治疗的主要目标是新陈代谢的正常化、防止高温和横纹肌溶解症。治疗主要包括:停止触发因素、维持正常核心体温和丹曲林治疗。患者应在手术室将病情稳定,然后转入 ICU 继续监测及治疗。有些患者可能会在恢复室而不是手术室出现 MH。处理是与在手术室相同的,除了可能有时没有必要进行气管插管。可以预计到有由于致命性高热产生的并发症,如 DIC、脑水肿,以及由横纹肌溶解症引起的并发症,如高钾血症引起的心脏骤停和表现为肌红蛋白尿的肾功能衰竭。根据指示应咨询血液科专家和肾病科专家。
由吸入麻醉药引起的 MH 的初期管理
吸入性麻醉药必须停止。琥珀胆碱(氯化琥珀胆碱)加剧情况恶化,不能用于治疗肌肉强直。清除触发源的时间取决于暴露的时间。现代麻醉工作站相比旧机器具有更大的吸入麻醉剂贮器。[80]Kim TW, Nemergut ME. Preparation of modern anesthesia workstations for malignant hyperthermia-susceptible patients: a review of past and present practice. Anesthesiology. 2011;114:205-212.http://anesthesiology.pubs.asahq.org/article.aspx?articleid=1925458http://www.ncbi.nlm.nih.gov/pubmed/21169802?tool=bestpractice.com[81]Cottron N, Larcher C, Sommet A, et al. The sevoflurane washout profile of seven recent anesthesia workstations for malignant hyperthermia-susceptible adults and infants: a bench test study. Anesth Analg. 2014;119:67-75.http://www.ncbi.nlm.nih.gov/pubmed/24806140?tool=bestpractice.com麻醉剂蒸发器移除 1 个多小时之后,患者仍有可能吸入微量麻醉药。在急性 MH 危机时,活性炭过滤器可增强挥发性麻醉剂的清除。[82]Block FE Jr. Malignant hyperthermia and charcoal absorbent: too hot to handle. Anesth Analg. 2011;112:1270-1271.http://www.ncbi.nlm.nih.gov/pubmed/21613194?tool=bestpractice.com[83]Bilmen JG, Gillies RI. Clarifying the role of activated charcoal filters in preparing an anaesthetic workstation for malignant hyperthermia-susceptible patients. Anaesth Intensive Care. 2014;42:51-58.http://www.ncbi.nlm.nih.gov/pubmed/24471664?tool=bestpractice.com应进行高流量吸氧和空气以减少在工作站中参与气体的暴露。如果新鲜气体流速降低,应最大限度地减少反弹效应;[81]Cottron N, Larcher C, Sommet A, et al. The sevoflurane washout profile of seven recent anesthesia workstations for malignant hyperthermia-susceptible adults and infants: a bench test study. Anesth Analg. 2014;119:67-75.http://www.ncbi.nlm.nih.gov/pubmed/24806140?tool=bestpractice.com此外,应该提供备用氧源。需要对呼出的二氧化碳的监测,并在可能情况下监测每分钟通气量(通气 1 分钟的气体体积)。如果短暂(数分钟)暴露在吸入麻醉剂,并快速消除吸入麻醉剂,MH 可以通过这些措施完全缓解,但是这很罕见。
如果怀疑 MH,必须尽快静脉给予丹曲林。[84]Association of Anaesthetists of Great Britain and Ireland. Malignant hyperthermia crisis: AAGBI safety guideline. 2015. http://www.aagbi.org/ (last accessed 14 July 2016).http://www.aagbi.org/sites/default/files/MH%20laminate.pdf丹曲林会导致肌肉无力,当快速静脉给予丹曲林时,患者如果没有进行气管内插管,应该快速准备好气管内插管的相关设备。应反复给予初始剂量丹曲林,直到肌张力恢复正常、酸中毒消退、心率恢复正常。[85]Glahn KP, Ellis FR, Halsall PJ, et al. Recognizing and managing a malignant hyperthermia crisis: guidelines from the European Malignant Hyperthermia Group. Br J Anaesth. 2010;105:417-420.http://bja.oxfordjournals.org/content/105/4/417.longhttp://www.ncbi.nlm.nih.gov/pubmed/20837722?tool=bestpractice.com首次发作 36 小时之内,应在 ICU 内继续进行减量的预防性丹曲林给药,因为在这段时间内经常有症状复发。[86]Burkman JM, Posner KL, Domino KB. Analysis of the clinical variables associated with recrudescence after malignant hyperthermia reactions. Anesthesiology. 2007;106:901-906.http://www.ncbi.nlm.nih.gov/pubmed/17457120?tool=bestpractice.com
可以复溶冻干丹曲林,因而给药比传统的静脉制剂更迅速。在未静脉使用丹曲林的情况下,在术中通过鼻胃管给予丹曲林后疑似 MH 终止。[87]Kang BJ, Song J, Kim SK, et al. A suspected case of malignant hyperthermia that was successfully treated with dantrolene administration via nasogastric tube. Korean J Anesthesiol. 2012;63:378-380.http://ekja.org/DOIx.php?id=10.4097/kjae.2012.63.4.378http://www.ncbi.nlm.nih.gov/pubmed/23115697?tool=bestpractice.com
