AACN CCRN (Adult)Free Critical-Care Registered Nurse (Adult) practice test

Correct answer: B. Apply transcutaneous pacing pads

Transcutaneous pacing pads are the most urgent priority for symptomatic complete (third-degree) heart block causing bradycardia and hemodynamic compromise. This measure delivers immediate temporary support to restore an adequate ventricular rate and maintain organ perfusion until a definitive treatment can be arranged. Watchful waiting is unsafe because the patient is already hemodynamically unstable with critically reduced cardiac output. An arterial line assists with ongoing hemodynamic monitoring but does not treat the life-threatening conduction failure and must not delay pacing. Chest compressions are reserved for pulseless patients; as long as the patient retains a pulse, electrical pacing takes priority over CPR.

Correct answer: C. Non-ST-Elevation Myocardial Infarction (NSTEMI)

NSTEMI is a form of acute coronary syndrome (ACS) caused by sudden reduction in coronary blood flow. Clinical manifestations across the ACS spectrum include chest pain or discomfort, nausea, hemodynamic compromise, dyspnea, dysrhythmias, and anxiety. Atherosclerotic plaque rupture triggers thrombus formation; in NSTEMI, the resulting ECG changes are transient and typically manifest as T-wave inversion and ST-segment depression rather than persistent ST elevation.

Correct answer: C. NSTEMI

NSTEMI is characterized by ST-segment depression and T-wave inversion on the ECG, which differ from the ST elevation seen in STEMI. Major risk factors for NSTEMI include elevated serum cholesterol, hypertension, diabetes mellitus, and cigarette smoking. Additional contributing factors include advancing age, male sex, family history, physical inactivity, obesity, excess alcohol intake, and a diet low in fresh produce and polyunsaturated fats. Reperfusion management of NSTEMI involves heparin, IV beta-blockers within 24 hours of presentation, and initiation of lipid-lowering therapy. STEMI is defined by ST elevation, while third-degree AV block involves complete cessation of AV conduction.

Correct answer: C. Deliver high-flow oxygen via non-rebreather mask

High-flow oxygen via mask is the first priority because the clinical findings indicate acute pulmonary edema, likely from acute heart failure or cardiogenic shock. Immediate oxygenation support prevents irreversible tissue hypoxia and cardiac arrest while additional interventions are prepared. A urinary catheter may later be needed to track urine output but does not resolve the acute hypoxic threat. An arterial blood gas helps quantify the degree of respiratory failure but must never delay essential supportive care; oxygenation and ventilation are always addressed before further diagnostics. A chest X-ray confirms the diagnosis and guides management but is a diagnostic step that follows initial stabilization, as it cannot address life-threatening hypoxia.

Correct answer: B. Perform prompt synchronized cardioversion

Fusion and capture beats in a wide-complex tachycardia occurring in a patient with structural heart disease are highly diagnostic of ventricular tachycardia. Even when the patient is currently hemodynamically stable, prompt synchronized cardioversion is typically recommended because patients with underlying cardiomyopathy are at high risk for rapid deterioration or degeneration into ventricular fibrillation. Adenosine is not appropriate for rhythms suspected to be ventricular in origin; it is ineffective and may trigger hemodynamic collapse. Transcutaneous pacing targets symptomatic bradyarrhythmias and high-degree AV block, not sustained ventricular tachycardia in a stable patient. Passive observation with a delayed repeat ECG risks sudden clinical deterioration and delays definitive treatment of a potentially lethal arrhythmia.

Correct answer: D. Diastolic dysfunction

Diastolic dysfunction commonly results from ventricular hypertrophy. The thickened ventricular wall reduces cavity compliance and limits filling during diastole, producing a reduced stroke volume despite a preserved ejection fraction. Systolic dysfunction, by contrast, impairs myocardial contractility and reduces both stroke volume and ejection fraction. Biventricular failure may be present but cannot be determined from the information given. Mitral regurgitation diminishes stroke volume through a different mechanism involving valve incompetence during systole.

Correct answer: B. Initiate high-quality chest compressions

Initiating high-quality chest compressions is the immediate priority. This patient is pulseless and unresponsive, fulfilling the criteria for cardiac arrest. ACLS and critical care guidelines mandate starting effective CPR without delay to sustain perfusion to vital organs until advanced interventions are available. Checking a carotid pulse introduces unnecessary delay; the absence of a radial pulse combined with unresponsiveness is sufficient justification to begin resuscitation immediately. Synchronized cardioversion is for patients with a perfusing rhythm; pulseless arrest requires unsynchronized defibrillation when indicated, always preceded by CPR. A STAT ECG is useful in stable patients but must not delay chest compressions in a pulseless patient; rhythm identification occurs during pulse and rhythm checks within the resuscitation cycle.

Correct answer: C. Apply firm manual pressure directly over the access site

Applying firm manual pressure over the femoral access site is the priority action when a hematoma is expanding post-PCI. Direct compression controls ongoing bleeding, limits blood loss, and helps prevent serious sequelae such as compartment syndrome. Elevating the leg above heart level is not indicated and may actually worsen bleeding by reducing the direct compressive force at the puncture site; it is not a standard post-catheterization bleeding intervention. Analgesics address symptom relief but do not stop active vascular hemorrhage; hemostasis always takes precedence in this setting. A tourniquet is not appropriate for femoral access site hematomas; it can impair distal circulation and is not anatomically suitable given the location of the femoral artery.

Correct answer: C. Adenosine

Adenosine is the first-line pharmacologic agent for stable supraventricular tachycardia that has not responded to vagal maneuvers. It briefly blocks AV nodal conduction, which frequently terminates reentrant SVT and restores sinus rhythm. Lidocaine is an antiarrhythmic reserved for ventricular arrhythmias and is not effective for narrow-complex SVT. Epinephrine is used during cardiac arrest for pulseless rhythms such as asystole or PEA, not for managing stable SVT. Amiodarone has a broad antiarrhythmic spectrum and may be used in refractory atrial or ventricular arrhythmias, but it is not the first-line agent for converting SVT after failed vagal maneuvers.

Correct answer: D. Administer a diuretic per standing protocol

Administering a diuretic per protocol is the priority because the bilateral crackles and worsening dyspnea indicate volume overload and probable heart failure exacerbation following NSTEMI. Diuretic therapy reduces intravascular volume, relieves pulmonary congestion, and improves respiratory status and hemodynamics. Increasing the IV fluid rate would aggravate the situation by raising preload and intensifying pulmonary edema given the existing signs of fluid excess. Deep breathing exercises cannot effectively address underlying volume overload and will not rapidly reduce pulmonary congestion in this acute setting. PCI may be part of the overall ACS plan, but immediate respiratory stabilization from fluid overload must be addressed before procedural planning is prioritized.