Update in anaesthesia for Electro Convulsive Therapy: A forgotten anaesthetic sub speciality

JC Watts and K Butler discuss the key role the anaesthetist plays in the Electro Convulsive Therapy process

Introduction: a typical patient

An elderly patient with a previous history of anxiety and depression became severely depressed following bereavement. Antidepressants were not effective and they refused to eat, losing a significant amount of weight in a short time. Fluid intake was poor and they were admitted onto a medical ward with dehydration and acute kidney injury. This improved with intravenous fluids, but the patient continued to refuse diet, and despite attempts at NG feeding their weight loss continued. The patient was not co-operative with oral medication and so the mental status did not improve. A decision for electroconvulsive therapy (ECT) was made following discussion with the family. This was considered a significant risk, as the patient was now severely malnourished and bedbound, but the treatment was hoped to be lifesaving. The ECT was successful and after six treatments the patient had improved sufficiently to be transferred to a psychiatric ward for the rest of the treatment and was taking small amounts of diet and co-operative with medication. After two months the patient was well enough to be discharged home with community input.

Electro Convulsive Therapy

Electro convulsive therapy (ECT) was introduced into clinical practice following a supposed observation that those who suffered epilepsy did not also have schizophrenia. It soon became clear that it was most beneficial in the treatment of severe depression. The treatment has been in and out of favour over the decades, but has remained a mainstay of psychiatric treatment in severe cases [1].

ECT involves the passage of an electric current through the brain (using either bilateral or unilateral approaches) to induce a seizure. The amount of electricity used is titrated against the duration of the seizure and the clinical improvement. Different ECT machines will deliver differing amounts of electricity, but typically 0.75- 0.9 amps, 225-450 volts are used to deliver something of the order of 1,000 miliCoulombs in 5.3 secs [2].

It is surprising to many that anaesthesia and paralysis were not always administered for the procedure, due to fears that the drugs would modify the fit and therefore the therapeutic effects. It should be remembered however that the case which is the foundation of UK medico-legal negligence practice, the origin of the so-called Bolam test, relates to a patient who underwent ECT without muscle relaxation, and whom received serious injuries as a result. The doctors were judged not to have been negligent because the practice was regarded as reasonable by a responsible body of medical practitioners [3]. Nowadays, the risk of injury is routinely mitigated by the use of muscle relaxation.

Despite the fact that the ECT suite was often in an area distant to the main hospital, and performed on patients with multiple health problems, who were taking multiple medications and were receiving the therapy at least twice weekly, two regional audits in the 1970s and 80s showed that basic standards, including anaesthetic standards, were not being adhered to [4,5]. Fortunately, following pressure exerted by various authorities including the Royal College of Anaesthetists, the situation today is much better, with patients being properly assessed medically before the procedure, with the upskilling of psychiatric department staff, with the insistence on a named psychiatric and anaesthetic lead consultant, and the use of full, recommended AAGBI monitoring [6]. ECT is now subject to NICE guidance [7] and anaesthetic practice in the ECT suite is included as one of the recommended RCoA audit recipes [8], and so practice can be continually monitored and improved.

Practice and physiology of ECT

It is estimated that around 4,000 patients a year undergo ECT in the UK, and that a substantial number of these are performed under section 58a of the Mental Health Act [9, 10]. Despite this, it is not quite clear how ECT works. Blood flow through certain parts of the brain increases, as do some neurotransmitter levels, but the exact mechanism remains obscure. However, positive early results can be seen as 75-90 per cent of patients exhibit a dramatic and sustained improvement [11, 12].

The anaesthetist has a key role in ensuring that practise is safe, and so must have a high level of situational awareness, not least because the ECT suite is usually in an isolated area, some distance from the main hospital. Important issues to consider include the level of physical health of the patient; their reaction to previous ECT episodes; whether appropriate consent is being used; whether it is being done as an outpatient; and the physiological responses to ECT, which are variable. The electrical discharge will induce both parasympathetic and sympathetic effects. This can result in bradycardia, tachycardia, cardiac arrhythmia, and hypo or hypertension. General oxygen consumption increases, as do intracranial, intraocular and intragastric pressures. Other effects include anterograde amnesia, headaches and increased salivation. Overall mortality rate with ECT is thought to be about 1 per 80,000 treatments [13, 14, 15].

Anaesthesia should be administered by an experienced anaesthetist in accordance with established guidelines for working in isolated areas. The approach to provision of anaesthesia should be identical as that employed in any other sphere of practice. However, as patients may be travelling some distance for their ECT, pre-operative assessment processes may need to be modified to minimise unnecessary travel, particularly in those who are under Section. Absolute contra indications should be identified, and relative contraindications addressed as far as possible (see Table 1). Where ECT is thought to be particularly risky, then it should be arranged for the patient to have their therapy completed in a theatre environment. It should be noted that there are case reports of ECT having been successfully performed even when so called absolute contraindications have existed.

