Deck 19: Extracorporeal Membrane Oxygenation

Question 1

Because the minimum flow rate required to remove condensation in the gas compartment usually results in excessive elimination of carbon dioxide, what should the therapist do?

A) Reduce pump flow.
B) Blend sweep gas with a carbogen mixture.
C) Reduce the amount of oxygen blended in the sweep gas.
D) Add more oxygen to the sweep gas.

Answer 1

B
Because the minimum flow rate required to remove condensation usually results in excessive elimination of carbon dioxide, sweep gas is often blended with a carbogen mixture, which reduces the driving pressure across the membrane and maintains normocarbia.

Question 2

What is the advantage of having the centrifugal pump automatically respond to resistances against which it is pumping?

A) It avoids placing increased pressures on the heart.
B) It eliminates lowering pulmonary vascular pressures.
C) It maintains regulated flow through the system.
D) It ensures that the blood flows smoothly through the membrane oxygenator.

Answer 2

C
Centrifugal pumps are nonocclusive devices because energy is transferred to the blood by a rapidly rotating cone-shaped pump head that creates a constrained vortex. Blood is actively pulled inward and propelled outward by the energy created by the vortex, thus drainage is considered active. Because this type of pump is nonocclusive is it dependent on the patient's preload and afterload. As preload decreases, such as decreased venous drainage, or if afterload increases due to increased systemic vascular resistance, flow will decrease.

Question 3

What are the major advantages of venovenous ECMO?

A) Carotid artery ligation is not required.
B) Cardiovascular support is uninvolved.
C) It is less expensive than VA ECMO.
D) The internal jugular vein is not cannulated twice.

Answer 3

A
One advantage of VV support is that carotid artery ligation is not required, full pulsatile native blood flow is maintained, and the potential for air or particulate emboli from the circuit is less. A disadvantage is the lack of cardiovascular support. However, the presence of mild to moderate myocardial dysfunction should not discourage the use of the VV approach because the improved oxygenation and lower airway pressures achieved with implementation of VV ECMO often improve cardiac function.

Question 4

Which of the following conditions are cardiac applications of ECMO?
I) High cardiac output syndrome
II) Cardiac arrest
III) Preoperative stabilization
IV) Cardiomyopathy

A) I and II only
B) III and IV only
C) II, III, and IV only
D) I, II, III, and IV

Question 5

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

A) Decrease the amount of platelets transfused.
B) Increase the heparin dose.
C) Add plasminogen.
D) Increase blood flow to decrease contact time.

Question 6

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

A) High-flow oxygen therapy
B) Pressure control ventilation
C) Heliox
D) HFOV

Question 7

A neonate on mechanical ventilation with respiratory distress has a PaO₂ of 50 mm Hg, a of 20 cm H₂O and FiO₂ of 0.8. Why should the therapist suggest therapies other than ECMO?

A) The FiO₂ is not 1.0 yet.
B) Theis not high enough to justify ECMO.
C) The OI does not meet ECMO criteria.
D) The PaO₂ is within normal limits.

Question 8

Which of the following conditions is considered contraindications for neonatal ECMO?

A) Meconium aspiration
B) Less than 2 kg of weight
C) Prolonged mechanical ventilation (7-10 days)
D) Less than 36 weeks of gestation

Question 9

What are the most common causes of a decrease in venous return in ECMO?
I) Hypervolemic state
II) Malpositioning of the venous cannula
III) Kinking of the cannula
IV) Shifting of the mediastinum

A) I and III only
B) II and III only
C) I, II, and III only
D) II, III, and IV

Question 10

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

A) Add either colloids or crystalloids to fluid challenge the patient.
B) Perform hemofiltration.
C) Add either vasodilators or vasoconstrictors.
D) Conduct plasmapheresis.

