Anesthesia for ECT

1. Anesthesia for ECT Patrick McElhone, CRNA Chief CRNA Hines VA Hospital

2. Disclosures

3. Anesthesia for ECT • History • Theories on how ECT works • Indications for ECT • Complications of ECT

4. History of ECT • The concept of inducing convulsions to promote mental wellness has existed since the 16th century • Swiss alchemist Paracelsus gave camphor by mouth to induce convulsions and “cure lunacy”

5. Seizures Cure Catatonic Schizophrenia • In 1934, Ladislaw Meduna, a Hungarian psychiatrist, investigated a hypothetical inverse relationship between seizures and schizophrenia • Lack of glial cells in individuals with schizophrenia • Overgrowth of these cells in people with epilepsy.

6. Seizures Cure Catatonic Schizophrenia • Meduna hypothesized that inducing epilepsy would cure cure patients with schizophrenia • Meduna injected camphor in oil into a patient with catatonic schizophrenia, causing a 60 second grand mal seizure. • The patient went into a full recovery after a short series of such treatments

7. Development of ECT: Camphor to Electricity • Camphor was replaced by Metrazol • Frequent seizures • Vertebral fractures • Pulmonary tuberculosis • Myocardial damages • Hypertension • Alternative methods to induce Seizure • Electricity was recently used to induce seizures in dogs

8. Development of ECT • Italian scientists Cerletti and Bini defined the parameters to applying electricity to the human scalp to induce seizures • 1938, 39yo, found delusional at train station electrically induced seizures • Full recovery reported after 11 treatments • Electroconvulsive Therapy was born

9. How Does ECT Work: Psychological Effects • Patient’s expectations • Placebo effect • Force regression • Retrograde amnesia • Proven incorrect

10. How does ECT Work: Neurophysiological Effects • Anticonvulsant • Treatment of Intractable Seizures • Increased Seizure Threshold during treatment course • Decrease Seizure Duration over the treatment course • Increase inhibitory neurotransmitter • Decrease in excitatory neurotransmitters • Post-ictal bioelectrical suppression • All associated with improved clinical improvement

11. How Does ECT Work: Effects on Hippocampus • Promote neurogenesis dentate gyrus • Perera et al. • 12 ECT total (3x week/4 weeks) to monkeys • Increase in cell proliferation in the dentate gyrus • Increase lasted for 4 weeks • Meduna saw a lack of glial cells in schizophrenics and an over growth of glial cells in epileptics

12. How Does ECT Work? Decrease Glucocorticoid levels • Chronic Stress leads to decrease cell proliferation in the dentate gyrus • Basis for the animal model of depression • ECT can mitigate this response • Increase in BDNF

13. Indications for ECT • Schizophrenia • Catatonia • Mania • Depression

14. Indications for ECT • Increased Clinical Urgency • Depressive Hallucinations • Catatonia • Suicidal Ideations • Intolerance to psychotropic drugs • Failure of drug therapy • Patient Preference • Co-existing Medical Disorders for which psychoactive medication poses a risk • Pregnancy • Cardiac patients-TCAs

15. ECT for Schizophrenia • First use of ECT • Fell out of use with antipsychotic medications in 1950s • Most common indication for ECT in India and other Asian Countries • Indications: • Augment to pharmacotherapy • Rapid improvement is needed • Refractory to medication • Catatonia

16. ECT for Schizophrenia • Combined with antipsychotics • Multitude of studies showing improvement when combined with Clozepine • Effects were not persistent and required continuation in treatments

17. ECT for Mania • 80% Manic patient had remission or marked improvements • Showed improvement when pharmacotherapy did not • Lower seizure threshold • Improvement seen in few treatments

18. ECT For Depression • Treatment Resistant Depression • 80% of all ECT in US • 50% of patients showed improvements • 50% relapse with 12months

19. ECT For Depression compared to medication • 20% higher response vs. tricyclic antidepressants • 45% higher response vs. MAOIs • “No study has found any treatment to be superior to ECT for the treatment of major depression

20. Complications of ECT • Skeletal Injuries • Cervical Fractures-Unmodified • Long Bone Fractures-Unmodified • Cognitive Decline • Memory Loss • Concentration and Attention Problems • Confusion • Brain Injury?? TBI? • Why??? • Complications from procedure/anesthesia

21. Bilateral vs Uni-lateral Electrode Placement • Bilateral • Most common in use • Better seizures • Memory loss • Uni-lateral • Less impairment of new learning capacity • Less amnesia for remote events • Possible to not trigger seizure

22. "Well, what is the sense of ruining my head and erasing my memory, which is my capital, and putting me out of business? It was a brilliant cure but we lost the patient....” -Ernest Hemingway

23. Anesthesia in ECT aka Modified ECT • 1940s Neuromuscular blocking agents (NMB) used to prevent joint/bone injury during treatment • Curare • Succinylcholine • Short acting IV anesthetics were administered to prevent memory of being paralyzed • Unmodified ECT • Done without anesthesia is still practiced in Japan, China and India

24. Anesthesia for ECT Overview • Akinesia #1 • Prevent excessive motor activity during seizure • Musculoskeletal Injury • Oxygen consumption • Amnesia • Prevent recall of being paralyzed • Autonomic Stability • Managed parasympathetic and sympathetic effects of ECT • Analgesia • Ensure patient comfort from procedure • Myalgia from succinylcholine • Headaches from ECT

