ECMO Flashcards
(183 cards)
1
Q
Venous blood is drained via a cannula from what location(s) of the patient body?
A
Right Internal Jugular (RIJ)
Superior Vena Cava (SVC)/Right Atrium/Inferior Vena Cava (IVC)
2
Q
Veno-Arterial ECMO oxygenated blood is returned to the patient via a cannula in what location(s) of the body?
A
Aorta (neck/central)
Femoral Artery (peripheral)
Carotid Artery (neonates)
3
Q
Veno-Venous ECMO oxygenated blood is returned via a cannula in what location of the body?
A
RA/Tricuspid Valve
4
Q
BASIC path of blood flow via ECMO?
A
- Patients blood is drained via Venous Drainage Cannula
- Venous line to the Pump
- Pump to the Oxygenator
- Oxygenator to the Return Cannula
5
Q
The Centrifugal pump is preload … and afterload …
A
dependent
sensitive
6
Q
What is the “heart” of the ECMO circuit?
A
the pump
7
Q
How does the Centrifugal pump pull-in blood?
A
fluid/blood is pulled into the center of the vortex (pump inlet) and pushed toward the outer edge of the path of rotation (pump outlet)
8
Q
Patients mush have sufficient … to support desired …
A
preload volume
flow
9
Q
A decrease in volume will decrease
A
flow; “chatter”
10
Q
Anything that increases resistance in the circuit will decrease …
A
flow; including pts SVR on V-A ECMO
11
Q
Pump flow is controlled by:
A
RPMs
12
Q
To increase flow, what do you increase?
A
RPMs
13
Q
Are Centrifugal pump flow pulsatile?
A
NO, they are NON-pulsatile
14
Q
What is the oxygenator made out of?
A
Polymethylpentene (PMP) - gas permeable fibers
15
Q
Where does blood flow in the oxygenator?
A
around the outside of the fibers
16
Q
In the oxygenator, gas exchange occurs by:
A
true diffusion (surface area, concentration, pressure gradients)
17
Q
What controls ECMO PO2?
A
FiO2 on blender
18
Q
What controls ECMO PCO2?
A
Sweep Gas (flow meter); can also affect PO2
19
Q
The heater-cooler is incorporated where?
A
the oxygenator; water flows around one side and blood on the other side
20
Q
Cardio Quip heater-cooler allows for:
A
temperature management (normo- or hypothermia)
21
Q
What is the ECMO Circuit made of?
A
PVC tubing and heparin-coated to help prevent thrombosis (bioline)
22
Q
What are the three locations we can cannulate for ECMO?
A
Central
Neck (neonates/small peds)
Femoral (peds/adults)
23
Q
Femoral cannulation allows:
A
rapid cannulation in an emergency
24
Q
Femoral cannulation may compete with:
A
native cardiac output; retrograde flow
25
Femoral cannulation requires what to be placed?
re-perfusion line to prevent lower limb ischemia
26
Neck cannulation placement for V-A ECMO:
RIJ vein and R carotid artery
27
Veno-venous ECMO is ONLY for:
respiratory support; NO cardiac support
28
Veno-venous ECMO draws blood from ... and returns the blood ...: (dual-lumen tube - Avalon)
SVC + IVC
directly to the tricuspid valve
29
Veno-venous ECMO, other cannulation site(s):
- femoral vein - femoral vein
access cannula is low (sub-diaphragmatic)
return cannula is in the Right Atrium
- Femoral vein - RIJ
access cannula is low
return cannula is in RIJ
30
Indication of ECMO for Adults:
ARDS
Pneumonia
Pneumonitis
Status Asthmaticus
Trauma/Pulmonary Contusion
Post-cardiotomy shock
Bridge to/from heart transplant/MCS
hypothermic cardiac arrest
cardiogenic shock
cardiomyopathy
myocarditis
Massive MI
Massive PE
Cardiac Arrest
31
Indications for ECMO Pediatric:
more often resp. indications; viral PNA, asthma
cardiogenic shock
myocarditis
32
Indications for ECMO Neonates:
PPHN
Diaphragmatic Hernia
Meconium Aspiration
Asphyxia
Hypoxic-Ischemic Encephalopathy (HIE)
33
When do we place a patient on ECMO?
