Free CMC practice questions

Answer: B

• A. An aneurysm develops over weeks and causes HF, VT, or thrombus, not an acute shunt.
• B. Correct. A new murmur at the left sternal border with a thrill and an oxygen saturation step-up from the right atrium to the PA indicates a left-to-right shunt through a septal rupture.
• C. Free wall rupture causes tamponade or PEA, not a new murmur with a shunt.
• D. Papillary rupture causes acute MR with large v waves, but no oxygen saturation step-up.

A post-infarction ventricular septal rupture creates a left-to-right shunt, so oxygenated LV blood enters the RV and raises the PA oxygen saturation above the SVC or RA value (a step-up of more than about 7–8%). It is more common after anterior MI (apical septum) and in late-presenting or unreperfused infarcts. Management includes afterload reduction, mechanical support (IABP or Impella) to reduce the shunt, and surgical or percutaneous repair.

Sources: Kern's Cardiac Cath Handbook, 7th ed.; Jacobson, CV Nursing Practice, 3rd ed.

Answer: B

• A. The guideline target is HR 60 to 80, already met. More β-blockade does not reopen an obstructed branch artery.
• B. Correct. Branch artery occlusion with limb malperfusion makes this a complicated type B dissection, which needs intervention, usually endovascular stent-grafting when anatomy is suitable.
• C. The target is SBP under 120 mm Hg or the lowest pressure that maintains end-organ perfusion. Pushing BP lower worsens flow to an already ischemic limb.
• D. This treats an embolic or thrombotic occlusion. Here the limb is ischemic because the dissection flap compromises the artery, and anticoagulation adds bleeding risk in an unrepaired dissection.

Acute aortic syndromes are treated first with IV β-blockers to an HR of 60 to 80 and an SBP under 120 mm Hg (or the lowest pressure that keeps organs perfused), with vasodilators added for BP. Uncomplicated type B dissection is managed medically, but rupture, branch artery occlusion with malperfusion, extension, rapid enlargement, refractory pain, or uncontrolled hypertension make it complicated, which needs intervention. The nurse's role is to recognize new limb, renal, mesenteric, or spinal ischemia early.

Sources: ACC/AHA Aortic Disease Guideline (2022)

Answer: B

• A. Immediate cardioversion is reserved for hemodynamic instability.
• B. Correct. In stable AF with preserved EF, calcium channel blockers or β-blockers are first-line for rate control.
• C. Adenosine does not convert AF. It may briefly reveal the underlying rhythm only.
• D. Digoxin has a slow onset and is weak during high sympathetic tone. It is an adjunct.

For stable AF with rapid ventricular response, the priorities are rate control (target resting HR below 110, or lower if symptomatic), stroke risk assessment (CHA₂DS₂-VASc) and anticoagulation, and deciding on a rhythm-control strategy. With preserved EF, IV diltiazem or a β-blocker is first-line. With reduced EF, β-blockers (if not decompensated), amiodarone, or digoxin are used. Cardioversion is needed urgently for instability, and elective cardioversion requires attention to AF duration and anticoagulation.

Sources: AHA 2025 Adult ACLS Algorithms; ACC/AHA/ACCP/HRS AF Guideline (2023)

Answer: A

• A. Correct. Outside alcohol or benzodiazepine withdrawal, benzodiazepines deepen and prolong delirium, and this patient has no history that suggests withdrawal.
• B. Rechecking the CAM-ICU sounds careful, but giving the lorazepam is the problem: it is likely to leave her more confused and at higher risk of falls and aspiration.
• C. Restraints often increase agitation and injury and are a last resort when other measures fail; she is still redirectable with her family present.
• D. Swapping to an antipsychotic is tempting, but antipsychotics do not correct the underlying problem, routine use is not recommended, and the 2025 PADIS update could not recommend them for delirium; at most, a low dose is used briefly for severe agitation.

