Transcript CONDUCT OF PERFUSION - cardiac anesthesia basics

CONDUCT OF
PERFUSION
October 16, 2003
Brian Schwartz, CCP
PURPOSE OF CPB
• PROVIDE SURGEONS WITH A
MOTIONLESS AND BLOODLESS FIELD
• PROVIDE PROTECTION TO VITAL
ORGAN SYSTEMS
Your Objectives
• Understand the components of the CPB
circuit
• Understand the sequence for assembly of
the circuit
• Able to calculate the predicted hemoglobin
and hematocrit
• Understand the determinants of oxygen
consumption
Conduct of Perfusion
• Purpose of CPB: support patient’s
metabolic needs while providing a
motionless, bloodless cardiac surgical field
• Parameters that must be met:
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Proper flow rate
Oxygen delivery
Carbon dioxide removal
Anticoagulation
Temperature
Blood pressure
Blood recovery
Components of the CPB Circuit
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Oxygenator
Heat exchanger
Venous reservoir
Gas flow meter
Variety of pumps
Tubing
Cannulae
Hemoconcentrator
Alarms
Drugs
Assembly
• The set up is dependent upon:
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Procedure
Patient size
Surgeon’s preference
Perfusionist’s preference
CONDUCT OF PERFUSION
• WE ARE TALKING ABOUT OUR DUTIES
AND RESPONSIBILTIES PRE-OP,
INTRA-OP, AND POST-OPERATIVELY
THE PERFUSIONIST’S TIME LINE
• GET A HANDLE ON THE SCHEDULE
• REVIEW PATIENT’S CHART
• SELECTION OF DISPOSABLE
EQUIPMENT
• ASSEMBLE HLM
• PLUG IN POWER AND GAS LINES
• PLUG IN HEATER/COOLER (WATER
TEST)
Time Line (cont)
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CO2 flush the circuit
Prime the circuit
Test all occlusions
Check list
Perform all quality controls
ALWAYS BE PROPARED TO GO ON
CPB
TIME LINE (CONTINUED)
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PRIME CIRCUIT
PERFORM CHECK LIST
ADMINISTRATION OF HEPARIN
INITIATION OF CPB
TERMINATION OF CPB
ADMINISTRATION OF PROTAMINE
BREAKDOWN AND CLEANUP OF HLM
PRE-BYPASS CALCULATIONS
• PREDICTED HEMATOCRIT
– 70 X KG = TBV
– TBV X HCT = TRBC
– TBV + PRIME + ANES. DRIPS = TCBV
– TRBC/RCBV = DILUTIONAL HCT
PRE-BYPASS CALCULATIONS
• HCT IF SEQUESTERING BLOOD
– TRBC – { 500 cc x HCT } / TCBV – 500 cc
HEPARIN ADMINISTRATION
• DESCRIBED AS AN ANTICOAGULANT
• MUST FULLY ANTICOAGULATE
PATIENT
• SITE OF ACTION: ATlll AND INHIBITS
FACTORS IX AND XI OF THE CLOTTING
CASCADE
• GIVE 300-400 UNITS/KG
– IN RIGHT ATRIUM OR CENTRAL LINE
HEPARIN ( CONTINUED )
• HALF LIFE = 1-2 HOURS
• 3-5 MINUTES AFTER ADMINISTERING
TAKE AN ACT…..MUST BE >480
SECONDS
• SOME PATIENTS MAY BE HEPARIN
RESISTENT
– THEY ARE ATIII DEFICIENT
– GIVE FRESH FROZEN PLASMA
CANNULATION
• SURGEONS NOW PLACE THE
CANNULAE INTO THE HEART
• VENOUS CANNULAE
– IN RIGHT ATRIUM WITH 2 STAGE
– SINGLE STAGE IN THE IVC AND THE SVC
CANNULATION
• ARTERIAL CANNULAE
– AORTA OR FEMORAL ARTERY
• RETROGRADE CARDIOPLEGIA
• ANTEGRADE CARDIOPLEGIA
• VENT
PURPOSE OF VENT
• PLACED IN THE AORTIC ROOT OR IN
THE LEFT VENTRICLE
• USED TO PREVENT DISTENTION OF
THE HEART
• USE A ONE-WAY VALVE
INITIATION OF BYPASS
• SURGEONS READY TO BEGIN CPB.
THEY WILL TELL YOU TO “GO ON”
– ALWAYS REPEAT COMANDS BACK TO
AVOID MISTAKES
• PUT 02 ON 100%, SWEEP ON, REMOVE
ARTERIAL CLAMP, SLOWLY TURN
PUMP ON. CAREFULLY MONITOR
ARTERIAL LINE PRESSURE !!!!!!!!
BYPASS
• UNCLAMP VENOUS LINE AND
INCREASE FLOW TO YOUR 2.4 INDEX
• IF YOU SENSE A HIGH LINE PRESSURE
AS YOU INITIATE
BYPASS…IMMEDIATELY TERMINATE
BYPASS!!!!!!
