Làm thế nào để đồng bộ cardioversion khác nhau từ khử rung tim? Đồng bộ cardioversion cũng có kết quả trong quá trình khử cực của cơ tim, nhưng cardioversion cung cấp cho quá trình khử cực được hẹn giờ (đồng bộ) với hoạt động điện của bệnh nhân nội tại. | CHAPTER 7 Cardiac Rhythm Disturbances 85 o T F Defibrillation should be attempted in asystole. False. Unless there is reasonable doubt that the dysrhythmia may actually be VF o What is defibrillation The untimed asynchronous depolarization of a critical mass of myocardial cells to allow spontaneous organized myocardial depolarization to resume. o What will happen if organized depolarization does not resume after defibrillation VF will continue or will progress to electrical silence at which point restoration of spontaneous cardiac activity may be impossible. o How does synchronized cardioversion differ from defibrillation Synchronized cardioversion also results in depolarization of the myocardium but cardioversion provides depolarization that is timed synchronous with the patient s intrinsic electrical activity. o Why is synchronized cardioversion inappropriate in the patient with VF VF has no organized cardiac electrical activity with which to synchronize. o Successful defibrillation requires the passage of sufficient electric current amperes through the heart. On what two factors does this current flow depend The energy joules provided and the transthoracic impedance ohms which is the resistance to current flow. o If transthoracic impedance is high what must be done to achieve sufficient current for successful defibrillation or cardioversion Increase the electrical current. o What eight factors determine transthoracic impedance Energy selected Electrode size Paddle-skin coupling material Number of shocks Time intervals between shocks Phase of ventilation Size of chest Paddle electrode pressure o What is the optimal energy dose for defibrillation in infants and children Trick question the optimal energy dose has not been established sorry . o Although available information does not demonstrate a relation between energy dose and weight pediatricians are committed to that relationship with or without evidence. So what starting dose has been arbitrarily recommended .
