1. CHSU AND PICU Staff Meeting
Greg Merritt, BSRC, RRT-NPS
Pediatric Clinical Educator

2. December Objectives
ECMO
CPT
Oxygen (flow verses fio2)

3. ECMO extracorporeal membrane oxygenation
prolonged mechanical cardiac and pulmonary support
In simple terms, venous blood is removed from the patient, passed through an artificial membrane to remove CO2, add O2 and the blood is then returned to the patient.

4. History of Cardiopulmonary Support
1952: first successful ASD closure
development of cardiopulmonary bypass
goals:
support circulation
oxygenation/ventilation
bloodless surgical field
ECMO as a technology was unavailable until after the development of hemodialysis and cardiopulmonary bypass. Research for cardiac and pulmonary support began before the turn of the century but became very aggressive in the 1930s. By 1950, research began in humans. Several obstacles needed to be overcome for successful bypass. This included a method to oxygenate/ventilate the blood and a method to support the circulation while providing a bloodless surgical field for the surgeon to work.

5. History of Cardiopulmonary Support
low flow bypass
cross circulation
slow intraoperative transfusion of hyperoxygenated blood
Methods to provide adequate oxygenation included: low blood flow rates (about 10cc/kg/min via occlusion of the vena cava, sparing of the azygous system, this allowed adequate oxygenation for about 30 minutes), cross-circulation, utilization of animal lungs, slow intraoperative transfusion of hyperoxygenated blood (donor had arm inserted into warm water bath during donation to hyperoxygenate the blood), and finally utilization of artificial lung/oxygenator.

6. Cross-Circulation
Successful surgical management of 45 patients. No donor mortality or morbidity. ASD, PDA, VSD, tetralogy of Fallot, pulmonary stenosis, anomalous pulmonary venous return. 28 of 45 patients survived (62%).

7. History of Cardiopulmonary Support
film oxygenator
membrane oxygenator
bubble oxygenator
Lillehei was one of the first to use a prosthetic heart/lung machine for cardiac surgery, thereby opening the door to routine and successful use of extracorporeal circulation for cardiac bypass. But as experience with this technique developed during the 1950s, it became obvious that this life-sustaining technique became lethal when used for more than a few hours. Thrombocytopenia, coagulopathy, hemolysis, generalized edema and deterioration of organ function all occurred in proportion to the amount of time spent on bypass.
Film oxygenators spread anti-coagulated blood thinly over a surface and then exposed the blood to oxygen. This method was difficult to utilize because the equipment was very cumbersome. It was realized that the toxicity seen with bypass was a result of direct exposure of blood to oxygen.
In bubble oxygenators, oxygen was bubbled through the blood as it went through the oxygenator. These oxygenators were easy to assemble and were disposable but has the added difficult of oxygen bubble removal prior to reinfusion to prevent air embolization.

8. ECMO silicone rubber membrane oxygenator first successful ECMO 1972
first successful neonatal ECMO 1976
Membrane oxygenator then developed. The blood and gas paths are physically separated by a semi-permeable membrane which allows oxygen diffusion to the RBCs. This method allowed for large blood volume movement without the risk of air embolism or excessive hemolysis. Initially this method was very cumbersome because very large surface areas were required for the gas exchange.
But the development of a new material called silicone rubber allowed the production of small but efficient oxygenators. These oxygenators allow for prolonged bypass without excessive blood trauma, acidosis or multi-organ failure.
1972: first successful ECMO case: young man with multi-trauma including ruptured aorta. Supported on ECMO for several days.
1976: first successful neonatal case. PPHN
: Phase I safety and efficacy. 50 infants with predicted mortality of 100%, 66% survival
Bartlett Play the winner, prospective randomized trial. 12 pts met ECMO criteria, 1 child randomized to conventional therapy - died. Remaining patients reassigned to VA ECMO - all survived.

9. ECMO Goals
support cardiac and respiratory systems until disease process resolves
avoid chronic lung injury from volutrauma
ECMO goals are simple in concept: to provide cardiac/pulmonary support until a reversible disease process resolves. An important goal of ECMO to to prevent chronic lung disease from ventilator induced volutrauma. This is important to remember as we can often maintain a patient with medical management but the cost may be severe chronic lung disease.

10. ECMO Precautions NO Suctioning Past ETT NO Deep Nasal/Oral Suctioning
NO Cuff Blood Pressure Checks
NO Needle Sticks
NO Rectal Temperatures
NO Line Removals

11. Respiratory Lung rest for pulmonary failure
Prevention of total lung collapse
Gentle pulmonary toilet
Increase vent settings when pulmonary compliance improves and ECMO is weaned

12. Selection Criteria failure of maximal medical management
reversible cardiac or pulmonary disease
GA > 34 weeks
birth weight >2 kg
no major malformations
no coagulopathy or severe hemorrhage

13. Qualifying Criteria AaDO2 > 600 torr PaO2 < 50 mmHg OI > 40
acute deterioration
problems with criteria
Goals are to determine criteria that predict a high probability of death.
Alveolar-arterial gradient = atomospheric pressure (PaCO2 + PaO2)/FiO2, >600 torr for over 12 hours
PaO2 < 50 mmHg for > 4 hours
OI = PAW X FiO2 X 100/PaO2
20-40 has 50-80% mortality
>40 = 80-90% mortality

14. Reversible Disease PPHN meconium aspiration pneumonia/sepsis
congenital diaphragmatic hernia
respiratory distress
cardiac support
Survival
PPHN: 79% (CMC 62%)
mec aspiration 94% (CMC 89%)
pneumonia 53% (we had 0 pts)
sepsis 76% (100%)
respiratory distress 84% (25%)
CDH 54% (44%)
Overall neonatal runs are down. Peak was 1992 with 1500 runs had 500 runs.

15. CPT Devices
There has been a lot of discussion about which device to use for CPT. Specifically – “What is the largest patient that the Neocussor can be used on? I looked through the data as well as call the technical support. I had a tough time getting specifics from the company. The company said it is based off the size of the chest. I expressed that they should not use the Neocussor on patients larger than 1800g. I also expressed that hand CPT are better than percussor or vibes

16. Oxygen Therapy
We discussed the use of high flow oxygen therapy and how much oxygen is actually delivered to the patient. We also discussed “meeting inspiratory demand?Lastly we discussed how HFNC can mask the patients true respiratory status.

17. Questions??
1. How effective is aerosol delivery due to a large amount of rainout.