Schulenburg H E, Sri-Chandana C, Lyons G, Columb M O, McLure H A
Department of Anaesthesia, D Floor, Jubilee Building, The General Infirmary at Leeds, Great George Street, Leeds LS1 3EX, UK.
Br J Anaesth. 2007 Nov;99(5):717-20. doi: 10.1093/bja/aem272. Epub 2007 Sep 24.
Volumes of local anaesthetics for sub-Tenon's anaesthesia vary. Lower volumes produce less akinesia, whereas higher volumes increase chemosis and intra-ocular pressures. Hyaluronidase is often added to local anaesthetics to improve akinesia without increasing the volume of the injection, but this is controversial. This randomized, sequential allocation study examines the addition of hyaluronidase on the minimum local anaesthetic volume (MLAV) required for a sub-Tenon's block.
Sixty-two patients having sub-Tenon's blocks for cataract surgery were randomized into two groups. The control group (n=31) received 2% w/v lidocaine and the study group (n=31) received 2% w/v lidocaine with hyaluronidase 15 IU ml(-1). Using parallel up-down sequential allocation from a 4 ml starting volume, the volumes in both groups were changed using a testing interval of 1 ml according to the quality of globe akinesia. The median effective local anaesthetic volume (MLAV) was calculated for both groups using probit regression.
The groups were similar for age, sex, and ocular axial length. The MLAV in the hyaluronidase group was 2.6 ml [95% confidence interval (CI), 2.1-3.l] and 6.4 ml (95% CI, 5.1-8.1) in the control group (P<0.002).
Hyaluronidase permits a significant 2.4-fold (95% CI, 1.8-3.4) reduction in MLAV for sub-Tenon's anaesthesia.
用于球后麻醉的局部麻醉药剂量各不相同。较低剂量产生的眼球运动麻痹较少，而较高剂量会增加结膜水肿和眼内压。透明质酸酶常被添加到局部麻醉药中，以在不增加注射剂量的情况下改善眼球运动麻痹，但这存在争议。这项随机、序贯分配研究探讨了添加透明质酸酶对球后阻滞所需最小局部麻醉药剂量（MLAV）的影响。
62例接受球后阻滞进行白内障手术的患者被随机分为两组。对照组（n = 31）接受2% w/v利多卡因，研究组（n = 31）接受含15 IU ml⁻¹透明质酸酶的2% w/v利多卡因。从4 ml起始剂量开始采用平行上下序贯分配法，根据眼球运动麻痹的情况，两组剂量均以1 ml的测试间隔进行调整。使用概率回归法计算两组的中位有效局部麻醉药剂量（MLAV）。
两组在年龄、性别和眼轴长度方面相似。透明质酸酶组的MLAV为2.6 ml [95%置信区间（CI），2.1 - 3.1]，对照组为6.4 ml（95% CI，5.1 - 8.1）（P < 0.002）。
透明质酸酶可使球后麻醉的MLAV显著降低2.4倍（95% CI，1.8 - 3.4）。
