European Journal of Cardiovascular Medicine

Electroconvulsive therapy (ECT) remains a pivotal treatment for various psychiatric disorders, offering rapid and significant improvements where medication may fail or provide inadequate relief. Despite its efficacy, the physiological stress induced by ECT, particularly on the cardiovascular system, necessitates careful consideration of anesthetic management to mitigate potential risks. The choice of anesthetic agent is crucial, as it can significantly influence the hemodynamic responses to ECT, thereby affecting patient safety and treatment outcomes. This review focuses on the cardiovascular effects of three commonly used anesthetic agents in ECT: etomidate, propofol, and thiopental, providing a comparative analysis to guide clinical practice.

The induction of anesthesia in ECT is associated with transient but significant changes in cardiovascular dynamics, including alterations in heart rate, blood pressure, and cardiac output. These changes are primarily driven by the intense sympathetic stimulation following the induced seizure, which can pose risks, particularly in patients with preexisting cardiovascular conditions ^1,2. Understanding the differential impact of anesthetic agents on these parameters is essential for optimizing patient care.

Etomidate is often favored for its minimal cardiovascular effects, preserving hemodynamic stability, which is particularly advantageous in patients with compromised cardiac function ³. However, its use has been associated with adrenal suppression and the potential for seizure prolongation, aspects that must be weighed against its hemodynamic benefits ⁴.

Propofol, known for its rapid onset and short duration of action, effectively blunts the cardiovascular response to ECT. It reduces the seizure threshold and duration, which could potentially impact the efficacy of ECT, yet its antiemetic properties and favorable recovery profile make it a popular choice ^5,6.

Thiopental, another agent with a long history of use in ECT, provides effective anesthesia with a moderate impact on cardiovascular dynamics. It may, however, prolong seizure duration and has been associated with slower recovery times compared to propofol ^7,8.

The optimal anesthetic agent for ECT should balance the need for adequate seizure activity, minimal cardiovascular disturbance, and rapid recovery. This study critically examines the data comparing the cardiovascular effects of etomidate, propofol, and thiopental in the context of ECT, aiming to provide evidence-based recommendations for clinical practice.

Aims and Objectives

The primary aim of this study was to observe and compare the effects of intravenous etomidate, intravenous propofol, and intravenous thiopentone as inducing agents on the cardiovascular system in electroconvulsive therapy (ECT). The objective was to measure heart rate, systolic blood pressure, diastolic blood pressure, and mean arterial pressure in patients undergoing ECT using etomidate, propofol, and thiopentone as inducing agents at the following intervals: before induction (Baseline), 1 minute post-ictal, 5 minutes post-ictal, and 10 minutes post-ictal.

This hospital-based observational study was conducted over a one-year period from July 2017 to June 2018 in the Department of Anaesthesiology of Assam Medical College and Hospital, Dibrugarh. The source of data comprised patients undergoing ECT in the Department of Psychiatry of the same institution. The study included a total of 90 patients of either sex, aged between 20 to 60 years, all of whom were undergoing ECT for the first time. These individuals were classified as ASA-I and ASA-II grade according to the American Society of Anesthesiologists' physical status classification system. The participants were divided randomly into three groups of 30 patients each. The study received approval from the Institutional Ethics Committee (H) of Assam Medical College & Hospital, Dibrugarh. Written informed consent was obtained from patients and their relatives after explaining the study procedure in their native language.

Inclusion criteria were set to include all new patients scheduled for ECT, patients between 20 to 60 years of age of both sexes, patients with ASA grade I or II, and those patients and relatives willing to sign informed consent. Exclusion criteria included patients with a history of full stomach, ASA grade III or higher, renal or hepatic impairment, recent cerebrovascular accident, congestive cardiac failure or valvular heart disease, respiratory tract disease, high-risk pregnancy, hypertension and ischemic heart disease, diabetes mellitus, epilepsy, history of myocardial infarction in the last six months, history of drug allergy, neurological and other endocrine abnormalities, and refusal by the patient or relatives or both.