Question 11

Which of the following mechanisms affect the output of VV ECMO?
I) Size of the tubing
II) The rotations per minute
III) Tension of the rollers
IV) Patient's blood pressure

A) I, II, and III only
B) I and IV only
C) II, III, and IV only
D) I, II, III, and IV

Question 12

What is the key reason for making ECMO so successful in newborns?

A) Newborns do not have as a high risk for bleeding as other age groups.
B) Newborns require less ECMO flows.
C) Newborns have fewer side effects when treated with heparin drips.
D) Most clinical conditions treated with ECMO in newborns are reversible.

Question 13

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

A) Inadequate flow
B) Increased bladder tension
C) Hemolysis
D) Recirculation

Question 14

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

A) Too many platelet transfusions
B) Defective heparin
C) Blood flow too slow
D) Deficiency of ATIII

Question 15

Which of the following parameters have been suggested as factors that may help predict outcome for pediatric ECMO?
I) PaO₂ <50 mm Hg
II) PaO₂/FiO₂ <75
III) OI >35
IV) Pre-ECMO pH <7.20

A) II, III, and IV only
B) I, II, and III only
C) I, II, and IV only
D) II and IV only

Question 16

Which of the following statements describes venoarterial ECMO?

A) A cannula is inserted into the subclavian vein for the removal of blood.
B) Blood is removed from the venous circulation through the external jugular vein.
C) Blood returns to the heart through the subclavian artery.
D) A cannula is inserted into the right common carotid artery for arterial return.

Question 17

Which of the following are the principle components of the ECMO system?
I) A pump
II) A standardized ECMO circuit
III) A gas exchange device
IV) A ventilator

A) II and III only
B) I and IV only
C) II, III, and IV only
D) I, II, and IV

Question 18

In the gas membrane exchanger, what is one of the limiting factors to the transfer rate of oxygen across the membrane?

A) The flow of blood
B) The concentration gradient of the gas across the membrane
C) The thickness of the blood film between the membrane layers
D) The flow of gas in relationship to the flow of blood

Question 19

Which of the following groups of patients has the highest mortality rate when treated with ECMO?

A) Neonates with respiratory support
B) Pediatric patients with cardiac support
C) Neonates with cardiac support
D) Pediatrics with use as a bridge to heart transplant

Question 20

During administration of venovenous ECMO, the therapist notices that the SvO₂ is greater than SaO₂. What is the best explanation to this phenomenon?

A) The blood flow through the pump is too slow.
B) Recirculation is excessive.
C) Native cardiac output has increased.
D) iNO is being administered concomitantly.

Question 21

How can membrane malfunction be suspected?

A) Narrowing of the premembrane and postmembrane PaCO₂
B) Widening of the premembrane and postmembrane PaO₂
C) Presence of large clots in the circuit
D) Presence of air bubbles

Question 22

The therapist in charge of a patient on ECMO has noticed an increase in premembrane pressures. What is the most probable explanation?

A) Very high pump flow
B) Clotting in the circuit
C) Damage of the raceway
D) Excessive sweep flow

Question 23

Which of the following patient has the best predicted survival following application of ECMO?

A) 5-year-old with liver failure
B) 6-year-old with pertussis
C) 1-year-old with respiratory syncytial virus
D) 10-year-old with sepsis

Question 24

What is considered the most concerning complication of ECMO in the newborn?

A) Disseminated intravascular coagulopathy
B) Pneumonia
C) Intracranial hemorrhage
D) Hemosiderosis

Question 25

What is the ECMO flow considered as minimal support?

A) 90 to 100 mL/Kg
B) 70 to 80 ml/kg
C) 40 to 50 mL/Kg
D) 20 to 30 mL/Kg

Question 26

Which of the following "resting ventilator settings" are typically used in ECMO for respiratory support?
I) PCV-SIMV
II) PIP 20 to 25 cm H₂O
III) PEEP 2 to 3 cm H₂O
IV) Frequency 12-15

A) I and III only
B) II and III only
C) I, II, and IV only
D) I, II, III, and IV