- deteriorating cardiopulmonary status despite cardiovascular/respiratory support
1.) 3+ high dose inotropic and/or vasopressor agents, IABP, Impella
2.) Hypotension, low CO, worsening acidosis, increasing lactate, decreased U/O
3.) High Vent Support (PIP, PEEP, Paw, FiO2, HFOV/HFJV, iNO)
4.) Hypoxemia, hypercarbia, acidosis, worsening CXR
34
VIS - Vasoactive and Inotropes Score for ECMO consideration
>61
35
Cardiac Index of pt that requires ECMO
<2.0 L/min/m2 ( cardiac output / BSA )
36
P/F Ratio potentially requiring ECMO
<50 x3 hrs or <80 x6 hrs
37
Ventilation Index potentially requiring ECMO
>50 x4 hrs
38
Oxygenation Index potentially requiring ECMO
>/= 40
39
Murray Score potentially requiring ECMO
(P/F Ratio, Compliance, PEEP, CXR)
>3
40
When NOT to place pt on ECMO
- Mechanical Ventilation >7 days w/ high settings
- End-Stage COPD
- Metastatic CA
- Multi-System Organ Failure (MSOF)
- Severe Sepsis
- CNS Injury ( traumatic, ischemic, embolic, hemorrhagic)
- Age >70
- Active Hemorrhage
- Inability to withstand Anti-coagulation
- Lack of informed consent/experienced staff/proper equipment
41
When NOT to place Neonates on ECMO
<34 weeks
<2 kgs
Intracranial Hemorrhage
Lethal Chromosomal Anomaly
42
ECMO is NOT a ... and only buys ...
cure
time for healing or medical therapies
43
Goal of ECMO is to maintain
homeostasis
44
Veno-arterial ECMO supports CO with
pump flow
45
ECMO "full support" in adults: pediatrics:
Cardiac Index 2-2.5L/min/m2 (V-A); 3-4 L/min (V-V), 4-5 L/min (V-A)
100-150 ml/kg (V-A); 80 ml/kg (V-V)
46
MAP goal on ECMO
CVP goal on ECMO
LAP goal on ECMO
35-70 (age dependent)
>10
<10
47
Venous Gas PO2, PCO2, pH, Sat normal:
35-50
40-55
7.30-7.45
65-75
48
ECMO Gas PO2, PCO2, pH, Sat normal:
200-300
35-45
7.35-7.45
100
49
Arterial Gas PO2, PCO2, pH, Sat normal:
50-150
35-50
7.30-7.45
>90
50
Typical heparin infusion
20-40 units/kg/hr
51
Direct Thrombin Inhibitor
Bivalirudin
52
Renal function; normal MAP with pulsatile flow to maintain
urine output
53
Venous cannula malposition may cause hepatic congestion so watch for climbing
CVP with decreasing flow
54
How often should you change cannula site dressing?
every 3 days or PRN
55
Secure ECMO cannulas to .. and circuit tubing to ...:
the patient
the bed
56
Cardiohelp has an integrated
- centrifugal pump and oxygenator
- pressure sensors (pre-pump, post-pump, post-oxygenator)
- temp. sensor (arterial) and optical measurement via infra-red sensor (venous)
57
Cardiohelp has 2 different HLS sizes:
5.0 (max flow)
7.0 (max flow)
58
Venous Cannula/Pre-Pump creates what kind of pressure?
NEGATIVE
59
Post-Pump/Arterial Cannula creates what kind of pressure?
