**6. Steps of institution of ECPR**

With continued CPR, femoral artery and vein are cannulated percutaneously. After proper timeout, cannulas are connected to ECMO circuit and ECMO is initiated. After the achievement of adequate ECMO flows, CPR is stopped. Mild therapeutic hypothermia is achieved for 24–48 hours by cooling the patient to 33–34°C through integrated heat exchanger in the ECMO circuit. Permissive hypothermia reduces the tissue metabolism including cerebral metabolism, giving a better chance of survival of the patient, and reducing the progressive cerebral injury [54–56]. The patient is

**Figure 4.** *Steps of institution of ECPR.*

connected to the ventilator to reduce the work of breathing. IV heparin is infused for anticoagulation and routine arterial blood gas (ABGs) and lactate monitoring are done to measure the success of ECMO, and mean arterial pressure (MAP) is aimed at 70 mmHg. As soon as a patient is stabilized on ECPR, he should be wheeled to the cath lab for angiography for coronary angiography with or without stenting. To prevent the ischemia in the limb with arterial cannula, 6–7 Fr, arterial cannula is inserted distally and sliced into the arterial cannula allowing perfusion of the distal limb. However, insertion of distal limb perfusion cannula may be extremely challenging in patients with peripheral vascular disease, profound shock with collapsed and constricted arteries, or obesity. The alternative in such patients may be to use retrograde limb perfusion through dorsalis pedis, anterior tibial, or posterior tibial artery. Reports have shown favorable results with retrograde limb perfusion with decreased incidence of leg ischemia and fasciotomy [57, 58]. In patients with small femoral vessels, an alternate technique may be to insert 12 Fr or 14 Fr bilateral femoral arterial cannula instead of a single 17 Fr or 19 Fr arterial cannula. The steps of ECPR are shown in **Figure 4**.