CAUSES OF HIGH AORTIC LINE
PRESSURE
• KINK IN THE A-LINE
• CANNULAE IMPROPERLY POSTIONED
• CROSS-CLAMP TOO CLOSE TO
CANNULAE
• ARTERIAL CANNULAE TOO SMALL
• SYSTEMIC PRESSURE TOO HIGH
• AORTIC DISECTION
• ARTERIAL FILTER OBSTRUCTED
CAUSES OF POOR VENOUS
RETURN
• KINK IN VENOUS LINE OR CANNULA
• AIRLOCK
• OXYGENATOR IS NOT POSITIONED
LOW ENOUGH
• VENOUS CANNULA PLACED TO FAR
DOWN INTO THE CAVA
• VENOUS CANNULA FALLS OUT
CHATTERING
• A TERM USED IF THE HEART IS
COMPLETELY EMPTY AND YOU SEE THE
VENOUS LINE JUMPING AROURD
• CHATTERING IS CAUSED BY EXCESSIVE
NEGATIVE PRESSURE IN THE VENOUS LINE
CAUSING A SUCTION EFFECT….SIMPLY
PLACE A CLAMP (PARTIALLY) ON THE
VENOUS LINE TO REDUCE THE NEGATIVE
PRESSURE
SAFTEY CHECKS TO DO ON
BYPASS
• FLOWING AT PROPER RATE
• A-LINE PRESSURE IN NORMAL
• OXYGEN IS ON AND THAT ARTERIAL BLOOD
IS RED….COMPARE A/V LINES
• O2 SAT’S NORMAL
• MAP BETWEEN 50-70
• TEMP’S
• ACT>480
• MAKE SURE ALL SAFETY DEVICES ARE ON
MONITORING
• EKG
– WHILE THE CROSS-CLAMP IS ON THERE
SHOULD BE NO ACTIVITY
– WHEN CLAMP COMES OFF, BE ON THE LOOK
OUT FOR ST ELEVATIONS, V-TACH, AND V-FIB
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PA PRESSURES
CIRCUIT
OPERATING TEAM
KEEP COMMUNICATION OPEN
TRAFFIC AROUND PUMP
CHARTING
• VITAL SIGNS MUST BE TAKEN EVERY 15
MINUTES
• ACT’S MUST BE TAKEN EVERY 30 MIN
• BLOOD GASES MUST BE TAKEN EVERY 30
MINUTES OR AFTER CHANGES HAVE BEEN
MADE
– FIRST BLOOD GAS SHOULD BE TAKEN 5-10
MINUTES AFTER CPB
– DON’T FORGET TO GET A WARM GAS BEFORE
TERMINATING BYPASS
NORMAL ARTERIAL GAS
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pH: 7.35-7.45
p02: Greater than 100
02 Sat: 96-100%
K+: 3.5-5.3
BICARB: 22-28 MEQ/L
BE: -2.5 TO + 2.5
NORMAL VENOUS GAS
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pH: 7.35-7.39
P02: 38-42
02 Sat: 65-75%
pCO2: 44-48mmHG
Bicarb: 22-28 mmHG
BE: -2.5 to +2.5
Determine Oxygen Consumption
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Oxygen content=1.34 x Hb x Sat + .003xp2
Oxygen Capacity =1.34 x Hb + .003 x pO2
Oxygen Saturation = O2 content/ Capacity
Oxygen Consumption= aO2 content – vO2 content x
flow (L/min) X 10
CALCULATE AMOUNT OF
BICARB TO GIVE
1. WT (KG) X BASE DEFICIT X .3
2. EQUATION #1 DIVIDED BY 2 =
AMOUNT OF BICARB TO GIVE
EXAMPLE: 70 X 3 X .3 = 63
63 / 2 = 32 mEq
POST BYPASS
• MONITOR PATIENTS HEMODYNAMICS
• NEVER DISMANTLE PUMP UNTIL
CHEST IS CLOSED
• PROTAMINE
• MANY PATIENTS HAVE REACTION
• TURN OFF PUMP SUCKERS
• MONITOR PA AND MAP
PROTAMINE REACTIONS
• TYPE I
– SYSTEMIC HYPOTENSION
– REDUCED SVR
• TYPE II
– ANAPHYLACTIC REACTION RESULTING IN
HYPOTENSION, BRONCHOSPASM, AND EDEMA
• TYPE III
– CATASTROPHIC PULMONARY
VASOCONSTRICTION WITH INCREASED PA
PRESSURES, HYPOTENSION, DECREASED LA
PRESSURES, AND DILATED RIGHT VENTRICLE
CLEAN-UP
• SEND ALL BLOOD TO CELL SAVER
• DISMANTLE TUBING
• CLEAN UP PUMP FOR ANY BLOOD
STAINS
• PAPER WORK
• SET UP BACK UP PUMP
• SET UP BACK UP CELL SAVER