P064: CASE REPORT: CLINICAL AND PSYCHIATRIC CONSIDERATIONS OF INTRAOPERATIVE AWARENESS DURING ELECTROCONVULSIVE THERAPY
Carmelina Gorski, BS1; Brent R Carr, MD2
1University of Florida College of Medicine, Gainesville, USA; 2Department of Psychiatry, University of Florida, Gainesville, USA
Introduction: Intraoperative awareness is a rare but potentially devastating complication of general anesthesia, characterized by consciousness with subsequent recall during a procedure. Reported incidence ranges from 0.1% to 0.4%, though true prevalence is likely underestimated due to delayed or incomplete memory formation. Patients who experience awareness are at significantly increased risk for post-traumatic stress disorder (PTSD), anxiety, and long-term psychological sequelae. Electroconvulsive therapy (ECT), a brief procedure requiring general anesthesia and neuromuscular blockade, presents unique challenges in balancing adequate anesthetic depth with seizure quality. Despite widespread use of methohexital and succinylcholine in ECT, reports of intraoperative awareness in this context are exceedingly rare, and guidance on prevention and management remains limited.
Case Presentation: We describe a 61-year-old Caucasian woman with treatment-resistant major depressive disorder who presented with worsening depression and suicidal ideation after discontinuing ECT due to repeated episodes of intraoperative awareness at an outside institution. She reported recall of auditory stimuli and bite block placement during multiple ECT sessions while paralyzed. During one episode, persistent consciousness despite supplemental anesthetic resulted in aspiration of blood prior to loss of consciousness. These events were followed by marked anxiety, fear, and physiologic signs consistent with heightened sympathetic activation, including pre-procedural tachycardia and hypertension. After resuming ECT at our institution, no further episodes of awareness occurred. This was achieved through meticulous documentation of her prior experiences, close inter-session communication, and individualized titration of methohexital dosing. Optimal anesthetic depth required doses substantially exceeding standard recommendations, with effective dosing ranging from 2.6–3.0 mg/kg of ideal body weight. Adjunctive use of beta-adrenergic blockade helped mitigate anxiety-related hemodynamic responses. In select sessions, benzodiazepines were administered to address heightened fear related to prior awareness.
Discussion: Intraoperative awareness during ECT has been described in only two published case reports and mentions small cohort studies. This case underscores the difficulty of predicting awareness based on traditional risk factors and highlights the unreliability of intraoperative physiologic markers. Insufficient anesthetic dosing in the setting of intact neuromuscular blockade carries substantial psychological risk, while overdosing risks seizure suppression and prolonged emergence. The effective dose of methohexital in this patient varies greatly from normal dosing, which is between 0.6 mg/kg to of 2.0 mg/kg, with most of patients receiving 1.0 ±1 mg/kg. Patients with a history of awareness represent a particularly vulnerable population requiring tailored anesthetic strategies and enhanced interdisciplinary communication.
Conclusion: Although rare, intraoperative awareness during ECT can result in profound psychological trauma and treatment discontinuation in patients for whom ECT may be lifesaving. Thorough pre-procedural assessment, acknowledgment of prior awareness, and individualized anesthetic dosing are essential to minimizing risk and maintaining patient trust and adherence.
