What is the maximum calculated flow for a baby on VA ECMO?
120 cc/kg/min
How long should it take to achieve full flow in VA ECMO?
20-30 min
When assessing a patient on VA ECMO, what is the best indicator of adequacy of oxygenation?
Pre-membrane oxygen saturation
Calculate oxygen content for a baby on VA ECMO
*Use the patient ABG
* CaO2 = (Hgb * Sat * 1.36) + (PaO2 x 0.0031)
* units are in mL O2 / 100 mL blood
Calculate oxygen delivery
DO2 = [ O2 content x (Pump flow cc/min / 100) ] / patient's weight in kg
Calculate oxygen consumption
VO2 = AVDO2 x flow
* Remember to divide by 100 for the mL O2 / 100 mL blood
* And divide by patient's weight to get mL O2/kg/min
What are the 4 ways to assess sufficiency of oxygenation in VV ECMO?
Arterial oxygen saturation
Pre-oxygenator PO2 or saturation
Cerebral venous oxygen saturation
Calculated oxygen consumption "across the oxygenator
What is the best indicator of adequacy of oxygenation in VV ECMO?
Patient arterial saturation
What are the 4 factors in recirculation in VV ECMO?
Pump flow
Catheter position
Cardiac output
Right atrial size (intravascular volume)
What are the benefits of the cephalad cannula in VV ECMO?
Increased oxygen adding capability
Increased venous return
Decompression of the cerebral circulation
Monitoring tool
What is the maximum calculated flow in VV ECMO?
150 cc/kg/min
During VV ECMO, how would you cause cephalad blood flow to increase?
Decrease the sweep gas flow (increase the pCO2)
What does it mean when the post-membrane PO2 and the patient PO2 are the same high value?
The patient has no native cardiac output
What is the difference between a roller head pump and a centrifugal pump?
A centrifugal pump is pre-load dependent and afterload senstive; a rollerhead pump is occlusive
What determines flow on a roller head pump?
RPM and size
What is the purpose of the Transonics Flow Probe?
Measure real flow
What is the Quadrox D oxygenator made of?
Polymethylpentene
Where do you measure a venous saturation on the ECMO circuit?
Pre-membrane
What are the two forms of cannulation used in Cardiac ECMO?
Peripheral and transthoracic
A patient just placed on VA ECMO has a LA pressure of 25 and echo shows atrial septal wall bowing. What does the patient need?
Atrial septostomy
The venous return (bladder) alarm suddenly alarms, and you have no flow. What do you do first?
Decrease the flow/RPM to try to get *some* flow
What are potential causes of venous return (bladder) alarms?
1. Cannula (kinked, malpositioned, dislodged)
2. Blood (hypovolemia, bleeding)
3. Hemo/pneumo
What is the proper clamping procedure for taking a patient off bypass?
Arterial - bridge - venous (A-B-V)
What is the amount of waste blood that should be sampled prior to any blood draw from the ECMO circuit?
0.8 mL
Which pressure sensor may alarm for clot formation within the membrane?
Pre-membrane
What are potential causes of a post-membrane alarm?
Patient moving
Hypertension
Arterial side clot formation
Baby breathing
What are potential causes of a venous return alarm?
Large diuresis
Change in pump flow
Change in cardiac output
What are the two emergencies when you should turn off the pump flow first, before taking a patient off bypass?
Air in
Blood out
The UF space of the CVVH circuit should be monitored for changes in...?
Color
The blood path of the CVVH circuit should be monitored for...?
Clots
Air
What is the first sign of hemofilter clotting/clogging in traditional CVVH?
Increased flow to the patient with increased pre/post pressures and decreased bladder pressure
What is the first sign of hemofilter clotting/clogging in Diapact CVVH?
Increased Pre-membrane pressure
What should you do in the event of a high pre-membrane pressure alarm with traditional CVVH in line?
Likely the blood path is clotted and the flow is increased to the patient, so decreased the flow back to the previous amount delivered to patient, and troubleshoot the filter
Ultrafiltrate is...?
The fluid and solutes which are removed via convection during CVVH
ACT's will typically (increase/decreased) during hemofiltration?
Decrease (CVVH clears heparin)
Describe how to change a pigtail catheter.
Prepare supplies, stop flow, clamp each side, remove and replace the pigtail, open the venous side, draw blood/remove air/flush, open arterial clamp, start flow
Describe how to move air from the venous limb/cannula
Guide it to the oxygenator
Why would you remove an arterial filter?
Clots, obstruction
When do you hand crank?
Power failure, pump failure
What is the calculated oxygen index?
MAP x FiO2 / PaO2
What are typical rest vent settings in a neonate?
20/10 x 10, 30%
What are steps to take in an adolescent on VV ECMO who has difficulty with lung recruitment?
Bronchoscopy
Prone position
What is the heparin loading dose for a neonate?
40 units/kg
When should you draw the initial ACT?
Right after starting flow
When do you start a heparin drip?
