Extracorporeal Life Support is an advanced form of support where blood is pumped outside of the body for oxygenation and the returned to circulation.

Respiratory Therapists are often involved in this type of therapy which means that this is an important topic to learn about. Hopefully, this study guide can help make that process easier for you.

Below, we have provided practice questions for your benefit as well. So if you’re ready, let’s get started.

What is Extracorporeal Life Support?

Extracorporeal Life Support is a form of therapy used for providing cardiac and respiratory support to patients who are unable to perform gas exchange or perfusion with their own organs.

It involves pumping blood out of the body into a machine where oxygenation takes place. Then, the blood can be pumped back into circulation in the body.

This is a very serious type of support that should only be used in life-threatening situations where conventional forms of treatment were unsuccessful.

Types of Extracorporeal Life Support:

Here is a list of the types of Extracorporeal Life Support that you should be familiar with:

  • Extracorporeal Membrane Oxygenation (ECMO)
  • Venoarterial (VA)
  • Venovenous (VV)
  • Extracorporeal CO2 Removal (ECCO2R)

In general, ECMO is considered to be the most common type of Extracorporeal Life Support. The others can, technically, be classified as types of ECMO.

What is ECMO?

Extracorporeal Membrane Oxygenation (ECMO) is a type of extracorporeal life support that involves pumping blood out of the body through a membrane for gas exchange of oxygen and carbon dioxide to occur.

It can be used for the management of severe, life-threatening respiratory failure or cardiogenic shock in patients who have not responded well to conventional types of treatment.

Respiratory Therapists are often involved with this type of treatment although state licensure laws may limit involvement in some states.

Venoarterial Extracorporeal Membrane Oxygenation

Venoarterial ECMO is a type of extracorporeal life support where venous blood is drained from the patient and ran through the machine for oxygenation. The blood becomes saturated with oxygen and can be returned to the patient’s body via arterial circulation.

This type of ECMO is typically used in patients with cardiovascular failure and provides hemodynamic support. It’s most commonly indicated for the treatment of cardiogenic shock.

Venovenous Extracorporeal Membrane Oxygenation

Venovenous ECMO is a type of extracorporeal life support where venous blood is drained from the patient and ran through the machine for gas exchange. However, with this type of support, the blood is returned to the patient’s body via venous circulation.

This type of ECMO is typically indicated for the treatment of acute respiratory failure that is due to viral or bacterial pneumonia. Unlike Venoarterial ECMO, Venovenous ECMO provides no hemodynamic support.

Extracorporeal Life Support Practice Questions:

1. When is ECMO indicated?
It can be used for the management of severe, life-threatening respiratory failure or cardiogenic shock in patients who have not responded well to conventional types of treatment.

2. What are the 3 types of ECMO?
Venovenous, venoarterial, and Arteriovenous.

3. In hypoxic respiratory failure due to any cause, ECLS should be considered when?
It should be considered when the risk of mortality is greater than 50%, and is indicated when the risk of mortality is greater than 80%.

4. A 50% mortality rate is associated with a P/F of what?
With a P/F of greater than 150 on an FIO2 of greater than 90%.

5. An 80% mortality risk is associated with a P/F of what?
Less than 100 on an FIO2 of greater than 90%.

You can now get access to our Cheat Sheet Database for FREE — no strings attached.

6. ECMO is recommended for MLIS greater than what?
3

7. Gas flow in an ECMO circuit is referred to as what?
Sweep Flow

8. The higher the sweep flow, the more?
The more CO2 is eliminated.

9. Which form of ECMO involves a complete lung bypass?
Veno-Arterial ECMO

10. In order for venovenous ECMO to support oxygenation and CO2 removal, we must have adequate what?
Cardiac function.

11. Patients with an acute lung injury and preserved cardiac function would be considered for which type of ECMO?
Venovenous ECMO

12. Which form of ECMO should be considered for patients with cardiogenic shock, with or without an acute lung injury?
Venoarterial ECMO

13. What form of ECMO is best indicated for patients with COPD and pre-lung transplant patients?
Arteriovenous EMCO

14. Which group has the best survival rate treated with ECMO?
Neonates with respiratory support

15. What is the key reason for making ECMO so successful in newborns?
Most clinical conditions treated with ECMO in newborns are reversible.

