E Lecture 4 Applying ECT Part 2

Applying ECT - II: 

Applying ECT - II E-Lecture 4

Outline: 

Outline Seizure Monitoring Missed Seizures Focal seizures Frequency & number of treatments Maintenance ECT Medication and ECT

Seizure induction: 

Seizure induction Hyperventilation (approximately 20 breaths) immediately before electrical stimulus enhances seizure duration Manual ventilation with 100% O2 during clonic phase Measured O2 saturation should never fall below 90%

Monitoring seizure activity: 

Monitoring seizure activity Hallmark of generalised cerebral seizure activity: tonic– clonic (or grand mal) seizure 1. initial tonic contraction of muscles 2. longer clonic phase of rhythmic alternating contraction & relaxation of muscles of limbs bilaterally. Latent Phase = a possible delay of a few seconds between the end of electrical stimulation and before onset of seizure.

ECT-induced seizure : 

ECT-induced seizure

Monitoring seizure activity: 

Monitoring seizure activity Potential dissociation between generalised cerebral seizure activity and visible convulsive activity: IV induction agents -  visible convulsive activity Muscle relaxants -  visible convulsive activity Prescribed psychotropic drugs with anticonvulsant properties Liston et al (1988) reviewed 10 studies conducted between 1982 – 1987 length of visible convulsion : length of cerebral seizure activity on EEG on average, length of the convulsion was approximately 70% the length of cerebral seizure activity measured by EEG.

Seizure duration & clinical efficacy : 

Seizure duration & clinical efficacy Duration of cerebral seizure activity / tonic– clonic convulsion NOT related to clinical efficacy Question whether generalised cerebral seizure activity occurs if at the first treatment: convulsion lasts < 15 seconds EEG recording shows seizure activity lasting < 25 seconds brief convulsive / seizure activity might be result of focal / partial seizure → i.e. of questionable therapeutic efficacy However some patients recover with ECT and yet display only short tonic– clonic convulsions (?more likely in elderly) Quality of desired activity cannot simply be related to duration alone

Recommendations: 

Recommendations Aim to induce the type of generalised cerebral seizure activity described above In absence of EEG monitoring, or where technical problems mean such monitoring is unreadable, then aim to induce tonic–clonic (grand mal) convulsive activity on both sides of the body as described above

Methods of monitoring Timing of convulsion: 

Methods of monitoring Timing of convulsion Convulsion should be timed from end of electrical stimulation to end of generalised , (i.e. bilateral), clonic activity. When significant discrepancy occurs between end of generalised clonic activity and end of clonic activity in one limb then it would be prudent to record both times. Convulsive activity of facial muscles can be seen with focal cerebral seizure activity should not be counted if occurs on its own

Methods of monitoring Timing of convulsion 2: 

Methods of monitoring Timing of convulsion 2 To observe whether aim of ECT has been achieved With brief convulsion helps ensure that necessary quality of seizure activity has indeed been induced EEG monitoring alone vulnerable to technical problems: EEG tracing may be unreadable due to artefact Connecting cables may become disconnected Machine may unexpectedly run out of paper

Methods of monitoring Cuff technique: 

Methods of monitoring Cuff technique minimises influence of muscle relaxant on assessment of convulsive activity isolating one forearm or leg by inflating a BP cuff above systolic BP: as patient is drifting off to sleep before muscle relaxant is administered Cuff pressure above systolic BP isolates distal part of limb from circulating muscle relaxant unmodified convulsive activity can be observed IMPORTANT to maintain cuff pressure well above systolic BP seen during seizure activity circulating muscle relaxant may leak into distal part of limb may be concentrated there, as venous return is occluded

Methods of monitoring Cuff technique 2: 

Methods of monitoring Cuff technique 2 Keep Length of time cuff kept inflated to a minimum deflate as soon as convulsion has ended In Unilateral ECT cuff should be applied to one of ipsilateral limbs to ensure that a bilateral convulsion occurs Technique not widely used. no difference between length of convulsion in cuffed and uncuffed limbs in one English ECT clinic Routine use cannot be recommended

Methods of monitoring Cuff technique 3: 

Methods of monitoring Cuff technique 3 But may still be helpful when: Only brief convulsive activity seen at outset of ECT course & where EEG monitoring not available Substantial proportion of patients who display brief convulsive activity will experience typical generalised cerebral seizure activity, and will therefore not require restimulation or increased electrical dose at next treatment Unusually large dose of muscle relaxant is administered for total muscle paralysis Eg . in patient with recent fracture of a long bone

Methods of monitoring EEG monitoring: 

Methods of monitoring EEG monitoring Most direct available means of measuring seizure activity in brain itself Major disadvantages: Poor experience of the technique, ECT machines with EEG monitoring = more expensive ECT staff require extra training and supervision to use it effectively Especially useful: Where complete paralysis is required When assessing brief convulsive activity at the outset of an ECT course To detect prolonged seizures = avoids: markedly increased cognitive adverse effects without any commensurate therapeutic benefit IMPORTANT now that minimising cognitive adverse effects has become a priority for contemporary ECT practice .

