REVIEW OF CPB

Question 1

Pre-Bypass PROCESS

Answer 1

 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

Question 2

WHAT IS Pre-Bypass Checklist

Answer 2

 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.

Question 3

Patient prebyass

Answer 3

 Chart reviewed

 Procedure verified

Question 4

Sterility

Answer 4

 Components checked for package integrity/ expiration date

 Heat exchanger(s) leak tested

Question 5

pump

Answer 5

 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

Question 6

elctrical

Answer 6

Power cords securely connected

Question 7

Gas Supply

Answer 7

Gas line securely connected  Blender functional  Hoses leak-free  Gas exhaust is unobstructed

Question 8

Lines/Pump Tubing

Answer 8

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

Question 9

Cardioplegia

Answer 9

olution(s) checked  System debubbled/ leak-free

Question 10

Safety Mechanisms

Answer 10

Alarms operational and engaged  Arterial filter/ bubble trap debubbled  Cardiotomy reservoir vented

Question 11

Monitoring

Answer 11

Temperature probes in place and calibrated  Pump pressure monitors calibrated  In-line and/or online sensors calibrated  Oxygen analyzer calibrated

Question 12

Temperature control

Answer 12

Water source connected and functional

Question 13

supplies

Answer 13

 Tubing clamps available
 Drugs available and properly labeled  Solutions available  Blood available  Sampling syringes/laboratory tubes available

Question 14

Anticoagulation

Answer 14

eparin time and dose verified  Anticoagulation tested and reported

Question 15

back up

Answer 15

Hand cranks available

 Emergency lighting available  Duplicate circuit components available

Question 16

Preparing to Initiate – Handing up lines

Answer 16

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

Question 17

Preparing to Initiate - Heparin

Answer 17

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

Question 18

Cannulation

Answer 18

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

Question 19

Immediately pre-bypass

Answer 19

 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

Question 20

Initiation of Bypass

Answer 20

 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

Question 21

Whew… we’re on!  NOW WHAT?!

Answer 21

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

Question 22

Cross Clamp Placement

Answer 22

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

Question 23

Cardioplegia: Abbreviated Version

Answer 23

 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

Question 24

Run the Case

Answer 24

 Manage Volume/ Fluid Balance  Blood products
 Hemoconcentration  Manage Anticoagulation  Manage Hypothermia  Manage Blood Gases (Acid/Base Balance)  Management of Myocardial Protection

Question 25

What Does “Adequacy of Perfusion” Mean?

Answer 25

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

Question 26

Adequacy of Perfusion

Determinants:

Answer 26

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

Question 27

Hemodynamic Support

Answer 27

 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

Question 28

Flow Rates

Answer 28

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

Question 29

Preparation for Termination

Answer 29

 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

Question 30

Final Checks before coming off

Answer 30

 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

Question 31

coming off

Answer 31

 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

Question 32

Another approach to coming off

Answer 32

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.

Question 33

once off bypass

Answer 33

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.

Question 34

post bypass

Answer 34

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