如果核心温度高于 40℃(104°F)或快速升高,有必要实行紧急措施降低温度。应当迅速经静脉给予冷平衡盐溶液,优选不含钾的。患者应当被除去覆盖物,暴露在空气中来进行散热。冰袋应放置在腹股沟、腋窝、颈部和头部周围,直到体核温度降低到 38℃ (100.4°F)。[85]Glahn KP, Ellis FR, Halsall PJ, et al. Recognizing and managing a malignant hyperthermia crisis: guidelines from the European Malignant Hyperthermia Group. Br J Anaesth. 2010;105:417-420.http://bja.oxfordjournals.org/content/105/4/417.longhttp://www.ncbi.nlm.nih.gov/pubmed/20837722?tool=bestpractice.com
由于液体可能会进入水肿的肌肉,故可能会需要补充大量液体。应通过测量血液 PH 值、二氧化碳分压和钾浓度来指导碳酸氢盐的用药。大量通气、静脉注射钙离子、碳酸氢盐、注射含有胰岛素的葡萄糖对于治疗高钾血症是由必要的。高钾血症可导致心律失常和心脏骤停,除了极端的措施,如对严重横纹肌溶解症病例连续静脉-静脉血液滤过之外,还需要心脏复苏。[88]Fang S, Xu H, Zhu Y, et al. Continuous veno-venous hemofiltration for massive rhabdomyolysis after malignant hyperthermia: report of 2 cases. Anesth Prog. 2013;60:21-24.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3601726/http://www.ncbi.nlm.nih.gov/pubmed/23506280?tool=bestpractice.com如果存在急性 MH 发作,在治疗心律失常时,应避免使用钙通道阻滞剂。[89]Migita T, Mukaida K, Yasuda T, et al. Calcium channel blockers are inadequate for malignant hyperthermia crisis. J Anesth. 2012;26:579-584.http://www.ncbi.nlm.nih.gov/pubmed/22349750?tool=bestpractice.com由于需要高心排出量以满足氧耗,可能会出现心力衰竭。
在 ICU 中继续治疗
患者应在 ICU 中观察,并预防性施用丹曲林。初始治疗后的前 36 小时内肌肉代谢增加的复发风险高。[86]Burkman JM, Posner KL, Domino KB. Analysis of the clinical variables associated with recrudescence after malignant hyperthermia reactions. Anesthesiology. 2007;106:901-906.http://www.ncbi.nlm.nih.gov/pubmed/17457120?tool=bestpractice.com如果核心温度高于 38°C(100.4°F),应继续施用冷静脉注射液,并用冰袋冷敷腹股沟、腋下、颈部和头部等位置。
肌红蛋白尿和较低的肾排出量都是即将发生肾衰竭的标志。如果出现这些情况,应给予碳酸氢盐,尿量应保持在 2mL/kg//小时以上。碳酸氢盐疗法碱化尿液可能能减少肌红蛋白对肾小管的损伤。如果尿量在水分补充良好的情况下持续下降,应给予甘露醇。含甘露醇的丹曲林制剂静脉给药后,在约 10% 的患者中观察到静脉炎。[90]Brandom BW, Kang A, Sivak EL, et al. Update on dantrolene in the treatment of anesthetic induced malignant hyperthermia. SOJ Anesthesiol Pain Manag. 2015;2:1-6.http://www.symbiosisonlinepublishing.com/anesthesiology-painmanagement/anesthesiology-painmanagement21.pdfThe North American Malignant Hyperthermia Registry尚不清楚究竟是丹曲林中的甘露醇还是丹曲林本身导致了静脉炎。
DIC 应该像其他热损伤的患者一样治疗。通常需要更换凝血因子。血浆置换可能会有所帮助。如有必要,可咨询凝血专家对进一步的药物治疗进行指导。DIC 和肾功能衰竭通常会让患者死于暴发性 MH。
运动或热诱导横纹肌溶解症的管理
MH 易感患者过度产热导致了急性横纹肌溶解症,这是 MH 很罕见但可能致命的表现。[11]Groom L, Muldoon SM, Tang ZZ, et al. Identical de novo mutation in the type 1 ryanodine receptor gene associated with fatal, stress-induced malignant hyperthermia in two unrelated families. Anesthesiology. 2011;115:938-945.http://www.ncbi.nlm.nih.gov/pubmed/21918424?tool=bestpractice.com[66]Gronert GA, Tobin JR, Muldoon S. Malignant hyperthermia: human stress triggering. Biochim Biophys Acta. 2011;1813:2191-2192http://www.ncbi.nlm.nih.gov/pubmed/21839781?tool=bestpractice.com该病表现为剧烈运动或热相关疾病后出现肌僵直和深色尿。症状通常会伴随核心体温的恢复而消退。在阴凉处休息和增加口服补液通常可以使核心体温恢复。可能需要静脉补液和丹曲林,但通常情况下不需要。如果接触吸入麻醉剂或琥珀胆碱,这些患者存在 MH 风险,因此应避免接触这些药物。[36]Hirshey Dirksen SJ, Larach MG, Rosenberg H, et al. Future directions in malignant hyperthermia research and patient care. Anesth Analg. 2011;113:1108-1119.http://journals.lww.com/anesthesia-analgesia/Fulltext/2011/11000/Future_Directions_in_Malignant_Hyperthermia.28.aspxhttp://www.ncbi.nlm.nih.gov/pubmed/21709147?tool=bestpractice.com