Methods of monitoring EEG monitoring 2: 

Methods of monitoring EEG monitoring 2 Necessary cerebral seizure activity is by definition synchronous neuronal activity that is generalised - occurs in both cerebral hemispheres Single-channel EEG recording is not recommended – cannot distinguish focal from generalised cerebral seizure activity harder to distinguish artifacts from true cerebral seizure activity At least one channel from each side of the head is required. ECT machine manufacturers can supply self-adhesive, pre-gelled, disposable EEG electrodes

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EEG monitoring Prolonged seizures: 

EEG monitoring Prolonged seizures Prolonged cerebral seizure activity is a recognised adverse effect of ECT  risk of adverse cognitive effects without any commensurate  in clinical efficacy treatable if detected No consensus about definition of a prolonged seizure 1st edition RCPsych handbook suggested  2 minutes APA (2001) subsequently suggested  3 minutes Once identified should be terminated immediately: by further dose of induction agent or by IV benzodiazepine drug

Prolonged seizures: 

Prolonged seizures Mayur et al (1999) – from India: 16% had prolonged cerebral seizure activity on 1st ECT one-third of cases only detectable by EEG monitoring convulsion itself was not prolonged defined prolonged cerebral seizure activity as  2 minutes highest prevalence of prolonged cerebral seizure activity ever reported Much lower prevalence subsequently reported from two Scottish centres ?special features of Indian sample Eg . the large proportion of young people. Abrams (2002): high prevalence did not accord with his own clinical experience, usually seen only where there was some unusual aspect of the patient or the treatment Eg . coexisting brain disease

Prolonged seizures: 

Prolonged seizures Concerns: prevalence of prolonged cerebral seizure activity may be higher than appreciated prolonged seizures may not be detected if seizure monitoring relies only on timing visible convulsion. Some isolated case reports: non-convulsive prolonged cerebral seizure activity or status epilepticus detected only because of simultaneous EEG monitoring Risk of prolonged cerebral seizure activity is highest at first treatment in a course Despite lack of research Specialist Committee recommended that EEG monitoring should be provided in all ECT clinics

Missed Seizures: 

Missed Seizures Absence of both visible convulsion & EEG seizure Causes: Insufficient stimulus intensity Excess dynamic impedance Premature stimulus termination Hypercarbia Dehydration Effects of other treatment ( eg benzos ) Pt may develop marked bradycardia Atropine / glycopyrrolate should be available

Missed Seizures 2: 

Missed Seizures 2 Re-check electrode position Allow at least 20 seconds (delayed seizure) Restimulate at a higher dose Future Rx Consider decrease in anaesthetic dose ? Benzodiazepine reversal

Focal Seizures: 

Focal Seizures Maybe due to excess anaesthetic agent Recheck electrode position Allow 45-90 seconds – central repolarisation could occur ?might need more anaesthesia Restimulate at a higher dose

Prolonged / Tardive seizures: 

Prolonged / Tardive seizures Prolonged seizure = duration  2mins Tardive seizure = late return of seizure activity = maintain oxygenation = monitor EEG activity = anaesthetist should be prepared to abort seizure with further doses of anaesthetic agents / benzodiazepines

Frequency of treatments: 

Frequency of treatments UK ECT Review Group - bilateral ECT given 3x weekly was not more efficacious than 2x weekly (measured by  in depressive symptoms after a complete course of treatment) Individual RCTs - show clearly that higher frequency of Rx = more cognitive adverse effects meta-analysis of comparative effects on cognitive function not possible

Frequency of treatments 2: 

Frequency of treatments 2 Greatest reduction in depressive symptoms occurs with 1 st bilateral ECT Rx 3x vs 2x weekly: No difference in  depressive symptoms after 3 ECT Rx Advantage of 3x weekly seen only after 4 ECT Rx clinically meaningful only after 5 ECT Rx Not certain that 1 week 3x weekly Rx sufficient to initiate this course of more rapid clinical improvement.

