Cunningham A J, Kelly C P, Farmer J, Watson A G
Can Anaesth Soc J. 1982 Nov;29(6):617-21. doi: 10.1007/BF03007750.
Maintenance of a normal to low intraocular pressure during ocular surgery is of critical importance. The prime considerations for anaesthetic management include adequate depth of anaesthesia, normal carbon dioxide and arterial oxygen tensions, stable cardiovascular status and avoidance of stimuli likely to raise central venous pressure. Non-depolarizing muscle relaxants are associated with a reduction in intraocular pressure. Metocurine, a non-depolarizing relaxant, formerly known as dimethyltubocurarine, has been recently reintroduced into clinical practice. Metocurine has been reported to be 1.8 times more potent than d-tubocurarine and has the clinically advantageous cardiovascular effects of stable heart rate and mean blood pressure with minimal associated histamine release. When combined with pancuronium, metocurine potentiates the neuromuscular blocking properties, so that small doses of both drugs in combination produce effective neuromuscular block. This study was designed to assess the suitability of metocurine 0.3 mg.kg-1 and metocurine 0.08 mg.kg-1 plus pancuronium 0.02 mg.kg-1 as muscle relaxants for ocular surgery. The results demonstrated that metocurine and metocurine-pancuronium combination in the above doses combined with sodium thiopentone 5 mg.kg-1 produced ideal conditions for intubation of the trachea in 4.45 (+/- 0.19 SE) minutes and 4.35 (+/- 0.16 SE) minutes respectively. In both treatment groups intraocular pressure was reduced below control values and a pattern of intraocular pressure stability ideal for ocular surgery was obtained during the 10 minutes observation period. The delayed onset of sufficient paralysis for tracheal intubation - 4.45 (+/- 0.19 SE) minutes for metocurine and 4.35 (+/- 0.16 SE) minutes for the combination - makes these techniques unsuitable for emergency ocular surgery because of the long interval when the airway is unprotected.
眼科手术期间维持正常至低眼压至关重要。麻醉管理的主要考虑因素包括足够的麻醉深度、正常的二氧化碳和动脉血氧张力、稳定的心血管状态以及避免可能升高中心静脉压的刺激。非去极化肌松药与眼压降低有关。美托库铵是一种非去极化肌松药，曾称为二甲基筒箭毒碱，最近已重新应用于临床实践。据报道，美托库铵的效力比d-筒箭毒碱强1.8倍，具有临床有利的心血管效应，即心率和平均血压稳定，组胺释放极少。与泮库溴铵合用时，美托库铵可增强神经肌肉阻滞特性，因此两种药物小剂量联合使用可产生有效的神经肌肉阻滞。本研究旨在评估0.3mg·kg-1美托库铵以及0.08mg·kg-1美托库铵加0.02mg·kg-1泮库溴铵作为眼科手术肌松药的适用性。结果表明，上述剂量的美托库铵和美托库铵-泮库溴铵组合分别与5mg·kg-1硫喷妥钠合用，分别在4.45（±0.19标准误）分钟和4.35（±0.16标准误）分钟产生了理想的气管插管条件。在两个治疗组中，眼压均降至对照值以下，并且在10分钟观察期内获得了适合眼科手术的眼压稳定模式。气管插管所需的充分麻痹起效延迟——美托库铵为4.45（±0.19标准误）分钟，联合用药为4.35（±0.16标准误）分钟——由于气道无保护的间隔时间长，使得这些技术不适合急诊眼科手术。
