Postoperative Lipolysis, Intraperitoneal and Subcutaneously during Epidural Analgesia

Objective: The introduction of epidural anesthesia in the first postoperative days has shown in previous studies not only better pain relief but also lower postoperative metabolism and inflammation in these patients. It has certainly not been possible to establish the mechanisms behind this.

Methods: 14 patients with epidural anesthesia were compared with 6 patients without epidural anesthesia after major gastrointestinal surgery. Metabolic microdialysis measurements were used subcutaneously and intraperitoneally for comparison. The assays were glucose, pyruvate, lactate and glycerol.

Results: The results showed significantly lower glycerol levels in patients with post-operative pain relief with epidural catheters both intraperitoneally and subcutaneously. No differences could be detected in analyzes of glucose, pyruvate and lactate, but differences in glycerol could be detected. Intraperitoneally with epidural catheter median glycerol value was 97.5 vs 152 μmol / L for patients without epidural catheter. Subcutaneous median was 245 μmol / L in patients with epidural catheter vs 336 in patients without. Higher glycerol values were observed subcutaneously compared to intraperitoneal.

Conclusion: Probably the higher glycerol levels seen subcutaneously are due to greater fat content in subcutaneous tissue. We interpret the lower glycerol levels seen in postoperative pain relief in patients with epidural catheters, both subcutaneously and intraperitoneally as a sign that the hormone-induced initiation of lipolysis is controlled by neurogenic mechanisms of the autonomic nervous system.