ECMO and mechanical circulatory support

Advanced module on extracorporeal membrane oxygenation (VV and VA), referral and ECPR, IABP and Impella, daily ECMO rounds, complications and emergencies, and weaning — written so a junior can recognise when to call for help and safely look after an ECMO patient overnight.

6 topics

01
VV vs VA ECMO: modes and indications
How the two ECMO configurations work, who each is for, contraindications, and the physiology a junior must understand before touching the circuit.
6 stepsAlgorithmNew
02
ECMO referral: who, when and how
Practical referral criteria for respiratory and cardiac ECMO and ECPR, the scores used (Murray, RESP, SAVE), what the ECMO centre needs on the phone, and how to prepare for retrieval.
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03
IABP and Impella basics
How intra-aortic balloon pumps and microaxial flow pumps work, current evidence and indications, setting up and troubleshooting, and the checks each shift.
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04
Daily ECMO checks and rounds
A structured patient-and-circuit checklist for every ECMO patient: neurology, haemodynamics, pump, oxygenator, anticoagulation, ventilator 'rest', and the daily plan.
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05
ECMO complications and emergencies
Recognition and first actions for air in the circuit, pump failure, decannulation, bleeding, LV distension, differential hypoxia, haemolysis, thrombosis, limb ischaemia and HIT.
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06
Weaning and decannulation
Judging readiness and running trials off VV and VA ECMO, echo criteria for VA weaning, decannulation, and care afterwards.
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Drugs in this module

Doses written for this module's context. The same drug may read differently in another module.

Unfractionated heparin (UFH)

Indirect thrombin/Xa inhibitor (via antithrombin)

Indications: Standard circuit anticoagulation on VV/VA ECMO; IABP and Impella systemic anticoagulation
Adult dose: Cannulation bolus 50–100 units/kg IV (many centres use about 5,000 units). Infusion typically started at 7.5–20 units/kg/h once bleeding is controlled, titrated to anti-Xa 0.3–0.7 units/mL or aPTT about 1.5–2.5 × baseline (unit protocol). Low-intensity targets (anti-Xa 0.2–0.3 units/mL) or temporary holds are used on VV ECMO with active bleeding.
Preparation (India): 5,000 units/mL vials (1 mL and 5 mL). Common infusion: 25,000 units in 50 mL NS = 500 units/mL.
Renal / hepatic: No renal adjustment. Antithrombin deficiency causes heparin resistance (high dose needed, low anti-Xa).
Cautions: HIT (check platelets daily; 4Ts if fall >50%). Bleeding. aPTT is unreliable on ECMO (confounded by coagulopathy, low fibrinogen, inflammation); prefer anti-Xa where available.
Monitoring: anti-Xa or aPTT 6-hourly until stable then 12–24-hourly; ACT at bedside only as a crude check; platelets, fibrinogen, antithrombin if resistance.

Bivalirudin

Direct thrombin inhibitor (IV)

Indications: Anticoagulation on ECMO when HIT is suspected/confirmed or heparin resistance
Adult dose: No bolus usually; start about 0.025–0.05 mg/kg/h and titrate to aPTT 1.5–2.5 × baseline (reported ranges up to ~0.2 mg/kg/h; reduce in renal failure and per protocol on CRRT).
Preparation (India): 250 mg lyophilised vial; e.g. 250 mg in 50 mL NS = 5 mg/mL.
Renal / hepatic: Partly renally cleared: reduce dose substantially in AKI.
Cautions: No reversal agent. Stasis areas of the circuit (and stagnant blood in the LV on VA) can clot because the drug is cleaved locally.
Monitoring: aPTT (or dilute thrombin time where available) 4–6-hourly initially.

Argatroban

Direct thrombin inhibitor (IV)

Indications: Alternative anticoagulant for HIT on ECMO
Adult dose: Critically ill/ECMO: start low, about 0.2–0.5 mcg/kg/min (standard HIT dose 2 mcg/kg/min is often too high in critical illness and hepatic dysfunction); titrate to aPTT 1.5–3 × baseline.
Preparation (India): Limited availability and costly in India; check pharmacy.
Renal / hepatic: Hepatic clearance: markedly reduce in liver dysfunction or congestion.
Cautions: Raises INR (confounds warfarin transition).
Monitoring: aPTT 2–4 hours after each change.

Dobutamine

Beta-1 agonist inotrope

Indications: VA ECMO: maintain LV ejection/aortic valve opening and prevent LV distension; low-output states during weaning trials
Adult dose: 2.5–10 mcg/kg/min IV infusion (up to 20 mcg/kg/min).
Preparation (India): 250 mg/20 mL ampoule; 250 mg in 50 mL = 5,000 mcg/mL.
Cautions: Tachyarrhythmias, myocardial oxygen demand, hypotension from beta-2 vasodilation.
Monitoring: Heart rate and rhythm, arterial pulse pressure, echo LV ejection.

Milrinone

Phosphodiesterase-3 inhibitor (inodilator)

Indications: RV support, LV support on VA ECMO, weaning
Adult dose: 0.125–0.5 mcg/kg/min IV infusion; loading dose usually omitted in shock (hypotension).
Preparation (India): 10 mg/10 mL ampoule; 10 mg in 50 mL = 200 mcg/mL.
Renal / hepatic: Renally cleared: reduce to 0.125–0.25 mcg/kg/min in AKI.
Cautions: Hypotension, arrhythmias, long half-life (longer in AKI).
Monitoring: MAP, arrhythmia, renal function.

Levosimendan

Calcium sensitiser / K-ATP opener (inodilator)

Indications: Facilitating VA ECMO weaning (observational data); low-output states
Adult dose: 0.05–0.2 mcg/kg/min IV for 24 h, usually without bolus in hypotensive patients.
Preparation (India): 12.5 mg/5 mL vial; 12.5 mg in 500 mL D5W = 25 mcg/mL.
Renal / hepatic: Active metabolite persists about a week; avoid in severe renal/hepatic impairment.
Cautions: Hypotension (vasodilation), hypokalaemia, AF.
Monitoring: MAP, K+, rhythm.

Tranexamic acid

Antifibrinolytic

Indications: Significant bleeding on ECMO/MCS (cannula site, mucosal, post-cardiotomy)
Adult dose: 1 g IV over 10 min, may follow with 1 g over 8 h; reduce in renal impairment.
Preparation (India): 500 mg/5 mL ampoules widely available.
Renal / hepatic: Reduce dose in renal impairment (seizure risk).
Cautions: Theoretical circuit/oxygenator thrombosis; seizures at high doses.
Monitoring: Circuit inspection for clot, oxygenator pressure gradient.

Noradrenaline (norepinephrine)

Alpha-1 > beta-1 agonist vasopressor

Indications: MAP support on ECMO (usual MAP target 65–80 mmHg on VA ECMO; avoid excess afterload)
Adult dose: 0.05–0.5 mcg/kg/min IV via central line; titrate to MAP.
Preparation (India): 2 mg/2 mL ampoules (check whether the label states base or bitartrate). Common: 4 mg in 50 mL = 80 mcg/mL; 8 mg in 50 mL = 160 mcg/mL.
Cautions: On peripheral VA ECMO excess vasopressor raises LV afterload and can stop aortic valve opening.
Monitoring: Arterial line, pulse pressure, echo, limb perfusion.

6 topics

VV vs VA ECMO: modes and indications

ECMO referral: who, when and how

IABP and Impella basics

Daily ECMO checks and rounds

ECMO complications and emergencies

Weaning and decannulation

Drugs in this module

Module references (25)