ICU Basics

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The CSC exam has 90 questions (75 scored) with a 2-hour limit. Topic percentages follow the revised AACN CSC test plan for exams taken on or after November 19, 2026. Exams before then use the earlier plan, a few points different; the CSC Exam Guide shows both.

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Question 1 · Procedures

A patient with an acute type A aortic dissection involving the proximal arch undergoes emergent replacement of the ascending aorta and hemiarch. Systemic circulation must be stopped while the open distal anastomosis is performed. Which strategy BEST protects the brain during this period?

  1. Hypothermic circulatory arrest with selective antegrade cerebral perfusion
  2. Full-flow retrograde perfusion through the femoral artery with MAP above 90
  3. Normothermic arrest with high-dose barbiturates to suppress EEG activity
  4. Lumbar CSF drainage to lower intracranial pressure during the arrest
Show the answer and rationale

Answer: A

  • A. Correct. Hypothermia reduces cerebral metabolic rate, and antegrade perfusion through the head vessels keeps oxygen flowing to the brain.
  • B. Retrograde femoral flow during a dissection can pressurize the false lumen and cause malperfusion. It does not protect the brain while the arch is open.
  • C. Barbiturates may be an adjunct, but at normothermia cerebral metabolic demand remains far too high to tolerate arrest.
  • D. Lumbar drains protect the spinal cord during descending and thoracoabdominal repairs. They are not used to protect the brain during arch repair.

An open distal (hemiarch) anastomosis requires stopping systemic flow. Cerebral protection relies on hypothermia, which lowers the cerebral metabolic rate by about 6–7% per °C, combined with selective antegrade cerebral perfusion through the axillary or innominate artery (or, less often, retrograde perfusion through the SVC). After surgery, the nurse should expect rewarming-related coagulopathy and should perform early, frequent neurologic assessments to detect stroke.

Sources: Hardin & Kaplow, Cardiac Surgery, 4th ed.; ACC/AHA Aortic Disease Guideline (2022)

Question 2 · Complications

A patient who is a combat veteran with PTSD is recovering in the ICU after CABG. During the night, the patient startles awake, is diaphoretic, and pulls away when touched. Which nursing approach is MOST appropriate?

  1. Speak before touching and reorient calmly, limiting restraint
  2. Keep bright lights on all night to prevent nightmares
  3. Give IV haloperidol before any assessment
  4. Apply wrist restraints to prevent the patient from pulling lines
Show the answer and rationale

Answer: A

  • A. Correct. Trauma-informed care reduces triggers and helps the patient feel safe.
  • B. Constant light disrupts sleep and increases delirium risk.
  • C. Medication without assessment misses the cause and may not help.
  • D. Restraints can trigger traumatic memories and worsen agitation.

Preexisting behavioral health conditions such as PTSD, anxiety, and depression influence ICU recovery. Trauma-informed care includes introducing oneself and explaining actions before touching, reorienting calmly, offering choices and control, minimizing restraints, reducing noise and nighttime interruptions, involving family, and continuing home psychiatric medications when appropriate. The nurse also assesses for delirium, pain, and withdrawal as contributing causes.

Sources: AACN Essentials of Critical Care, 5th ed.; Urden, Critical Care Nursing, 9th ed.

Question 3 · Complications

On postoperative day 1 after a 180-minute bypass run, a patient has a temperature of 38.3°C, HR 104, RR 22, and WBC 15,800/mm³. The sternal and leg incisions are clean, the chest radiograph shows only basilar atelectasis, and lactate is 1.4 mmol/L. The nurse understands that these findings MOST likely represent:

  1. An expected inflammatory response to cardiopulmonary bypass
  2. Sepsis requiring broad-spectrum antibiotics within 1 hour
  3. A delayed febrile transfusion reaction to intraoperative blood
  4. Early mediastinitis requiring wound cultures and exploration
Show the answer and rationale

Answer: A

  • A. Correct. Early fever, tachycardia, and leukocytosis are common after bypass and are not necessarily infection.
  • B. SIRS criteria alone do not define sepsis, and there is no evidence of infection or organ dysfunction.
  • C. Febrile transfusion reactions occur during or within hours of the transfusion, not a day later.
  • D. Mediastinitis usually presents days later with wound drainage, sternal instability, and bacteremia.

