

Hearing aid

Glasses

Television/ Music therapy

Proper sleep

A bundle for delirium prevention ??

Role of doctor & Nursing staff

Introduce yourself, smile and be friendly with patients.

A bundle for delirium prevention ??

Treating/Preventing delirium

Non-pharmacological (Summary) Up to 40% risk reduction achieved Repeated reorientation of patients Early mobilization Visual and hearing aids (and wax

removal!) Early catheter, line etc. removal Minimize restraints and sedatives Sedation Interval Sleep protocol Delirium bundle

First address complication of critical illness that may lead to delirium (hypoxia, hypercapnia, hypoglycemia, shock, electrolyte imbalances)

Any drug intended to improve cognition may have adverse psychoactive effects thus paradoxically exacerbating delirium.

Pharmacological treatment

Haloperidol recommended as drug of choice for treatment of ICU delirium by SCCM

Blocks D2 dopamine receptors, resulting in amelioration of hallucinations, delusions, unstructured thought patterns

SCCM guidelines-hyperactive delirium to be treated with 2 mg intravenously, followed by repeated doses (doubling previous dose) every 15 to 20 minutes while agitation persists

Haloperidol

Once agitation subsides scheduled doses (every 4 to 6 hours) may be continued for few days, followed by tapered doses for several days.

Common doses for ICU patients range from 4 to 20 mg/day

Adverse effects Adverse effects – extrapyramidal, prolonged QTc, – extrapyramidal, prolonged QTc, torsades (3.8%), neuroleptic malignant syndrometorsades (3.8%), neuroleptic malignant syndrome

Haloperidol

Treating delirium – atypical antipsychotics

Olanzepine, quetiapine, risperidone Alter multiple neurotransmitters

including DA, NA, serotonin, ACh, histamine

Suggestion of decreased extrapyramidal side-effects compared to haloperidol

As effective as haloperidol

Dexmedetomidine, novel α2- receptor agonist that does not act on GABA receptors, may to be alternative sedative agent less likely to cause delirium.

Pandharipande P. et al (2007) showed ICU patients sedated with dexmedetomidine spent fewer days in coma and more days neurologically normal than lorazepam.

Benzodiazepines are not recommended for management of delirium

Dexmedetomidine

Conclusion

Delirium is a frequent disease in the ICU and associated with poor outcomes.

Delirium is often under recognized, can be monitored and rapidly identified.

New approaches to manage and prevent delirium are emerging everyday.

Dexmedetomidine has a place in this new strategies.