When ACT < 300
What is the heparin drip concentration?
50 units/mL
When should you give platelets when a patient is being placed on ECMO?
After cannulation and starting flow
As a general rule, sweep gas flow rate is (less/the same/more) than ECMO pump flow rate.
The same
What should be done to decrease the pCO2?
Increase the sweep gas flow rate
What is the purpose of the oxygen challenge test?
To determine readiness for a trial off ECMO (passing is generally a PaO2 > 300)
What is the usual weaning increment for a neonatal patient on VA ECMO?
How about for pediatrics?
10-20 cc/min
100-200 cc/min increments
What are some interventions that may be used to stop ongoing hemorrhage?
Personal pressure
Avitene
Amicar
Transexemic acid
Name 2 indications for the use of FFP
Low fibrinogen
Elevated PT
Describe the major difference between trialing off VA vs VV ECMO
Clamp vs Cap
An increase in blood flow and saturation measured in the cephalad catheter during a trial off may indicate...?
Increased pCO2
What is the minimum blood flow to consider when weaning off of VV ECMO for a neonate? VA ECMO for a neonate?
VV ECMO: 40-50
VA ECMO: 20
Name two reasons to electively discontinue ECMO.
Stroke
Bleed
Identification of lethal factors
What are the target platelet and fibrinogen levels for a neonatal ECMO patient who is actively bleeding?
Platelets: > 150
Fibrinogen: > 150
What is a typical ACT target range for a patient with active bleeding?
140-170 sec
How does a low ATIII level affect the ACT?
A low ATIII level decreases the ACT
Where is NovoSeven (Factor 7) given?
To the patient (ideally) or post-membrane
Why is it important to not give coagulation factors back to back or simultaneously?
To avoid clotting
What is Avitene?
Purified bovine collagen
What are the important factors to assure CO2 exchange in the membrane?
Surface area
Sweep gas flow rate
Blood flow rate
CO2 gradient
What are the important factors to assure O2 exchange in the membrane?
Blood flow, surface area, O2 gradient, FiO2
When de-airing a port it should be (open/closed) after priming?
Closed
An ACT of 120 could be caused by...?
Starting CVVH, diuresis
Platelets are given...where?
In the post-membrane sampling port
What should you monitor to ensure adequacy of hand cranking in VV ECMO?
Patient oxygen saturation
What are the clinical signs of pneumothorax in ECMO?
Decreased patient oxygen saturation, decreased pulse pressure, increase HR, decreased venous return (decreased bladder pressure)
How to determine if the oxygenator is working well?
Analyze pre- and post-membrane gases (CO2, O2)
Describe the use of cryo
For when fibrinogen (low) is not responsive to FFP or in case of massive hemorrhage
Cryo is given directly to the patient, and can cause ACT to (increase/decrease)
Decrease
How is cardiac ECMO flow determined?
Visualization by the surgeon, cardiac index
Pre- and post- oxygenator pressures slowly increasing is a sign of problem...where?
In the arterial filter
pRBCs are given...where?
Pre-membrane (ACT port)
Where is the highest pressure in ECMO?
Just pre-membrane
Where are the air traps in ECMO?
Bladder (or cone), oxygenator, arterial filter
What happens when you open the roller head pump cover?
The pump stops (for safety)
Pumps will servo-regulate based on which alarm?
Threshold alarm
What happens when a clamp is place on the circuit of a centrifugal pump?
The RPMs stay the same but the flow decreases
What are the flow alarms set to in centrifugal pumps?
+/- 500 cc/min
What is the negative pressure side of the circuit?
From the patient to after the cone or raceway
How do you manage a slowly decreasing flow in an awake patient on a centrifugal pump?
Increase the RPMs
What is the reason to give a heparin bolus at cannulation?
To avoid clotting in the cannulas
What is the concentration of heparin in a neonate? In a child?
50, 100
How long should it take to reach maximum calculated flow in VV ECMO?
10-15 min
How to manage a hep assay of 0.1?
Increase heparin
How can you improve oxygenation in VA ECMO?
Increase flow
Increase hemoglobin
How can you improve oxygenation in VV ECMO?
Minimuze recirculation (catheter position, cardiac output, RA volume, flow)
Where is the tip of the Avalon catheter?
IVC
What are the major factors affecting output of the roller head pump?
RPM's of the rollers
Size of the roller head, size of the tubing, occlusion, downstream resistance
Oxygen exchange in the membrane is dependent on...?
Blood flow rate
CO2 exchange in the membrane is dependent on...?
Sweep gas flow rate
Gas diffusion gradient
How to calculate oxygen delivery from the pump?
Use the post-membrane blood gas
Heparin requires...? to work
ATIII
What is the starting dose for a heparin drip?
25 u/kg/hr
What is the major function of aminocaproic acid (Amicar)?
Prevent lysis of pre-existing clots
What is the calculated flow in cardiac ECMO?
~200cc/kg/min over 5 min per surgeon request