Exposure of blood to the bypass circuit, surgical trauma, and ischemia–reperfusion activate complement and cytokines. The result is a systemic inflammatory response with fever, tachycardia, leukocytosis, and sometimes vasoplegia in the first 48–72 hours. Meeting SIRS criteria is common and not specific for infection. Fever that persists beyond about 72 hours, new wound findings, rising lactate, or organ dysfunction should prompt an infectious workup.

Sources: Hardin & Kaplow, Cardiac Surgery, 4th ed.; Sepsis-3 Definitions (2016)

Question 4 · Complications

A patient has a cardiac arrest on postoperative day 1 after CABG and achieves return of spontaneous circulation after 8 minutes but remains comatose. The surgeon asks about targeted temperature management. Which factor is the MOST important consideration?

  1. the patient’s age over 75
  2. mediastinal bleeding risk, because hypothermia impairs coagulation and platelet function
  3. whether the arrest rhythm was shockable
  4. the sternotomy dressing, which prevents surface cooling pads from being applied
Show the answer and rationale

Answer: B

  • A. Age alone does not exclude temperature management.
  • B. Correct. Cooling worsens coagulopathy and platelet function, so a fresh sternotomy with chest tubes carries a real risk of re-bleeding and tamponade. The team weighs neuroprotection against bleeding and often chooses controlled normothermia (36 °C) with strict fever avoidance.
  • C. Current guidance supports temperature control for comatose survivors regardless of the initial rhythm.
  • D. Pads can be placed on the thighs and back, and intravascular cooling is available; the dressing is a logistical detail, not the deciding factor.

Post-arrest care after cardiac surgery follows the same principles as elsewhere, with modifications. Active bleeding is a relative contraindication to cooling below 36 °C, so many centers choose 36 °C with aggressive fever prevention for at least 72 hours. Tamponade and graft occlusion are also considered as causes of the arrest, and early re-exploration may be needed.

Sources: AHA 2025 Part 11: Post-Cardiac Arrest Care; Hardin & Kaplow, Cardiac Surgery, 4th ed.

Question 5 · Complications

A patient was extubated 4 hours ago after 3 days of intubation and intraoperative TEE for valve surgery. The patient is alert and asks for water. The voice is hoarse, and the patient reports mild throat soreness. Which action is MOST appropriate?

  1. Start thickened liquids to reduce the aspiration risk
  2. Give small sips of water and watch for coughing
  3. Keep the patient NPO for 72 hours as a precaution
  4. Complete a standardized swallow screen before intake
Show the answer and rationale

Answer: D

  • A. Choosing a diet texture without an assessment may be unnecessary or unsafe.
  • B. Aspiration after extubation is often silent. Coughing may not occur even when the patient aspirates.
  • C. Automatic prolonged NPO delays nutrition and medications without evidence of benefit.
  • D. Correct. Prolonged intubation and TEE increase the risk of postextubation dysphagia. A validated screen guides safe intake or referral.

Postextubation dysphagia is common after prolonged intubation, intraoperative TEE, and cardiac surgery, and much of the resulting aspiration is silent. Before any oral intake, the nurse should complete a standardized bedside swallow screen per protocol, including a check for voice changes, wet vocal quality, cough, and desaturation during trial swallows. The patient should be referred to speech-language pathology if the screen is failed or risk is high, with the head of the bed elevated.

