Immediate Care in ED
Routine care immediately after initiating support includes:
- Distal perfusion cannula should be inserted as soon as time allows, max 4 hrs post cannulation (e.g. post coronary angiography / PCI)
- Mechanical ventilation with PEEP ≥ 10 to prevent pulmonary oedema, reduce minute ventilation (reduced pulmonary blood flows)
- Establish right-sided arterial line (radial or brachial) and titrate vasopressors to MAP target
- 12 Lead ECG
Early access insufficiency should trigger early checks
- Bedside check for aortic insufficiency with echo
- Distended, non-ejecting LV with “empty RV” (Aortic regurgitation may not appear severe due to rapid equalization of pressures)
- Abdominal FAST scan for obvious source of abdominal bleeding
- Fluid bolus to account for dilution post initiation of extracorporeal support
- Loss of pulsatility
Patients in refractory arrhythmias may have another attempt at electrical cardioversion after several minutes of extracorporeal support. Restoring coronary perfusion pressure and improving perfusion and acid-base may favour successful cardioversion at this point. However, coronary ischaemia (if present) needs to be addressed as well as other reversible factors such as hyperkalaemia and/or if relevant hypothermia. Multiple attempts should therefore be avoided unless those factors are resolved.
Restoration of a potentially perfusing rhythm increases the likelihood of LV ejection and thus reduces risks of LV distension and pulmonary oedema.
Emergency coronary angiography should be strongly considered for all ECPR patients independent of age and presenting rhythm in the absence of an obvious alternate non-cardiac cause.
The cardiology team should be informed at the time of set-up for all ECPRs and be presented with the history and ECG post cannulation for assessment.
If acute coronary ischaemia is suspected, then the patient should be transferred to the cardiac catheterisation laboratory immediately.
The cardiologist will undertake coronary angiography using the left radial artery approach (to preserve the right for routine arterial monitoring), or if not feasible the femoral artery. The femoral artery may also be preferred when transaortic LV decompression is anticipated. Access via the ECMO circuit is currently not feasible with the current locally available setup. At the conclusion of coronary angiography the arterial sheath may be left in situ depending on the circumstances and will be removed in the ICU.
LV distension in cardiac cath lab
ECPR patients are at high risk of developing LV distension syndrome. These patients should be discussed with a specialised centre before the end of the coronary angiogram.
- Patients that remain with a pulse pressure less than 10mmg at the end of the procedure
- OR patients that fit the clinical syndrome with high LVEDP, low ejection fraction and early pulmonary oedema
Patients fulfilling these criteria require a careful multidisciplinary discussion including the VES ECMO consultant to decide upon the best further option.
LV venting options in this scenario include
All patients require the medical management steps of LV distension syndrome and require review upon return to ICU. In particular, patients without any pulsatility need to be evaluated regarding the need to advance to a surgical LV vent if a transaortic vent is chosen in first place. This should be concluded within hours and may require intervention overnight. Alternate causes of loss of pulsatility need to be considered in parallel such as hypovolaemia and bleeding.
Mandatory for any patient who receives a LV venting device
- Additional flow meter to monitor flow through the venting limb
- Favouring heparin anticoagulation
- Optimise medical management for LV distention
CT Imaging post ECPR
Routine CT imaging is performed in all ECPR cases as soon as practical. If the cause of the cardiac arrest is unclear, the scan will occur after the cannulation in the Emergency & Trauma Centre – otherwise after cardiac cath lab on the way to ICU.
Cause of arrest unclear – as a minimum (and maybe extended as clinically indicated):
- CT brain
- Arterial phase CT abdo/pelvis
Cause for cardiac arrest identified in the cath lab – recommended as a minimum:
- CT brain
- Arterial phase CT abdo/pelvis immediately followed by chest CT without contrast
Note: the principles of CT imaging in ECMO are particularly relevant for this patient cohort.
The rationale for routine CT imaging is early identification of causes of cardiac arrest, catastrophic brain injuries and solid organ bleeding in the abdomen from prolonged mechanical chest compressions. This often occurs early and may present with access insufficiency. Injuries e.g. liver lacerations are commonly amenable to interventional radiology.
Targeted temperature management
Targeted temperature management of 36.0°C degrees can generally be achieved by use of the oxygenator heat exchanger. If the patient presents already below this temperature then rewarm at 0.25°C per hour until 36.0°C is achieved. It is important to note that the ongoing temperature may need to be set below or above 36°C to achieve a body core temperature of 36°C. The body core temperature is easily taken with the use of bladder temperature probe catheters (on the cardiohelp console the circuit temperature may serve as a surrogate). The targeted temperature should be maintained strictly for a period of 24 hours post cardiac arrest. For daily management of temperature see here.
Note: The extracorporeal diversion of blood generally cools the patient, active cooling (e.g. via a cooling mat) therefore is seldomly required.
Initial ICU Management
Reduce minute ventilation (e.g. PCV with PC of 10 cmH2O, rate of 10). Titrate PEEP as required. High PEEP may assist in attenuating LV distension in left ventricular dysfunction and reduce the risk of pulmonary oedema. It may also improve LV afterload. Minimum FiO2 on the ventilator should be 0.5.
Noradrenaline should be titrated for a MAP of 65 mmHg. If an inotrope is required to achieve pulsatility, adrenaline infusion allows for immediate support. TTE should be performed to assess cardiac function and check for regurgitant lesions. LV distension is a common problem in this patient group, generally develops early and should be addressed promptly with medical management and LV venting options as indicated.
Sedation may be required if there are signs of awakening. Morphine and midazolam infusions are commonly used, propofol may be added. The former is preferred if blood pressure is unstable and vasopressors are required.
Renal / Electrolytes
Frequent monitoring and appropriate correction of electrolytes (K+, Mg2+, PO43-) is required. Post cardiac arrest transient AKI is common. Renal replacement, if required, should be provided with continuous clearance via the ECMO circuit.
Hyperglycaemia is common and should be treated according to the usual ICU Insulin infusion protocol. Calcium infusions are toxic to injured neurons, thus calcium should not be administered to correct asymptomatic hypocalcaemia in patients with suspected hypoxic ischaemic encephalopathy.
In post cardiac arrest patients on ECMO it is not uncommon for the patient to be coagulopathic with an increased bleeding risk (especially if the patient undergoes PCI covered with dual antiplatelet agents). Most will have received heparin as a bolus during cannulation with the cannula flushes and in the cath lab. IIb/IIIa antagonists in addition should be used with caution. Once it is clear that the patient is not actively bleeding, heparin infusion may be commenced, with the APTT targeted as per the usual anticoagulation guideline.
Prognostication after cardiac arrest
The assessment of neurological recovery after ECPR does not principally differ from other cardiac arrest patients and is generally undertaken at 96 hours (>48 hours after cessation of sedation) and is based largely on the clinical neurological examination.
However, it is important to note that some patients will have progressing multi-organ failure in the first 24-48 hrs and may not be supportable with ECMO. Further, patients that do require sedation with recurrent access insufficiency on waking can be challenging. Early team discussion including potential reconfiguration may be considered to avoid ongoing sedation.
In ECPR patients, the assessment will follow the standard Alfred ICU pathways. Organ donation may be considered in patients who meet the criteria for brain death or, if severe neurological injury is diagnosed, then donation after circulatory death (DCD) may be considered, as this is likely to occur shortly after the withdrawal of VA ECMO support. See end of life care.
Ongoing ICU management
See here for