Geldner G F, Schweiger S, Hetz W, Rügheimer E
Institut für Anaesthesiologie, Universität Erlangen-Nürnberg.
Anaesthesist. 1995 May;44(5):334-8. doi: 10.1007/s001010050161.
The aim of this study was to compare the intubating conditions of a mivacurium-induced neuromuscular block 90 s after a divided administration with three different methods of induction of anaesthesia.
After approval by the local ethics committee, we investigated 36 ASA I and II patients undergoing a 2-h scheduled, elective surgery, in whom a TIVA was induced by one of three different drugs, edomidate, methohexital or propofol. After stable anaesthesia was reached, 0.15 mg/kg and 0.1 mg/kg of mivacurium, spaced 30 s apart, was injected. Endotracheal intubation was performed 90 s after the first micacurium injection and the intubation conditions were graded (1: excellent, 2: good, 3: poor; 4: impossible). The neuromuscular function was stimulated every 20 s by a nerve stimulator in a train-of-four (TOF) pattern, and the time to complete distinction of a TOF response as well as the time of reoccurrence of the first twitch was taken. A minute prior to injection of the relaxant and every minute for 5 min, the systolic and diastolic blood pressure, mean arterial pressure (MAP) and heart rate were measured. The neuromuscular block was maintained with a mivacurium infusion on a level of one twitch response. After cessation of the mivacurium infusion we recorded the time of reappearance of the second, third and fourth twitch responses.
All patients could be intubated 90 s after mivacurium except for one, who was excluded for abnormal difficult intubation conditions. The etomidate group had significantly (chi 2 test) worse intubation grades than the methohexital group. In none of the groups did we observe any significant cardiovascular response due to the mivacurium injection, neither in blood pressure nor in heart rate. All groups showed similar onset of the maximal neuromuscular block (4 +/- 1.8 min) and recovery of the first TOF reaction (11.3 +/- 3.4 min). There was no difference in recovery from neuromuscular block maintained by infusion at the end of surgery.
A dose of mivacurium 3.57 times the ED95 does not produce any haemodynamic instability, if it is divided into two parts to induce a TIVA. After this dose, all patients could be safely intubated within 90 s. A prolongation of the neuromuscular block after higher mivacurium doses could not be seen, and this dose did not produce a more rapid onset of the maximal block in any group. The time for recovery from a mivacurium infusion did not differ among the groups. Etomidate, due to its short half-life, seems not ideal for induction of a TIVA together with mivacurium in the dosage used. Mivacurium meets the demands of good controllability as required for a TIVA and can be recommended for a 90-s injection-intubation interval as well as for maintenance of the neuromuscular block.
本研究的目的是比较在采用三种不同麻醉诱导方法进行分次给药后90秒时米库氯铵诱导的神经肌肉阻滞的插管条件。
经当地伦理委员会批准后，我们对36例ASA I级和II级、计划进行2小时择期手术的患者进行了研究，这些患者通过三种不同药物之一依托咪酯、美索比妥或丙泊酚诱导实施全凭静脉麻醉（TIVA）。在达到稳定麻醉状态后，间隔30秒注射0.15mg/kg和0.1mg/kg的米库氯铵。在首次注射米库氯铵后90秒进行气管插管，并对插管条件进行分级（1：优，2：良，3：差；4：无法插管）。每隔20秒用神经刺激器以四个成串刺激（TOF）模式刺激神经肌肉功能，记录完成区分TOF反应的时间以及第一个肌颤搐再次出现的时间。在注射松弛剂前1分钟以及之后5分钟内每分钟测量收缩压、舒张压、平均动脉压（MAP）和心率。用米库氯铵输注维持神经肌肉阻滞在一个肌颤搐反应水平。在停止米库氯铵输注后，记录第二个、第三个和第四个肌颤搐反应再次出现的时间。
除1例因异常困难插管条件被排除外，所有患者在米库氯铵注射后90秒均可插管。依托咪酯组的插管分级明显（χ²检验）比美索比妥组差。在任何一组中，我们均未观察到因注射米库氯铵而引起的任何显著心血管反应，无论是血压还是心率方面。所有组的最大神经肌肉阻滞起效时间（4±1.8分钟）和第一个TOF反应恢复时间（11.3±3.4分钟）相似。手术结束时通过输注维持的神经肌肉阻滞恢复情况无差异。
如果将米库氯铵分为两部分用于诱导TIVA，3.57倍ED95的剂量不会产生任何血流动力学不稳定。给予此剂量后，所有患者均可在90秒内安全插管。未观察到更高剂量米库氯铵后神经肌肉阻滞延长的情况，且该剂量在任何一组中均未使最大阻滞起效更快。各组从米库氯铵输注中恢复的时间无差异。依托咪酯由于其半衰期短，在所使用的剂量下似乎并非与米库氯铵一起诱导TIVA的理想药物。米库氯铵满足TIVA所需的良好可控性要求，可推荐用于90秒的注射 - 插管间隔以及维持神经肌肉阻滞。
