Abstract
Electroconvulsive therapy (ECT) is effective in the treatment of depression, mania and its place in the treatment of schizophrenia is becoming clearer [1–6]. However, the practice continues to be viewed critically. Pippard and Ellam [7] in a comprehensive UK review, surveyed 2755 psychiatrists, visited 180 sites and viewed the administration of ECT at 101 of them. The focus was broad and included an examination of premises, staff and clinical aspects. They found that 27% of clinics had serious deficiencies and noted that where the doctor and patient agreed about outcome, only 63% of patients were rated as much improved. In a followup 10 years later, they continued to express concerns over standards of practice [8, 9]. A four-fold difference in routine settings between clinics was noted as was the lack of restimulation for missed and brief seizures and the lack of desire for EEG monitoring.
Since then there has been little published regarding auditing the practice of ECT. A retrospective examination of notes for patients who received ECT at a state hospital in South Australia between 1981 and 1985 found that missed seizures were infrequent, occurring in 3.6% of unilateral and 2.6% of bilateral treatments [10]. Experiences of Australian psychiatric registrars have also been described [11] and along with the UK [12–14] and the US [15], all have found that the majority of residents had received little training or supervision.
The above authors have also commented on the difficulty in monitoring ECT. It seemed that if a method could be found in which a broader range of practice could be assessed without the burdens of time, travel and finance, useful comparative data could be collected. Further, if clinical decision making could be incorporated, a closer approximation to in vivo practice might be possible. It was decided that a standardized vignette might meet these requirements where identified aspects of concern could be incorporated and practitioners readily surveyed. Given the issues raised in the literature regarding a lack of re-stimulation despite missed and brief seizures, a decision was made to examine seizure adequacy and clinician's response to an apparent deterioration in seizure characteristics.
The criteria by which an electrically induced seizure is said to be adequate and therefore therapeutic, continues to be debated. Until recently the length of the motor and/ or of the EEG seizure has been considered important. However, this has itself varied with the UK accepting 15 seconds of motor and 20 seconds of EEG activity [16]. Lerer's group in Israel, 20 and 25 seconds (personal communication) and Fink in the US, 25 and 30 seconds, respectively (personal communication). Others have challenged this view, arguing that there is no association with outcome, seizure duration regularly decreasing over a treatment course without loss of effectiveness [17, 18]. The latter writers propose monitoring of EEG parameters, focusing on greater ictal amplitude, morphological regularity and post ictal suppression. Subsequent to this, Sackeim has argued that unilateral ECT at six times initial seizure threshold is the treatment of choice [19]. An attempt to develop a hypothetical vignette in which the above debate could be meaningfully incorporated became increasingly complex and difficult. For this reason, an actual case was used.
Methods
Questionnaire
The questionnaire consisted of a vignette of a 25-year-old woman who presented with a 6-month history of major depression (DSM-IV, melancholia type) and who had been unresponsive to three different classes of antidepressants. She had commenced a course of bilateral ECT following stimulus dose titration, commencing at 50.4 mC, had received two treatments and had begun to respond. The EEG tracings and stimulus parameters of each treatment were attached to the questionnaire. Using a Thymatron DGx (Somatics, Illinois, US) device, treatment 1 was administered at 50.4 mC and resulted in a 54 second EEG with high amplitude, morphological regularity, a 50 second motor seizure and a post ictal suppression index, an algorithm used by this device was < 95%. Treatment 2 was 75.6 mC and resulted in a 32 second EEG duration with similar morphology, a 25 second motor seizure and a post ictal suppression index < 87%. Neither the 41% or 50% change in EEG and motor seizure duration, respectively, nor the change in the post ictal suppression index were pointed out. Rather, it was left for the clinician to review the standard printouts as would occur in an actual clinical setting. Further, this case was also chosen as the parameters of the second treatment still met our locally agreed criteria for adequacy. The rationale was to specifically examine response to changes in seizure parameters rather than to absolute figures.
