REVIEW OF CPB Flashcards
Pre-Bypass PROCESS
Review the patient chart.
Calculate/ determine the necessary blood flow
Determine proper cannulas required for procedure
Calculate drug doses
Calculate predicted hematocrit
Discuss with surgeon Aware of predicted hct Plan for blood product usage
WHAT IS Pre-Bypass Checklist
Checklist that is completed prior to handing up the lines (most of it)
Usually has a component to complete once lines are up at the field just prior to initiation of bypass.
Patient prebyass
Chart reviewed
Procedure verified
Sterility
Components checked for package integrity/ expiration date
Heat exchanger(s) leak tested
pump
Speed controls operational
Roller heads smooth and quiet
Occlusions set
Flow meter in correct direction/ calibrated
Flow rate indicator correct for patient and tubing size
Holders secure
elctrical
Power cords securely connected
Gas Supply
Gas line securely connected Blender functional Hoses leak-free Gas exhaust is unobstructed
Lines/Pump Tubing
Connections secure Tubing direction traced and correct No kinks noted One way valve(s) in correct direction Debubbled/leak-free Patency of arterial line/ cannula verified
Cardioplegia
olution(s) checked System debubbled/ leak-free
Safety Mechanisms
Alarms operational and engaged Arterial filter/ bubble trap debubbled Cardiotomy reservoir vented
Monitoring
Temperature probes in place and calibrated Pump pressure monitors calibrated In-line and/or online sensors calibrated Oxygen analyzer calibrated
Temperature control
Water source connected and functional
supplies
Tubing clamps available
Drugs available and properly labeled Solutions available Blood available Sampling syringes/laboratory tubes available
Anticoagulation
eparin time and dose verified Anticoagulation tested and reported
back up
Hand cranks available
Emergency lighting available Duplicate circuit components available
Preparing to Initiate – Handing up lines
Hand up lines Prime was recirculating warm. Arterial AND Venous Lines clamped Lines handed up
Surgeon/ Assistant/ Scrub Tech will ask to divide the lines. Make sure the arterial and venous lines are in fact clamped!! Will remove the pre-bypass filter
Preparing to Initiate - Heparin
Heparin is given
Loding dose usually 300units/kg given via central line
3-5 minutes later draw an ACT Goal of 480 seconds for initiation of bypass Suckers may be turned on once ACT reaches 2x baseline
Cannulation
Once heparin is in, surgeon will put in purse string sutures
Cannulate De-air arterial cannula and clamp the cannula Bring up arterial line to the cannula Will ask to “come forward”/ “roll up”/ “trickle flow”… Turn on arterial pump SLOWLY!!
Will make a wet-wet connection to the arterial cannula Check for air/bubbles Surgeon will remove clamp on arterial cannula
Check for pulsations Make sure there is adequate line pressure, and adequate
pulsations May be asked to do a test transfusion
Make sure the cannula is in fact in the aorta and not in a false lumen/ misplaced.
If pressure rises greatly during test transfusion Check cannula placement! Check cannula position
Cannulation Venous cannula will be placed
Connected to venous line
Retrograde cardioplegia cannula placed
Now all lines should be placed, we should be ready to go on bypass.
ACT should be complete by this time
Immediately pre-bypass
Double check you’re ready!! Everything’s clamped that should be clamped. Last chance to change anything Last chance to check/tighten any and all connections FiO2 is preset CDI is ready to be turned on Timers are ready to be turned on Heater-cooler is set appropriately
Initiation of Bypass
Surgeon will instruct to “go on bypass”/ “let’s go on” Repeat command – LOUD!!! “Going on bypass” Thengoon
Start arterial pump first Give a little preload Start slow, don’t just hit the patient with 5 liters right away!!
Remove the clamp from the venous line Watch your level Make sure it rises
Keepturninguparterialpumpuntilyoureachfullflow Meanwhile… Openshunts Turn on gas flow
Start your timers Announce “On bypass at _______”
Gettofullflow Most places announce when full flow is obtained (“At full flow!”) Anesthesia stops ventilating
Whew… we’re on! NOW WHAT?!
Do Checks/Scan What are we flowing? Arterial Line Pressure? Oxygen started? Arterial sat coming up? SaO2 / SvO2 normal? Patient blood pressure normal? Temperature – time too cool? Once you’re happy and stable…
Turn on Anesthetic Gas (Vaporizer)
Get ready for AoXC placement Make sure CPG line is filled / clear of bubbles to the table Cool to desired systemic temperature
When you’re settled, draw ACT Never want to be caught behind with heparinization
Cross Clamp Placement
Once you’re cool enough, and surgeon is ready Surgeon will instruct “Flow Down” Repeat command: “Flow Down” Do the action – turn your flow down
Confirm the action: “Flow is down” AoXC on
Listen for the clicks of the clamp Once the AoXC has been placed, the surgeon will tell you “Cross clamp on, come back up on flow”.
