Anaesthesia for ECT Jan P Mulier, MD PhD Chairman anaesthesiologie 1150 1850 1947 1977 2010 Anaesthesia for ECT Jan P Mulier, MD PhD Chairman anaesthesiologie sint Jan brugge-oostende www.publicationslist.org/jan.mulier JPMulier VVP 29 09 2009

Introduction Electro convulsive therapy (ECT) is the electrical induction of a grandmal seizure. ECT indication is growing Geriatric ECT Ambulant repetition at low frequency High repetition frequency A short general anaesthetic and muscle relaxant is usually given for the procedure. JPMulier VVP 29 09 2009

Anaesthetic Problems with ECT1 Patient Population. Patients are often elderly with associated comorbidity Drug Interactions. frequently taking psychotrophic drugs. Repeat General Anaesthetics. ECT is usually given 2x, 3x a week over several weeks. Location. administered at isolated sites away from operating theatres. Help to deal with unexpected problems can be delayed or unavailable. Like Any Anaesthetic. Nausea. Myalgia. JPMulier VVP 29 09 2009

Anaesthetic Problems with ECT2 Dental dammage due to biting during ECT Use patient adapted bite blocks Poor venous access Small canule 22 G Lowest dose possible of anesthetics To minimize suppression of epileptic insult Awareness prevention Sympathetic storm after short suppression Sufficient Hypnotic with cardiovascular stabilization Deep muscle relaxation not needed Just enough to prevent mechanical damage JPMulier VVP 29 09 2009

Effects of ECT Central Nervous System: Musculoskeletal: increase in cerebral blood flow, oxygen consumption, intracranial and intraocular pressure. confusion, agitation or amnesia. headache after the procedure. Musculoskeletal: musculoskeletal injury. The current directly stimulates the jaw muscles and causes the teeth to clench which lead to dental or oral injury. oxygen extraction is increased with desaturation Cardiovascular System: parasympathetic stimulation with risk of bradycardia and hypotension sympathetic stimulation with tachycardia, hypertension and dysrhythmias. Gastrointestinal System: intra gastric pressure rises increased salivation, nausea and vomiting. JPMulier VVP 29 09 2009

Anaesthetic Management Aims Safety. Pleasant and stress free environment Rapid loss of consciousness and attenuation of the hyperdynamic response. Reduction of seizure movements to avoid injury but allowing a visual assessment. Minimal interference with seizure activity. Prompt recovery of spontaneous ventilation and consciousness Preoperatively history, physical examination, and investigations as appropriate. Identify and optimise co-existing disease informed consent. However the underlying condition may lead to patients refusing Ensure that the patient is fasted. JPMulier VVP 29 09 2009

Anaesthetic Management Monitoring Pulse oximeter to monitor cardiac rate and any desaturation that may occur during the fit. ECG and non invasive blood pressure. The psychiatric team monitors the electroencephalogram. Induction Preoxygenate the patient. Use a sleep dose of one of the following intravenous induction agents: methohexitone, propofol, thiopentone, or etomidate. Maintain the airway with an anaesthetic facemask, hand ventilating with 100% oxygen. JPMulier VVP 29 09 2009

Commonly used induction agents 1. Methohexital rapid action, short duration (Mokriski et al, 1992), minimal anticonvulsant effects (dose-related), The APA Task Force on ECT recommends its use as an induction agent of choice (APA, 1990). dose is 0.5-1 mg/kg. 2. Thiopental greater anticonvulsant effects and longer duration of action 3. Ketamine slower onset, delayed recovery, nausea, hypersalivation, ‘bad trips’, and ataxia during recovery (McInnes & James, 1972). increased seizure threshold, dose is 0.5-2 mg/kg (APA, 1990, 2001). 4. Propofol rapid onset, short duration, pain on injection. It has potent anticonvulsant properties (APA, 1990), as evidenced by a number of studies. Propofol (dose 0.75-1.5 mg/kg) resulted in: 1) markedly decreased the intensity and the duration of seizure (Avramov et al, 1995; Boy & Lai, 1990; Chanpattana, 2000; Kirkby et al, 1995; Rampton et al, 1989; Rouse, 1988), Nevertheless, randomized trials between propofol and either methohexital or thiopental do not demonstrate a difference in the therapeutic outcome or the speed of postictal recovery (Martensson et al, 1994; Matters et al, 1995). 5. Etomidate pain on injection, myoclonic activity during induction. low cardiac output state increased seizure threshold (APA, 1990). dose is 0.15-0.3 mg/kg. JPMulier VVP 29 09 2009