POSITIVE
60
Delta P on Cardiohelp
Pressure difference between Post-Pump/Pre-Oxygenator Internal Pressure and Post-Oxygenator Arterial Pressure
61
Part on cardiohelp
Post-Oxygenator Arterial Pressure
62
Pint on cardiohelp
Post-Pump, Pre-Oxygenator Internal Pressure
63
Pven on cardiohelp
Pre-Pump Venous Pressure
64
The Cardiohelp can detect and react to ...
retrograde flow of blood; back-flow protection - activates zero flow mode automatically to prevent backflow
65
How long does the battery last on Cardiohelp?
90 mins
66
Cardiohelp screen automatically locks after how long?
3 mins of inactivity
67
Adult Quadrox-I recommended flow range
.5-7 l/min
68
Small Adult Quadrox-I recommended flow range
.5-5 L/min
69
Pediatric Quadrox-I max flow
2.8 L/min
70
Neonatal Quadrox-I max flow
1.5 L/min
71
Nautilus Oxygenators have what type of flow
transverse flow path with circular profile
72
Transverse Flow in Nautilus Oxygenators minimize
surface contact area while achieviing a low side pressure drop
73
Circular profile in Nautilus Oxygenators eliminates
corners where low flow and stasis are known to occur; improvesw long term gas transfer
74
Nautilus Oxygenator recommended blood flow rate
0.5-7 L/min
75
CentriMag:
Typical RPM?
Typical flow?
Target ACT?
Target PTT?
Max Pump flow?
Max Pressure?
- 3000-4000
- 4-5 LPM
- 160-180 ses
- 50-60 secs
- 10 LPM
- 600 mmHg
76
A CentriMag (pump) requires a ...
motor; each primary console supports 1 CentriMag
77
If CentriMag RPMs are below 1000, what must happen?
outflow tubing must be clamped
78
Cardio Quip Normal Mode puts out how much wattage
1600w
79
Cardio Quip Low Mode puts out how much wattage
800w
80
Cardio Quip:
Water Min ... Max ...
Max flow rate
Temp. Control
1 gal (3.8L) ; 2.5 gal (9.5L)
20 lpm
0-42*
81
Spectrum Monitor; Transit time is the phase delay between
the pair of sensors measuring up stream transit time and down stream transit time
82
Spectrum Monitor;
Transit time decreases when
Transit time increases when
traveling down stream
traveling up stream
83
Spectrum Monitor; What does it mean if transit times are equal
blood flow is static
84
Spectrum Monitor; Emboli is measured by
detecting reduction in the ultrasonic signal strength
85
Spectrum Monitor; the level of emboli volume within the flowing blood will be dependent on
the level of signal reduction multiplied by the number of signal reduction events
86
Spectrum Monitor;
measures HCT
measures Hgb
15-50%
5-17%
87
Veno-Arterial ECMO used in
Veno-Venous ECMO used in
Veno-Arterial/Veno ECMO used in
pts with failing hearts
pts with failing lungs
pts with failing heart and lungs; mixing can occur distal to coronaries and lung support is required to perfuse the heart
88
Veno-Arterial ECMO sites:
Femoral Vein drainage and Femoral Artery Return
Femoral Vein drainage and Axillary Artery Return
Right Atrium or Femoral Vein drainage and Aorta Return
89
Veno-Arterial/Veno ECMO Site:
femoral cannulation with an additional cannula inserted into the Right Atrium and connected to the arterial limb of the circuit
90
Veno-Venous ECMO sites:
Internal Jugular w/ Avalon (dual lumen)
Femoral Veins
Internal Jugular and Femoral Vein
91
What do we bolus a patient with before placing ECMO?