A series of questions followed starting with dosing options of 50.4, 75.6 and 100.8 mC charge. Participants were asked to specify what dosage they would administer for the next treatment, how confident they were in this decision on a 5-point visual analogue scale and in free prose, why they made that decision. Age, gender, choice of laterality and occupation was then noted. Respondents were then asked to rate themselves on three, 5-point, visual analogue scales as to their experience with EEG monitoring, whether or not they regularly see the EEG and whether or not they are involved in the practical administration of ECT. A lower score reflected less involvement across all conditions. Finally, number of months experience with EEG monitoring was recorded separately.
Subjects
A 2 page questionnaire was distributed to three separate groups: the addresses of all known Directors of ECT in Australia (Victoria, New South Wales, Queensland, South Australia, Western Australia and Tasmania), participants at the Royal Australian and New Zealand College of Psychiatrists 1998 Congress in Melbourne, Australia, and the mailing list of the Association for Convulsive Therapy. If a participant was a member of more than one group, their response was counted only once.
Analysis
Analysis of results was computed by EPI INFO 5, a public domain software statistical package for epidemiological and disease surveillance, Version 5, developed by the Center for Disease Control, Atlanta, 1990. Results were considered statistically significant when their corresponding p value was 0.05 or less by two tailed analysis.
Results
Subjects
Ninety-eight Australians and 138 Americans replied. Staff other than Directors of ECT or consultant psychiatrists were excluded from data analysis. An administrative error precluded accurate calculation of the response rate for either group. The mean ages of the Australian and US respondents were 46.6 and 41.4 years, respectively, and was not significantly different. Sixty-nine per cent of the Australian respondents were male compared with 85.5% of the US sample (χ2 = 6.75, p = 0.01). Of the Australia respondents, 63.3% were Consultants and/or Directors compared with 94.5% from the US sample. This was highly significant (χ2 = 20.01, p < 0.0001).
Dosage chosen
Considerable variability in the dosage selected by respondents was noted as 17.3% would have reduced the charge administered, 46.8% would have kept it the same and 30% would have increased it. Of the 5.9% who specified ‘other’, 9.1% would have decreased the charge to 25.0 mC and 90.9% would have increased it to either 126.0 or 151.2 mC charge.
Analysis by country revealed differences (χ2 = 6.75, p = 0.03). The Australian respondents were significantly more likely to maintain the current dosage while the US respondents were twice as likely to prescribe a lower dosage. In detail, one in five US psychiatrists would have reduced the dosage to 50.4 mC despite a change in EEG parameters. There was no significant difference between the US and Australia on increasing the dosage.
Rationale
The reasons given for the dosage selected were given in prose and were subsequently grouped according to common themes. Only 26.1% and 32.3% of Australian and US respondents, respectively, commented upon the change in stimulus parameters alone; 43.5% of Australian and 57.4% of US psychiatrists indicated that the tracings were adequate but were concerned about cognitive side-effects. Clinical improvement was significantly (χ2 = 9.3, p = 0.002) more likely to be cited by Australian (10.9%) compared with US psychiatrists (< 1.9%).
Confidence and experience
Australians felt most confident when the dose remained unchanged and least confident when they reduced it; the Americans were equally confident with either choice. Confidence level for Australians was related to whether they seldom or always see the EEG (χ2 = 37.8, p = 0.04) but was unrelated to whether they were involved in the practical administration of ECT (χ2 = 27.2, p = 0.34). The confidence of the US group was unrelated to either.
Dosage and experience
In addition, in the US, the Consultant Psychiatrists and/or Directors of ECT were statistically more likely to be involved in administering ECT (95.4% compared with 63.3%) than their Australian counterparts (p < 0.0001). The experience of the US group with EEG monitoring was 91.1 months compared with 15.3 months for the Australian group.
It appears that given their greater experience, the US group was more confident in choosing any dosage (χ2 = 26.2, p = 0.05) compared with their Australian counterparts who, with less experience, were more likely to keep the dosage unchanged (χ2 = 38.3, p = 0.0008). Neither viewing the EEG or being involved in the practical administration of ECT made a difference to the dosage chosen.
