Electroconvulsive Therapy Emergencies: Managing Complications

Electroconvulsive therapy (ECT) is considered one of the most effective treatments in psychiatry – particularly for treatment-resistant depression, acute suicidality, and catatonic states. Despite its excellent safety profile, it is a procedure that involves brief general anesthesia, neuromuscular blockade, and controlled cerebral seizure activity. This alone makes it clear: anyone working on an ECT team must be prepared for emergencies. While the mortality rate is in the range of 1:50,000 to 1:100,000 treatments – comparable to the risk of general anesthesia – the complications that can occur require rapid, structured management. This article summarizes the most relevant emergency scenarios and provides you with a practice-oriented guide for their management.

Monitoring Fundamentals in ECT

Before we turn to complications, it is worth looking at the monitoring that forms the basis for early detection of any complication. Standard monitoring during an ECT treatment includes:

• ECG (at least 3-lead): detection of arrhythmias, ST-segment changes, asystole
• Pulse oximetry: continuous SpO₂ monitoring
• Non-invasive blood pressure measurement: at frequent intervals, ideally every 1–2 minutes during the peri-ictal phase
• EEG (at least 2 channels): assessment of seizure duration and quality, detection of prolonged seizures and non-convulsive status epilepticus
• Capnography: increasingly recommended for ventilation monitoring, especially during mask ventilation
• Peripheral nerve stimulation (TOF): for assessment of neuromuscular blockade
• Cuff method: a blood pressure cuff on one extremity is inflated above systolic pressure before succinylcholine administration to allow assessment of motor seizure activity distally

The entire team – anesthesiologist, psychiatrist, nurse – should go through a structured checklist before treatment begins, covering not only monitoring but also the availability of all emergency medications and airway management equipment.

Cardiovascular Complications

The heart is the organ most frequently affected by complications during ECT. The electrical stimulus and the resulting generalized seizure trigger a characteristic biphasic autonomic response.

The Biphasic Autonomic Response

1. Parasympathetic phase (immediately after the stimulus, lasting seconds): Vagal stimulation leads to bradycardia, occasionally asystole
2. Sympathetic phase (during and after the seizure, lasting minutes): Catecholamine release with tachycardia, hypertension, increased myocardial oxygen consumption

This sequence explains why both bradycardic and tachycardic complications can occur – and why the timing of the complication is crucial for therapy.

Asystole and Bradycardia

Transient asystole lasting a few seconds is a physiological phenomenon and occurs in up to 20% of ECT treatments. It becomes clinically relevant when it:

• Persists for more than 5–10 seconds
• Becomes hemodynamically significant
• Transitions into persistent bradycardia

Management:

• Atropine 0.5–1 mg IV is the first-line agent. In patients with a known tendency toward ECT-associated asystole, prophylactic administration of glycopyrrolate (0.2–0.4 mg IV) or atropine before the stimulus may be considered.
• For persistent asystole: proceed according to the ACLS algorithm for asystole/PEA – begin chest compressions, epinephrine 1 mg IV every 3–5 minutes, evaluate reversible causes (Hs and Ts).
• Transcutaneous pacing should be immediately available.

Hypertensive Crisis and Tachycardia

Sympathetic activation can drive systolic blood pressure above 200 mmHg – in patients with pre-existing hypertension or pheochromocytoma, potentially much higher. At the same time, heart rates of 130–160/min are not uncommon.

