general hlm/ecc Flashcards
What is ECC?
describes the circulation of the blood outside of the body by means of a heat lung machine. the purpose is to replace the function of heat and lung outside of the body to allow special open heart surgery
Name the functional groups of ECC.
- tubic system
- pumps (art, vent, sucker, cardio)
- venous/cardiotomy reservoir
- oxygenator, heat exchanger
- arterial filter
- cannulas
Name the functional groups of an HLM.
- pumps
- mast system
- drivable rolls
- sensors
- gasblender
What monitor devices exist on an HLM?
- flow sensor
- pressure sensor
- temperatuer sensor
- level sensor
- bubble sensor
What is a line?
a blood leading tube, for example the arterial line transporting the oxygenated blood to the patients aortic cannula
How does the venous drainage work?
drainage from patient to reservoir is driven by gravity, therefore the reservoir should be situated below the patient.
for children, the resistance is often times to high to let the blood be drained by gravity alone. therefore, a low negative pressure is applied to suck the blood out of the vcs/i (centrifugal or air sucker at reservoir)
What is the venous clamp used for?
to control the flow from the patient to the reservoir
Which factors damage blood the most?
- shear stress
- foaming
- foreign surface contact
- pressure swings
- occlusion
- vacuum
What mechanism exist to avoid air?
- centrifugal pump
- open reservoir
- closed reservoir with purge line
- arterial filter
How does a blender work?
It’s a gas flow meter to mix the medical gases which are used to oxygenate the blood (like O2 – CO2 – air)
Explain the function of a prebypass filter.
is placed between the arterial and venous line of the heart lung machine before the connection with the patient. its purpose is to filter out production residues from the tubular system. pore with is 0.2 µm
Explain the function of the arterial filter.
Its main purpose is to filter out the air bubbles from arterial blood (using circular rotation through long way to get rid of the air bubbles).
The mesh width is 20 – 40 Micron (can’t be smaller other ways it will filter out the erythrocytes also)
What materials are used for the tubic system?
PVC or silicone (arterial line)
What problems arise with the use of soft PVC?
it is cheap and easily accessible but it contains softeners that can possibly migrate to the blood
What is a customer package?
every disposable component of the ECC in a complete package ready to be used. The composition can be chosen individually