Patients were randomly allocated into one of the three groups – Group E, Group P, and Group T. Group E received IV etomidate 0.2mg/kg of body weight, Group P received IV propofol (1%) 2mg/kg of body weight, and Group T received IV thiopentone (2.5%) 4mg/kg of body weight as inducing agents. Routine investigations were conducted, including hemoglobin level, complete blood count, blood urea nitrogen, serum creatinine, random blood sugar, liver function test, X-ray chest PA view, and electrocardiography. All patients were advised to fast for 6 hours before undergoing ECT and were allowed to continue antipsychotic medication until the day of the procedure. Loose teeth or dentures were removed, and patients were asked to empty their bladder before the procedure.

Upon arrival to the ECT room, standard monitors for SPO2, ECG, pulse rate, and non-invasive recordings of systolic, diastolic, and mean arterial pressure were connected, and all baseline parameters were recorded. An 18G IV cannula was secured for each patient, and a 500ml crystalloid Ringer Lactate infusion was started. Premedication with anticholinergic glycopyrrolate (0.005mg/kg IV) and antiemetic ondansetron (4mg IV) was administered 5 minutes prior to the procedure. Patients were pre-oxygenated with 100% oxygen for 3 minutes before induction. General anesthesia was administered according to the group allocation until the loss of verbal response in Group P and Group E and loss of eyelid reflex in Group T. Seizure duration was monitored using the isolated one-arm technique. Following the onset of anesthetic effect, depolarizing muscle relaxant succinylcholine (0.5mg/kg) was administered for neuromuscular relaxation, and patients were ventilated with 100% oxygen. An oropharyngeal airway was inserted to prevent tongue bite, and bitemporal electrodes were placed for brief stimulus administration. Hemodynamic variables were recorded at specified intervals, and patients were ventilated until spontaneous respiration returned and full recovery was achieved.

Statistical analysis was conducted using descriptive data presented as Mean ± SD and percentages. Data were entered into a Microsoft Excel 2010 spreadsheet, and results were analyzed using chi-square tests and ANOVA, with a p-value <0.05 considered significant.

In the comprehensive study conducted to observe and compare the cardiovascular effects of intravenous etomidate, propofol, and thiopentone used as inducing agents in electroconvulsive therapy, various demographic, clinical, and hemodynamic parameters were meticulously analyzed. The study encompassed a total of 90 patients, evenly divided into three groups based on the anesthetic agent administered.

The demographic analysis revealed no significant difference in age distribution across the groups, with p-value standing at 0.8450, indicating a homogeneous age composition among the groups. Specifically, the age group of 20—29 years constituted approximately half of each group, with 53.33% in Group E, 50.00% in Group P, and 56.67% in Group T. The mean age, calculated as 30.03 ± 8.56 for Group E, 31.53 ± 10.34 for Group P, and 30.97 ± 11.24 for Group T, further supported the age-related homogeneity among the groups.

Sex distribution among the groups also did not show a statistically significant difference, with a p-value of 0.866286. The ratio of male to female participants varied slightly across the groups, with Group T having the highest male to female ratio of 2:1, followed by Group P and Group E with ratios of 1.73:1 and 1.5:1, respectively.

The weight distribution across the groups indicated a balanced representation of various weight categories, yielding a p-value of 0.9435. The majority of participants across all groups fell within the 41—50 Kg and 51—60 Kg weight ranges, suggesting a similar body mass index among the participants.

the ASA status, which denotes the physical status classification by the American Society of Anesthesiologists, the distribution between ASA I and ASA II was nearly equal across the groups, with a p-value of 0.949478. This uniform distribution underscores the comparability of the groups in terms of baseline health status.

The heart rate analysis before and after the induction of anesthesia revealed significant intra-group variations at the 1 minute and 5 minute postictal intervals. The heart rate increased from baseline in all groups, with Group E showing a significant increase at 1 minute (p < 0.001) and 5 minutes (p = 0.00717) postictal. Group P and Group T exhibited similar trends, with significant increases at 1 minute (Group P p = 0.00182, Group T p = 0.00011) and 5 minutes (Group P p = 0.04362, Group T p = 0.00557) postictal. However, by the 10-minute mark, the heart rate changes from baseline were not statistically significant, indicating a return towards baseline values.

Systolic blood pressure demonstrated significant increases from baseline in all groups at 1 minute and 5 minutes postictal, with p-values of <0.001 across all groups at the 1-minute mark. The increases were transient, as indicated by the nonsignificant changes at the 10-minute postictal measurement, highlighting the short-term impact of ECT on systolic blood pressure.