16. What are the different uses of ECMO?
It is mostly used for neonatal hypoxemic respiratory failure. Some examples of clinical conditions include: PPHN, MAS, RDS, sepsis, and air leak syndrome.

17. Which of the following strategies is greatly responsible for decreasing the need for ECMO in neonates?
HFOV

18. Which condition is considered the 1st contraindications for neonatal ECMO?
Less than 2 kg of weight.

19. What are the suggested indications for pediatric ECMO?
PaO2/FiO2 greater than 75, oxygen index greater than 35, and a pre-ECMO pH less than 7.20.

20. What are the cardiac applications of ECMO?
ECPR, CDH, Fulminant myocarditis, and Cardiomyopathy.

21. What statement describes venoarterial ECMO?
A cannula is inserted into the right common carotid artery for arterial return.

22. During the administration of venovenous ECMO, the therapist notices that the SvO2 is greater than the SaO2. What is the best explanation of this phenomenon?
The native cardiac output has increased.

23. During venovenous ECMO, what effect does the cardiac output have on oxygenation?
Changes in cardiac output, either way, will have little influence on the patient’s oxygenation.

24. What are the major advantages of venovenous ECMO?
Cardiovascular support is uninvolved.

25. What mechanisms affect the output of venovenous ECMO?
The size of the tubing, the rotations per minute, and the tension of the rollers.

The Egan’s book — aka the Bible of Respiratory Therapy — is one I recommend for all students.
As an affiliate, we receive compensation if you purchase through this link.

26. The therapist should evaluate raceway occlusion because too much roller tension could be associated with which of the following events?
Hemolysis

27. What is the advantage of having the centrifugal pump automatically respond to resistances against which it is pumping?
It maintains regulated flow through the system.

28. In the gas membrane exchanger, what is one of the limiting factors to the transfer the rate of oxygen across the membrane?
The thickness of the blood film between the membrane layers.

29. Because the minimum flow rate required to remove condensation in the gas compartment usually results in excessive elimination of carbon dioxide, what should the respiratory therapist do?
Blend sweep gas with a carbogen mixture.

30. What are the most common causes of a decrease in venous return in ECMO?
Hypovolemic state, malpositioning of the venous cannula, kinking of the cannula, and shifting of the mediastinum.

31. It is not uncommon for patients undergoing ECMO to experience renal failure. What can be done to enhance renal function?
Perform hemofiltration.

32. The ECMO specialist has noticed excessive clotting in the circuit despite increased doses of heparin. What is the most feasible explanation for this event?
Deficiency of ATIII.

33. The respiratory therapist in charge of a patient on ECMO is monitoring the ACT every 30 minutes. The last ACT was 100 seconds. What should the therapist suggest at this time?
Increase the heparin dose.

34. The respiratory therapist in charge of a patient on ECMO has noticed an increase in pre-membrane pressures. What is the most probable explanation?
Clotting in the circuit.

35. How can membrane malfunction be suspected?
Narrowing of the pre-membrane and post-membrane PaCO2.

36. What ventilator settings are typically used in ECMO for respiratory support?
A tidal volume of 5-7 ml/kg, PIP 25-25 cm H2O, and a frequency 10-12.

37. What is the ECMO flow that is considered as minimal support?
30 mL/Kg

38. What is considered the most concerning complication of ECMO in a newborn?
Intracranial hemorrhage.

39. What are the main uses of ECMO?
Neonatal Hypoxemic Respiratory Failure, i.e. Persistent pulmonary HTN of the newborn (PPHN), Meconium aspiration syndrome (MAS), Respiratory distress syndrome (RDS), Sepsis, and Air leak syndromes.

40. What are the uses of ECMO for cardiac applications?
Congenital heart disease, fulminant myocarditis or cardiomyopathy, and extracorporeal cardiopulmonary resuscitation (ECPR).

41. What are the modes of Venoarterial ECMO support?
Right common carotid & right internal jugular. Central cannulation. 80% of CO supported by ECMO. Nonpulsatile.

42. What are the modes of Venovenous ECMO Support?
Blood drained and re-infused back into the venous circulation. Recirculation. The preferred mode of ECMO support in infants & children.

43. What are the types of ECMO systems?
Pumps, i.e. Roller pumps and Centrifugal pumps. Artificial Gas Exchange Devices, i.e. Silicone membranes and Microporous membranes, Temp regulation, Circuits & circuit preparation, Cannulas & establishing support, and Hemofiltration.