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

Question 6 · Complications

A 74-year-old patient with chronic kidney disease received a high-dose tranexamic acid infusion during a redo mitral valve replacement. Three hours after ICU arrival, with propofol off, the patient has a generalized tonic-clonic seizure that stops after lorazepam 4 mg IV. Forty minutes later the patient still does not open the eyes to voice, and the nurse sees small rhythmic twitches of the right eyelid and the corner of the mouth. A head CT shows no acute change. Which action is MOST appropriate NEXT? Data are: Glucose 132 mg/dL Na⁺ 138 mEq/L SpO₂ 98% on the ventilator T 36.9°C

  1. flumazenil to reverse the lorazepam.
  2. restart the propofol and reassess at morning rounds.
  3. urgent EEG and a second antiseizure medication.
  4. hourly neuro checks while the postictal state clears.
Show the answer and rationale

Answer: C

  • A. Reversing the benzodiazepine to improve the exam removes seizure protection and can provoke further seizures; it is not used after a seizure.
  • B. Sedation may blunt visible movements, but without EEG it hides whether seizures continue, and waiting until morning delays treatment of possible status epilepticus.
  • C. Correct. Failure to regain consciousness with subtle rhythmic movements suggests nonconvulsive status epilepticus, which needs EEG for diagnosis and a longer-acting second-line drug after the benzodiazepine.
  • D. Tempting because drowsiness after a seizure and lorazepam is expected, but ongoing rhythmic facial twitching with no recovery suggests the seizure has not stopped.

The tranexamic acid label notes that the most common setting for TXA-induced seizures is cardiovascular surgery, where doses up to 10 times the usual dose are used, and the drug is renally cleared, so chronic kidney disease adds risk. Merck defines status epilepticus as a tonic-clonic seizure lasting more than 5 minutes or two or more seizures without full recovery of consciousness between them, and says nonconvulsive status often appears as prolonged mental status change that may need EEG for diagnosis. After lorazepam (0.05 to 0.1 mg/kg, typically 4 mg IV), a longer-acting second agent such as levetiracetam, fosphenytoin or valproate is given. The negative CT, normal glucose and normal sodium make a structural or metabolic cause less likely and point toward ongoing seizure activity.

Sources: Merck Manual, Professional Version; CYKLOKAPRON (tranexamic acid) Injection Prescribing Information

Question 7 · Complications

Four patients arrive in the cardiac surgery ICU after mitral valve repair with an annuloplasty ring. Based on the intraoperative TEE reports, which patient is at HIGHEST risk for systolic anterior motion (SAM) with outflow obstruction?

  1. A dilated LV with an LVEF of 30% and functional regurgitation from annular dilation
  2. Posterior leaflet prolapse in a large LV with a normal septum
  3. A small, hyperdynamic LV with a basal septal bulge and a tall posterior leaflet
  4. A hyperdynamic LV with a C-sept distance of 32 mm and a 12 mm posterior leaflet
Show the answer and rationale

Answer: C

  • A. Tempting because this patient is the sickest, but a large, weakly contracting cavity keeps the septum far from the coaptation point, which protects against SAM; low output is the bigger worry here.
  • B. Degenerative prolapse is the usual repair, but a large ventricle and a normal septum leave a wide outflow tract and a long coaptation-to-septum distance, so the risk is low.
  • C. Correct. A small, vigorous cavity, a thick basal septum and excess posterior leaflet tissue push the coaptation point toward the septum, so the anterior leaflet is swept into the outflow tract.
  • D. A vigorous ventricle adds some risk, but a coaptation-to-septum distance well above 25 mm and a short posterior leaflet keep the coaptation point away from the outflow tract, so the anatomic risk is low.

SAM after repair occurs in roughly 2% to 10% of contemporary series. Echo predictors include a coaptation-to-septum (C-sept) distance under 25 mm, a posterior leaflet taller than about 15 to 20 mm, a low anterior-to-posterior leaflet ratio, a basal septum 15 mm or thicker, an aortomitral angle under about 120 degrees and a small LV (end-diastolic diameter under about 45 mm). A hyperdynamic ventricle adds to the anatomic risk. The nurse caring for such a patient avoids underfilling, tachycardia, inotropes and vasodilators, which all bring the leaflet closer to the septum.

