Subdural block during attempted caudal epidural analgesia for labor

Subcutaneous tunnelling of epidural catheters for postoperative analgesia to prevent accidental dislodgement: a randomized controlled trial

The use of subcutaneous tunnelling to prevent movement of epidural catheters was examined in a prospective controlled trial. There were 113 patients in the standard group and 100 in the tunnelled group. The groups were similar with respect to age, sex and weight. There were 176 thoracic catheters, and 37 lumbar catheters. Mean duration of catheterization in the tunnelled group was 3.5 +/- 1.3 days and in the standard group, 3.1 +/- 1.5 days. In total, 60 catheters moved significantly from their initial position: 17 (28%) moved inwards and 43 (72%) moved outwards. 159 catheters were still functioning at the time of their removal, 76 standard and 83 tunnelled. This represents 67 and 83% of the two groups respectively. Subcutaneous tunnelling was shown to prevent clinically significant inwards (P = 0.043) and outwards (P = 0.0005) movement of epidural catheters and is more likely to result in a functional epidural blockade at the time of catheter removal (P = 0.0084).

Epidural analgesia: prospective audit of 1062 patients

A prospective survey of one thousand and sixty-two patients receiving epidural analgesia in surgical wards was undertaken over a two-year period. The duration of infusion ranged from one to fourteen days, with a mode of three days. There were 1131 episodes where a local anaesthetic and opioid mixture was used and 160 where opioids were used alone. Local anaesthetic was not used without opioids. 23% of catheters were removed prematurely because of catheter related problems including accidental dislodgement (13%) and skin site inflammation (5.3%). No epidural abscess or haematoma was identified. In 14% of the total number of episodes there was either no demonstrable block or complications occurred requiring a change of solution: 30% of this group were salvaged following intervention by the Acute Pain Service (APS). The incidence of respiratory depression was 0.24%. There was no case of delayed respiratory depression. Epidural analgesia can be used safely in surgical wards provided that regular review of the patients is undertaken. It must be anticipated however, that up to 20% of patients will not receive adequate analgesia for the first 48 hours postoperatively. The failure rate could be halved if accidental dislodgement of epidural catheters could be eliminated.

Postoperative epidural opioid analgesia: what are the choices?

The administration of hydrophilic opioids via a continuous infusion results in selective spinal analgesia with a low incidence of side effects. Lipophilic opioids may also be associated with spinal effects. However, the doses required to produce postoperative analgesia also produce plasma concentrations within the MEAC. Thus, in clinical practice it may not be possible to limit epidural doses of lipophilic opioids to those associated with spinal analgesia. Regardless of the mechanism of action, epidural administration of lipophilic opioids may offer no clinical advantages over the IV route. Notwithstanding, epidural administration of small doses of lipophilic opioids in combination with local anesthetics may offer significant clinical advantages over systemic administration of opioids alone. Dose-ranging studies will be necessary to determine the ideal concentrations of opioids and local anesthetics, as well as the ratios of the two drugs to obtain optimal analgesia with minimal incidence of side effects.