Benzodiazepines are the treatment of choice for alcohol or benzodiazepine withdrawal, but they should be avoided for delirium from any other cause because they sedate without clearing the confusion and tend to make it last longer. A glass of wine a week makes withdrawal very unlikely, so the nurse questions the lorazepam order. The better plan is to look for precipitants (pain, urinary retention, infection, new drugs), keep the family involved, reorient her and protect sleep. Antipsychotics are not used routinely, and restraints are reserved for danger that other measures cannot control.

Sources: Merck Manual Professional: Delirium (2025); SCCM PADIS Focused Update (2025)

Answer: A

• A. Correct. A conservative strategy after shock resolves reduces lung water and increases ventilator-free days.
• B. Routine liberal fluids after shock resolves worsen lung edema without protecting the kidneys.
• C. In FACTT, the conservative strategy did not increase the need for dialysis.
• D. Extra fluid increases extravascular lung water and worsens oxygenation.

The ARDS capillary membrane is leaky, so fluid moves readily into the alveoli. The FACTT trial showed that a conservative fluid strategy after shock resolves (diuresis guided by CVP or PAOP and perfusion) increased ventilator-free and ICU-free days without increasing renal failure. Resuscitation takes priority while shock is present. After that, the aim is an even to negative balance, guided by urine output, perfusion, electrolytes, and creatinine.

Sources: AACN Essentials of Critical Care, 5th ed.; Vincent, Textbook of Critical Care, 8th ed.

Answer: A

• A. Correct. Dementia is a major risk factor for delirium, which is often triggered by infection and medications.
• B. Without focal deficits, a stroke is less likely, though a new focal finding would require evaluation.
• C. This is reversed. Delirium is acute and fluctuating, and dementia is chronic and progressive.
• D. Dementia progresses gradually. An abrupt change signals a new process.

Delirium superimposed on dementia is common and is associated with worse outcomes. Delirium is an acute change in attention and cognition that fluctuates and has an identifiable cause, such as infection, medications (opioids, anticholinergics, benzodiazepines), electrolyte problems, hypoxia, urinary retention, pain, or sleep deprivation. Family input about the patient’s baseline is essential. Management addresses causes and uses nonpharmacologic strategies.

Sources: AACN Core Curriculum, 8th ed.; Bradley & Daroff's Neurology, 8th ed.; SCCM PADIS Guideline (2018)

Answer: B

• A. Stopping calcium replacement would cause severe systemic hypocalcemia.
• B. Correct. The patient’s ionized calcium is low and symptomatic. Replacement is titrated to a systemic iCa of about 1.0–1.2 mmol/L.
• C. The post-filter iCa is already in the target range for circuit anticoagulation, and more citrate would worsen the systemic hypocalcemia.
• D. Pre-filter calcium would reverse the citrate effect and clot the circuit. Calcium is returned post-filter or through a separate line.

Regional citrate anticoagulation chelates calcium in the circuit (post-filter iCa target about 0.25–0.40 mmol/L), which prevents clotting. Calcium is then replaced systemically to keep the patient’s iCa at about 1.0–1.2 mmol/L. Two separate values guide two separate adjustments: citrate is titrated to the post-filter iCa, and calcium is titrated to the systemic iCa. Perioral tingling, muscle cramps, a prolonged QT, and hypotension are signs of hypocalcemia.

Sources: AACN Procedure Manual, 8th ed.; AACN Essentials of Critical Care, 5th ed.; AACN Core Curriculum, 8th ed.

Answer: A

• A. Correct. Pure α₁ support raises pressure without β₁ stimulation that would worsen tachycardia or outflow obstruction.
• B. Phenylephrine raises SVR.
• C. A pure afterload increase would further lower cardiac output in a failing ventricle.
• D. Phenylephrine’s reflex bradycardia would worsen this.

