Testing whether the epidural works: too time consuming?

Abstract

When using epidural anaesthesia (EDA) for pain relief after major surgery, a failure rate of 10% is common. A crucial step in improving the care of patients with EDA is to define the position of the epidural catheter. The aim of this study was to investigate how much time it takes to determine whether the block is sufficient by assessing the extent of loss of cold sensation before induction of anaesthesia. One hundred patients listed for abdominal surgery were included in the study. After an epidural catheter had been inserted and an intrathecal or an intravenous position had been made unlikely by the use of a test dose, the patient was given a bolus dose of local anaesthetic plus an opioid in the epidural catheter. The epidural block was tested every 2 min, starting at 5 min and ending at 15 min. When at least four segments were blocked bilaterally, the testing was stopped, the time was noted and the patient was anaesthetised. An epidural block was demonstrated after 5-6 min in 37 patients, after 7-8 min in 43 additional patients and after 9-10 min in 15 patients. In one patient, it took 12 min and in three patients, it took 15 min. In two patients, no epidural block could be demonstrated. Testing an epidural anaesthetic before the induction of anaesthesia takes only 5-10 extra minutes. Knowing whether the catheter is correctly placed means better quality of care, giving the anaesthetist better prerequisites for taking care of the patient post-operatively.