Mod2: CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT

Question 1

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

When CPB is initiated, why is ventilation is stopped?

Answer 1

Pulmonary blood flow ceases

This is a critical time to talk with the perfusionist

Question 2

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

prior to discontinuing ventilation, It’s imperative to ensure that

Answer 2

full pump flow has been established

Until left ventricular volume reaches a critically low level, ventricular ejection continues

Question 3

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

Prematurely stopping ventilation can cause

Answer 3

Right to left Shunting of

the remaining pulmonary blood flow,

causing hypoxemia

Question 4

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

Upon initiation of bypass, there may be some initial hypotension that occur, why?

Answer 4

Reduced blood viscosity,

secondary to the hemodilution, and also

Dilution of circulating catecholamines

Question 5

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

BP should be controlled by vasopressors that can be given by either

Answer 5

the anesthesia provider, or

by the perfusionist

It’s best a this point to have an open dialogue with the perfusionist regarding BP support

Question 6

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

You should also know your institution policy regarding administration of drugs while on pump; why?

Answer 6

Some institutions will have the drugs only given by the perfusionist

While others will have drugs given by both anesthesia and perfusion

Question 7

On bypass, MAP will be determined by

Answer 7

pump flow rate and

systemic vascular resistance

So at a constant SVR, the MAP is proportional to pump flow

MAP = Pump flow x SVR

Question 8

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

The ideal flow is

Answer 8

2-2.5 L/min/m²

(50-60 ml/kg/min)

Question 9

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

The ideal Map is

Answer 9

50-80mmHg

With higher perfusions being for pts with renal disease or carotid artery disease

Higher (70-90 mmHg) if patient had carotid artery stenosis or renal insufficiency

Question 10

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

Hypertension is considered to be pressures above

Answer 10

100 mmHg

Question 11

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

Pressures above 150 are associated with

Answer 11

Aortic dissection, and

Cerebral hemorrhage

Question 12

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

If pt is hypertensive while on pump, the perfusionist can

Answer 12

Increase the volatile anesthetic

Decrease pump flow (short-term fix), or

Give a vasodilator (e.g., NTG)

Question 13

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT​}

Arterial Hypotension or Decreases peripheral perfusion (systemic pressures) can be caused by?

Answer 13

Inadequate venous return, d/t

• cannula too small, kinked, bleeding*
• Low pump flow*
• Poor occlusion*
• Kinked arterial cannula*
• Reduced vascular tone*
• Having the table too low*

^{(remember the venous reservoir if filled by gravity, so if the bed is too low, this could cause in decrease in venous return)}

Question 14

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

Treatment for Arterial Hypotension or Decreases peripheral perfusion (systemic pressures) includes?

Answer 14

​Increase volume

Increase pump flows

Vasopressors

Question 15

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

Arterial Hypertension can be caused by

Answer 15

Light anesthesia

Response to hypothermia

_{But also}

• High pump flows*
• Arterial cannula misdirection*
• Vasoconstrictors*

Question 16

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

Treatment for Arterial Hypertension is to:

Answer 16

Decrease pump flow

Increase anesthetic depth

Make sure there are no background vasopressor running

Vasodilators

Narcotics

Question 17

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

T/F: With the initiation of bypass, you must also assess the field, patient, and communicate with perfusion to ensure adequate pump pressures

Answer 17

True

Question 18

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

With the initiation of bypass Assess patient/field for how long?

Answer 18

30-60 seconds after CPB initiated

Question 19

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

With the initiation of bypass Assess pupils for correct cannula placement by looking for

Answer 19

unilateral dilation/conjunctival chemosis

Question 20

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

With the initiation of bypass Asses face for correct cannula placement by looking for or at:

Answer 20

Symmetry

Temperature

Edema

Question 21

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

With the initiation of bypass, palpation of carotid pulses will reveal thrills only; why?

Answer 21

Non-pulsatile flow

Question 22

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

Upon initiation of bypass, when will you check ACT, ABG, and other lab values?

Answer 22

Immediately, then

every 20-30 minutes

Question 23

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

With the initiation of bypass, Excessive decreases in MAP or persistent pump alarms can be indicative of:

Answer 23

Malpositionned cannula

Question 24

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

Upon initiation of bypass and because of pt’s positioning, it may be difficult to do a physical assessment. What could indicate a malpositionned cannula?

Answer 24

Unilateral dilation,

Face color or symmetry

Increases in CVP

Question 25

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

After bypass is initiated, what happens to coronary and systemic circulation after the Aortic Cross-clamping is placed in the ascending aorta?

Answer 25

Aortic Cross-clamping separates coronary perfusion from systemic circulation

This causes cessation of coronary perfusion

Prevents blood regurgitation through aortic valve

Question 26

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

After bypass initiation & Aortic Cross-clamping, what happens next?