Phenylephrine is a pure α₁ agonist without β activity. It is useful for hypotension with tachyarrhythmias, for dynamic LVOT obstruction (HOCM, systolic anterior motion), where increasing afterload and avoiding inotropy reduces obstruction, and for anesthesia-related vasodilation. It is a poor choice when contractility or heart rate is inadequate.

Sources: Jacobson, CV Nursing Practice, 3rd ed.; Elsevier's 2025 Intravenous Medications; Elisha et al., Nurse Anesthesia, 7th ed.

Answer: A

• A. Correct. The pressure at which the Doppler signal first returns approximates the MAP in continuous-flow LVAD patients.
• B. The problem is a lack of pulsatility, so repeating is unlikely to help.
• C. Pulses are often impalpable in continuous-flow LVAD patients.
• D. Automated cuffs rely on pulsatile oscillations, which are minimal with continuous flow, regardless of limb.

Continuous-flow LVADs produce little arterial pulsatility, so automated oscillometric cuffs, palpated pulses, and pulse oximetry may be unreliable. The standard non-invasive method is a manual cuff with a Doppler probe over the brachial or radial artery, recording the pressure at which flow first returns. This approximates the MAP (closer to systolic pressure when native pulsatility is significant). The 2023 ISHLT guideline targets a MAP of 75–90 mm Hg: staying at or below 90 reduces stroke risk and supports pump flow, and pressures below 75 are avoided.

Sources: AACN Procedure Manual, 8th ed.; Hardin & Kaplow, Cardiac Surgery, 4th ed.; Urden, Critical Care Nursing, 10th ed.

Answer: A

• A. Correct. Low CVP with high blood loss means the LV is underfilled. Reducing the speed and restoring volume resolves the suction.
• B. A higher speed worsens suction when the LV is underfilled.
• C. The purge protects the motor and never controls flow. Pausing it can damage the pump.
• D. The position signal is appropriate, and repositioning is done by the provider under imaging, not by the nurse.

The Impella is a microaxial pump placed across the aortic valve. It draws blood from the LV and ejects it into the ascending aorta. Suction alarms occur when the inlet does not have enough blood, from hypovolemia, bleeding, RV failure, or malposition against the ventricular wall. With a correct position signal and clear hypovolemia from bleeding, the nurse should lower the P-level, give volume or blood, notify the provider about the bleeding, and monitor for hemolysis (dark urine, rising plasma-free hemoglobin), which suction worsens.

Sources: AACN Procedure Manual, 8th ed.; EACTS/STS/AATS Temporary MCS Guideline (2025); Hardin & Kaplow, Cardiac Surgery, 4th ed.

Answer: A

• A. Correct. RSBI ≈ 52, the patient is awake, and a good cough helps protect the airway after extubation.
• B. Good mechanics, but the patient cannot protect the airway or manage secretions.
• C. The RSBI is 34 ÷ 0.26 ≈ 131. A value above 105 predicts failure.
• D. A sustained rise in heart rate over 20% with diaphoresis indicates SBT failure despite an acceptable RSBI.

The rapid shallow breathing index (RR ÷ tidal volume in liters) is a screening tool. Values below 105 favor successful weaning. SBT success also requires the absence of failure signs: RR above 35, SpO₂ below 90%, HR change greater than 20%, arrhythmias, SBP above 180 or below 90, agitation, diaphoresis, or accessory muscle use. Extubation readiness also depends on mental status, cough strength, secretion burden, and airway patency (a cuff leak in selected patients).

Sources: AACN Essentials of Critical Care, 5th ed.; AARC CPG: Spontaneous Breathing Trials (2024); ARDSNet Ventilation Protocol Card (2008)

Answer: D

• A. The patient is stable, so drug therapy and consultation come first.
• B. Vagal maneuvers are for narrow-complex tachycardia and are not first-line for wide-complex VT.
• C. Adenosine is considered only for regular, monomorphic wide rhythms, and this option misstates the indication.
• D. Correct. Amiodarone 150 mg over 10 minutes or procainamide, with expert consultation, is appropriate for stable wide-complex tachycardia.

