The effect of anaesthetist grade and frequency of insertion on epidural failure: a service evaluation in a United Kingdom teaching hospital

BACKGROUND Despite being a commonly performed procedure, epidural catheter insertion has a significant failure rate. There is a lack of guidance as to how regularly the procedure should be performed in order to maintain competence. This study aimed to quantify whether increasing frequency of practice is associated with a reduction in failure rates. METHODS Data were collected prospectively on all patients undergoing intra-abdominal or thoraco-abdominal surgery who received epidural analgesia as part of their post-operative analgesic regimen over a 36 month period. Records were examined to identify the reason for epidural catheter removal, classified according to standardised definitions, the seniority of the inserting anaesthetist, and whether or not they were a permanent member of the anaesthetic department. Data were analysed using independent t tests, Mann-Whitney tests and Fisher's test. RESULTS 881 epidurals were inserted during the study period. 48 hour failure rate was 27.2%, whilst by 96 hours 33.9% of epidurals had failed. Increasing frequency of epidural insertion did not show a significant decrease in failure rate at either 48 (p = 0.36) or 96 hours (p = 0.28). However, long-term survival of epidurals at 96 hours was greater if inserted by permanent rather than temporary members of staff (non-permanent 60/141, 42.6% vs permanent 228/715, 31.9%, OR 1.58 (CI 1.09-2.29) p = 0.02). CONCLUSION This study demonstrates that failure rates for postoperative epidural analgesia in major surgery are not dependent upon the frequency with which practitioners insert epidural catheters. However, failure rates are dependent on permanency of anaesthetic staff. These findings are significant when placed in the context of the General Medical Council's requirements for clinicians to maintain competence in their clinical practice, suggesting that institutional factors may have greater bearing on epidural success or failure than frequency of task performance.