Answer 26

Cardioplegia administered

Question 27

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

After bypass initiation & Aortic Cross-clamping, Cardioplegia administered. What’s an important consideration in pts with aortic insufficiency?

Answer 27

The cardiac protection provided by antegrade cardioplegia may not provide sufficient protection to the heart

Retrograde cardioplegia would also likely be used

Question 28

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

How is Cardioplegia administered?

Answer 28

Given every 15-20 minutes

Question 29

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

T/F: When Cardioplegia is administered, Aortic insufficiency may reduce cardiac protection

Answer 29

True

Antegrade cardioplegia must be combined with Retrogade cardioplegia in Aortic insufficiency

Question 30

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

T/F: During bypass and depending on the institution, the anesthesia provider doesn’t have much responsibility in regards to maintaining hemodynamics

Answer 30

True

The perfusionist will be the primary monitor of pump flow and MAP and treating them accordingly

Question 31

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

During bypass time, while it isn’t our responsibility per se to manage hemodynamics, we should stay vigilant to:

Answer 31

MAPs,

especially if they are consistently low or high

Because the perfusionist may need support in managing them in the form of either a vasopressor infusion, or narcotics, benzos and muscle relaxants

Question 32

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

During bypass time, we will also collaborate with the perfusionist to make sure that arterial blood gas values are within normal ranges. Why is this important?

Answer 32

CO2 can be reduced by increasing the fresh gas flow on the bypass machine

Question 33

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

During bypass time, we will also monitoring urine output, ensuring that it stays at a minimun of?

Answer 33

0.5 ml/kg/hr

Question 34

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

In general, bypass time is the time used to prepare for:

Answer 34

Weaning and coming off pump

So ensuring that all iV push drugs are refilled,

Infusions are primed and ready to go,

Charting is kept up to date,and

Any other preparatory work that’s needed

Question 35

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

During bypass time, assess for adequate depth of anesthesia by monitoring for:

Answer 35

Shivering

Breathing

Question 36

_{CARDIOPULMONARY BYPASS PERIOD MONITORING AND MANAGEMENT}

During bypass time, Assess temperature for adequate systemic hypothermia by monitoring for:

Answer 36

Core vs Shell temperature

Question 37

_{WEANING FROM BYPASS}

Prior to cardiopulmonary bypass being discontinued, patient must be rewarmed. Deciding the appropriate time to rewarm is important. Why is that?

Answer 37

Adequate time must be given to the process

Rewarming too fast can have a negative effect, including neurologic complications

Question 38

_{WEANING FROM BYPASS}

Prior to cardiopulmonary bypass being discontinued, Air must be evacuated from the heart and any bypass grafts. Why is that important?

Answer 38

To reduce the chance of entry into systemic circulation

Especially during valvular repair surgeries, where the heart is actually openned

Question 39

_{WEANING FROM BYPASS}

Air going down into the coronary arteries can also cause:

Answer 39

Dysrhythmias

Question 40

_{WEANING FROM BYPASS}

Prior to cardiopulmonary bypass being discontinued, Air must be evacuated from the heart and any bypass grafts. Which imaging technique can assist with this?

Answer 40

TEE

Heart allowed to beat after air removed

Question 41

_{WEANING FROM BYPASS}

Prior to cardiopulmonary bypass being discontinued, the aortic cross-clamp must be removed from the aorta. Why?

Answer 41

So that blood has a clear path from the left side of the heart into systemic circulation

Question 42

_{WEANING FROM BYPASS}

Prior to cardiopulmonary bypass being discontinued, lung ventilation must be resumed. When?

Answer 42

When pulmonary blood flow commences

Ventilation will also aid in air evacuation

Question 43

_{WEANING FROM BYPASS}

Prior to cardiopulmonary bypass being discontinued, and while lung ventilation is resumed, what would be the benefit of using Valsalva maneuver?

Answer 43

Removes air from lungs

Aids in filling cardiac Chambers

Recruits atelectatic alveoli

Question 44

_{WEANING FROM BYPASS - REWARMING}

Rewarming must occur gradually. The gradient between arterial outlet and venous inflow should be no more than?

Answer 44

10° C

Question 45

_{WEANING FROM BYPASS - REWARMING}

During rewarming, the gradient between arterial outlet and venous inflow should be no more than 10° C. Why is that crucial?

Answer 45

Prevents cerebral overheating

Prevent gas bubble (gasious emboli) formation.

Gasious emboli start to form because the gas solubitlity will decrease with increase temeperatures

Question 46

_{WEANING FROM BYPASS - REWARMING}

During rewarming, why should surgical teams limit arterial outlet blood temperatures to less than 37 degrees C?