Number of Treatments: 

Number of Treatments No RCTs Not possible to predict reliably no. of ECT Rx’s required Each individual needs individual assessment Good practice to assess after every 2 Rx’s Bilateral ECT If no improvement after 6 adequate Rxs – stop If slight improvement try till 12 Rx’s – stop if no further improvement Unilateral ECT If no improvement after 4-6 adequate Rx’s – switch to bilateral When starting bilateral – disregard no. of unilateral Rx’s Start counting from 1 st bilateral – then proceed as for bilateral

ECT as a continuation or maintenance treatment : 

ECT as a continuation or maintenance treatment Relapse following an ECT course is common – Some patients still relapse despite prophylactic pharmacological Rx Such patients often require a further course of ECT in order to recover Some patients respond only to ECT → continuation / maintenance ECT Before advent of effective drug treatments ECT was often used to – prevent early relapse of the index episode of illness (continuation ECT) prevent further episodes or recurrences of illness (maintenance ECT)

Continuation ECT: 

Continuation ECT Prophylactic Rx over first 6 months of remission. Should be considered when: Index episode of illness responded well to ECT Early relapse despite adequate continuation drug treatment Inability to tolerate continuation drug treatment Patient’s attitude & circumstances are conducive to safe administration. Case reports suggest prolonged courses of ECT are effective and can be given without cumulative adverse cognitive effects RCT sponsored by NIMH still awaited

Continuation ECT: 

Continuation ECT Reduction in frequency of ECT until a stable state is reached i.e the maximum spacing between treatments without return of symptoms Allowing for individual variation, monthly is an appropriate goal. Suggested protocol: Acute ECT until a clinical response achieved Reduce to weekly Reduce to every 10 days Reduce to every 2 weeks Reduce to every 3 weeks Reduce to monthly Monitor for cognitive S/E At least using MMSE every month Psychometric tests for intelligence + memory + language Baseline Follow-up every 12 months

Stopping continuation ECT: 

Stopping continuation ECT Relapse is most likely within the first 12 months of recovery continuation ECT for at least 1 year after recovery with reviews as above Full review of need for long-term ECT after 1 year: consultation with the patient, carers and staff involved If course given to prevent relapse (continuation ECT) → consider terminating course at this stage. Maintenance ECT: For prevention of further episodes course should be continued indefinitely full review every 12 months No way of predicting how likely a relapse or recurrence is following the withdrawal of continuation ECT.

Psychotropic drug treatment during and after ECT : 

Psychotropic drug treatment during and after ECT The Maze (1953) William Kurelek Painted when admitted to Maudsley Hospital with schizophrenia

Benzodiazepines: 

Benzodiazepines may  therapeutic efficacy of ECT due to powerful anticonvulsant properties Recommendations Wherever clinically possible, concomitant prescription of benzodiazepines should be avoided during a course of ECT. If a hypnotic drug is clinically indicated at night, consider using a non-benzodiazepine drug. Long-established benzodiazepine drug use should not be stopped suddenly just a few days before a course of ECT because there is the risk of a dramatic lowering of seizure threshold. If the dose cannot be gradually reduced and stopped before the administration of ECT, it may be better to continue the drug during ECT, perhaps in reduced dosage.

Antidepressants: 

Antidepressants Antidepressants should not be abruptly discontinued before ECT, particularly with a short half-life or SSRIs* Monoamine oxidase inhibitors do not need to be discontinued before ECT, but anaesthetist should be informed in advance Probably better to prescribe an effective antidepressant drug at least before the end of a course of Rx → to provide adequate early prophylaxis. In elderly / patients with pre-existing cardiac disease, potential cardiotoxicity should influence the choice of drug. In patients premedicated with an SSRI, it would be prudent to start with a low electrical dose (25–50 mC ) at the first treatment* (*may cause prolonged cerebral seizures )

Lithium: 

Lithium Co-administration of lithium is not a C/I to ECT. Preliminary evidence: early introduction of lithium reduces likelihood of early relapse of depressive illness after ECT Lithium with ECT may be one risk factor among several for adverse effects Eg . prolonged cerebral seizure activity Lithium lowers seizure threshold May be prudent to start with low electrical dose (25–50 mC ) at first treatment

Anti-epileptic Drugs: 

Anti-epileptic Drugs If prescribed for epilepsy should continue throughout course of ECT As mood stabiliser , no evidence-based recommendation can be made may be better to continue prescription during the course of ECT AEDs may : raise the seizure threshold shorten seizure duration modify the convulsion ECT titration schedules have to take account of co-administration of AEDs If induction of seizures becomes problematic during course of ECT prescribed AED daily dose may need to be reduced

Antipsychotics: 

Antipsychotics No synergistic effect shown between ECT and antipsychotic drugs in Rx-resistant schizophrenia or depression Small dose of a sedative antipsychotic preferred to a benzodiazepine if a hypnotic drug is indicated Manufacturer of clozapine suggests drug is withheld for 12 hours before any general anaesthetic next dose can be given at the usual time and at the usual dose if the patient’s vital signs are stable Clozapine may lower seizure threshold → may be prudent to start with a low electrical dose (25–50 mC ) at first treatment

Caffeine: 

Caffeine ? co-administration of caffeine (adenosine antagonist) might augment therapeutic effects of ECT by prolonging cerebral seizure activity One RCT: IV caffeine 5 minutes before ECT prolonged cerebral seizure activity by about one-third but had no effect at all on the seizure threshold Recommendation Co-administration of caffeine unlikely to  therapeutic effects of ECT

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