慢性肌病管理
易感 MH 患者中出现的慢性肌病尚无治疗方法。肌病通常是亚临床,表现为肌酸激酶的慢性升高。这些患者可能需要更加避免热的环境中。MH 患者的组织病理学结果联合肌病的症状可以诊断为中央轴空病。
MH 患者在门诊手术中心的管理
在最近几年,独立门诊手术中心 (ASC) 的外科就诊量继续增加。据估计,2006 年美国有 3500 万次手术在 ASC 中进行。[91]Larach MG, Dirksen SJ, Belani KG, et al; Society for Ambulatory Anesthesiology; Malignant Hyperthermia Association of the United States; Ambulatory Surgery Foundation; Society for Academic Emergency Medicine; National Association of Emergency Medical Technicians. Special article: Creation of a guide for the transfer of care of the malignant hyperthermia patient from ambulatory surgery centers to receiving hospital facilities. Anesth Analg. 2012;114:94-100.http://journals.lww.com/anesthesia-analgesia/Fulltext/2012/01000/Creation_of_a_Guide_for_the_Transfer_of_Care_of.12.aspxhttp://www.ncbi.nlm.nih.gov/pubmed/22052978?tool=bestpractice.comASC 中 MH 发作的真实发病率不得而知。MH 触发因素在 ASC 中的使用值得积极供应丹曲林和其他的 MH 疗法。如果在 ASC 中出现 MH 的发作,则应确立将护理工作正式转交给具有更高护理水平的医院的指导原则。促进这些正式关系的指导原则不仅包括在 ASC 识别和开始治疗,还包括审核转送事项及接收医疗机构能力,以及由指定转诊团队实施做出的这些决策。[91]Larach MG, Dirksen SJ, Belani KG, et al; Society for Ambulatory Anesthesiology; Malignant Hyperthermia Association of the United States; Ambulatory Surgery Foundation; Society for Academic Emergency Medicine; National Association of Emergency Medical Technicians. Special article: Creation of a guide for the transfer of care of the malignant hyperthermia patient from ambulatory surgery centers to receiving hospital facilities. Anesth Analg. 2012;114:94-100.http://journals.lww.com/anesthesia-analgesia/Fulltext/2012/01000/Creation_of_a_Guide_for_the_Transfer_of_Care_of.12.aspxhttp://www.ncbi.nlm.nih.gov/pubmed/22052978?tool=bestpractice.com此外,很重要的一点是应强调 ASCs 必须按照美国恶性高热协会的建议储存丹曲林。而且,已发表的分析认为在 ASC 储存丹曲林具有成本效益。[92]Aderibigbe T, Lang BH, Rosenberg H, et al. Cost-effectiveness analysis of stocking dantrolene in ambulatory surgery centers for the treatment of malignant hyperthermia. Anesthesiology. 2014;120:1333-1338.http://www.ncbi.nlm.nih.gov/pubmed/24714119?tool=bestpractice.com已有专门针对 ASC 的关于 MH 易感患者或 MH 危机的详细指导原则,包括恰当储存含耗材和药品的 MH 推车、定期进行模拟演练以及提供认知辅助材料以帮助治疗。[93]Litman RS, Joshi GP. Malignant hyperthermia in the ambulatory surgery center: how should we prepare? Anesthesiology. 2014;120:1306-1308.http://www.ncbi.nlm.nih.gov/pubmed/24710219?tool=bestpractice.com由于运输过程中危重患者的发病和死亡风险增加,转诊团队应该在途中继续治疗 MH 发作,直到病人已经到达接收机构,病情稳定,并由接收机构继续治疗为止。[91]Larach MG, Dirksen SJ, Belani KG, et al; Society for Ambulatory Anesthesiology; Malignant Hyperthermia Association of the United States; Ambulatory Surgery Foundation; Society for Academic Emergency Medicine; National Association of Emergency Medical Technicians. Special article: Creation of a guide for the transfer of care of the malignant hyperthermia patient from ambulatory surgery centers to receiving hospital facilities. Anesth Analg. 2012;114:94-100.http://journals.lww.com/anesthesia-analgesia/Fulltext/2012/01000/Creation_of_a_Guide_for_the_Transfer_of_Care_of.12.aspxhttp://www.ncbi.nlm.nih.gov/pubmed/22052978?tool=bestpractice.com