Abstract Objective To observed the neuromuscular blockade，intubation conditions and safety of intramuscular rocuronium in children with congenital heart disease in Chinese. Methods Thirty infants，47 days to 24 months of age，scheduled for elective surgical procedures were randomly allocated to injected intramuscular rocuronium （1 or 2 mg/kg） or succinylcholine （4 mg/kg） into deltoid muscle，respectively. The adductor pollicis twitch were measured by accelerometry. Intubation condition were assessed at twitch depression to >75%. Results The number of patients achieved >75% twitch depression after 6 minutes of drugs administration were 4，9，and 0 (P<0.01)。 Intubation condition were consistently good-excellent when twitch depression achieved >75% in all groups. The onset of twitch depression achieved >75% and maximum were 4.7±1.9和7.2±2.5min after 2 mg/kg of rocuronium, respectively. Time of 25% twitch recovery were 61±17，113±25 and 15±3min after drugs administration respectively。Heart rate and blood pressure were stable and no local or systemic side effects appeared after drugs administration. Conclusions Intramuscular rocuronium，2 mg/kg，can provide good-excellent intubation condition within 4 to 6 min and long duration of action about 2 hours. Duration of action of large dose rocuronium might limit clinical utility. Intramuscular succinylcholine does not provide satisfactory tracheal intubating condition in children with congenital heart disease in Chinese.
Key words: rocuronium； succinylcholine；neuromuscular blockade； intubation conditions；intramuscular injection； anesthesia；children
小儿麻醉诱导时常用肌松药提供良好的气管插管条件或用以治疗喉痉挛。小儿常会发生静脉穿刺困难的情况，可能需要经非静脉途经使用肌松药，以便于迅速地控制气道。本研究观察了先心病小儿肌注罗库溴铵的肌松效果、插管条件和安全性,并与肌注琥珀胆碱进行比较,为临床应用肌松药肌注的方法提供参考。
资料与方法
研究对象 30例先心病择期全麻手术患儿，年龄47天～24月,体重2.8～10.0kg, 男26例,女14例,其中紫绀型先心病患儿8例,非紫绀型先心病患儿22例,肝肾功能正常，无出凝血功能异常或神经肌肉传导疾病。
方法 术前30min口服咪唑安定0.5mg/kg。麻醉诱导: 静注阿托品0.01～0.02mg/kg、氯铵酮2～3mg/kg、咪唑安定0.1mg/kg。待患儿入睡后行肌松定标,采用TOF-Watch加速度仪刺激尺神经和测定拇内收肌收缩功能,每10s单刺激尺神经，观察肌颤搐(Th)的抑制程度。面罩手控呼吸，间断静注咪唑安定和芬太尼维持麻醉。患儿随机分为4组（每组10例）,组I、II分别肌注罗库溴铵1、2 mg/kg,组III肌注琥珀胆碱4mgkg。肌注罗库溴铵浓度10mg/kg，肌注琥珀胆碱浓度25mg/kg，肌注部位均为上肢三角肌。待Th抑制>75%以上时行气管内插管。接麻醉机控制呼吸，维持PETCO2 4~5kPa。10min内Th抑制未达到75%的患儿经静脉追加罗库溴铵1mg/kg后气管插管,这些患儿10min后的肌松时效数据不再计算。记录肌松起效时间、阻滞深度、恢复时间、插管条件、副作用。插管条件按Magorian的评分方法进行分级[1]。肌注肌松药后15min内和术毕时观察注药部位和躯干皮肤有无红肿、皮疹等表现。
统计处理 数据以_x±s表示。采用方差分析和X2检验。以P<0.05作为显著性差异标准。
一结 果
三组患儿的性别、年龄、体重、身高、疾病分类等一般情况均无显著性差别(表1)。
表1 患儿分组的一般情况(_x±s) Tab 1 Demographic information of study in children (_x±s) | Group | I | II | III | | Drug | rocuronium | rocuronium | succinylcholine | | Dose mg/kg | 1 | 2 | 4 | | Age(month) | 11.1±8.6 | 11.7±9.1 | 11.2±8.8 | | Weight(kg) | 7.2±2.2 | 7.5±2.4 | 7.3±2.1 | | Height(cm) | 69±7 | 71±8 | 70±7 | | Female[n(%)] | 3(30) | 4(40) | 3(30) | | Cyanotic [n(%)] | 3(30) | 2(20) | 3(30) | 肌注肌松药的肌松作用见表2,3和图1。各组Th抑制75%的起效时间分别为5.0±2.5、4.7±1.9和8.9±0.8min。