Diastolic blood pressure showed a similar pattern of significant increase at 1 minute postictal (Group E p < 0.001, Group P p = 0.00044, Group T p < 0.001), with the increases being less pronounced by the 5-minute mark and not statistically significant by the 10-minute postictal time point.

Mean arterial pressure (MAP) across the groups increased significantly from baseline at 1 minute postictal, with p-values of <0.001 for all groups. This increase was somewhat sustained at 5 minutes postictal but was not statistically significant by the 10-minute mark, similar to the trends observed in heart rate and blood pressure.

In summary, the study demonstrated that while there were significant short-term increases in heart rate, systolic and diastolic blood pressure, and mean arterial pressure following ECT, these effects were transient and began to return to baseline values within 10 minutes postictal. The lack of significant differences in the inter-group comparisons suggests that the cardiovascular effects of intravenous etomidate, propofol, and thiopentone are comparable in the context of ECT, providing valuable insights for anesthesiology practice in such settings.

The present study aimed to evaluate and compare the cardiovascular effects of three commonly used intravenous anesthetic agents—etomidate, propofol, and thiopentone—in patients undergoing electroconvulsive therapy (ECT). Our findings revealed no significant inter-group differences in heart rate, systolic blood pressure, diastolic blood pressure, or mean arterial pressure changes post-ECT, suggesting that all three agents are comparably safe from a cardiovascular standpoint. These results are particularly relevant in clinical settings where the choice of anesthetic may be influenced by the patient's underlying cardiovascular status.

Our observation that the heart rate significantly increased from baseline at 1 minute postictal in all groups aligns with the findings of Wagner et al.[9], who reported similar cardiovascular responses following ECT. The transient increase in heart rate and blood pressure is consistent with the sympathetic stimulation typically induced by seizure activity[10]. However, our study extends these findings by comparing three different anesthetic agents, demonstrating that the choice of etomidate, propofol, or thiopentone does not significantly alter these hemodynamic responses in the short term.

The return of cardiovascular parameters to baseline levels by the 10-minute postictal mark in our study is in agreement with previous research indicating the short-lived nature of ECT-induced hemodynamic changes[11]. This rapid normalization of cardiovascular function underscores the safety of ECT, particularly when conducted under carefully monitored anesthesia.

Contrary to our findings, a study by Mizrak et al.[12] suggested that propofol might be associated with a more pronounced decrease in blood pressure compared to thiopentone, attributed to propofol's potent vasodilatory effects. The discrepancy between these findings and our own could be due to differences in study populations, ECT protocols, or anesthesia management practices, highlighting the importance of context in interpreting these results.

Our study's limitations include its observational design and the specific patient population of ASA I and II individuals, which may not fully represent the broader demographic undergoing ECT. Furthermore, while we observed no significant differences in the immediate postictal period, we did not assess longer-term cardiovascular outcomes, which could be relevant for patient safety and the optimization of ECT protocols.

This study contributes to the growing body of evidence suggesting that etomidate, propofol, and thiopentone are comparable in terms of cardiovascular safety for use in ECT anesthesia. Future research should focus on larger, randomized controlled trials to explore these findings further, including potential differences in longer-term cardiovascular outcomes following ECT.

The comparative analysis of cardiovascular effects induced by intravenous etomidate, propofol, and thiopentone in patients undergoing electroconvulsive therapy (ECT) revealed no significant differences in the immediate postictal hemodynamic responses among the three anesthetic agents. Heart rate and blood pressure measurements, taken at intervals up to 10 minutes post-ECT, indicated a transient increase from baseline values in all groups, which returned to near-baseline levels by the 10-minute mark. These findings suggest that from a cardiovascular perspective, etomidate, propofol, and thiopentone are equally viable options for anesthesia in ECT, offering flexibility in anesthetic choice based on individual patient profiles and clinical considerations other than cardiovascular effects alone.

Our study contributes to the body of knowledge affirming the safety of ECT, particularly when administered with appropriate anesthetic management. It underscores the importance of monitoring cardiovascular parameters and adjusting anesthesia protocols as needed to ensure patient safety. Further research is warranted to explore potential differences in longer-term cardiovascular outcomes and to investigate the impact of these anesthetic agents in patients with varying degrees of cardiovascular risk.

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