NO.73-过敏反应与类过敏反应（part5） « 医药家园

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1. 1、 该过敏反应的可能原因是什么？
   包括mzyw,术中输血,还有术中用药
   2、 如何zl该手术中出现的过敏反应？
   zl的目标是纠正动脉低氧血症,抑制化学介质的继续释放和恢复血管内容量。立即停止应用可疑有超敏反应的yw和停止使用mz药;保持呼吸道通畅;严重者立即皮下-注射肾上腺素5µg/kg;应用抗过敏ywzl过敏症状,适当补充液体,还有应用升压yw升血压
   3、 在患者苏醒后如何告知患者？
   可以如实告知患者术中发生的过敏反应,并告知这是正常现象,已经处理了不会有什么后遗症和并发症的
   4、 mz之前使用术前用药是否有用？
   比如术前应用js和非那根等yw可以起到一定的预防作用的

2. anaphylaxis:过敏反应，过敏症：①系统性或全身性过敏，过敏性休克；为速发型或即发型过敏反应(immediate hypersensitiity，q..)的表现，即致敏者接触特异抗原或半抗原后发生的危及生命的呼吸窘迫，并常继以循环虚脱和休克，伴有荨麻疹、搔痒和血管水肿。通常引起过敏反应的物质如膜翅目毒液，花粉浸液，某些食物，马及家兔血清，异种酶和js，某些yw(如青霉素、利多卡因)等；②原来用于接触毒素后不引起免疫反应(预防作用)而是发生过敏反应的一类情况的通用术语，以后进而包括一切由异体抗原诱发的系统性过敏反应以及各种实验模型，如被动性皮肤过敏反应，现在则已归入比较广泛的速发型(I型)过敏反应的概念中.
   anaphylactoid reaction (pseudoanaphylaxis) 假过敏反应，假过敏性：类似全身过敏反应或过敏性休克的一种反应，因静脉注射经琼脂、白陶土或淀粉处理过的血清所致，不涉及抗原抗体反应.
   1. What is the likelihood that this is an episode of anaphylaxis?
   mz（yw、血液、液体、和器具）、手术（xd液、器具、）、护理（器具、手术敷料、床单、输液管道等）、患者自身（被手术打开的囊肿、羊水）等患者在术中有可能接触到的一切因素，都有可能导致术中过敏。
   2. How do you treat an episode of intraoperatie anaphylaxis?
   处理术中过敏，首先对症处理保证患者生命安全（地米、钙剂、肾上腺素-ifi necessary）， 同时严密监测、查找过敏源，我的经验是依据mz记录、手术步骤、护理记录采取“时间患者的反应”来逐项排出 ，别忘了既往过敏史；这样常见的和不常见的原因都能找到；其次， 记录过敏反应发生及处理、患者反应；
   3. What would you tell this patient after he is recoered and conscious?
   -你曾经在手术中发生了****过敏（如果已经查明证实）， 现在你很安全。
   以后看病的时候记着告诉你的医生 ，你对****过敏；
   4. Is there any role for premedication prior to a future anesthetic
   就我看来， mz术前所用 的yw，尤其是zj药 有可能会掩盖过敏的症状 ， 给分析带来困难和干扰。 另一方面， 如果患者术中换血（失血） 的话又会使术前药的药代学发生变化，这时， 不论是预防作用还是副作用都要重新评估。对术中过敏反应来讲 ， {zh0}的预防办法就是 明确既往过敏史、不接触过敏原。当前一般性的术前mz用药 其主要目的不是预防过敏。
   