10,000 units of heparin; 5,000 units of heparin if pt is known to be on heparin
92
ECMO Start:
Initial RPM start
Initial FiO2
Initial Sweep
1700 RPMs
80-100%
2-3
93
Indications for ECMO in Neonates
Meconium Aspiration
CDH (Congenital Diaphragmatic Hernia)
RDS (Respiratory Distress Syndrom)
Sepsis/PNA
PPHN (Persistant Pulmonary Hypertension)
Air Leak Syndrome
Congenital Airway Abnormalities
Pre-Post Cardiac Surgery
94
Physiologic Criteria for ECMO in Neonates
- Reversible cardiorespiratory failure
- Oxygenation Index (OI) >40 for >/= 4 hrs
- OI >20 despite max therapy >/= 24 hrs or decompensation
- Severe hypoxic respiratory failure w/ acute decompensation (PaO2 <40)
- Progressive respiratory failure and/or pulmonary hypertension with evidence of right ventricular dysfunction or continued high inotropic requirement
95
Indications for ECMO in Pediatrics
- Post Cardiac Surgery
- Pulmonary Vasoactive Crisis
- Cardiomyopathy due to renal failure, myocarditis, burns
- Acute viral respiratory infections
- Severe Asthma
- Bridge to transplant (CF pts)
96
Absolute Contraindications for ECMO in Neonates/Pediatrics
- Catastrophic brain injury without prospect for recovery
- untreatable metastatic malignancy
- End-stage organ failure without prospect for recovery or transplant
97
Relative Contraindications for EMCO in Neonates/Pediatrics
- Severe multi-organ failure
- Severe trauma with coagulopathy and hemorrhage
- Severe immunocompromised
- Extremes of age
- Severe aortic regurgitation
- Unfavorable vasculature such as aortic dissection
98
Exclusion Criteria for Neonates
Gestational Age < 32-34 weeks
Weight < 2 kgs
ICH grade greater than 2
Coagulopathy
Lethal Congenital anomalies
Congenital heart disease rule out
Duration on vent; 10-14 days
99
Exclusion Criteria for Pediatrics
Severe CNS injury
Malignancy
Severe immunodeficiency
Advanced liver failure
Pulmonary Fibrosis
Active Hemorrhage
Prolonged Ventilation
100
VV ECMO supplies high oxygenated blood to the:
pulmonary circulation and myocardium
101
VV ECMO in neonates spares the
carotid artery and may result in shorter cannulation time
102
Neonates: On VV ECMO, the pulmonary bed serves as a
filter for any emboli that may occur
103
Neonates: VA ECMO requires
ligation of the carotid artery
104
Neonates: VA ECMO provides what kind of blood flow to the body
non-pulsatile
105
Neonates: VA ECMO supplies less oxygenated blood to the
myocardium
106
Neonates: VA ECMO risks what in the circuit?
thrombus that will embolize to the systemic circulation
107
Neonatal: On VA ECMO, they have an increase risk of developing what?
neurological complications/developments
108
Technical Complications of ECMO in Neonates
bleeding
rupture IVC
vein retraction
rupture atrium
kinking of cannulas
too far in/not in far enough
hepatic perfusion
dislodgement
limb ischemia
"north-south" syndrome
109
Flow (Q)
volume - time (ml/min or L/min) movement of a fluid or gas
110
Velocity (V)
speed at which fluid moves in a given direction
111
Resistance (R)
internal or external forces which oppose flow
112
Pressure (P)
force exerted causing fluid movement
113
Pressure Gradient (P1-P2)
difference in pressure between two points
114
Viscosity (h)
thickness of fluid
115
Fluid flow varies directly with
velocity and cross sectional area of its conduit
116
A larger diameter conduit allows
the same flow at a reduced velocity
117
A smaller diameter conduit requires
an increased fluid velocity to maintain the same flow rate
118
Velocity changes are achieved by
changes in pressure
119
To achieve the same flow in a smaller conduit, what must happen
velocity must be higher
120
A smaller diameter conduit creates/needs:
higher velocity (requires higher pressure)
higher resistance
lower flow
lower volume
121
Fluid ALWAYS moves from:
highest to lowest pressure; path of least resistance
122
Flow varies directly with ... and varies inversely with ...
pressure gradient
resistance
123
Two types of flow:
laminar flow
turbulent flow
124
Things that cause resistance:
conduit length (L)
fluid viscosity (h)
conduit radius
125
Resistance varies directly with ... and ... and inversely with ...
conduit length ; fluid viscosity
radius to the 4th power
126
2 ways to Resist
Series
Parallel
127
Increase in viscosity:
- lower temperature
- higher hematocrit
- higher density (very high platelets, WBC, protein count)
128
Poiseuille Law:
Flow varies directly with ... and ...