Sources: Torre et al., SAM After Mitral Valve Repair (2026)

Question 8 · Therapeutic Interventions

The evening before elective CABG, a patient without diabetes reads the ERAS order to drink a clear carbohydrate beverage 2 hours before surgery. The patient says, “I was told nothing after midnight.” Which information should the nurse give?

  1. the drink should be finished 30 minutes before surgery.
  2. clear drinks are allowed up to 2 hours before.
  3. fasting from midnight is required for safe anesthesia.
  4. the drink is safe if mixed with milk for protein.
Show the answer and rationale

Answer: B

  • A. Thirty minutes is too close to induction; the clear-liquid limit is 2 hours, which allows the stomach to empty.
  • B. Correct. Clear liquids, including carbohydrate drinks, may be taken until 2 hours before anesthesia without raising aspiration risk.
  • C. Midnight fasting is the older habit many patients are taught, but current fasting guidance permits clear liquids until 2 hours before.
  • D. Adding milk makes it no longer a clear liquid, so it would need a longer fast and would defeat the purpose of the order.

Fasting guidelines from the American Society of Anesthesiologists allow clear liquids up to 2 hours before general or regional anesthesia, and their examples of clear liquids include carbohydrate-rich nutritional drinks. Trials found that 2 to 4 hours of clear-liquid fasting caused less thirst and hunger than longer fasts, with no consistent difference in gastric volume or acidity. ERAS cardiac pathways adopted shorter fasting and carbohydrate loading to reduce the catabolic stress of a long fast, although trials in on-pump surgery have not shown a clear effect on insulin resistance. Teaching covers what counts as clear, the 2-hour cutoff and how to time the drink.

Sources: ASA Preoperative Fasting Guidelines (2017); Jaffer et al., ERAS in Cardiac Surgery Review (2025); Nur et al., Carbohydrate Loading in On-Pump Surgery RCT (2026)

Question 9 · Therapeutic Interventions

After cardiac surgery, a patient on norepinephrine 0.15 mcg/kg/min has MAP 78, CI 1.7, SVR 2,300, PAOP 18, and cool extremities. Which change is MOST appropriate?

  1. Wean norepinephrine and add an inotrope
  2. Add vasopressin to improve organ perfusion
  3. Give a 1 L crystalloid bolus for low output
  4. Increase norepinephrine to raise MAP further
Show the answer and rationale

Answer: A

  • A. Correct. The MAP is adequate, but the CI is low and SVR high. Reducing afterload and supporting contractility improves output.
  • B. Adding a vasoconstrictor would increase the already high SVR.
  • C. A PAOP of 18 indicates adequate or high LV filling. More volume risks pulmonary edema.
  • D. A higher afterload would further lower the cardiac output of a struggling ventricle.

SVR = 80 × (MAP − CVP) ÷ CO, normally about 800–1,200 dynes·sec/cm⁻⁵. An excessively high SVR increases LV afterload and can lower cardiac output even when the MAP looks acceptable. For low CI with high SVR and adequate filling, the approach is to reduce vasoconstrictors when possible, add an inotrope (dobutamine, milrinone, or epinephrine), and consider vasodilators or mechanical support. Targets should include perfusion (CI, SvO₂, lactate, urine output), not MAP alone.

Sources: Hardin & Kaplow, Cardiac Surgery, 4th ed.; Bojar, Cardiac Surgery Periop Care, 6th ed.; AACN Essentials of Critical Care, 5th ed.

Question 10 · Therapeutic Interventions

The nurse is teaching a patient going home after CABG with an endoscopic saphenous vein harvest from the right leg. Which statement indicates correct understanding?

  1. “I should keep my leg down as much as possible to help it drain.”
  2. “I’ll sit in the recliner with my legs crossed to stay comfortable.”
  3. “Numbness on the inside of my lower leg means the graft failed.”
  4. “I’ll raise my leg when I sit and avoid crossing my legs.”
Show the answer and rationale

Answer: D

  • A. Keeping the leg dependent increases swelling.
  • B. Crossing the legs impairs venous return and increases edema.
  • C. Numbness along the medial leg is usually from saphenous nerve irritation, not graft failure.
  • D. Correct. Elevation and avoiding leg crossing reduce swelling and protect venous return in the harvest leg.