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3. 参考答案：
   1、 该过敏反应的可能原因是什么？
   注意当时是否应用了某些yw或制剂非常重要，尤其是当首次使用时更应注意。多数情况下，相对于新开发或近期刚引进的yw，常规yw或制剂如血制品或通过mz药给与的橡胶（编者注：如各种溶剂）等很少导致过敏反应[1]。如果这确实属于过敏，mz医生英觉得自己很“幸运”，因为这时过敏的一些早期症状很明确。mz期间的过敏反应的诊断极富挑战性，因为患者躯体的大部分在手术单下，无法看到，同时mzyw本身有时可出现与过敏早期症状类似的表现。mz期间经常会出现过敏反应的{wy}表现是严重的支气管痉挛或突然的心血管性虚脱。
   mz期间非特异性、非免疫性组胺释放也比过敏反应的几率高，常出现在使用mf或某些肌肉松弛剂时。考虑该患者的症状与组胺释放有关，但很难区分是免疫性或非免疫性组胺释放。
   2、 如何zl该手术中出现的过敏反应？
   首先应停止使用可能导致过敏的制剂或mz剂。增加吸入氧浓度到{bfb}，并开始静脉输液。过敏指南推荐皮下或肌肉注射肾上腺素0.2～0.5mg[2]，但静脉注射的出现和mz期间过敏反应的严重程度提示，静脉注射更有效。肾上腺素以5～10 mcg的梯度增加，除非出现严重的低血压或心血管性虚脱[3]。心血管性虚脱时推荐剂量0.1～0.5mg静脉注射[3]。同时使用其它yw如抗组胺药（0.5～1 mg/kg苯海拉明）、注射肾上腺素维持血压（5～10 mcg/min）、支气管扩张剂（沙丁胺醇、异丙阿托品喷雾剂）[3]。
   虽然认为皮质js不能迅速发挥效应，但仍应使用，因为其可抑制过敏反应几小时后出现的炎症细胞浸润。
   3、 在患者苏醒后如何告知患者？
   应尽可能的明确致敏剂。检测血清纤维蛋白溶酶以确认过敏反应，同时检测制剂特异性IgE抗体。通过皮内试验确定诊断。患者应佩戴识别其过敏物质的腕带，应随时随身携带Epi-pen，并告知其保健医生自己的yw过敏史。
   4、 mz之前使用术前用药是否有用？
   术前使用H1、H2阻滞剂和类固醇，对预防放射性造影剂的反应有一定效果，但这些反应并非IgE介导[4]。尚没有证据表明术前给药可预防IgE介导的过敏反应发生，并且这些yw的使用实质上可掩盖过敏的早期症状，导致发生过敏时只有一种表现。
   What is the likelihood that this is an episode of anaphylaxis?
   It is important to notice if there was any medication or agent that was recently administered, especially if it was the first time that it was gien. For the most part, medications or agents such as blood products or latex that hae been gien throughout the anesthetic are less likely to cause an allergic reaction than agents that were recently introduced (1). If this is indeed an allergic reaction, the anesthesiologist should consider him/herself , as some of the early presenting signs of anaphylaxis are manifested here. The diagnosis of anaphylaxis during an anesthetic is often challenging as most of the body is coered by drapes, and the anesthetic itself may sometimes mimic early signs of anaphylaxis. Frequently, the only sign of anaphylaxis during an anesthetic is seere bronchospasm or sudden cardioascular collapse.
   Nonspecific, nonimmunologic histamine release is also far more frequent than anaphylaxis and is common with medications such as morphine and certain muscle relaxants. While the symptoms of this patient are consistent with histamine release, it may be difficult to differentiate between immunologic and nonimmunologic histamine release.
   How do you treat an episode of intraoperatie anaphylaxis?
   The first line of action ought to be to discontinue the potential causatie agent and the anesthetic. The inspired oxygen should be increased to {bfb} with potential airway support, and intraenous fluid replacement should be commenced. While the Allergy literature recommends 0.2-0.5 mg epinephrine subcutaneously or intramuscularly (2), the presence of an intraenous and the seerity of anaphylaxis during an anesthetic suggest that an intraenous approach is more effectie. Epinephrine should be gien in 5-10 mcg increments unless seere hypotension or cardioascular collapse is present (3). Doses of 0.1-0.5 mg I hae been recommended in cases of cardioascular collapse (3). Other medications that should be gien include antihistamines (0.5-1 mg/kg diphenhydramine), epinephrine infusion to support the blood pressure (epinephrine 5-10 mcg/min) and bronchodilators (albuterol and ipratropium bromide nebulizers) (3).
   Although corticosteroids should not be expected to proide any immediate benefit, they should be gien as they may help to decrease the swelling and inflammation that often accompany anaphylaxis hours after its initial presentation.
   What would you tell this patient after he is recoered and conscious?
   An attempt should be made to diagnose the causatie agent. Serum tryptase should be drawn to confirm that the episode represented true anaphylaxis and agent-specific IgE antibodies should also be obtained. Definitie diagnosis is made with the use of intradermal skin tests. The patient should wear a bracelet that identifies what he is allergic to, should carry an Epi-pen at all times, and should inform healthcare proiders about his drug allergy.
   Is there any role for premedication prior to a future anesthetic?
   Premedication with H1 blockers, H2 blockers and steroids, has a role for reactions to radiocontrast media, but these reactions are not IgE mediated (4). There is no eidence to support the use of premedication to preent IgE mediated anaphylaxis, and their use may actually mask the early signs of anaphylaxis, leaing a full blown episode as the first and only presentation.
   References:
   1. Weiss ME, Adkinson Jr NF, Hirshman CA. Ealuation of allergic drug reactions in the perioperatie period. Anesthesiology 1989;71:483-86.
   2. Grupe S. Algorithm for the treatment of acute anaphylaxis. J Allergy Clin Immunol 1998;101:S469-471.
   3. Ley JH. Allergy and aderse drug reactions. American Society of Anesthesiologists Annual Meeting Refresher course Lectures 2000;162:1-7.
   4. Weiss ME. Drug allergy. The Medical Clinics Of North America 1992;76:857-82.