25. AkinesiaNeuromuscular Blocking Agents • Competitively block acetylcholine at the neuromuscular junction • Prevent motor end plate activation • 2 primary types • Depolarizing • Succinylcholine • Non-deplolarizing • Rocuronium • Vecuroniom • Cis-atricurium

26. Depolarizing neuromuscular blocking agents • Succinylcholine (Anectine) • Activates the motor end-plate • Cause a prolong depolarization • Fasciculations • Relaxation occurs during the relative refractory period • Primary NMB used in ECT • Dose 0.5-1.5mg/kg • Contraindications • Malignant Hyperthermia • Paralysis/Weakness • Burns • Hyperkalemia

27. Non-deplorazing neuromuscular blocking agents • Block end-plate but do not cause any action • Longer duration of action • Rocuronium • Cisatricurium • Reversible • Neostigmine • Blocks acetylcholinesterase • Allows competitive build-up of Acetylcholine • Sugamadex • Binds to free rocuronium • Rapid, complete

28. Amnesia agents for ECT“Remember why we are here”

29. GABAergic agents • Activate gaba receptors • Influx of Cl- Channels • Hyperpolarization of neuron • Anticonvulsants • Limits effectiveness in ECT • Medications • Methohexital • Etomidate • Propofol

30. Methohexital (Brevital) • “Gold Standard” • Barbiturate • No Change on ECT induced seizure duration • Dosage: • 0.75-1.0mg/kg • Increased dosage • Chronic ETOH • Benzodiazepines • Contraindicated in acute intermittent porphyria

31. Etomidate • Gabametic • Increases seizure duration • Compared to methohexital, thiopental, and propofol • Useful seizure <20s • Dosage • 0.15–0.3 mg/kg • Hemodynamically stable • Increased sympathetic response

32. Propofol • Potent anticonvulsant effects during ECT • 1-1.5mg/kg • 1.5mg/kg still shown to allow adequate seizure • Minimal hypnotic dosage 0.75mg/kg compares to methohexital

33. Ketamine • NMDA receptor antagonist • Blocks glutamate • Decrease seizure duration compared to methohexital • Enhances sympathomimetic activity • Increases ICP

34. Autonomic stability-Initial Response to ECTHemodynamic Changes with ECT • Parasympathetic Surge • Anticipate bradycardia • Asystole • Increase secretions • Anticholinergics Pretreatment • Glycopyrrolate 0.2-0.4mg • Less tachycardia • Atropine 0.4mg-1.0mg • Sympathomimetics during arrest • Epinephrine 10-100mcg

35. Autonomic Stability-Second Response to ECT • Sympathetic Surge • Increased BP 20-40% • Increase HR >20% • Last 3-5min • Risks: • Myocardial Ischemia • Treatment • Beta receptor antagonists • Labetalol • Esmolol • Vasodilators • Hydralazine

36. Regional Cerebral Oxygen Saturation During Electroconvulsive Therapy: Monitoring by Near-Infrared SpectrophotometrySaito, Shigeru MD; Miyoshi, Sohtaro MD; Yoshikawa, Daisuke MD; Shimada, Hitoshi MD; Morita, Toshihiro MD; Kitani, Yasuharu MDAnesthesia & Analgesia:  October 1996 - Volume 83 - Issue 4 - pp 726-730Neurosurgical Anesthesia • 43 patients, ECT under GA • Continually monitored • Heart rate (HR) • Mean arterial blood pressure • Regional cerebral oxygen saturation (rSO2) •  rSO2 changed conisently • Initially, -9.4% +/- 0.9% • Later, +8.7%, =?- 0.9% • Demonstrated a close correlation between the increase in rSO2 and the mean blood pressure after the electrical shock (r2 = 0.832, P < 0.0001)

37. Analgesia in ECT • Muscle aches-myalgia • Succinylcholine • Headache-ECT electrodes • Treatment • Ketoralac • IV NSAIDs Acetaminophen • Opioids • Fentanyl 25-50mcg • Best assessed after ECT

38. Complications from ECT • Airway • Difficult airway management • Larygnospasm • Respiratory • Aspiration • Prolonged muscle weakness • Cardiovascular • Effects of ECT • Bradycardia/asystole • Tachycardia • Cardiovascular • Effects of anesthetics • Prolonged seizures • Propofol • Midazolam • Emergence delerium • Midazolam

39. Airway Management • NMB induce apnea • Ventilatation • Oxygenation • NMB abolish the airway protective reflexes • Increased risk of aspiration

40. Apnea • Mask Ventilation-most common • Supra-glottic airway • Prolonged apnea • Difficult mask ventilaiton • Endotracheal Intubation • High risk for aspiration • Prolonged apnea

41. Aspiration • Nothing by mouth • Endotracheal tube intubation for high risk patients • GERD • Hiatal Hernia • Delayed gastric emptying • Extubate awake and airway reflexes have returned

42. Equipment for ECT Anesthesia • Machine • Suction • Monitors • Nerve Stimulator! • EKG and BP • Pulse-Oximetry and ETCO2 • Airway • Oral Airway • Bite Block • Endotracheal tube • IV • Drugs

43. Balanced Individualized Anesthesia for ECT

44. Experiences? Questions? Thank you