Patients should be prepared as usual for a general anaesthetic, and anaesthetic technique should be tailored to produce a rapid onset and offset of anaesthesia. Propofol is commonly used, and there is usually no requirement for premedication. Research is continuing into which combination of anaesthetic agents will produce the optimum conditions, and minimise distressing side effects. Suxamethonium in reduced dose is the muscle relaxant of choice, although if contraindicated it is possible to substitute a non-depolarising relaxant. Intubation is required only if specifically indicated, and most patients can be managed with pre-oxygenation, an oropharyngeal airway and bag and face mask. AAGBI monitoring standards should be adhered to.

Conclusion

The scenario outlined above illustrates a typical case where ECT can prove lifesaving, despite the risks of an anaesthetic in an elderly patient with co-morbidities. ECT in these patients without capacity to consent obviously requires a multidisciplinary approach and discussions with the family. The situation of managing a psychiatric patient on a medical ward can be challenging for staff, particularly if the mental health services are located in a different hospital so regular input is not available. Despite the fact that ECT is often an urgent or lifesaving treatment, clearly the patient’s medical condition must be stabilised first. As anaesthetists we are often the last specialists to be involved after failed drug treatment, and are then presented with a chronic condition that has suddenly become an urgency. In our experience, it is best to treat these patients in the same way as a patient with a fractured neck of femur: their condition including electrolyte imbalances should be optimised as far as feasible in the time available.

ECT lists have several disadvantages for anaesthetists, as organisational issues can affect normal practices. However, it also has its rewards as it is rare in theatre practice to see patients on a weekly basis and watch their condition improve. To witness patients who initially are unable to show any verbal communication or eye contact, over a period of a few weeks, be able to converse with you and share a little small talk or banter is truly fulfilling.

In summary, ECT lists can be a rewarding experience for anaesthetists, providing that a multidisciplinary approach ensures that the procedure is as planned, and as safe, as possible. The anaesthetist plays a key role in that process.

References

1. Medicine Michigan Electroconvulsive Therapy Program A Brief History of ECT (http://www.psych.med.umich.edu/ect/history.asp last accessed 20th June 2017)
2. Org ECT machines https://www.ect.org/resources/machines.html last accessed 20 June 2017
3. Bolam vs Friern Hospital Management Committee[1957] 1 WLR 582
4. Pippard J Audit of electroconvulsive treatment in two National Health Service Regions British journal of psychiatry 1992 160; 621-38
5. Pippard J Ellam L Electroconvulsive treatment in Great Britain British journal of psychiatry 1981 139: 563-8
6. ECT Accreditation service ECT Accreditation Service (ECTAS) Standards for the administration of ECT Thirteenth Edition: April 2016 http://www.rcpsych.ac.uk/pdf/ECTAS%2013th%20Edition%20Standards.pdf last accessed 20 June 2017
7. Guidance on the use of electroconvulsive therapy 2003 (updated 2009; reviewed 2014 https://www.nice.org.uk/guidance/ta59 last accessed 20th June 2017
8. Paw H GW Gopalswarmy HK 6.4 Anaesthesia for electroconvulsive therapy (ECT) in ECT clinics in Royal College of Anaesthetists | Raising the Standard: a compendium of audit recipes 3rd Edition 2012
9. Bickerton, D., Worrall, A. & Chaplin, R. Trends in the administration of electroconvulsive therapy in England.Psychiatric Bulletin, (2009) 33,61–63.
10. ECT without consent in England; the highest users https://ectstatistics.wordpress.com/ last accessed June 2017
11. Information about ECT http://www.rcpsych.ac.uk/healthadvice/treatmentswellbeing/ect.aspx last accessed June 2017
12. Easto A Waite J The ECT Handbook 3^rd edition RCPsych publications 2012
13. Uppal V, Dourish J, Macfarlane A Anaesthesia for electroconvulsive therapyContin Educ Anaesth Crit Care Pain (2010) 10 (6): 192-196.
14. Mayo C Kaye AD, Conrad E, et al Update on anesthesia considerations for electroconvulsive therapy. Middle East Journal of Anaesthesiology  2010, 20(4):493-498]
15. Wang X, Chen Y, Zhou X et al Effects of Propofol and Ketamine as Combined Anesthesia for Electroconvulsive Therapy in Patients With Depressive Disorder Journal of ECT:June 2012 – Volume 28 – Issue 2 – p 128–132

Authors:

Butler K and Watts JC, Consultants in Anaesthesia, East Lancashire NHS University Trust, Royal Blackburn Hospital, Haslingden Road, Blackburn.

Staff Writer