Cardiopulmonary resuscitation (CPR)
Cardiopulmonary resuscitation (CPR) is a skill that has significant impact on asystolic patient survival. This week, we'll discuss some recent changes in the performance of this skill. Today we'll discuss some new antiarrhythmic drug recommendations.
1. How are recommendations for drug treatments classified?
2. What is the status of bretylium for the treatment of ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT)?
3. What is the status of lidocaine for the treatment of ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT)?
4. What is the role of amiodarone in the treatment of ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT)?
今天我们讨论新的抗心律失常药物。
1. 治疗心律失常药物循证医学如何分类？
2. 溴苄胺在室颤（VF）或无脉性室性心动过速（VT）治疗中处于何种地位？
3. 利多卡因在室颤（VF）或无脉性室性心动过速（VT）治疗中处于何种地位？
4. 胺碘酮在室颤（VF）或无脉性室性心动过速（VT）治疗中的作用是什么?
Pharmacotherapy Changes in the ACLS Guidelines: Impact on UIHC Practitioners
参考答案：
1.治疗心律失常药物循证医学如何分类？
2000年国际指南会议在决定对心律失常药物的使用问题上使用了循证医学原则。这些药物被分为以下几种：
如下图。
2.溴苄胺在室颤（VF）或无脉性室性心动过速（VT）治疗中处于何种地位？
一旦在VF或无脉性VT电除颤后推荐使用Ⅱb类药物治疗，溴苄胺现已被排除在该系统外[2]。部分是因为世界上生产溴苄胺的自然资源近乎耗尽、有限的优点以及高副作用，特别是在复苏后出现低血压。溴苄胺是Ⅱb类药物，乙胺碘呋酮（另一Ⅱb类药物）可以代替溴苄胺使用。
3.利多卡因在室颤（VF）或无脉性室性心动过速（VT）治疗中处于何种地位？
利多卡因被乙胺碘呋酮替代，并被归于不确定的分类中，因为其在在VF或无脉性VT中作用能够很弱且支持其的文献都已经过时。此外，在MI>8年以上情况时，利多卡因已不被推荐常规用于预防性室性心律失常的治疗[2]。然而对急性心梗，利多卡因似乎可减低VF的发生，但是不会降低死亡率。结果是，利多卡因不被推荐预防性使用。利多卡因仍旧用于顽固性VF和无脉性VT、室早导致的血流动力学损害，以及血流动力学稳定性VT[1]。
4.胺碘酮在室颤（VF）或无脉性室性心动过速（VT）治疗中的作用是什么?
虽然关于乙胺碘呋酮的抗心律失常作用只有一些证据支持，但是用于VF或无脉性VT的的药物中，乙胺碘呋酮比其他药物（包括利多卡因、镁（如果低镁）、和普鲁卡因酰胺）有更多的文献支持[1]。此外，对于稳定的单一型和多样型VT，乙胺碘呋酮推荐作为Ⅱb类药物。最后，对于血流动力学稳定范围较大的复杂心动过速，特别是对于心功能不全的病人，乙胺碘呋酮作为优于利多卡因和腺苷的Ⅱb类药物而被推荐[2]。 
How are recommendations for drug treatments classified?
The "International Guidelines 2000" conference used the principles of evidence-based medicine in determining their final recommendations on drugs. These drugs were divided into the following classes (1):
What is the status of bretylium for the treatment of ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT)?
Once a recommended IIb therapy following defibrillation for VF/ pulseless VT, bretylium has now been omitted from this algorithm (2). In part, this stems from the world's natural sources for bretylium being almost exhausted, the limited information confirming its benefit, and the high incidence of side effects, in particular hypotension, in the postresuscitation setting. Bretylium was and remains a Class IIb drug. In lieu of bretylium, amiodarone (another Class IIb drug) can be used.
What is the status of lidocaine for the treatment of ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT)?
Lidocaine was supplanted by amiodarone and placed in the "indeterminate" classification due to the weak and dated references supporting its use for VF/pulseless VT. Moreover, lidocaine is no longer recommended for routine prophylaxis of ventricular arrhythmias in the setting of an MI > 8 years ago (2). For acute MI, however, lidocaine appears to reduce the incidence of VF, but does not lower mortality. Consequently, lidocaine is not recommended as a routine prophylaxis. Lidocaine does remain in use for persistent VF/pulseless VT, hemodynamically compromising PVC's, and hemodynamically stable VT (1).
What is the role of amiodarone in the treatment of ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT)?
Although only fair evidence exists on its antiarrhythmic properties, amiodarone has greater literature support than other agents used in the VF/pulseless VT algorithm (which include lidocaine, magnesium (if hypomagnesemic), and procainamide) (1). Moreover, for stable monomorphic and polymorphic VT, amiodarone has been recommended as a Class IIa agent. Finally, for hemodynamically stable wide complex tachycardia, especially in patients with compromised cardiac function, amiodarone has been promoted as a class IIb drug ahead of lidocaine and adenosine (2).
References:
1. 2000 Handbook of Emergency Cardiovascular Care for Healthcare Providers. American Heart Association. 2000.
2. Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Part 6: advanced cardiovascular life support: 7C: a guide to the International ACLS algorithms. The American Heart Association in collaboration with the International Liaison Committee on Resuscitation. Circulation. 2000;102(8 Suppl)
142-57.
Site Editor: Stephen B. Corn, M.D. and B. Scott Segal, M.D.
Department of Anesthesia, Harvard Medical School
Founders and Editors-in-Chief: Stephen B. Corn, M.D. and B. Scott Segal, M.D.
Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School 
