BCEN CENFree Certified Emergency Nurse practice test

Correct answer: D. Blood cultures

This patient's presentation — fever, new murmur, and IV drug use history — is highly suggestive of infective endocarditis (IE). Blood cultures are the essential first step because they identify the causative organism before antibiotics are started. At least three sets should be drawn prior to initiating empiric therapy to maximize diagnostic yield. An ECG can reveal arrhythmias or conduction abnormalities that may accompany IE, but it does not establish the diagnosis. A chest X-ray might detect pulmonary septic emboli in right-sided endocarditis but is not the primary diagnostic tool. A CBC may show leukocytosis consistent with infection, yet this finding is nonspecific and does not direct definitive treatment.

Correct answer: A. Emergency thoracotomy or pericardiocentesis

The combination of hypotension, jugular venous distension, and muffled heart sounds after penetrating chest trauma indicates pericardial tamponade. Definitive management requires surgical decompression via thoracotomy or pericardiocentesis, and the emergency nurse must prepare for immediate operative intervention or a bedside procedure. Chest tube placement addresses pneumothorax; however, equal breath sounds and muffled cardiac tones point toward tamponade rather than pulmonary injury. Obtaining CT imaging in an unstable trauma patient delays life-saving care — tamponade is a clinical and ultrasound-supported diagnosis, not one requiring CT. Blood transfusion may support volume status but does not relieve the obstructive shock caused by pericardial compression.

Correct answer: A. Pericardial tamponade

Hypotension, jugular venous distension, and muffled heart sounds form Beck's triad, the hallmark presentation of pericardial tamponade. Blood accumulating in the pericardial sac compresses the ventricles, producing obstructive shock. Tension pneumothorax can also cause hypotension and JVD, but breath sounds would be diminished or absent on the affected side rather than producing muffled heart tones. Massive hemothorax leads to hypovolemic shock and decreased breath sounds but does not typically cause muffled cardiac tones. Acute myocardial infarction may precipitate chest pain and dysrhythmias but does not generate the triad described here.

Correct answer: A. Beck's triad is present in only a portion of patients with cardiac tamponade.

Beck's triad — hypotension, jugular venous distension, and muffled heart sounds — is classically associated with cardiac tamponade, yet it appears in only roughly one-third of affected patients. Many individuals present with incomplete or subtle findings, so clinicians must also consider pulsus paradoxus, tachycardia, and dyspnea. The triad alone does not confirm tamponade; confirmation requires clinical suspicion combined with imaging such as bedside echocardiography or the FAST exam in trauma. Hypertension is not a component of the triad — hypotension is the correct finding. Waiting for the full triad before suspecting tamponade is inappropriate, as hemodynamic instability in the setting of trauma warrants consideration regardless of how many components are present.

Correct answer: C. Painful red nodules on the fingers

Osler nodes are painful, immunologically mediated embolic lesions appearing on the fingers or toes and are classic for infective endocarditis. Their presence alongside fever and a murmur in a high-risk individual — such as an IV drug user — strongly supports the diagnosis. Pulmonary infiltrates may reflect septic emboli but are a nonspecific finding. Nail clubbing indicates chronic hypoxia or long-standing disease processes rather than acute infection. Petechiae can occur in endocarditis but are less diagnostically specific than Osler nodes.

Correct answer: B. Maintain good oral hygiene and seek regular dental care

Maintaining proper oral hygiene and receiving consistent dental care is the most impactful preventive strategy for this patient. Poor oral health allows bacteria such as Streptococcus viridans to enter the bloodstream, which elevates the risk of bacterial endocarditis — particularly in individuals with pre-existing valve abnormalities. Avoiding tobacco and marijuana benefits cardiovascular health overall but does not directly reduce bacteremia risk, making it less targeted for IE prevention. Antibiotic prophylaxis before medical procedures is reserved for high-risk patients (e.g., those with prosthetic valves, prior IE, or specific congenital heart conditions) undergoing defined procedures such as dental extractions, not all medical encounters. Limiting alcohol is beneficial for general cardiac health but is not a primary risk factor for endocarditis unless severe alcoholic cardiomyopathy is present.

Correct answer: C. Blunt cardiac injury

Direct blunt trauma to the chest can cause myocardial contusion, which manifests as conduction abnormalities, arrhythmias, or mild troponin elevation. New bundle branch blocks are a recognized consequence, and continuous ECG monitoring is essential for safe management. Acute MI is unlikely in this context unless the patient has significant coronary artery disease or a traumatic coronary dissection. Aortic dissection classically presents with tearing, radiating pain and mediastinal widening on imaging. Pneumothorax would be apparent on imaging and does not produce the ECG changes described.

Correct answer: C. Pericardial tamponade

Beck's triad — hypotension, JVD, and muffled heart sounds — is the hallmark of pericardial tamponade. Penetrating chest trauma raises immediate concern for cardiac injury and blood accumulating within the pericardial sac, restricting ventricular filling. Tension pneumothorax can also produce hypotension and JVD, but would more characteristically include absent unilateral breath sounds and tracheal deviation. Massive hemothorax leads to hypovolemia and dullness to percussion over the affected side, but does not typically produce muffled heart sounds. Flail chest causes paradoxical chest wall movement and respiratory compromise, not the triad described here.

Correct answer: B. Perform needle decompression followed by chest tube placement

Tension pneumothorax is a clinical diagnosis in the unstable patient and represents obstructive shock requiring immediate decompression rather than imaging. Needle decompression relieves the elevated intrathoracic pressure and restores venous return; this must be followed by tube thoracostomy to prevent recurrence. Waiting for a chest X-ray in an unstable patient risks preventable cardiac arrest — point-of-care ultrasound may assist if immediately available, but it must not delay decompression. Positive pressure ventilation prior to chest decompression can worsen a tension pneumothorax by further increasing intrathoracic pressure and precipitating cardiovascular collapse; airway management should follow decompression. Vasopressors do not correct the underlying mechanical obstruction of venous return; addressing the cause — trapped air under pressure — takes priority over pharmacologic support.

Correct answer: B. Stop smoking completely

Smoking is the most significant modifiable risk factor for peripheral vascular disease. It accelerates atherosclerosis, narrows peripheral arteries, and diminishes extremity blood flow. Cessation is the single most effective action for slowing disease progression and improving circulation. Reducing processed food consumption is associated with lower cardiovascular risk overall, but its impact is less pronounced than quitting smoking. Omega-3 fatty acids may reduce vascular inflammation to some degree but do not reverse established atherosclerosis in peripheral vessels. Daily aspirin has a role in reducing platelet-related clotting events yet does not address the underlying arterial narrowing as effectively as eliminating tobacco use.