Discussion
The execution of clinical decision making by practising consultant psychiatrists in ECT is difficult. In response to a standardized clinical vignette based on an actual patient, 98 Australian and 138 American psychiatrists responded. Considerable variability emerged with 17.3% decreasing the dose, 46.8% choosing to maintain the present dosage and 30% suggesting that the appropriate decision was to increase the electrical charge for the third treatment. This decision to reduce was significantly more likely to occur with US psychiatrists with one in five choosing to do so. As to reasons given for these decisions, approximately half considered that the current dosage was adequate, with only one-third in each country commenting upon the change in seizure parameters. Interestingly, the Australian sample was significantly more likely to offer clinical improvement as their rationale although this was the sole basis for their decision in only 10.2% of replies. A number of other findings were noteworthy. In the US, the consultant psychiatrists and/ or Directors of ECT were statistically more likely to be involved in administering ECT (94.5% compared with 63.3%) than their Australian counterparts (p < 0.0001). However, of particular interest was the lack of any statistical association between involvement in the practical administration of ECT and the dosage chosen. Not surprisingly, US psychiatrists had greater experience with EEG monitoring. Yet this was unrelated to either dosage chosen, confidence or experience with EEG monitoring.
A number of remarks may be made tentatively in relation to this data. The first is that variability in dosage selection is likely to reflect the same variation in the literature as to what constitutes an adequate seizure. For this particular woman who received ECT at our service, two-thirds of responding psychiatrists would have either decreased or kept the dosage the same. In contrast, and according to our locally developed protocol, a reduction in any single parameter (clinical response, motor duration, EEG duration, EEG morphology or post ictal suppression index) prompts a 50% increment in the milliCoulombs of charge delivered. As a result this patient received 100.8 mC on her third treatment. She remained on this dosage until the end of her course of 8 treatments which finished with an EEG and motor seizure of 51 and 49 seconds, respectively, and a post ictal suppression index of 98%. Although she remains well 2 years later, the question may legitimately be raised as to whether or not such active maintenance of seizure parameters is clinically significant. That is, had this woman received either the same or a reduced dosage would the clinical outcome have been any different?
While there were sampling biases, the lower representation of consultant psychiatrists in the Australian group tends to support the observations of others that clinical responsibility for ECT has been delegated to junior staff in Australia at the time of this survey [9, 11]. However, at least in this questionnaire-based study, involvement in the practical administration of ECT by consultant psychiatrists was unrelated to the dosage chosen. That is, it may not matter if the task of ECT administration is delegated to junior staff provided there are protocols that are clearly understood, implemented and monitored by interested and experienced ECT clinicians. In Victoria, Australia, a Director of ECT must be trained and appointed to each area mental health service that administers ECT; their responsibility being to ensure that appropriate standards are met. As has been discussed elsewhere, a team approach has been found to be particularly helpful and avoids problems of individual credentialling when in reality a team is involved in the administration of ECT [20].
What then may be reasonably concluded from this study? The data is limited by the uncertain response rate, the use of a questionnaire and the inherent assumption that self report reflects actual practice. In addition it uses a vignette that uses bilateral rather than unilateral ECT as this was the standard practice in our facility in 1998. Further, and given the variation in the literature as to what constitutes an adequate seizure, it was not surprising to find the curve of responses fitting a bell shaped curve. However, by its standardization it provides a ready and reproducible methodology by which responses across two geographically separate areas may be explored. Finally, this paper is presented in order to stimulate debate around how best we may respectfully compare and contrast the clinical practice of ECT. Audits in the current literature have typically focused on physical aspects of a service, demographic details of the patient and ECT procedures and protocols – all indirect measures of actual ECT practice. Similarly with the methodology suggested here, its very nature is also indirect. It may be that simulated ECT mannequins provide the closest approximation to the clinical situation and can simultaneously test and teach, ensuring optimal practice for the administration of ECT [21]. In the absence of this option, the development of standardized clinical vignettes may usefully fill this gap.
Footnotes
Acknowledgements
Our thanks to Frank Moscarillo, Max Fink and John Tiller for their support.