Flow varies inversely with ... and ...
1.) the pressure gradient (P1-P2) and vessel radius to the 4th power (r4)
2.) vessel length (L) and fluid viscosity (h)
129
Poiseuille; to increase flow
bigger pressure gradient
bigger diameter conduit (radius)
shorter length conduit
decrease fluid viscosity
130
Poiseuille; things that decrease flow
smaller pressure gradient
smaller diameter conduit (radius)
longer length conduit
increased fluid viscosity
131
Centrifugal pumps being afterload sensitive; increased resistance reduces flow with:
smaller tubing
smaller cannula
increased SVR
higher hematocrit
circuit geometry (twists, turns, kinks)
clot in oxygenator
132
To maintain flow when resistance increases:
increase pressure (increase pump RPMs)
133
A sudden change in flow at the same RPMs indicates:
a change in systemic resistance
134
Centrifugal pumps being pre-load dependent; flow will be reduced if:
- venous cannula or venous line has more resistance; cannula too small or cannula mal-positioned (cannula tip pushed against the vessel wall)
- low CVP (not enough blood volume)
135
Points of high resistance:
oxygenator
connectors
small diameter tubing segments
cannulas
kinks
clots
anything w/ a clamp
136
Fluid will always find take the path of least resistance such as:
shunts
open bridge
purge lines
leaks
137
Boyles Law
gas volume varies inversely with pressure; Increase pressure/Decrease volume - Decrease pressure/Increase Volume
138
Charles Law
gas volume varies directly with tempurate; Increase in temperature/Increase volume - Decrease in temperature/Decrease volume
139
Gay-Lussacs Law
gas pressure varies directly with temperature;
Increase pressure/Increase Temp - Decrease pressure/Increase Temp
140
Avogadros Law
equal volumes of all gases, at the same temperature and pressure, have the same number of molecules
141
Daltons Law
the total pressure exerted to equal to the sum of the partial pressure of the individual gases
142
The Ideal Gas Law
volume of a gas is directly proportional to the number of moles and temperature of a gas and inversely proportional to the gas pressure
143
Henrys Law of Solubility
amount of gas that dissolves in a liquid is directly proportional to the gas solubility coefficient, and the partial pressure of that gas in equilibrium with that liquid
144
Ficks Law of Diffusion
the rate of membrane diffusion varies directly with the surface area of the membrane and pressure gradient across the membrane nad varies indirectly with the membrane thickness
145
Oxygen Content (CaO2)
(Hgb x 1.34 x SaO2) + (PaO2 x .003)
146
Oxygen Delivery (DO2)
CaO2 x CO (or Q=flow rate)
147
Hemoglobin picks up and holds on to oxygen in the lungs and increase HbO2 (Oxy-Hemoglobin) affinity:
decrease in hydrogen (acid)
decrease in PCO2
decrease temperature
148
Hemoglobin unloads oxygen at the tissues and has a decreased in HbO2 affinity:
increase in hydrogen (acid)
increase PCO2
increase Temperature
149
Oxygen Consumption (VO2)
CO L/min x (CaO2 - CvO2)ml/L
150
O2 Extraction Ratio (O2ER)
O2ER normal or DO2:VO2 ratio
VO2/DO2 x 100
20-25% or 4-5:1
151
CO2 is transported as:
Dissolved CO2 in plasma - 5%
Bound to plasma proteins - 5%
Bound to Hemoglobin in RBC - 20%
Bicarbonate in Plasma - 70%
152
CO=
HR x Stroke Volume (mL/beat)
153
Stroke Volume depends on:
preload
contractility
afterload
154
Normal CO:
Adults
Neonates
60-70 mL/kg/min or 2.6-3.2 L/min/m2
150-200 mL/kg/min
155
Preload - how full is the heart/circulatory system?
