碘造影剂所致速发型过敏反应

碘造影剂是影像学诊断中最常用的药物,根据分子结构可分为离子和非离子型,根据渗透压可分为高渗、低渗和等渗型.碘造影剂通常较为安全,但也可发生严重不良反应,例如重度速发型过敏反应.重度速发型过敏反应可导致血管性水肿、严重低血压、意识丧失、心律失常、呼吸骤停和心搏骤停等.离子型和非离子型碘造影剂致重度速发型过敏反应的发生率分别为0.1%～0.4%和0.02%～0.04%.碘造影剂致速发型过敏反应的最主要危险因素为造影剂过敏史,其他危险因素为哮喘病史和对药物或食物过敏史等.速发型过敏反应的机制可能与嗜碱粒细胞和肥大细胞释放组胺有关,组胺的释放可由碘造影荆溶液渗透压或化学结构的直接膜效应、激活补体系统及形成缓激肽和激活IgE介导的抗原抗体反应引起.防治措施:(1)尽量应用非离子型低渗、等渗碘造影剂;(2)对有危险因素者建议行皮肤试验并前驱给予糖皮质激素或抗组胺药物;(3)对中、重度速发型过敏反应者需行对症支持治疗.

Immediate hypersensitivity reactions induced by iodinated contrast media

Iodinated contrast media(ICM) are the most commonly used drugs in diagnostic visualisation technique.ICM may be classified as ionic and nonionic according to their chemical structure or high-osmolar,low-osmolar,and iso-osmolar according to their osmolality.ICM are generally considered to be relatively safe,but serious adverse reactions may occur,such as severe immediate hypersensitivity reactions.Severe immediate hypersensitivity reactions may lead to angioedema,unconsciousness,profound hypotension,arrhythm...