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Central anticholinergic syndrome (CAS). Dr. S. Parthasarathy MD., DA., DNB, MD ( Acu ), Dip. Diab . DCA, Dip. Software statistics,Ph D (physiology) Mahatma gandhi medical college and research institute, puducherry , India .
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Central anticholinergic syndrome (CAS) Dr. S. Parthasarathy MD., DA., DNB, MD (Acu), Dip. Diab. DCA, Dip. Software statistics,Ph D (physiology) Mahatma gandhi medical college and research institute, puducherry, India
Central anticholinergic syndrome (CAS) is a clinical entity • which shows central and peripheral effects produced by over dosage • or abnormal reaction to clinical dosage of anticholinergic drugs
Symptoms • Central • Peripheral • Lowest age reported is 4
Central • Agitation • Amnesia • Ataxia • Asynergia • Confusion,excitement • Hallucinations • Delirium • Somnolence
Central • Nausea • Emotional instability • Hyperpyrexia, • Hyperalgesia • Convulsions • Muscle incoordination
Peripheral • Dry mouth • Dry skin • Arrhythmias • Mydriasis • Blurred vision • Micturition and bowel dysfunction • Thirst
Basic mechanism • Cholinergic synapses necessary for memory • and anticholinergics ?? • Acetylcholine and anaesthetics • GABA modifies Cholinergic synapses • EEG behavioral dissociation
Incidence • After GA, 9.4 % • After RA with sedation 3.3 % • Reported from 4 year child onwards • From Immediate postop to first week
Old age- more incidence • The decreased cholinergic reserve in older persons • Other drugs
Drugs and CAS • Antidepressants • Anticholinergics • Antipsychotics • Antispamodics • Halo,enflurane • Morphine, pethidine • Ketamine • Antiparkinson drugs
What is this ?? • An elderly patient is scheduled for enucleation of a blind, painful eye. Scopolamine, 0.4 mg IM, premedication. • preoperative holding area, the patient becomes agitated and disoriented. • The only other medication the patient has received is 1%atropine eye drops.
Differential diagnosis • Metabolic encephalopathy • ABG, renal parameters ,electrolytes • Neurologic damage • CT scan
How to conclude as CAS • Method of exclusion • Profile • Physostigmine challenge • 0.04 mg / kg IV or IM • 5 – 15 minutes symptoms improve
Physostigmine • A cholinesterase inhibitor • Rapidly hydrolysed • Raised BP and tachycardia !! • No problem with neostigmine • Analgesia • Usually one dose is enough
Other drugs • Galantaminehydrobromide • 4 amino pyridine • Tacrine • But nonspecific
Delayed recovery • naloxone and flumazenil, • Usually the patients recover to go back to sleep • In CAS , recovery after physostigmine is usually complete
How to avoid ?? • Atropine • Phenergan • Physostigmine just before recovery
Acta AnaesthesiolBelg. 1976;27(2):45-60 • treated 200 cases in which the CAS was diagnosed with physostigminesalicylate (0.04 mg/kg). • successfully treated 2 cases of apparently central anticholinergic hyperpyrexia in the same way. • suggest that physostigmine be included in the armamentarium of every anesthetist