Circuits and Components

Question 1

What 3 pressures do you measure in an ECMO circuit

Answer 1

pre oxygenator pressure
post oxygenator pressure
venous inlet (negative pressure)

Question 2

better bladder – talk about it

Answer 2

the venous “reservoir” of an ECMO circuit
a ridged exterior tube with an inner cylastic membrane - outflow is connected to a roller pump, can keep the inner cylastic membrane expanded will create negative pressure sucking blood from the pts atrium (kinda like a centrifugal pump)
you keep a pressure manometer on that outer membrane, “bladder pressure (negative inlet pressure)” set the point to right before cavitation.

Question 3

how does drainage work with ECMO?

Answer 3

kinetic assisted venous drainage, siphoning it out

Question 4

what shunt may be in the ECMO circuit

Answer 4

an arterial venous shunt, with a CDI usually unit
arterial - high pressure
venous - low pressure

Question 5

Never use what kind of caps in an ECMO circuit?

Answer 5

vented caps for transducers, bc they can suck air into the circuit easily

Question 6

Where do you put heparin in, in an ECMO circuit?

Answer 6

pre oxygenator, to avoid clots in the oxygenator.
not before the centrifugal pump bc it can have too much negative pressure and suck in the whole syringe of heparin on accident
neonates - the majority of places still do heparinize for ECMO
use an ACT test 160-220sec

Question 7

What ACTs are you looking for on ECMO?

Answer 7

160 (180)-220 sec

Question 8

Where do you put the flow probe on an ECMO circuit?

Answer 8

After the bridge before the patient so you are totally sure that flow is going to the patient

Question 9

whats the protocol for the bridge in the ECMO circuit?

Answer 9

you keep it clamped the whole time you are on ECMO
who ever is sitting ECMO will have to unclamp and clamp the bridge every 7 minutes to ensure no clots are forming.

sometimes there is a bridge made with two male-male stopcocks filled with saline and you dont have to unclamp all the time. but if you want to test if the patient is ready to come off of ECMO you open them up.

Question 10

3 cannula selection types for ECMO?

Answer 10

Arterial
Venous
Dual Lumen (V-V Cannula)

Question 11

0-3 flow?

Answer 11

200 cc/kg

Question 12

3-10kg flow?

Answer 12

150 cc/kg

Question 13

10-15 kg flow?

Answer 13

125 cc/kg

Question 14

15-30 kg flow?

Answer 14

100 cc/kg

Question 15

> 30 kg flow?

Answer 15

75 cc/kg

Question 16

> 55 kg flow?

Answer 16

65 cc/kg

Question 17

Will you use vacuum is ECMO?

Answer 17

NO

Question 18

If you pressurize the VR in a normal CPB circuit with vacuum - what happens?

Answer 18

the venous line is the least compilable so if the VR is over pressurized the pressure will shoot everything right up the venous line directly into the RA
make sure the relief pop-off valve is OPEN

Question 19

V-A ECMO

Neonate cc/kg/min??

Answer 19

100-150 cc/kg/min

Question 20

V-A ECMO

Ped cc/kg/min?

Answer 20

75-100 cc/kg/min

Question 21

V-A ECMO

Adult cc/kg/min?

Answer 21

50-75 cc/kg/min

Question 22

V-V ECMO

Neonate cc/kg/min??

Answer 22

100-120 cc/kg/min

Question 23

V-V ECMO

Ped cc/kg/min?

Answer 23

90-100 cc/kg/min

Question 24

V-V ECMO

Adult cc/kg/min?

Answer 24

75-90 cc/kg/min

Question 25

Cannulation choices -- Flow with Pediatric is what related?

Answer 25

weight related (cc/kg) Have a large enough venous cannula to gravity drain the amount of blood flow that is required (but small enough to fit)

Question 26

Cannulation choices -- Flow with Adults is related to what?

Answer 26

usually indexed (L/min/m2) Have a large enough venous cannula to gravity drain the amount of blood flow that is required (but small enough to fit)

Question 27

Arterial ECMO cannulation aim? critical velocity of pressure drop????

Answer 27

Aim: utilize the smallest cannula w/ the highest flow rate Do NOT exceed pressure drop > 100 mmHg Critical velocity is reached when laminar flow becomes turbulent (Reynolds #) Higher pressures = higher sheer stress = hemolysis = bad

Question 28

Avalon V-V ECMO

Answer 28

MOST used cannula? 4-5 LPM 31 FRENCH

Question 29

Venous ECMO cannula aim? pressure drop?

