General Questions 2 Flashcards
Fluid removed during hemofiltration
Occurs due to pressure gradients
Heparin dosages may need to be altered when CVVH is added in the system because
The hemodiafilter absorbs all the heparin
The following are signs and symptoms of oxygenator failure
Increased pre membrane pressure, decreased oxygen and CO2 transfer, hematuria, blood leak from the gas egress
ECMO improves oxygen delivery by which mechanism
-Improving oxygen content through stabilization of hemoglobin saturations -improving oxygen content by taking over at least 60% of the blood flow through a functioning membrane lung, away from the sick native lung
-stabilzing oxygen delivery by taking over at least 60% of the cardiac output through the ECMO pump
Membrane failure can be characterized by a raising pump CO2 level because of the following
- changes in blood flow patterns caused by clot formation
- changes in sweep gas flow patterns caused by clot formation
- Alteration in membrane surface area caused by fibrin formation
- changes in oxygen concentration due to fibrin formation
Another ultimate goal of ECLS
To maximize oxygen delivery
What supplies do you take from the cannulation cart for an adult being cannulated for VA ECMO
Dilators (pikA, sorin dilators) venous and Arterial cannulas, reperfusion cannula (7” tubing and double male adapter, may need micro puncture introducer set), sterile instruments, typically size 0 suture (silk or prolene)
What supplies do you take from the cannulation cart for an adult being cannulated for VV ECMO
Dilators (venous dilators only), venous cannulas, sterile instruments, sutures
What is a reperfusion cannula? When is it used and why?
Low limb extremity to prevent ischemia. Only used for VV ECMO.
Define Cardiac Output
Amount of blood pumped by the heart in L/min
Define Cardiac index
CO/BSA = CI
Hemodynamic parameter that relates to the cardiac output from the left ventricle in one minute to the BSA
Define BSA
Body surface area
CO = HR x SV
For native cardiac function
CI = CO/BSA = SV x HR/BSA
CO = CI x BSA
Used to assess our ECMO flow
Define viscosity
How thick the blood is
How does viscosity affect ECMO flow
If the blood is thicker, it can decrease flows
Define Afterload
The amount of resistance that the heart has to overcome to open the aortic valve. On ECMO, the Afterload is the patient’s blood pressure or cannula size resistance
Define Preload
Volume of blood in the ventricle & your end diastolic pressure
Explain what increased Preload does to ECMO flow
It allows you to be able to flow more (negative pressure becomes less negative). Would not limit your ability to flow
Explain what decreased Preload does to the ECMO
On ECMO, Preload is determined by the amount of volume in the patient and can decrease flows if Preload is decreased
Explain how increased Afterload affects ECMO. Describe what you would see on the pressure monitor for the patient and what the cardiohelp would read
It would decrease your flows. The Arterial pressure would increase
Explain how decreased Afterload affects ECMO
It would increase your flows
What is the initial bolus of heparin for a 3.5 kg infant?
100 IU (bolus dose) x 3.5
350 IU