CVP (central venous or right atrial pressure)
LAP (Left Atrial Presure) - PCWP (pulmonary capillary wedge pressure) or PAD (pulmonary artery diastolic pressure)
156
Afterload - how much resistance does the heart push againts?
SVR - systemic vascular resistance (LV)
PVR - pulmonary vascular resistance (RV)
157
Stroke Volume + afterload =
blood pressure (Arterial BP or PAP)
158
1. Normal PAP Systolic/Diastolic
2. Normal Right Atrium
3. Normal Right Ventricle
4. Normal Aorta Systolic/Diastolic
5. Normal Left Atrium
6. Normal Left Ventricle
7. Normal Pulmonary Artery Wedge Pressure
1. S: 15-25 mmHg, D: 8-15 mmHg
2. 0-8 mmHg
3. S: 15-25 mmHg, D: 0-8 mmHg
4. S: 110-130 mmHg, D: 70-80 mmHg
5. 4-12 mmHg
6. S: 110-130 mmHg, D: 4-12 mmHg
7. 8-12 mmHg
159
Frank Starling Law of the Heart
increased filling pressure stretches the heart and increases its force of contraction
160
Increasing the force of contraction expels more blood from the left ventricle so that ...
cardiac output increases when the preload increase
161
ECMO can augment, support, or replace all of the patients requirements for:
- Oxygenation in respiratory failure (O2 content)
- CO2 clearance in ventilatory/resp. failure (CO2 transport)
- Circulatory support in the acute heart failure or circulatory collapse (Cardiac Output and O2 Delivery)
162
Clotting Cascade:
Contact Activation/Intrinsic Pathway
- XII -> XIIa -> XI -> XIa -> IX -> IXa -> X -> Xa
- twelvE -> EleveN -> NinE -> eight -> Ten
163
Clotting Cascade:
Tissue Factor - Extrinsic Pathway
VII -> VIIa -> Xa
164
Clotting Cascade:
Common Pathway
X -> Xa -> Prothrombin (II) -> Thrombin (IIa) -> Fibrinogen (I) -> Fibrin (Ia)(binds platelets)
165
Clotting Cascade:
Clot formation
ADP/Thromboxane/Thrombin
Platelet --------^------>
Platelet Activation --(GP IIb/IIIa)--> Platelet Aggregation (platelet activation + fibrin (Ia)
166
Platelet activation occurs due to
thrombin generation
167
Thrombocytopenia occurs due to
increased platelet activation and aggregation
168
Factor XIIa reaches max concentration within ... of ECMO initiation
10 mins
169
Activation of the intrinsic and extrinsic pathways lead to activation of
Factor X
170
Thrombin:
increases expression of pro-inflammatory mediators causing neutrophil activation
induces endothelial cell production of platelet activating factor
171
Fibrin:
clot formation
172
Complement Activation elevate levels within ... of ECMO initiation
2 hours
173
Increase complement products contribute to
platelet activation and aggregation
174
Thrombin stimulates the release of
tissue plasminogen activator (t-PA)
175
t-PA converts plasminogen to
plasmin
176
Plasmin breaks down
fibrin (and fibrinogen) into fibrin degradation products; fibrinolysis
177
Unfractionated Heparin binds to:
anti-thrombin III (AT) and inactivates thrombin (factor IIa) and factor Xa; prevents conversion of fibrinogen to fibrin
178
Initiation of Heparin prior to cannulation:
Check aPTT every ... from bolus until aPTT ...
10,000 units
1 hr from 10,000 heparin bolus ; <80
179
Target aPTT on Bivalirudin
60-80 seconds
180
ACT goal
180-220 seconds
181
anti-Xa assay goal
0.3-.7 IU/ml
182
aPTT assay goal with Heparin
70-110 seconds correlates with anti-Xa 0.3-.7 IU/ml
MAX aPTT 150 seconds
183
