ECMO Troubleshooting

OVERVIEW

Approach to problems specific to patients requiring ECMO therapy

  • high free hemoglobin level (normal is <0.1g/dL)
  • access insufficiency
  • bleeding from ECMO cannula site
  • pump failure
  • unintended ECMO decannulation

HIGH FREE HAEMOGLOBIN LEVEL

  • Look for intravascular haemolysis
    — dark/red urine or CRRT effluent with high K+
  •  Circuit should be assessed for signs of malfunction:
    — “noisy” pump head (pump head thrombosis), visible access insufficiency, or high transmembrane pressure gradient (oxygenator thrombosis)
  •  If clinical evidence of haemolysis or circuit malfunction
    -> rapid response contact ICU Consultant immediately
  •  If neither present -> repeat free Hb level
  • if >0.10 g/dL -> likely low level haemolysis
    — access insufficiency without visible kicking (may require echocardiography to detect venous “suck-down” with a multistage cannulae)
    — vessel- cannula impingement due to pericardial collection or retroperitoneal haematoma
    — excessive speed settings with small cannulae (greater than 4000 RPM)

 ACCESS INSUFFICIENCY

Identify:

  • visible access insufficiency = shaking of access line (‘kicking’)
  • access insufficiency without visible kicking may cause haemolysis (high free Hb) and may require echocardiography to detect venous “suck-down” with a multistage cannulae

Seek and treat for causes:

  • Hypovolaemia/Bleeding
  • Poorly sited access cannula (too low)
  • Cardiac tamponade (common post sternotomy)
  • Excessive RPM setting (pump speed)
  • Patient coughing or straining
  • Positional (e.g. after turning the patient)
  • Acute vasodilatation (e.g. sedation bolus)
  • Increased intra-abdominal pressure
  • Severe aortic regurgitation or severe pulmonary haemorrhage (VA ECMO)

BLEEDING FROM CANNULA SITE

Management:

  • Fully insert the cannula to the taper
  • Thrombotic (Kaltostat) dressings
  • Pressure (sand bag)
  • Cessation of heparin
  • Vascular surgical review
  • Repair and re-cannulation

Correct bleeding diathesis:

  • platelets >80
  • cryoprecipitate 5-10 ml/kg (1 bag ~ 20mL) -> fibrinogen >1.5
  • FFP -> INR <1.5
  • protamine 1mg/ 100 units of heparin in past 2 hours (max dose 50 mg)

PUMP FAILURE

Causes

  • Pump head/centrifugal pump disengagement
  • Electrical motor failure – either console or pump head
  • Battery failure (no AC power connected)
  • Rotaflow Power Isolation Switch “OFF”

Management

  • Clamp circuit
  • Call for help. Contact ICU Consultant and ECLS Coordinator
  • Examine for cause:
    — Console (front): Power (On/Off Switch)
    — Console (front): AC Power Supply Indicator lights
    — Console (rear): Power Isolation Switch
    — External Drive: Pump head position
  • Address Cause and re-establish pump function or obtain new console
  • Engage Emergency Drive Unit (“Hand-crank”)
    — Transfer Pump Head to Emergency Drive Unit
    — Rotate hand crank to 1000 rpm and remove circuit clamp
    — Gradually increase revs to previous speed
  • Transfer to new console
    — Ensure power to new console
    — Clamp circuit
    — Transfer Pump Head to new console
    — Establish pump speed to 1000 rpm and remove circuit clamp over 3-5 seconds while increasing pump speed to obtain full flow

UNINTENDED EMCO DECANNULATION

Effects:

  • bleeding from the cannula insertion site.
  • ECMO support will stop -> same as pump failure
  • Access cannula decannulation: air will rapidly enter and extensively de-prime the ECMO circuit and may reach the patient (see air embolism)
  • Return cannula decannulation: Patient’s blood volume will rapidly be lost from the circuit until the circuit is clamped.

AIR EMBOLISM

  • watch this space!

CARDIAC ARREST

  • watch this space!

References and Links

LITFL

Journal articles

  • Sidebotham D. Troubleshooting adult ECMO. J Extra Corpor Technol. 2011 Mar;43(1):P27-32. PMID: 21449237

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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