When to treat? A definitive threshold does not exist, but intervention should be considered with:

• Systolic blood pressure > 200 mmHg or diastolic blood pressure > 120 mmHg
• Tachycardia > 150/min
• ST-segment changes on ECG
• Clinical signs of end-organ damage

Pharmacological options:

• Esmolol 0.5–1 mg/kg IV bolus, followed if needed by an infusion (50–200 µg/kg/min): short-acting β₁-selective blocker, ideal for this situation. Reduces both heart rate and blood pressure.
• Labetalol 5–20 mg IV: combined α/β-blocker, somewhat longer duration of action
• Urapidil 12.5–25 mg IV: peripheral α₁-blocker and central 5-HT₁A agonist, well-established and widely available in Austria
• Nitroglycerin 0.5–1 mg sublingual or 1–5 mg/h IV: for primarily hypertensive episodes
• Clevidipine IV as an ultra-short-acting calcium channel blocker may also be considered

Caution: The hypertensive episode is usually self-limiting (minutes). Aggressive antihypertensive therapy carries the risk of rebound hypotension during the recovery phase. Dose cautiously and titrate to effect.

Myocardial Ischemia and Arrhythmias

In patients with coronary artery disease, there is a risk of myocardial ischemia due to the combination of tachycardia and hypertension. Ventricular arrhythmias, atrial fibrillation, and ventricular tachycardia have been described but are rare.

Management:

• ST-segment changes → immediate rate and blood pressure control (esmolol), 12-lead ECG, troponin measurement
• VT with pulse → amiodarone 150 mg IV over 10 minutes, synchronized cardioversion if needed
• VF/pulseless VT → immediate defibrillation and ACLS algorithm
• New-onset atrial fibrillation → synchronized cardioversion if hemodynamically unstable, otherwise rate control

Prolonged Seizures and Status Epilepticus

According to AHA and ECT specialty society recommendations, a seizure is considered prolonged if it lasts longer than 120 seconds on EEG (some centers use 180 seconds as the threshold). An unterminated seizure can progress to status epilepticus, which is associated with increased risk of brain injury, hypoxia, and cardiovascular complications.

Risk Factors

• Concurrent use of theophylline or lithium
• Hyponatremia
• Young patients
• First ECT treatment in a series
• High stimulus energy

Detection

EEG monitoring is indispensable here. Purely clinical monitoring frequently misses prolonged seizures because neuromuscular blockade suppresses motor activity. A non-convulsive status epilepticus is undetectable without EEG.

Stepwise Treatment

1. Hyperventilation – First attempt enhanced mask ventilation: hypocapnia raises the seizure threshold
2. Propofol 0.5–1 mg/kg IV – Rapid onset and usually already available in the ECT setting as the induction agent
3. Midazolam 2–5 mg IV – Classic benzodiazepine for seizure termination
4. Thiopental 50–100 mg IV – If available and other measures are insufficient

Important: Repeat EEG assessment after each intervention. Document the seizure duration precisely. A prolonged seizure alters the planning of subsequent ECT sessions (adjustment of stimulus parameters, change of anesthetic agent).

Airway Complications

ECT is typically performed under mask ventilation. A secured airway with endotracheal intubation is the exception. This results in specific risks:

Aspiration

• Patients should be fasting (at least 6 hours for solid food, 2 hours for clear fluids)
• For patients requiring rapid sequence induction (e.g., ileus, severe reflux), intubation or use of a supraglottic airway device should be considered
• If aspiration is suspected: immediate suctioning, intubation, bronchoscopy if needed

Laryngospasm

• Can occur particularly during the emergence phase when neuromuscular blockade is already wearing off
• Management: jaw thrust, PEEP maneuver, if necessary succinylcholine 0.25–0.5 mg/kg IV at a lower dose for relaxation, readiness for intubation

Bronchospasm

• Relevant in patients with bronchial asthma or COPD
• Management: salbutamol 2–4 puffs via spacer or nebulizer, for severe obstruction epinephrine 0.3–0.5 mg IM or titrated IV, deepening of anesthesia

Difficult Airway

A difficult airway must be identified before the ECT. The pre-anesthetic evaluation includes Mallampati score, mouth opening, thyromental distance, and history of previous intubations. Alternatives to mask ventilation must be readily available in the ECT room:

• Supraglottic airway devices (laryngeal mask)
• Video laryngoscope
• Cricothyrotomy kit (for absolute emergencies)

Other Relevant Complications

Prolonged Apnea

Prolonged apnea (> 5–10 minutes after succinylcholine administration) can occur in patients with pseudocholinesterase deficiency (butyrylcholinesterase deficiency). The incidence of homozygous deficiency is approximately 1:2,500.

