A 46-year-old previously healthy man comes to the hospital due to a day of pleuritic chest pain and dyspnea. The patient has had right leg swelling for the past week. He has smoked a pack of cigarettes daily for 12 years and works as a truck driver. Cardiopulmonary examination is within normal limits with the exception of tachycardia. The right lower extremity is swollen and tender up to the mid thigh. CT pulmonary angiography shows a right-sided pulmonary embolism, and duplex venous ultrasound reveals a thrombus in the right femoral vein. The patient is admitted to the hospital and started on low-molecular-weight heparin therapy. During morning rounds, he suddenly becomes unresponsive and has no palpable pulses despite electrical activity consistent with sinus bradycardia at 50/min on the cardiac monitor. Advanced cardiac life support measures, including external chest compressions and endotracheal intubation, are implemented. After 4 minutes of chest compressions, he is still pulseless and the monitor shows sinus bradycardia. Which of the following is the best next step in management of this patient?

Question

A 46-year-old previously healthy man comes to the hospital due to a day of pleuritic chest pain and dyspnea.  The patient has had right leg swelling for the past week.  He has smoked a pack of cigarettes daily for 12 years and works as a truck driver.  Cardiopulmonary examination is within normal limits with the exception of tachycardia.  The right lower extremity is swollen and tender up to the mid thigh.  CT pulmonary angiography shows a right-sided pulmonary embolism, and duplex venous ultrasound reveals a thrombus in the right femoral vein.  The patient is admitted to the hospital and started on low-molecular-weight heparin therapy.  During morning rounds, he suddenly becomes unresponsive and has no palpable pulses despite electrical activity consistent with sinus bradycardia at 50/min on the cardiac monitor.  Advanced cardiac life support measures, including external chest compressions and endotracheal intubation, are implemented.  After 4 minutes of chest compressions, he is still pulseless and the monitor shows sinus bradycardia.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c079_c96d_8f63_2fd3cddfe560_MD0005_00 This unresponsive patient has experienced cardiac arrest, with the cardiac monitor showing pulseless electrical activity (PEA). PEA is defined as an organized cardiac rhythm that is unable to generate sufficient cardiac output to create a measurable blood pressure or palpable pulse. Cardiac arrest due to either PEA or asystole (complete absence of cardiac electrical and mechanical activity) is managed the same based on the advanced cardiac life support protocol. Immediate cardiopulmonary resuscitation (CPR) consisting of effective chest compressions and assisted breathing should be administered. In addition, epinephrine 1 mg should be administered via the intravenous or intraosseous route every 3-5 minutes in an effort to increase organ and tissue perfusion. Shocks (defibrillation attempts) are not administered for cardiac arrest due to PEA or asystole. CPR should continue uninterrupted while attempts are made to identify and treat potentially reversible causes of PEA. This patient's PEA cardiac arrest is most likely due to a recurrent acute pulmonary embolism, and administration of tissue plasminogen activator with ongoing CPR likely provides the best chance of restoring a perfusing cardiac rhythm. causes (Choice A) Intravenous atropine is indicated in patients with symptomatic bradycardia (eg, hypotension, heart failure); however, sinus bradycardia in the absence of a pulse represents PEA rather than symptomatic bradycardia. Atropine is not used in patients with PEA cardiac arrest. (Choices B and D) Intravenous calcium gluconate is sometimes helpful for patients with cardiac arrest due to hyperkalemia, and sodium bicarbonate may be helpful in patients with cardiac arrest due to hyperkalemia, metabolic acidosis, or tricyclic antidepressant overdose. However, unless there is a high suspicion for such underlying causes, these agents should not be administered prior to epinephrine. (Choice E) Cardiac pacing is ineffective in patients with PEA or asystole cardiac arrest and is not recommended. Educational objective: Cardiac arrest due to pulseless electrical activity or asystole should be managed with prompt, uninterrupted cardiopulmonary resuscitation along with epinephrine every 3-5 minutes and early identification and treatment of potentially reversible causes. Atropine and cardiac pacing are not used for the treatment of pulseless electrical activity or asystole. References: Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. (http://www.ncbi.nlm.nih.gov/pubmed/20956224)

A 46-Year-Old Previously Healthy Man Comes to the Hospital Due