ECMO Extra Corporeal Membrane oxygenation Jennifer Tronson & Fitsum Tesfa RSPT 234

History

1953 to Today 1953 Gibbon uses artificial oxygenation and perfusion for the first successful open heart. 1954 Lillehei successfully utilizes live volunteers to serve as live cardiopulmonary bypass. 1955 The Mayo clinic improved on Gibbon’s device and used it in the repair of an atrial septal defect. 1965 Rashkind et al successfully used bubble oxygenation to support a dying neonate. 1969 Dorson et al utilized a membrane oxygenator for cardiopulmonary bypass in infants. 1975 Bartlett et al first successfully used ECMO in neonates with severe respiratory distress.

Indications

Neonates PPHN, MAS, RDS, Group B streptococcal sepsis, asphyxia and CDH Gestational age of 34 weeks or more Birthweight of 2000g or more Mechanical ventilation for 10-14 days or less Reversible lung injury Failure with maximal medical therapy OI greater than 40 in 3 of 5 postductal ABGs Acute deterioration

Pediatrics Decreased Cardiac Output due to right, left and biventricular failure post CHD repair Bridge to Cardiac Transplant

Contraindications

Neonatal Lethal chromosomal disorder Irreversible brain damage Uncontrolled bleeding Grade III or greater IVH Untreatable cardiac malformation Coagulopathy

Other Contraindications Irreversible Organ Damage ARDS longer than 7 days Advanced age, greater than 65 Prolonged CPR

Set Up

Types of ECMO VA-ECMO VV-ECMO Higher PaO2 Lower perfusion rates Bypasses pulmonary circulation Decreases pulmonary artery pressures Provides cardiac support Requires arterial cannulation Lower PaO2 is achieved Higher perfusion rates Maintains pulmonary blood flow Elevates mixed venous PO2 No cardiac support Requires only venous cannulation

VA-ECMO Set to provide 50-200ml/kg CO Start at 100ml/kg and titrate up or down based on blood gas results. Typically titrating down to 50ml/kg indicates readiness to wean. Sweep (flow) is adjusted based on CO2 removal needs O2% is set to achieve a PaO2 of 250mmHg on blood gas drawn at the pump.

Monitoring

Blood Gas Three draw sites Patient’s femoral artery Monitors the patient’s mixed blood- ECMO and Pulmonary Patients venous return to the ECMO machine Monitors the patient’s O2 consumption ECMO pump Monitors the blood that is going to the patient from the ECMO machine

CBC &Chemistry Hbg maintained at 12-15 g/dl by using pRBCs Plt maintained above 100,00/mcl with transfusions ACT maintained at 180-240 to avoid bleeding Fluids and electrolytes need to be monitored and hyper-alimentation should be used to compensate for the high energy requirements.

Ventilator Pip should be monitored to avoid increasing damage to the lungs Compliance should be monitored to trend improvement or worsening in underlying respiratory condition PEEP should be kept sufficiently high to reduce atelectatic sheer injury and low enough to not interfere with CO

Manipulations

Based on blood gas results Insufficient PaO2 in the descending aorta draw (femoral) is improved by increasing the percentage of CO provided by the ECMO machine and/or increasing FiO2 on the ventilator Excessive CO2 at this draw can be corrected by increasing the gas flow on the ECMO device to remove more CO2 before sending the blood back to the body or increasing VE on the ventilator

Based on blood gas results Insufficient PaO2 at the venous return draw is indicative of oxygenation that is insufficient for the bodies O2 consumption. Determine cause of increased O2 consumption and address cause or correct by increasing oxygenation with the percentage of CO provided by the ECMO device or increasing the FiO2 or MAP on the ventilator.

Complications & Hazards

Impaired Venous Drainage Impaired venous drainage can cause low circuit flow and high pump speeds in both venoarterial and venovenous ECMO. This can be caused by a drainage cannula being poorly positioned or by hypovolemia. Signs of hypovolemia can include low CVP and hypotension. You may see “chattering” in the tubing.

Tubing Blockages Another cause for low circuit flow and high pump speeds can be due to kinks in the tubing or a thrombus. Check for a decreased PO2 if obstruction is suspected. Check for resistance in the oxygenator. Normal pressure drop across the oxygenator is 50. Replace the affected circuit if thrombus is present.

Complications Heparin resistance may occur due to antithrombin III deficiency or administration of excess heparin. Recirculation in venovenous ECMO Clotting of the circuit is a common problem: oxygenator failure, consumption coagulopathy and emboli. Damage to the internal jugular vein may cause mediastinal bleeding.

Complications Seizures Intracranial bleeds Hemorrhagic complications and a decreased platelet count. Developing coagulopathy. Air trapped in the circuit. Pneumothorax

Works Cited https://www.elso.org/Portals/0/IGD/Archive/Fi leManager/e76ef78eabcusersshyerdocuments elsoguidelinesforadultcardiacfailure1.3.pdf https://www.elso.org/Portals/0/IGD/Archive/Fi leManager/8588d1a580cusersshyerdocument selsoguidelinesforneonatalrespiratoryfailure1 3.pdf http://emedicine.medscape.com/article/18186 17-overview#showall