Answer 29

Aim: drain the patient with the smallest cannula Be aware of the cannulation site Pressure drop is in the -30 to -40 range

Question 30

Veno-Arterial PEDS ECMO (V-A) cannulation sites?

Answer 30

Right Internal Jugular Vein | Right Common Carotid

Question 31

Veno-Venous PED ECMO (V-V) cannulation sites?

Answer 31

Internal Jugular Vein alone

Question 32

Veno-Arterial Adults ECMO (V-A) cannulation sites?

Answer 32

Femoral Venous | Femoral Arterial

Question 33

Veno-Venous Adults ECMO (V-V) cannulation sites?

Answer 33

Femoral Venous | Jugular Venous

Question 34

What is the tubing in an ECMO race way made of?

Answer 34

Super Tygon Tubing The race way is about 5 feet long so that you can walk the race every 5-7 days so the tubing in the raceway when it is getting worn out you can just move it down

Question 35

The Origen V-V Cannula | 12 Fr for children what wt?

Answer 35

2-5 Kg

Question 36

The Origen V-V Cannula | 15 Fr for children what wt?

Answer 36

4-8 Kg

Question 37

The Origen V-V Cannula | 18 Fr for children what wt?

Answer 37

7-12 Kg

Question 38

Veno-Venous ECMO | Venous blood is drained through what and arterialized blood returned where? (special kind of cannula)

Answer 38

through a single lumen of a double lumen cannula | Arterialized blood is returned via the other lumen

Question 39

V-V Canuula Size and ?Patient Weight Range ?F 2-5 kg ?F 4-8 kg ?F 7-12 kg

Answer 39

12F 15F 18F

Question 40

Poiseuille’s Law:

Answer 40

``` = ΔP x π r4/L x V x 8 ΔP:pressure difference or gradient r:radius of tube L:length of tube V: viscosity of the fluid 8:constant of proportionality *If you double the length, blood flow is cut in ½ *If you double the viscosity, blood flow is cut in half ```

Question 41

ECMO tubing material? standard sizes? how do the sizes come?

Answer 41

PVC or Silicone, Special tubing (Super Tygon) Standard sizes are ¼”, 3/8”, and ½” Durometer-measure of the hardness of a material. Hardness may be defined as a material's resistance to permanent indentation. Each has size x wall thickness (1/4” x 1/8” or ¼” x 3/32”)

Question 42

Super Tygon Special tubing is formulated to do what?

Answer 42

is formulated to withstand pump boot stress in roller pumps | Can walk the raceway every 7 days,Minimizes spalation

Question 43

``` Boot vs SV/Revolution 3/16” ?cc ¼” ?cc 3/8” ?cc ½” ?cc ```

Answer 43

``` 7cc (x100 = 700cc MAZ) 13cc (x100=1300cc MAX) 27cc (x100=cc MAX) 45cc (x100-cc MAX) * Do NOT exceed 100 rpm’s for maximum tubing flows ```

Question 44

Going on ECMO?

Answer 44

A-B-V | unclamp arterial, move it to the bridge, unclamp venous

Question 45

Coming off ECMO?

Answer 45

V-B-A (very bad accident) | clamp venous, unclamp bridge use that clamp to clamp the arterial line

Question 46

Kids can get inter-cranial bleeds when in what oxygen state?

Answer 46

hypoxic | acidosis ---> inter-cranial bleeding --->strokes

Question 47

Can any oxygenator work for ECMO?

Answer 47

Any oxygenator will suffice for off label use | Blood outside-Gas inside the fiber bundle

Question 48

``` Quadrox Adult Specifications BF rate? total prime volume? SA? material oxygen membrane? ```

Answer 48

0.5-7 LPM 250ml 1.8m2 polymethylpentene

Question 49

The ECMO bridge?

Answer 49

The bridge serves to prevent the ECMO circuit from being static when it is necessary to come off ECMO for a period of time Consider it an A-V shunt Can be done with 2 stopcocks and 1/8” tubing open when needed and reflush with saline you'll see-- No bridge ¼” and 3/8” bridge Luer lock 1/8” bridge

Question 50

ECMO monitoring?

Answer 50

Arterial Blood gases Venous Blood gases Venous Saturations Cerebral Oximetry

Question 51

NIRS on ECMO? | nanometers?

Answer 51

Near-infrared spectroscopy (NIRS) technology, such as that used in pulse oximetry, has been used and trusted in the world of medicine for decades. Near-infrared spectroscopy (NIRS) is a spectroscopic method that uses the near-infrared region of the electromagnetic spectrum (from about 800 nm to 2500 nm)