ECT anaesthesia

ECT anaesthesia

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  ANAESTHESIA FOR ELECTROCONVULSIVE THERAPY Presenter:Dr. Kundan Kishor Ghimire 2nd yr Resident Anaesthesia and Critical Care UCMS-TH
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  ELECTROCONVULSIVE THERAPY • Definition •Artificial induction of a grandmal seizure(tonic phase 10-15s, clonic phase;30-60s) • Through the application of electrical current to the brain • Stimulus applied through electrodes which are placed bilaterally in the fronto-temporal region or unilaterally on the non dominant side.
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  • Indications • TheNational Institute of Clinical Excellence (NICE) UK Guidelines (1) recommend that ECT be considered for patients who are suffering from: 1. Acute, life threatening depression (high suicide risk or very poor fluid and/or fluid intake) 2. Drug resistant depression 3. Acute catatonia (where first line treatment with intramuscular benzodiazepines has failed to produce improvement). 4. Mania, where treatment has failed to alleviate the condition, or is limited by side effects
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  Mechanism of Actionof ECT
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  •TREATMENT • Most patientsrequire between 6 and 10 treatments, performed on a twice a week basis. • usually administered bilaterally; • electrodes are placed over the poles of the temporal lobes. • unilaterally to the non-dominant hemisphere if there are concerns over post-ictal confusion.
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  • EEG monitoring:initially localised seizure, which becomes a generalised tonic-clonic seizure within 5-10 seconds. • seizure should ideally last for more than 15sec and less than 120sec. • A seizure longer than 120sec is classified as “prolonged” and pharmacological agents may need to be administered to terminate the seizure
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  • Contraindication • Absolutecontraindications • None • Relative contraindications • Myocardial infraction within the last 3 months or unstable angina • Cerebrovascular event in the last 3 months • Raised intracranial pressure or untreated cerebral aneurysm • Unstable major fracture or cervical spine injury • Pheochromocytoma • Uncontrolled cardiac failure or severe valvular disease • Deep venous thrombosis.
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  PHYSIOLOGICAL RESPONSE TOECT • Central Nervous System • Increase in intracranial pressure • Increased regional cerebral blood flow, cerebral oxygen consumption, and glucose utilization. • Increase in blood-brain barrier permeability. • Headache, confusion, and transient memory loss are common in the immediate post- treatment period.
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  • Cardiovascular System •Initial brief parasympathetic response: lasts for 10- 15seconds, bradycardia, hypotension or even • Sustained sympathetic response, peaking at 3-5 minutes, associated with release of catecholamines, a rise in systolic blood pressure (30-40%), and a rise in heart rate (more than 20%) • Increased myocardial oxygen consumption.
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  • Other Effects• • Increase in intraocular pressure • Increase in intragastric pressure • Nausea • Myalgia and feeling of general ill-ease • Damage to crowns, veneers, bridges, implants or intraosseous denture supports • Oral cavity damage to tongue and gums
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  • anaesthetic requirementsfor ECT • control of haemodynamic changes and complications, • amnesia and muscle relaxation. • Anaesthesia is brief due to the short nature the procedure. • rapid, return of consciousness and full orientation is desirable.
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  • History andPhysical examination • Detailed medical history and a thorough phyisical examination • History of psychotropic medications: antipsychotics, mood stabilizers antidepressant and anxiolytics. • Investigations • Full blood count, urea and electrolyte • Other additional test:
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  • Premedication • Forparasympathetic stimulation • Anticholinergic agents: • Glycopyrrolate 0.01mg/kg IM 3 min prior the scheduled surgery or IV just beore injecting the induction agents • For sympathetic stimulation: • Beta blocker: Esmolol(1-2mg/kg), labetolol(0.05- 0.4mg/kg)
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  • Pre-oxygenation • 100%oxygen at a rate of 15–20 breaths/min, beginning approximately 1 min before the induction. • continued until the resumption of spontaneous breathing. • Prior Hyperventilation reduce the seizure threshold and enhance the seizure duration
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  • Induction agents •short-acting induction agent. • most induction agents (barbiturates, etomidate, benzodiazepines, and propofol) have properties, small doses must be used. • Seizure threshold is increased and seizure duration is decreased by all of these agents. • methohexital, 0.5–1 mg/kg, is most commonly employed. • Propofol, 1–1.5 mg/kg,
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  • Muscle Relaxants •Used to reduce the risk of injury • Neuromuscular blockade is required from the of electrical stimulation until the end of the seizure. • succinylcholine (0.25–0.5 mg/kg). • . Controlled mask ventilation, using a self-inflating bag device or an anesthesia circle system, is required until spontaneous respirations resume.
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  • References: • Morganand Mikhails 6th edition • Indian journal of Anaesthesia. 2017 may:61(5):373-380