After saphenous vein harvest, the leg is prone to swelling, hematoma, and wound infection, especially in patients with obesity, diabetes, or peripheral artery disease. Teaching includes elevating the leg when sitting, avoiding crossing the legs and prolonged standing, wearing compression stockings if ordered, walking regularly, keeping the incisions clean and dry, and reporting redness, drainage, fever, or increasing pain. Numbness along the medial leg is common from saphenous nerve irritation and often improves.

Sources: Hardin & Kaplow, Cardiac Surgery, 4th ed.; Bryant & Nix, Acute & Chronic Wounds, 6th ed.

Question 11 · Therapeutic Interventions

An 84-year-old patient with an eGFR of 30 mL/min/1.73 m² is recovering from aortic valve replacement. Which analgesic order should the nurse QUESTION?

  1. Gabapentin 600 mg by mouth three times daily
  2. Oxycodone 2.5 mg by mouth every 4 hours as needed
  3. A lidocaine patch over the chest tube site
  4. Acetaminophen 650 mg by mouth every 6 hours
Show the answer and rationale

Answer: A

  • A. Correct. Gabapentin is renally cleared and in older adults can cause sedation, delirium, and respiratory depression with opioids.
  • B. A low opioid dose for breakthrough pain is reasonable.
  • C. Topical lidocaine is an opioid-sparing adjunct with little systemic effect.
  • D. Scheduled acetaminophen is safe and effective in older adults.

Gabapentinoids are sometimes used in multimodal analgesia, but in older adults and in kidney impairment they can accumulate and cause dizziness, sedation, falls, delirium, and additive respiratory depression with opioids. Doses must be reduced for kidney function, and routine use after cardiac surgery is debated. Multimodal analgesia in older adults emphasizes scheduled acetaminophen, regional techniques, and low-dose opioids with delirium monitoring.

Sources: Saunders Nursing Drug Handbook 2021; AACN Essentials of Critical Care, 5th ed.

Question 12 · Therapeutic Interventions

Two hours after CABG, a sedated patient on controlled ventilation (tidal volume 8 mL/kg, no spontaneous breaths) in sinus rhythm has MAP 62 mm Hg, CI 1.9 L/min/m², CVP 7 mm Hg, and a stroke volume variation of 17%. Chest tube output is minimal. Which intervention is MOST appropriate?

  1. Increase the PEEP to improve oxygen delivery
  2. Start dobutamine for low contractility
  3. Give furosemide to lower the CVP further
  4. A fluid bolus, then reassess stroke volume
Show the answer and rationale

Answer: D

  • A. More PEEP reduces venous return and would lower output further.
  • B. The data point to underfilling that is likely to respond to volume, not to primary pump failure.
  • C. Diuresis would worsen a preload-responsive low output state.
  • D. Correct. An SVV above about 12–13% under these conditions predicts that stroke volume will rise with fluid.

Stroke volume variation (and pulse pressure variation) reflects cyclic changes in LV stroke volume caused by positive-pressure breaths. In a patient on controlled ventilation with adequate tidal volumes, a closed chest, and sinus rhythm, an SVV above about 12–13% suggests the heart is on the steep part of the Starling curve and will respond to fluid. The measure is unreliable with spontaneous breathing, arrhythmias, low tidal volumes, an open chest, or RV failure. Response is confirmed by rechecking stroke volume after the bolus.

