小儿肺炎全身各系统病理生理变化的关键因素是() ["A．机体抵抗力低下","B．病原体侵入","C．毒素作用","D．缺氧和二氧化碳潴留","E．器官发育不成熟"]
防治重症哮喘病儿痰栓阻塞小支气管的最主要措施是() ["A．气管切开","B．应用糖皮质激素","C．吸痰管吸痰","D．口服祛痰药","E．多饮水"]
下列关于心电图的叙述，哪项错误() ["A．心房兴奋产生P波","B．P-R间期为0.12～0.20秒","C．QRS时间不应超过0.1秒","D．P-R间期反应希氏束的传导时间","E．T波在心室收缩时出现"]
有关房室传导阻滞(AVB)的叙述，下列哪项是错误的() ["A．I度和Ⅱ度I型对血流动力学无明显影响","B．Ⅱ度Ⅱ型可引起充血性心衰和阿-斯综合征发作，并可发展为高度AVB","C．高度AVB对血流动力学的影响与完全性AVB相似，易引起阿-斯综合征","D．各类传导阻滞都是由心脏病引起的","E．高度或完全性AVB病人麻醉前最好预先安置起搏器"]
哮喘持续状态是指哮喘发作严重，持续多长时间以上() ["A．72h","B．48h","C．36h","D．24h","E．12h"]
背景