各组Th抑制>75%在5min时分别为3、7、0例（P<0.01）,6 min时为4、9、0例（P<0.01）(表4)。各组Th抑制达到75%以上时气管插管条件均为优良。肌注肌松药10min后,各组中分别有3、0、7例的患儿Th抑制<75%,经静脉追加罗库溴铵1mg/kg后气管插管。各组的临床肌松作用时间（Th恢复至25%）分别为61±17、113±25min、15±3min。肌注肌松药后10min内HR和BP无明显变化,局部无明显红肿,无明显皮疹、支气管痉挛和严重心律紊乱的发生。表2 肌注肌松药的肌松作用(_x±s) Tab 2 Pharmacodynamics response of intramuscular relaxants (_x±s) | Group | I | II | III | | Drug | rocuronium | rocuronium | succinylcholine | | Dose (mg/kg,) | 1 | 2 | 4 | | Onest of 75% twitch depression [min (n)] | 5.0±2.5(7) | 4.7±1.9(10) | 8.9±0.82(3) | | Onset of peak twitch depression [min (n)] | 8.1±3.4(7) | 7.2±2.5(10) | 8.4±3.0(7) | | Peak twitch depression [% (n)] | 76±38(7) | 100±0(10) | 46±35(7) | | 25% twitch recovery [min (n)] | 61±17(7) | 113±25(10) | 15±3(3) |  不同的肌群对肌松药的敏感性、起效和消退速率各不相同。预测插管条件的最适宜指标是监测声带肌和膈肌的起效时间。由于技术方法方面的原因，声带肌和膈肌的肌松监测尚不能在临床上广泛应用。临床上最常用的肌松监测部位仍是刺激尺神经观察拇内肌的收缩强度，以此计算肌松药的起效时间和预测插管条件。业已证明，声带肌和膈肌的起效和消退均快于拇内收肌[9，10]。因此,在拇内肌达到最大阻滞之前声带肌和膈肌已经处于最佳的插管条件。虽然临床上常在拇内肌Th抑制>75%时进行气管插管，但是，究竟拇内肌至少阻滞到什么程度是进行气管插管的最佳时机尚无定论，这与肌松药的种类、剂量、用药方法，以及麻醉深度等因素有关。
结论：小儿肌注罗库溴铵2mg/kg 的起效时间明显快于1mg/kg, 能在4～6min内提供优良的插管条件,但肌松临床作用时间长达2h以上。肌注琥珀胆碱不能提供有效的肌松作用和插管条件。对于静脉通路开放困难,而又要求肌松作用快速起效的患儿,肌注罗库溴铵2mg/kg是恰当的选择,尤其适用于手术时间较长或术后需用呼吸支持的患儿。
【参考文献】
[1] Magorian T， Flannery KB， Miller RD. Comparison of rocuronium, succinylcholine, and vecuronium for rapid-sequence induction of anesthesia in adult patients. Anesthesiology, 1993,79:913-918.
[2] Liu LMP，DeCook TH，Goudsouzian NG， et al. Dose response to intramuscular succinylcholine in children. Anesthesiology, 1981, 55:599-602.
[3] Sutherland GA, Bevan JC, Bevan DR. Neuromuscular blockade in infants following intramuscular sccinylcholine in two or five percent concentration. Can Anaesth Soc J, 1983, 342-346.
[4] Mazze RI, Dunbar RW, Intralingual succinylcholine administration in children: An alternative to intravenous and intramuscular routes? Anesth Analg, 1968, 605-615.
[5] Rosenberg H, Gronert GA. Intractable cardiac arrest in children given succinylcholine (letter). Anesthesiology, 1992, 77:1054.
[6] Caildwell CB， Lau M， Fisher DM. Is intramuscular mivacurium an alternative to intramuscular succinylcholine? Anesthesiology, 1994, 80:320-325.
[7] Reynolds LM, Lau M, Brown R, et al. Intramuscular rocuronium in infants and children : Dose-ranging and tracheal intubating conditions. Anesthesiology, 1996, 85-231-239.
[8] Kaplan RF, Uejima T, Lobel G, et al. Intramuscular rocuronium in infants and children: A multicenter study to evaluate tracheal conditions, onset and duration of action. Anesthesiology, 1999, 633-638.
[9] Donati F， Meistelman C， Plaud B. Vecuronium neuromuscular blockade at the diaphragm, the orbicularis oculi and addictor pollicis. Anesthesiology, 1990, 73:870-875.
[10] Donati F， Meistelman C， Plaud B. Vecuronium neuromuscular blockade at the adductor muscles of the larynx and addictor pollicis. Anesthesiology, 1991, 74:833-837.
|