44. What needs to be monitored when the respiratory therapist is monitoring the circuit function?
Water temp, Venous saturation, Circuit integrity, Pre- and post-membrane blood gases, Air bubbles, Hemodynamics, Organ perfusion, Lab tests, and Neurologic assessment.

45. When do you use ECMO?
It is most commonly used in neonatal hypoxemic respiratory failure such as: Persistent pulmonary hypertension (PPHN), meconium aspiration syndrome (MAS), RDS, sepsis, congenital diaphragmatic hernia, air leak syndromes, and reversible lung disease.

46. When can ECMO be used?
ECMO can be used at greater than 32 weeks gestation and no intraventricular hemorrhage.

47. What are the cardiac applications for ECMO?
Congenital heart disease, myocarditis or cardiomyopathy, and extracorporeal cardiopulmonary resuscitation (ECPR).

48. What is the Venoarterial mode of ECMO?
A double cannula is inserted into the right common carotid and right internal jugular. It is a surgically placed catheter to aid in the movement of deoxygenated blood through the system and pump oxygenated blood back into the patient.

49. How much of the cardiac output is supported by ECMO?
80%

50. What is the Venovenous mode of ECMO?
Blood is drained and re-infused back into the venous circulation through the femoral vein and reinfused to the right side of the heart (right internal jugular). A surgically placed catheter to aid in the movement of deoxygenated blood through the system and pumped oxygenated blood back into the patient.

Respiratory Therapist Hoodie Sweatshirt

It doesn't get much better than this Respiratory Therapist Sweatshirt. Grab yours today.

51. Which mode of ECMO is preferred for support infants and children?
Venovenous.

52. What are the types of ECMO systems?
Pumps (roller and centrifugal), artificial gas exchange device, temp regulation, circuits, and circuit preparation, cannulas and establishing support, and hemofiltration.

53. What is used for anticoagulation?
Heparin

54. What should the Respiratory Therapist watch for during ECMO treatment?
The water temp, venous sat, circuit integrity, pre and post-membrane blood gas, and air bubbles which could cause a stroke and/or could shut down the pump.

55. What is the main goal of ECMO?
The main goal is to discharge the patient without any disability.

56. What is the survival rate for ECMO?
Greater than 65% in infants.

57. What is the most common mechanical complication that can occur during ECMO?
Clot formation

58. How can you wean a patient from ECMO?
Weaning occurs by gradually turning down the pump flow in VA, or by turning down the sweep flow in VV.

59. Does venovenous ECMO provide hemodynamic support?
No, no it does not.

60. During venoarterial ECMO, how is blood returned to the patient’s body?
It is returned to the body via arterial circulation.

Final Thoughts

So there you have it. That wraps up our study guide on Extracorporeal Life Support. As you can see, this topic is very complex. However, hopefully, you can use this study guide as a reference to make the learning process easier.

We have another guide that covers Hemodynamic Monitoring that I think you will enjoy. Thank you so much for reading and as always, breathe easy my friend.

References

The following are the sources that were used while doing research for this article:

  • Faarc, Kacmarek Robert PhD Rrt, et al. Egan’s Fundamentals of Respiratory Care. 12th ed., Mosby, 2020. [Link]
  • Rrt, Des Terry Jardins MEd, and Burton George Md Facp Fccp Faarc. Clinical Manifestations and Assessment of Respiratory Disease. 8th ed., Mosby, 2019. [Link]
  • Swol, Justyna. “Indications and Outcomes of Extracorporeal Life Support in Trauma Patients.” PubMed, June 2018, pubmed.ncbi.nlm.nih.gov/29538235.
  • “Extracorporeal Life Support in Critically Ill Adults.” National Center for Biotechnology Information, U.S. National Library of Medicine, 1 Sept. 2014, www.ncbi.nlm.nih.gov/pmc/articles/PMC4214087.
  • “Extracorporeal Life Support for Severe Acute Respiratory Distress Syndrome in Adults.” National Center for Biotechnology Information, U.S. National Library of Medicine, Oct. 2004, www.ncbi.nlm.nih.gov/pmc/articles/PMC1356461.

Disclosure: The links to the textbooks are affiliate links which means, at no additional cost to you, we will earn a commission if you click through and make a purchase.