Paravertebral Analgesia with Levobupivacaine Increases Postoperative Flap Tissue Oxygen Tension after Immediate Latissimus Dorsi Breast Reconstruction Compared with Intravenous Opioid Analgesia

Abstract

Background Directly measured tissue oxygen tension (Pto2) reflects the adequacy of local tissue oxygenation and influences surgical wound healing. Epidural analgesia increases Pto2 compared with intravenous morphine analgesia after abdominal surgery. The authors tested the hypothesis that paravertebral regional anesthesia and analgesia would increase Pto2 compared with intravenous opioid-based anesthesia and analgesia. Methods Twenty patients scheduled to undergo mastectomy with immediate latissimus dorsi breast reconstruction were randomized to receive either general anesthesia with postoperative intravenous morphine analgesia or combined general-paravertebral anesthesia with continuous paravertebral postoperative analgesia using levobupivacaine in this prospective, cohort study. All patients had a local tissue oxygen sensor implanted in the flap muscle. Data were downloaded continuously for 20 h postoperatively. Results The mean Pto2 over the 20-h period was significantly higher in patients receiving paravertebral anesthesia (75 +/- 38 vs. 44 +/- 23 mmHg [mean +/- SD]; P = 0.03). Intraoperative blood loss was less in paravertebral patients (1.2 +/- 0.4 vs. 1.7 +/- 0.5 l; P = 0.04). Dynamic visual analog scale pain scores were significantly lower in paravertebral patients. Intraoperative and postoperative fluids administered, hemoglobin, core temperature, intraoperative end-tidal carbon dioxide, and mean arterial pressure were similar in both groups. Conclusion The postoperative latissimus dorsi flap Pto2 was higher for 20 h after breast reconstruction with paravertebral analgesia compared with intravenous morphine analgesia.