Audit of a recently introduced stimulus dosing policy in an electroconvulsive therapy clinic

Aims and method To audit the clinical practice of seizure threshold estimation and subsequent stimulus dose adjustment in the electroconvulsive therapy (ECT) clinic. Case notes of patients who had ECTover a six-month period were audited. Resultswere discussed at an audit meeting and guidelines and training modified appropriately prior to the second cycle of the audit. Results Initialdosetitrationwas poorinthe firstperiod, but improved in the second. The majority of patients were insufficiently stimulated after missed seizuresin both periods and stimulus doses were not being reduced following prolonged seizures. Clinicalimplications Theaudit identifiedthe need for continuing supervision of trainees in addition to clear training and guidelines.

ratification, but would be a complex and time consuming process for the care coordinator.
User involvement is a difficult concept to quantify, although users were involved in devis ing the key indicators used. There is clearly a need for the development of valid and reliable measures of user involvement. This study is also limited by its relatively small sample. Due to the significant differences found between the study and non-study group, the 61% of users who participated are unlikely to be representative. There is a known association between substance misuse, which is significantly more prevalent in the non study group, and poor engagement with services (Sparr et al 1993). Those who did not attend review meetings may feel less involved with their care. Physical disabilities, which were significantly more common in the non-study group, may have contributed to non-attendance. The focus of the study on the aftermath of CPA meetings had the advantage of immediacy and good recall, but may not have allowed users time to reflect on what happened during the meeting. GUY Electroconvulsive therapy (ECT) is a recognised and effective treatment for severe depression. A response to treatment requires a moderately supra-threshold stimulus. Doses marginally above the seizure threshold do not have a therapeutic effect while grossly supra-threshold stimuli lead to increased cognitive side-effects without increased clinical improvement (Ottoson, 1960;Sackeim et al, 1993). There are large individual differences in seizure threshold. Sackeim et al (1987) showed that seizure thresh old ranged between 25 mC and 800 mC or more in their patient population, that is, a 40-fold inter-individual variation. Intra-individual changes in threshold of between 25 and 200% can also occur during a course of EOT (Sackeim et al, 1991).
A significant development in ECT practice has been the introduction of stimulus dosing. Prior to this the use of fixed dose strategies inevitably led to over-stimulation and cognitive side-effects in some patients or sub-therapeutic stimulation in others. Stimulus dosing allows us to set indivi dually tailored, moderately supra-threshold sti mulus doses and to adjust subsequent dose settings as seizure threshold rises. Pippard (1992) proposed that stimulus dosing should become standard UK practice following his influential ECT audit.
Stimulus dosing was introduced at Fulbourn hospital. Cambridge in August 1996. Junior doctors administering ECT underwent initial training with the ECT consultant (R.R.), who has sole responsibility for training and consul tant responsibility for the clinic. Continuing consultant or senior registrar supervision was then provided for at least one session weekly. Clinical practice in the six months following the introduction of the new protocol was audited. The results were presented at an audit meeting. The second cycle of the audit was completed in a further six-month period.

The study
The medical notes of all patients who started a course of ECT in Fulbourn hospital between October 1996 and March 1997 (Period A) were audited. The results of the audit were presented to the multi-disciplinary hospital audit meeting. Standards were discussed and methods of improving practice suggested. Revised guidelines were circulated to all interested parties, new training initiatives implemented and changes in documentation introduced.
Practice was re assessed in the six-month period July 1997-October 1997 (Period B).

Patient sample
Twenty patients were identified from Period A and 26 from Period B. Both groups were similar in terms of demographic and basic clinical data. Approximately twice as many females as males underwent ECT in both periods. In Period A the ratio of male to female was 1:2.3. In Period B it was 1:1.9. The mean number of treatments given in period A was seven with a range of 1-16. In period B the mean number was seven with a range of 1-14. Table 1) The percentage of correctly chosen initial stimu lus settings was high in both periods. Incorrect setting choice appeared to be due to minor errors rather than a lack of understanding of the protocol. Restimulation setting choice during dose titration was correct in only 43% of cases in Period A. This increased to 80% in Period B. The correct setting for first application after dose titration was chosen in 50% of cases in Period A and only increased to 60% in Period B. Guidelines for correct restimulation for missed or brief seizures were followed in only 50% (six out of 12) of cases in Period A. This figure went down to 42% (five out of 12) in Period B. The stimulus setting was reduced after a prolonged seizure (45 seconds or above) in only 35% (six out of 17) of cases in Period A and 36% (four out of 11) in Period B.

Comments
Our stimulus dosing policy was introduced to ensure that each patient received the lowest possible therapeutic dose thus reducing the likelihood of cognitive side-effects. Although the protocol was mostly followed correctly clinicians appeared unwilling to sufficiently increase sti mulus dose following inadequate seizures. We also found that clinical judgement was not used to reduce stimulus settings after prolonged seizures.
The latter was not specifically