Repeat command : “Cross clamp on, coming up on flow” Come up on flow gradually Watch line pressures
Cardioplegia: Abbreviated Version
After the AoXC is on, Cardioplegia will be given. Surgeon will instruct, “Start Cardioplegia” Repeat command “Starting Cardioplegia” Start cardioplegia
Watch delivery pressures Notify surgeon of flow and pressures Give antegrade and retrograde doses
Run the Case
Manage Volume/ Fluid Balance Blood products
Hemoconcentration Manage Anticoagulation Manage Hypothermia Manage Blood Gases (Acid/Base Balance) Management of Myocardial Protection
What Does “Adequacy of Perfusion” Mean?
Keep the patient safe!!!!! DO NO HARM
Supply the metabolic need of each tissue according to its need
Respiratory support / status Hemodynamic support / status Acid-base status Anesthetic support / status - Cerebral / myocardial protection
Adequacy of Perfusion
Determinants:
Maintain calculated flow rates Mean arterial pressure ~80-85 mmHg
Better neurological outcomes
SVO2 > 70%
Urinary output on bypass should be between 0.5 to 1 mls / kg / hr
Acid-Base status does not indicate metabolic acidosis Level of anesthesia (fast tracking)
Paralyzed, proper level of sedation
Hemodynamic Support
Normothermia range of 80-100 mmHg
necessary for proper organ function Decreased perfusion pressures ~50-60 mmHg
cerebral injury / kidney function reduced
Increased perfusion pressures > 100 mmHg increased intracranial pressures excessive blood return to heart fluid shifts create edema
increased SVR may decrease tissue perfusion
Flow Rates
Can be calculated two ways: body wt. (mls / min / kg) cardiac index (L / min / m2)
Average flow at normothermia (37oC) Adult Pediatric Neonate
adult:60 to 70 2.2 to 2.6
ped: 80 to 100 2.4 to 2.8
neo:120 to 150 mls/min/kg 3.0 to 3.4 L/min/m2
Preparation for Termination
Surgical correction is complete
Should be in the process of rewarming
Some cross clamp drugs should be given usually lidocaine, mannitol and magnesium sulfate
Surgeon will instruct “Flow down” Repeat command: “Flow down” Confirm action: “Flow is down” Surgeon will remove the AoXC Surgeon will let you know “Cross clamp is off”
May or may not instruct “Flow back up”
Confirm: “Cross clamp off at _____. Coming back up on flow”
Come back up on flow gradually Watch pressures
Temporary pacemaker is placed Usually
Final Checks before coming off
Should do an ABG close to AoXC removal Make sure EKG is acceptable Make sure Hct is acceptable to come off bypass
Make sure potassium is acceptable Make sure it’s in the normal range Will drop about 1.0mEq/L in the immediate post CPB period.
Check vents to see if any are still on Make sure anesthesia is ventillating the patient Make sure the PA Catheter is in the proper postion Make sure the bed is level and the transducers zeroed
coming off
Partially clamp the venous line
Watch filling pressures (CVP/PA)
Watch level
Have a hand on the arterial pump head knob
When filling pressures reach the target number, turn the pump down and maintain that filling pressure
Maintain that volume in the reservoir
When instructed, take a bigger bite of tubing on the venous line
Maintain the filling pressures Turn down the pump again Maintain
Continue to fill the patient
Come down on flow until you are off bypass
Off bypass! Turn off shunts (purge line, mannifold(s)) Clamp your arterial line Gas flow off Vaporizer off Timers stopped CDI off
Another approach to coming off
You’ll also see this variation of weaning from bypass.
Surgeon: “Come down to 1⁄2 flow and stay there”
What do you do? Clamp the venous line partially Fill patient!!! Come down on flow slowly to desired filling pressure # Adjust clamp on venous line accordinly.
once off bypass
Once you’re off, make the announcement
“OFF BYPASS @ ________”
Make sure everyone in the room is aware that you are no longer supporting the patient
Be prepared to transfuse residual pump blood via arterial cannula if needed
Be prepared to chase the circuit
“chasing” – transfuse most of the pump blood in the reservoir. Add crystalloid to the reservoir. This crystalloid will keep the circuit primed while displacing all the good pump blood back to the patient.
post bypass
Protamine given
PUMP SUCKERS OFF!!!
Once Protamine is in/started and patient is stable, surgeon will decannulate
Process pump blood Cell saver
Hemobag/ hemoconcentrator Restock
Post CPB ABG/ACT
Clean up Take lines from the table Dispose of pump