For a stable wide-complex tachycardia, the algorithm suggests an antiarrhythmic infusion (procainamide 20–50 mg/min until arrhythmia suppression, hypotension, QRS widening above 50%, or 17 mg/kg; amiodarone 150 mg over 10 minutes; or sotalol) and expert consultation. Adenosine may be considered only if the rhythm is regular and monomorphic. Any instability calls for synchronized cardioversion, and polymorphic VT is treated with defibrillation.

Sources: AHA 2025 Part 9: Adult ALS; AHA 2025 Adult ACLS Algorithms; AHA ACLS Provider Manual (2025)

Answer: B

• A. NMS requires antipsychotic exposure and presents with rigidity and fever.
• B. Correct. High-dose, prolonged propofol can cause mitochondrial toxicity with lactic acidosis, rhabdomyolysis, hypertriglyceridemia, arrhythmias, and cardiac failure.
• C. Malignant hyperthermia occurs with volatile anesthetics or succinylcholine and presents with hypercapnia and rigidity.
• D. Sepsis must be considered, but this constellation with high-dose propofol is classic for PRIS.

Risk factors for propofol infusion syndrome include doses above about 4–5 mg/kg/h (67–83 mcg/kg/min) for more than 48 hours, catecholamine or steroid co-administration, critical illness, and low carbohydrate intake. Early signs include unexplained metabolic acidosis, rising lactate, arrhythmias (especially Brugada-like patterns), rhabdomyolysis, hypertriglyceridemia, and AKI. Management is to stop propofol immediately and provide supportive care, possibly including RRT or ECMO. Green urine is a benign finding, not a sign of PRIS.

Sources: AACN Essentials of Critical Care, 5th ed.; Mosby's 2026 Nursing Drug Reference

Answer: D

• A. Both lines pass square-wave testing. The difference is physiologic.
• B. This is not a recognized cause of a radial–femoral pressure difference.
• C. An overdamped line would lower the systolic reading, but here the femoral MAP matches and the square-wave test is adequate.
• D. Correct. Systolic pressure normally rises and diastolic falls as the pressure wave travels to smaller arteries, while the MAP stays nearly constant.

As the arterial pressure wave moves from the aorta to smaller, stiffer peripheral arteries, reflected waves amplify the systolic peak and lower the diastolic trough (distal pulse amplification). The MAP, however, remains relatively constant, which is why vasoactive titration is based on MAP. In some states, such as vasoplegia after bypass or high-dose vasopressors, the radial MAP can underestimate central pressure, and a femoral line may be more accurate.

Sources: Lough, Hemodynamic Monitoring (2015); Saugel et al., Crit Care (2020); McGhee & Bridges, Crit Care Nurse (2002)

Answer: B

• A. Bicarbonate transiently raises CO₂ without improving perfusion and is not given routinely.
• B. Correct. An EtCO₂ below 10 mm Hg during CPR suggests inadequate compressions. Improving the compressions increases pulmonary blood flow.
• C. A low EtCO₂ is one prognostic factor, but it is not used alone to stop resuscitation, especially early in the arrest.
• D. Hyperventilation raises intrathoracic pressure, reduces venous return, and does not improve perfusion.

During CPR with a secure airway, EtCO₂ mainly reflects pulmonary blood flow, which depends on the cardiac output generated by compressions. Values below 10 mm Hg indicate poor-quality CPR or very low flow. The team should switch compressors, confirm depth (2–2.4 in) and rate (100–120/min), minimize pauses, and ensure full recoil. After cardiac surgery, CSU-ALS also calls for early resternotomy and internal massage when appropriate. A value near 0 suggests esophageal intubation or disconnection.

Sources: AHA 2025 Part 9: Adult ALS; AHA ACLS Provider Manual (2025)