Management:

• Continue ventilation until spontaneous breathing returns
• Maintain sedation to avoid awareness
• Do not panic – the prognosis is excellent as long as adequate ventilation is provided
• Determine pseudocholinesterase activity and dibucaine number post-procedurally
• Documentation and medical alert card entry

Dental and Soft Tissue Injuries

Despite the use of a bite block, dental fractures can occur, particularly with insufficient relaxation or pre-existing dental damage. A pre-treatment dental assessment is recommended.

Headache and Nausea

Common (up to 45% of patients), but not an emergency in the strict sense. Relevance exists when severe headache raises the differential diagnosis of intracranial hemorrhage. In cases of doubt, cerebral imaging is indicated.

Intracranial Pressure Elevation

ECT causes a transient increase in intracranial pressure. In patients with space-occupying intracranial lesions (relative contraindication), there is a risk of herniation. These patients should only be treated after careful risk-benefit analysis and in consultation with neurosurgery.

Structured Approach to ECT Emergencies

As with any emergency in anesthesia, the same applies here: a structured, team-based approach saves lives. The following principles should be embedded in the ECT setting:

Before Treatment

• Team briefing: clearly assign roles (who manages the airway, who administers medications, who documents)
• Emergency medications prepared and labeled:
  • Atropine 0.5 mg/mL
  • Epinephrine 1:10,000
  • Esmolol
  • Urapidil
  • Midazolam
  • Propofol (re-injection dose)
  • Succinylcholine (re-injection dose)
  • Sugammadex (if rocuronium is used as an alternative)
• Defibrillator checked and ready for use
• Airway equipment complete including backup options
• Suction functional and tested

During the Complication

1. Recognize and verbalize – "We have asystole" / "The seizure has lasted over two minutes"
2. Call for help – Request additional personnel early and with a low threshold
3. Apply the ABCDE approach – Even in the ECT setting, do not forget the structured patient assessment
4. Follow algorithm-based management – ACLS algorithms for cardiovascular complications, stepwise therapy for prolonged seizures
5. Closed-loop communication – Have orders repeated back, provide confirmation

After the Event

• Documentation: detailed, time-based, including all medications administered
• Debriefing: What happened? What went well? What can we improve?
• Reporting: to the department leadership and, if applicable, to a Critical Incident Reporting System (CIRS)
• Patient information: inform the patient about the event, adjust the ongoing treatment plan

Special Patient Populations

Patients on Anticoagulation

• Increased risk of intracerebral hemorrhage (extremely rare but described)
• INR check before each session for patients on vitamin K antagonists
• DOACs: document timing of last dose, plan treatment at trough level

Patients with Pacemakers or ICDs

• ECT is generally feasible
• Deactivate ICD before treatment (risk of inappropriate shock delivery due to artifacts)
• Keep magnet readily available
• Check pacemaker function post-procedurally

Pregnant Patients

• ECT is considered relatively safe during pregnancy
• Left lateral tilt from the second trimester onward
• Fetal monitoring before and after treatment
• Tocolysis readiness in case of preterm labor

Practical Training

Complications during ECT are rare – and that is precisely what makes them dangerous. When an emergency occurs, there is little time to look up algorithms or research dosages. The cardiovascular emergencies described in this article – from asystole to hypertensive crisis to ventricular tachycardia – follow ACLS algorithms that must be internalized through regular hands-on training. In the ACLS courses offered by Simulation Tirol, you train these algorithms hands-on with realistic simulation scenarios, develop routines in team communication, and gain the confidence you need when it matters most. Because knowledge alone does not save lives – trained competence does.