acute organic reaction
DESCRIPTION
lecture noteTRANSCRIPT
Acute Organic Reactions
Acute Confusional StateAcute Brain Syndrome
Prototype e.g. Delirium
Organic disorders-features
Diseases that affect the brain▪ 10 Disease of the brain▪ Systemic conditions that 20 affect the brain
Disrupts normal brain function through biochemical, electrical or mechanical disturbances
Delirium is the extreme form of organic reaction from dulling to Coma ( Glasgow Coma scale)
Delirium is a transient, organic mental syndrome of acute onset, characterized by disturbances in cognition, attention, perception, thinking, consciousness, psycho motor activity and sleep wake cycle.
Acute Organic Reaction -features
Aetiologically diverse but with similar syndrome
(manifestation): common final pathway Common at the extremes of age Commonly seen in general hospital settings or in
geriatric wards Occurs at rates ranging from 10% to 30% of all
hospital admissions (usually unrecognized) Usually acute in onset, fluctuating in nature and
lasts for few hours, days to weeks Reversible when cause treated It carries a high mortality rate (up to 25% ) when
untreated
Aetiology
Systemic conditions- 20 affects brain function Drug intoxication
▪ Anticholinergics, Psychotropics, Anticonvulsants, Antiparkinsonian, antiarrythmics, Steroids, Salicylate, Lithium, Alcohol, Cannabis, Ecstasy, …
Drug withdrawal▪ Alcohol, Benzodiazepines
Infections/ inflammations▪ Chest infections, UTI, Systemic infections- Typhoid, cerebral malaria,
Septicaemia, rheumatic chorea, influenza, streptococcal infection ▪ Meningitis, Encephalitis, HIV, Neurosyphilis, (10 affects brain)
Hypoxia ▪ Respiratory disease- bronchoneumonia, Heart disease (cardiac dysrhythmias,
CCF, silent coronary infarction), CO poisoning, Post anaesthesia, silent GI bleeding,
Metabolic causes ▪ Uraemia, Hepatic encephalopathy, Electrolyte imbalance, hypoglycaemia,
ketoacidosis, alkalosis, hypercapnia Endocrine
▪ Thyroid (hyperthyroid crisis, myxoedema madness), Adrenal, Pituitary problems, Addisonian crisis, Diabetic pre-coma
Aetiology ctd..
Nutritional ▪ Vitamin deficiencies (B12, Thiamine (Wernicke’s
encephalopathy), Pellagra, Folic acid..) Other rare causes
▪ Heavy metal poisoning▪ Non-metastatic effect of CA▪ SLE▪ Porphyria
Primary CNS conditions▪ Head injury- EDH, SDH▪ Cerebro vascular causes – CVA, TIA, SAH, hypertensive
enchephalopathy▪ Epilepsy- CPS, Post ictal confusion, petit mal status ▪ SOL
Clinical features
Impairment of consciousness▪ Dulling of awareness to …….coma
▪ Fluctuations, lucid intervals
▪ Diurnal variation
Disorientation▪ Time, place, person
Disturbances in attention and concentration▪ Difficulty in focusing and keeping attention
Memory impairment
▪ Amnesic gaps
Perceptual disorders
▪ Illusions
▪ Hallucinations –visual, tactile, auditory …..
Clinical features ctd.. Disorders of thinking
▪ Incoherence, fragmentation
▪ Stereotype thinking, preservation, impaired grasp
▪ Mental fatigue , defective reality testing, incomprehension
▪ Delusions – persecutory, occupational (delirium), others
Emotions
▪ Apathy and withdrawn
▪ Fear, anxiety, panic, terror..
▪ Depression
▪ Labile emotions
Psychomotor
▪ Hyper - hypo alertness (agitation or retardation) or mixed
▪ Diurnal fluctuation
Disturbance in sleep wake cycle
▪ Reversal
▪ Disturbing dreams and nightmares
Differential diagnosis
Chronic confusional state – Dementia
Acute on chronic
Psychotic illness
Dissociative illness
Investigations
Routine investigations▪ FBC, BP, BU, SE, FBS, LFT, Culture, ECG, CXR
….
Specific investigations▪ Drug levels, vitamins levels▪ TFT, Other endocrine levels▪ LP, Skull X ray▪ EEG▪ CT, MRI, PET…
Management - General
Find out the aetiology and treat it
General measures▪ Nutrition, fluid, electrolytes, other general health
measures
Nursing ▪ Quite, well lighted area▪ Simple environment with familiar objects – not having
any harmful objects▪ Keep under close observation▪ Risk assessment▪ Avoid changing staff▪ Clear instructions, adequate explanations, repeated
orientation▪ Be supportive
Vitamin B, Broad spectrum Antibiotics ?
Management - Pharmacological
Some general principles when prescribing medication use one drug at a time; Look for side-effects of prescribed medications keep the use of sedatives and antipsychotics to a
minimum; tailor dose according to age, body size and degree of
agitation; titrate dose to effect; increase scheduled doses if regular ‘as needed’ doses
are required all medication should be reviewed at least every 24
hours.
Agitation, Psychotic features & Sleep problems▪ Typical Antipsychotics – Haloperidol▪ Atypical antipsychotis – Risperidone, Olanzapine▪ Beware of QTc interval – ECG monitoring▪ Benzodiazepines – Lorezepam▪ Others
THANK YOU
References
Lishman’s Organic Psychiatry, 4th Edition, Wiley-Blackwell, 2009
Brain images from http://health.howstuffworks.com/human-body/systems/nervous-system/brain-pictures4.htm