Induction agents Brietal ideal but ? Hypnomidate Weinig epilepsie onderdrukking Geen sympatische sedatie rydene nodig Propofol meest gebruikte Beperkte epileptische onderdrukking Geen sympatische storm JPMulier VVP 29 09 2009

Muscle Relaxation incomplete muscular paralysis. 20-50mg. Maintain the airway and ventilate with 100% oxygen Insert an oropharyngeal airway or bite block before allowing the psychiatrist to administer the stimulus when suxamethonium fasciculations has finished. Appropriate: slight twitching of face and limbs Dose too high: no movements The adequacy of ECT is judged by duration of seizure. A prolonged seizure of 120seconds should be terminated with drugs. JPMulier VVP 29 09 2009

Practische procedure eerste ECT Eerste sessie: repetitieve stijgende stroomdosis tot voldoende lange epilepsie aanval gemeten met EEG of fysiche: 1 tot 4 stroomstoten met 2 minuten interval Linker arm: Infuus, pulse oximeter, bloeddrukmeter Rechter arm: bloeddrukmanchette of knelband om circulatie arm af te sluiten voor inspuiten van myoplegine Electrocardiogram Dubbele dosis propofol en myoplegine: 1 mg/kg myoplegine – 2 mg/kg propofol 1 en 2 stroomstoot Bijkomende normale dosis propofol en myoplegine: 0,5 mg/kg myoplegine – 1 mg/kg propofol 3 stroomstoot Afhankelijk van spierreactie en tijdsverschil ( > 2 minuten) nog een halve dosis bijgeven : 0,25 mg/kg myoplegine – 0,5 mg/kg propofol JPMulier VVP 29 09 2009

Practische procedure tweede ECT Daaropvolgende ECT telkens één stroomstoot op zelfde ampere, dosis afh van gewicht, sedatiegraad door antidepressiva, dosis gebruikt bij vorige ECT sessies 0,5 mg/kg myoplegine – 1 mg/kg propofol Knelband opspannen tot ver boven art bloeddruk voor inspuiten van myoplegine Bijtblok tussen tanden JPMulier VVP 29 09 2009

Dilemma’s Dosis: Brietal – Propofol – Ultiva Anti Epilepsie vs awareness / sympatic tone Dosis: Myoplegine – esmeron Visualisatie effect/ restcurarisatie vs protectie Bijtblok: Lip, tong letsels vs tandletsels Masker ventilatie: hyperventilatie Aspiratie vs intubatie JPMulier VVP 29 09 2009

Bijtblokken: Geen tanden -> geen bijtblok Normale stevige tanden -> bijtblok rechts + links: dikke rubber blok. Peridontitis, loszittende tanden, caries -> tandverzorging eerst en op maat gemaakte tandprotector boven en onder kaak: beste protectie doch duur Ontbrekende tanden, caries en geen tandprotector op maat gemaakt: alleen rechts of links rubber bijtblok of helemaal geen bijtblok JPMulier VVP 29 09 2009

Post ECT Care Treat headache with simple analgesics or intra nasal sumatriptan. Monitor the patient in recovery area until the patient is fully alert and able to ambulate. Post ECT agitation, confusion and aggressive behaviour can be attenuated by excessive stimulation during the recovery period. A small dose of benzodiazepine (eg midazolam) or haloperidol may be given. JPMulier VVP 29 09 2009

Side effects of ECT from the anesthesia, the ECT or both. Common side effects temporary short-term memory loss, nausea, muscle aches and headache. Less frequent: longer-lasting memory problems. Sustained hypertension or dysrhythm. JPMulier VVP 29 09 2009