Sources: AACN Essentials of Critical Care, 5th ed.; Lough, Hemodynamic Monitoring (2015)

Question 13 · Therapeutic Interventions

Three hours after an uncomplicated CABG, a patient is awake, follows commands, and moves all extremities. Current data: SpO₂ 97% on FiO₂ 0.40 and PEEP 5, RSBI 52, temperature 36.7°C, chest tube output 50 mL/hr, and norepinephrine 0.03 mcg/kg/min. Under the unit’s fast-track protocol, the nurse should:

  1. Delay extubation until all vasoactive drips are off
  2. Continue ventilation until chest tubes are removed
  3. Rest the patient overnight and reassess at rounds
  4. Proceed with extubation per the fast-track protocol
Show the answer and rationale

Answer: D

  • A. A low, stable vasopressor dose does not by itself prevent extubation under most fast-track protocols.
  • B. Chest tubes are not a contraindication to extubation. Tubes usually stay in for 24–48 hours.
  • C. Delaying extubation without a reason increases the risk of VAP and delirium, and prolongs ICU stay.
  • D. Correct. The patient meets typical early-extubation criteria: awake, adequate oxygenation and mechanics, warm, and not bleeding.

ERAS Cardiac and STS quality measures support extubation within 6 hours after cardiac surgery when criteria are met: the patient is awake and following commands, hemodynamically stable on no or low-dose support, normothermic, not bleeding significantly, and has adequate oxygenation (typically FiO₂ 0.5 or less, PEEP 5–8) and respiratory mechanics. Early extubation reduces ventilator days, VAP, delirium, and length of stay.

Sources: Hardin & Kaplow, Cardiac Surgery, 4th ed.; ERAS Cardiac/STS Perioperative Care (2024)

Question 14 · Monitoring and Diagnostics

A ventilated patient after mitral valve surgery is on PEEP 14 cm H₂O. The nurse is measuring the PAOP. Which statement is MOST accurate?

  1. Remove the patient from PEEP to get the true reading
  2. PEEP has no effect on the PAOP reading
  3. Read at end-inspiration for the most accurate value
  4. Read at end-expiration; high PEEP can overestimate it
Show the answer and rationale

Answer: D

  • A. Disconnecting from PEEP causes derecruitment and hypoxemia and changes hemodynamics.
  • B. Higher PEEP can be transmitted to the pulmonary vessels and raise readings.
  • C. End-inspiration includes the most airway pressure.
  • D. Correct. Transmitted airway pressure can raise the measured PAOP above the true transmural pressure.

Pulmonary artery occlusion pressure is measured at end-expiration, when pleural pressure is closest to zero. High PEEP (above about 10 cm H₂O) can be transmitted to the pulmonary vasculature, falsely raising the PAOP, especially when lungs are compliant. Patients are not taken off PEEP to measure it, because derecruitment worsens oxygenation. The value is interpreted as a trend alongside other data such as cardiac output and echocardiography.

Sources: AACN Procedure Manual, 8th ed.; AACN Practice Alert: PA/CVP Monitoring (2016); Bootsma et al., PA Catheter Part 1 (2022)

Question 15 · Monitoring and Diagnostics

A patient in septic shock has received 2 L of crystalloid and is on norepinephrine 0.12 mcg/kg/min, with a MAP of 66 mm Hg and lactate of 3.4 mmol/L. The team wants to know whether more fluid will increase cardiac output. Which assessment is MOST reliable?

  1. A single CVP value compared with a target of 8–12 mm Hg
  2. The BP response to a 1 L bolus given over 1 hour
  3. Hourly urine output over the next 2 hours
  4. A passive leg raise with real-time stroke volume monitoring
Show the answer and rationale

Answer: D

  • A. Static CVP values poorly predict fluid responsiveness.
  • B. Large empiric boluses risk overload, and BP is an insensitive marker of stroke volume change.
  • C. Urine output is affected by many factors and responds too slowly to guide individual boluses.
  • D. Correct. An SV or CO increase of 10% or more during a passive leg raise predicts fluid responsiveness without giving fluid.

The Surviving Sepsis Campaign suggests dynamic measures of fluid responsiveness over static ones. Options include a passive leg raise with cardiac output monitoring, pulse pressure or stroke volume variation in controlled ventilation without arrhythmias, or a small fluid challenge with SV measurement. The initial 30 mL/kg is followed by individualized fluid decisions, because a positive fluid balance is associated with worse outcomes.

Sources: Surviving Sepsis Campaign 2026; AACN Essentials of Critical Care, 5th ed.

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