CHRU of Tours, Department of Anaesthesiology and Intensive Care, Trousseau Hospital, Tours, France.
J Craniomaxillofac Surg. 2011 Apr;39(3):164-8. doi: 10.1016/j.jcms.2010.04.015. Epub 2010 Jun 3.
The main procedure specific complication of sagittal split osteotomy of the mandibular ramus (SSOMR) is inferior alveolar nerve (IAN) injury. This can be produced by poor intraoperative visibility of the IAN due to bone bleeding. In our centre, mandibular nerve blocks (MNBs) are usually performed for intra- and post-operative analgesia. We observed that MNB seems to decrease intraoperative bleeding and thus to improve IAN visibility. Our study was performed to evaluate the effect of MNB on intraoperative bleeding during SSOMR and, secondarily, on the duration of this procedure.
Patients scheduled for bilateral SSOMR under general anaesthesia were prospectively randomized into two groups. The Block group received bilateral MNB (5 mL ropivacaine 0.5% for each block) and the Control group sham MNBs (bilateral cutaneous puncture, without block). The operations were carried out under a standardised general anaesthetic. Post-operatively, the surgeon, blinded to group allocation, assessed intraoperative bone bleeding using a Numerical Rating Scale (NRS) (0: no bleeding, perfect visibility to 100: major bleeding, no visibility). Osteotomy duration, intraoperative anaesthetic requirements, and pain score in the recovery room were also recorded. Results are expressed as median [25-75th percentiles].
Nineteen patients were included in each group. Osteotomy under MNB had a decreased intraoperative bone bleeding score compared with controls (20 [0-40] versus 55 [20-80], p=0.0002). They had a dry surgical field more frequently (29% versus 5%, p=0.01), and a shorter mean time for the osteotomy (15 [12.25-17.75] versus 17.5 [15-21]min, p=0.009). Block patients had reduced intraoperative opioid consumption (770 [678-1430] versus 2310 [1908-3058]mcg of remifentanil, p=0.0001), and lower pain scores in the recovery room (0 [0-2] versus 3 [1-5], p=0.12).
MNB decreases intraoperative bone bleeding during SSOMR under general anaesthesia. Three hypotheses to explain this result are discussed.
下颌升支矢状劈开截骨术（SSOMR）的主要手术相关并发症是下牙槽神经（IAN）损伤。这可能是由于骨出血导致术中 IAN 可视性差引起的。在我们中心，下颌神经阻滞（MNB）通常用于术中及术后镇痛。我们观察到 MNB 似乎可以减少术中出血，从而提高 IAN 的可视性。我们的研究旨在评估 MNB 对 SSOMR 术中出血的影响，其次是对该手术过程持续时间的影响。
前瞻性随机将拟在全身麻醉下接受双侧 SSOMR 的患者分为两组。阻滞组接受双侧 MNB（每侧阻滞 5 毫升 0.5%罗哌卡因），对照组接受假 MNB（双侧皮穿刺，无阻滞）。手术在标准化全身麻醉下进行。术后，由对分组不知情的外科医生使用数字评分量表（NRS）（0：无出血，可视性完美至 100：大量出血，无可视性）评估术中骨出血情况。还记录了截骨术持续时间、术中麻醉需求和恢复室疼痛评分。结果表示为中位数[25-75 百分位数]。
每组纳入 19 例患者。与对照组相比，MNB 下截骨术的术中骨出血评分降低（20 [0-40] 与 55 [20-80]，p=0.0002）。他们的手术野更干燥（29% 与 5%，p=0.01），截骨术的平均时间更短（15 [12.25-17.75] 与 17.5 [15-21]min，p=0.009）。阻滞组患者术中瑞芬太尼的消耗减少（770 [678-1430] 与 2310 [1908-3058]mcg，p=0.0001），且恢复室疼痛评分较低（0 [0-2] 与 3 [1-5]，p=0.12）。
MNB 可减少全身麻醉下 SSOMR 术中的骨出血。讨论了三种解释这一结果的假设。
