A 62-year-old man is brought to the emergency department due to shortness of breath, chest pain, and palpitations that started earlier today. For the past month, he has had intermittent palpitations accompanied by shortness of breath. This time the symptoms persisted and he called 911. Medical problems include hypertension, obesity, chronic obstructive pulmonary disease, myocardial infarction, and carotid artery stenosis. The patient underwent coronary artery bypass grafting surgery 4 years ago. He follows up with a cardiologist twice a year, and there has been no recent change in his medical regimen. He is an ex-smoker and consumes no alcohol. He has no known drug allergies. On initial evaluation in the emergency department, he appears uncomfortable and tachypneic. Immediate ECG shows atrial fibrillation with a rapid ventricular response (140-150/min), narrow QRS complexes, and T-wave inversion in leads V4 to V6. The patient is connected to a cardiac monitor. While the team is securing intravenous access, the patient becomes unresponsive. He has no palpable pulses over the major arteries. The cardiac monitor continues to show a narrow-complex tachycardia consistent with atrial fibrillation. Which of the following is the most appropriate next step in management of this patient?

Question

A 62-year-old man is brought to the emergency department due to shortness of breath, chest pain, and palpitations that started earlier today.  For the past month, he has had intermittent palpitations accompanied by shortness of breath.  This time the symptoms persisted and he called 911.  Medical problems include hypertension, obesity, chronic obstructive pulmonary disease, myocardial infarction, and carotid artery stenosis.  The patient underwent coronary artery bypass grafting surgery 4 years ago.  He follows up with a cardiologist twice a year, and there has been no recent change in his medical regimen.  He is an ex-smoker and consumes no alcohol.  He has no known drug allergies.  On initial evaluation in the emergency department, he appears uncomfortable and tachypneic.  Immediate ECG shows atrial fibrillation with a rapid ventricular response (140-150/min), narrow QRS complexes, and T-wave inversion in leads V4 to V6.  The patient is connected to a cardiac monitor.  While the team is securing intravenous access, the patient becomes unresponsive.  He has no palpable pulses over the major arteries.  The cardiac monitor continues to show a narrow-complex tachycardia consistent with atrial fibrillation.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_be20_bed0_8f63_357d54af0a69_MD0005_00 This patient has developed sudden cardiac arrest with pulseless electrical activity (PEA) and should receive immediate cardiopulmonary resuscitation (CPR) with chest compressions. PEA refers to an organized cardiac rhythm (eg, sinus bradycardia, atrial fibrillation) that is unable to generate sufficient cardiac output to create a measurable blood pressure or palpable pulse. An underlying mechanical issue (eg, severe hypovolemia, massive pulmonary embolism, markedly impaired left ventricular contractility) is typically responsible. PEA often degenerates into asystole, which describes complete absence of organized cardiac electrical activity, and is managed the same as PEA per advanced cardiac life support (ACLS) protocol. PEA cardiac arrest requires rapid initiation and continuation of effective CPR, consisting of chest compressions, airway management, and intravenous epinephrine, in an effort to maintain organ and tissue perfusion until spontaneous circulation can be restored. PEA and asystole cardiac arrest often result from a potentially reversible cause, and identification and treatment of such a cause provides the best chance of achieving return of spontaneous circulation. reversible cause (Choice A) Per ACLS protocol, adenosine is appropriate for narrow-complex tachycardias in hemodynamically stable patients with a pulse; however, it is not used for patients in PEA cardiac arrest. (Choice B) Intravenous thrombolytics (eg, alteplase) can be administered to patients with PEA due to suspected pulmonary embolism or myocardial infarction. However, in any patient with cardiac arrest, chest compressions should be initiated without delay. (Choice D) Defibrillation is essential for patients with cardiac arrest due to ventricular fibrillation or pulseless ventricular tachycardia (disorganized cardiac rhythms). However, PEA describes cardiac arrest with an organized cardiac rhythm for which defibrillation is ineffective. (Choice E) Synchronized cardioversion is appropriate management for supraventricular tachycardia (eg, atrial fibrillation with rapid ventricular response) in a hemodynamically unstable patient with a pulse. However, when such a patient becomes pulseless, the management shifts to effective CPR for PEA cardiac arrest. Because the underlying cardiac rhythm is not the problem in PEA cardiac arrest, synchronized cardioversion is not performed and would not be appropriate until, if and when, a pulse is regained. Educational objective: Pulseless electrical activity (PEA) describes an organized cardiac rhythm that is unable to generate sufficient cardiac output to create a measurable blood pressure or palpable pulse. Patients with PEA cardiac arrest require immediate and continuous cardiopulmonary resuscitation until, if and when, the cause of the cardiac arrest can be identified and treated and return of spontaneous circulation is achieved. Neither defibrillation nor synchronized cardioversion are performed on patients in PEA cardiac arrest. References: Part 1: executive summary: 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. (http://www.ncbi.nlm.nih.gov/pubmed/26472989)

A 62-Year-Old Man Is Brought to the Emergency Department Due