///2012 Abstract Details
2012 Abstract Details2019-08-02T19:38:42-06:00

How experienced are experienced anaesthetic trainees on the labour ward? - Cusum graphical approach

Abstract Number: F-5
Abstract Type: Original Research

Angukumar Thangamuthu MBBS, Diploma in Anaesthesia, FCARCSI1 ; Purva Makani FRCA2


A recent prospective study of 1510 labour epidurals in our institution identified the highest incidence of dural punctures among anaesthetic trainees in their 3rd and 4rth year of training.(ST 3 and ST 4) and a failure rate of epidural placement of 19.36% which was not statistically different from that of the novice anaesthetist which was 21.4%( P value 0.4). Using Cusum analysis, we examined the epidural practice of our ST 3/4 trainees to identify ways in which their practice can be improved.


Following local audit governance approval, we collected data from a computerised database of all epidurals placed by nine ST3/4 trainees in our obstetric unit between December 2010 and September 2011. A standardised definition of epidural failure used at our institution comprises of the presence of any of the following: inadequate pain relief by 45 minutes of placement, dural puncture, resiting, mother dissatisfied at follow up visit. We used 20% as acceptable (f0) and 40% as unacceptable failure rate (f1) to plot the boundary lines of the Cusum graphs. Sequential epidural attempts for each of the 8 trainees were plotted on the graph with a rise of 1-f0 for failure and a fall by f0 for success 1.


The number of epidurals performed by the ST3/4 trainees ranged from 25 to 49. Six trainees achieved acceptable failure rates (graph crossing from one boundary line to another in a downward direction2) and the number of attempts to achieve this ranged from 11 to 41. One trainee had unacceptable failure rate after 21 epidurals and 2 trainees had inconclusive records after performing 25 to 27epidurals.


Frequently, the trainee is rostered to non obstetric areas of practice such as intensive care where oppurtunities for placing neuroaxial blocks may be far lower. This may result in a loss of competence or deskilling when they return to the labour ward on call rota. A period of supervised practice for trainees returning to labour ward from other areas of anaesthetic practice should be provided. Trainees should be encouraged to maintain a Cusum graphical record of their progress and this should be monitored by trainers to provide timely remedial support for doctors in difficulty.


1)Sivaprakasam.J.,Purva M Cusum analysis to assess competence: What failure rate is acceptable? The clinical Teacher 7(4) 257

2.Kestin. Statistical approach to measuring the competence of anaesthetic trainees . Br J Anaesthesia 1995;75:805-9

SOAP 2012