Patient Introduction

You are the overnight ICU fellow. You have just been called to the bedside.

Patient

Marcus Jeffries, 52M

Weight

82 kg

PMH

HTN, former smoker

Admitted 4 days ago with severe influenza A (H1N1) ARDS. Cannulated on Day 2 via femoral-femoral VV-ECMO (25 Fr drainage, 21 Fr return). Previously stable on current settings.

Baseline Stable State

SpO₂95%

HR92 bpm

MAP74 mmHg

Temp37.2°C

pH / PaO₂ / PaCO₂7.38 / 62 / 40

Lactate1.4 mmol/L

ECMO flow (Qb)4.0 L/min

Sweep / FiO₂ blender6 L/min / 1.0

Pre-ox / Post-ox SaO₂62% / 99%

Trans-membrane ΔP18 mmHg

VentPC-AC | FiO₂ 0.5 | PEEP 12

VasopressorsNE 0.03 µg/kg/min

Nurse Page

"He just got back from CT 20 minutes ago. His SpO₂ is dropping."

This simulation follows a single patient through five consecutive VV-ECMO crises. You must identify the correct intervention to advance to the next scenario. Incorrect answers are greyed out — try again before moving forward.

Simulation Complete

Marcus Jeffries is now stable on Day 14 of his ECMO run.

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First-attempt correct

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Wrong answers

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Total time (min)

Day	Crisis	Key Clue	Intervention
4	Recirculation	Pre-ox SaO₂ ↑↑, bright red drainage blood, post-transport	Reposition cannula
8	Oxygenator thrombosis	Post-ox SaO₂ ↓, ΔP ↑↑↑, hazy housing, subtherapeutic anticoag	Circuit exchange
10	Inadequate flow	Normal circuit, Qb low after premature wean	Increase ECMO flow
12	Hemorrhagic hypovolemia	Flow dropping, chugging, post-op bleeding, falling Hgb	Volume resuscitation
14	Increased VO₂ / P-SILI	Pre-ox SaO₂ ↓↓, agitation, high Vt & RR	Deepen sedation ± NMB

Systematic approach to VV-ECMO hypoxemia

Check the oxygenator. Post-ox SaO₂ should be ≥98%. If not → oxygenator failure; plan circuit exchange.

Check for recirculation. Pre-ox SaO₂ inappropriately high (approaching post-ox) → oxygenated blood is being re-drained. Reposition cannulae.

Check the flow. Is Qb adequate? Qb/QCO ratio ≥0.6 is needed. Flow dropping despite unchanged RPMs + chugging → hypovolemia.

Check the patient. Pre-ox SaO₂ ↓ with normal circuit → VO₂ increased. Look for agitation, fever, shivering, dyssynchrony.

Check the native lungs. Pneumothorax, mucus plugging, effusion, atelectasis — reversible pulmonary pathology.