Continuous lumbar epidural infusion of levobupivacaine: effects of small-or large-volume regimen of infusion

Epidural distribution of dye administered via an epidural catheter in a porcine model

BACKGROUND

Local anaesthetics are commonly delivered to the epidural space by either intermittent bolus or continuous infusion. While these methods have been investigated in terms of analgesia and total dose administered, they have not been compared in terms of their effect on the spread of injectate within the epidural space. This animal study compared the spread of dye delivered to the epidural space in a porcine model by either bolus or infusion.

METHODS

After ethical approval, epidural catheters were placed at three vertebral levels in seven anaesthetized pigs. Aqueous dye (1 ml) was injected into the catheter as a bolus, or as an infusion over 30 min. Animals were euthanized at the end of the study and necropsy performed immediately to quantify the extent of dye spread.

RESULTS

In seven animals, 20 catheters were successfully placed in the epidural space. The mean (sd) extent of dye spread was 8.9 (2.6) cm in the infusion group compared with 15.2 (2.7) cm in the bolus group (P<0.001). Segmental spread was significantly greater in the bolus group compared with the infusion group (P<0.01).

CONCLUSION

In the porcine epidural model, spread of one ml of epidural dye solution is more extensive after a single bolus compared with short term infusion.

Beyond opioid patient-controlled analgesia: a systematic review of analgesia after major spine surgery

Postoperative pain control in patients undergoing spine surgery remains a challenge for the anesthesiologist. In addition to incisional pain, these patients experience pain arising from deeper tissues such as bones, ligaments, muscles, intervertebral disks, facet joints, and damaged nerve roots. The pain from these structures may be more severe and can lead to neural sensitization and release of mediators both peripherally and centrally. The problem is compounded by the fact that many of these patients are either opioid dependent or opioid tolerant, making them less responsive to the most commonly used therapy for postoperative pain (opioid-based intermittent or patient-controlled analgesia). The purpose of this review was to compare all published treatment options available that go beyond intravenous opiates and attempt to find the best possible treatment modality.