ACCS ADULT CRITICAL CARE EXAM HIGH-YIELD QUESTIONS WITH VERIFIED ANSWERS & DETAILED RATIONALES

ACCS ADULT CRITICAL CARE EXAM HIGH-YIELD QUESTIONS WITH VERIFIED ANSWERS & DETAILED RATIONALES 1. A 45-year-old is admitted after cardiac arrest with ROSC after 8 minutes. He remains comatose with a GCS of 5. What is the single best predictor of poor neurological outcome at 72 hours post-arrest? A) Absent pupillary light reflex B) Myoclonus status epilepticus C) Bilateral absent N20 wave on somatosensory evoked potentials D) Serum NSE 60 μg/L Correct answer: C Rationale: Bilateral absence of the N20 waveform on SSEP has a false-positive rate near 0% for poor outcome if performed at ≥ 72 hours after arrest. Absent pupillary reflexes have a false-positive rate around 5-10%. Myoclonus can be benign. NSE is less specific. ________________________________________ 2. Which ventilator setting directly determines the inspiratory-to-expiratory (I:E) ratio in pressure-controlled ventilation? A) Tidal volume B) Peak inspiratory pressure C) Inspiratory time and respiratory rate D) Flow rate Correct answer: C Rationale: In pressure control, I:E ratio is determined by set inspiratory time and total cycle time (which depends on rate). Tidal volume is variable. Peak inspiratory pressure is set, not derived from flow. ________________________________________ 3. A 62-year-old with septic shock on norepinephrine 0.3 mcg/kg/min has a MAP of 58 mmHg. CVP is 8 mmHg, ScvO2 is 58%. What is the most appropriate next step? A) Increase norepinephrine B) Give 500 mL crystalloid bolus C) Start dobutamine D) Start hydrocortisone Correct answer: C Rationale: ScvO2 70% despite adequate MAP (target 65) and CVP (8–12) suggests ongoing oxygen extraction. Dobutamine improves oxygen delivery if preload is adequate. Increasing vasopressors worsens perfusion. Steroids are not first-line here. ________________________________________ 4. Following a motor vehicle accident, a 28-year-old has an open tibial fracture and is hypotensive with narrow pulse pressure and distended neck veins. What is the most likely diagnosis? A) Hemorrhagic shock B) Tension pneumothorax C) Cardiac tamponade D) Neurogenic shock Correct answer: C Rationale: Hypotension + narrow pulse pressure + distended neck veins in trauma suggests tamponade (Beck’s triad). Tension pneumothorax has absent breath sounds; hemorrhagic shock has flat neck veins. ________________________________________ 5. In a patient with severe metabolic acidosis (pH 7.10, PaCO2 25 mmHg, HCO3 8 mmol/L), which calculation confirms appropriate respiratory compensation? A) Winter’s formula: expected PaCO2 = 1.5 × HCO3 + 8 ± 2 B) Anion gap = Na – (Cl + HCO3) C) Delta gap = (AG – 12) / (24 – HCO3) D) PaO2/FiO2 ratio Correct answer: A Rationale: Winter’s formula predicts appropriate respiratory compensation in metabolic acidosis. Here expected PaCO2 = 1.5×8+8 = 20 ± 2; actual PaCO2 25 → mild hypoventilation (or mixed disorder). ________________________________________ 6. Which inotrope is most appropriate for a patient with acute decompensated heart failure, systolic BP 80 mmHg, and severe peripheral edema? A) Dobutamine B) Milrinone C) Levosimendan D) Epinephrine Correct answer: B Rationale: Milrinone (phosphodiesterase inhibitor) has inotropic and vasodilatory effects, beneficial in low-output heart failure with congestion and without severe hypotension. Dobutamine causes more tachycardia. ________________________________________ 7. A 55-year-old post-cardiac surgery has sudden desaturation, hypotension, and distended neck veins. Bedside echo shows a hyperdynamic left ventricle with a dilated, akinetic right ventricle. What is the most likely diagnosis? A) Massive pulmonary embolism B) Tamponade C) Tension pneumothorax D) Left ventricular failure Correct answer: A Rationale: Acute right ventricular dilation and hypokinesis with preserved left ventricular function in a postoperative patient suggests pulmonary embolism. Tamponade would show diastolic collapse. ________________________________________ 8. For a patient with acute liver failure and grade III hepatic encephalopathy, what is the most effective measure to reduce intracranial pressure? A) Lactulose B) Hyperventilation to PaCO2 28 mmHg C) Mannitol 0.5 g/kg D) Therapeutic hypothermia (32–34°C) Correct answer: C Rationale: Mannitol is first-line for acute ICP elevation in liver failure. Hyperventilation is only temporary bridge. Hypothermia not standard first-line. Lactulose treats encephalopathy but not acutely elevated ICP. ________________________________________ 9. Which electrolyte abnormality is most characteristic of refeeding syndrome? A) Hyperkalemia B) Hypophosphatemia C) Hypermagnesemia D) Hypernatremia Correct answer: B Rationale: Refeeding syndrome causes intracellular shift of phosphate, leading to severe hypophosphatemia, which can cause respiratory failure and cardiac dysfunction. ________________________________________ 10. A patient with community-acquired pneumonia has a CURB-65 score of 3. What is the recommended site of care? A) Outpatient with oral antibiotics B) Hospital ward C) High dependency unit D) Intensive care Correct answer: D Rationale: CURB-65 score 3–5 indicates severe pneumonia requiring ICU admission (mortality up to 30–40%). Score 0–1 outpatient, 2 consider short-stay hospital. ________________________________________ 11. Which sedative agent is preferred for neurological assessment in a patient with traumatic brain injury? A) Propofol B) Midazolam C) Ketamine D) Dexmedetomidine Correct answer: A Rationale: Propofol has short half-life, allowing rapid awakening for neurological exams. Dexmedetomidine causes less respiratory depression but longer offset. Ketamine may raise ICP. ________________________________________ 12. In a patient with severe ARDS, prone positioning improves mortality primarily by: A) Increasing cardiac output B) Reducing ventilator-induced lung injury through more homogeneous ventilation C) Decreasing pulmonary shunt by redistributing perfusion D) Lowering oxygen consumption Correct answer: B Rationale: Prone positioning improves ventilation-perfusion matching and reduces regional overdistension and cyclic collapse, lowering VILI. Mortality benefit shown in PROSEVA trial. ________________________________________ 13. A 70-year-old with septic shock has a lactate of 6 mmol/L, MAP 60 mmHg on norepinephrine 0.5 mcg/kg/min, and central venous pressure 14 mmHg. What is the best next step? A) Increase norepinephrine B) Give 2 units of packed red blood cells C) Start vasopressin D) Give 1 L crystalloid