Answer 46

To avoid cerebral hyperthermia

Research has also notes that arterial outlet blood temperatures underestimate cerebral temperature

Limit arterial outlet blood temperatures to less than 37 C

Question 47

_{WEANING FROM BYPASS - REWARMING}

What happens if patient temperature not adequate prior to conduction?

Answer 47

Fibrillation can occur

Question 48

_{WEANING FROM BYPASS - REWARMING}

The rewarming phase is the most critical time for AWARENESS/RECALL. Why is that?

Answer 48

Potentiation of anesthetic effect due to hypothermia dissipates

Question 49

_{WEANING FROM BYPASS - REWARMING}

How should AWARENESS/RECALL be prevented?

Answer 49

Administer/increase anesthetic depth

Inhalational agents beneficial if fast tracking planned

Supplement muscle relaxation, narcotics, and benzodiazepines

Question 50

_{PREPARATION OF SEPARATION FROM BYPASS}

As temperature is corrected, the surgeon will:

Answer 50

Remove the aortic cross clamp and

Allow the heart to begin beating

Question 51

_{PREPARATION OF SEPARATION FROM BYPASS}

Once the aortic cross clamp is removed and the heart begins beating this is the time to oberve the heart directly by looking at the operating field, assessing its:

Answer 51

Contractility, rate and volume as the heart begins to beat

Question 52

_{PREPARATION OF SEPARATION FROM BYPASS}

Once the aortic cross clamp is removed and the heart begins beating, the surgeon will then request that the perfusionist allows the heart to:

Answer 52

Begin to fill

Perfusionist starts to give/take 50 – 100 ml increments of perfusate

The anesthesiologist assess the heart on the TEE

Question 53

_{PREPARATION OF SEPARATION FROM BYPASS}

What should be monitored while the heart is filling?

Answer 53

Filling pressures

Ventricular distention

Blood pressure

Question 54

_{PREPARATION OF SEPARATION FROM BYPASS}

What should be done if heart appears to not be able to handle the volume?

Answer 54

Inotropic support, with

Epinephrine, Dobutamine

Question 55

_{PREPARATION OF SEPARATION FROM BYPASS}

Which arrythmia is commonly seen after removal of the aortic cross clamp?

Answer 55

Ventricula Fibrillation

Question 56

_{PREPARATION OF SEPARATION FROM BYPASS}

What’s the pharmacologic treat for VF noted rafter removal of the aortic cross clamp?

Answer 56

Lidocaine 100 mg,

Magnesium 2-4 mg

Question 57

_{PREPARATION OF SEPARATION FROM BYPASS}

What’s the treatment for persistent VF noted rafter removal of the aortic cross clamp despite pharmacologic treatment?

Answer 57

Defibrillation with internal pads at 10-30 J

Question 58

_{PREPARATION OF SEPARATION FROM BYPASS}

Now we are almost prepared to fully disconnect from the CPB machine. There are a few mnemonics for weaning from bypass machine, but they pretty much all have the same preparatory steps.

Describe the Romanoff & Royster “CVP” mnemonic for weaning from CPB:

Answer 58

_{Romanoff & Royster “CVP” mnemonic for weaning from CPB}

Note that it includes every step that can possibly occur from the time that the pt is weaned from bypass to transport to the ICU

Question 59

_{PREPARATION OF SEPARATION FROM BYPASS}

What are the key components to cover prior to coming off bypass?

Answer 59

Temperature

Must be normothermic (36-37 C)

Rate/Rhythm

Normal (70-90) - Slow rate treated with pacemaker

Cardioversion for SVT

Defibrillation for arrhythmias

Inhalation

Ventilation and inhalational agents and gas flows on

Filling pressures

Acceptable - Inotropic agents on if needed

Laboratory results

ACT, ABG, HCT, Glucose, Potassium

All WNL, especially K+

Question 60

_{PREPARATION OF SEPARATION FROM BYPASS}

What’s a benefit of knowing potential pt’s profiles you may see while attempting to wean off bypass?

Answer 60

Can help you determine appropriate treatment depending on the clinical picture

(See table attached)

Question 61

_{PREPARATION OF SEPARATION FROM BYPASS}

Both systemic BP and PA pressures shoud increase or decrease at the same time. If PA pressures increase and systemic BP decreases, that’s representative of?

Answer 61

LV failure

Question 62

_{DISCONTINUATION OF BYPASS}

If the heart is able to handle the volume that’s given, the perfusionist will

Answer 62

Begin to decrease the pumps flows and

Allow the heart to fully resume cardiac output

• _{Decrease venous return to pump by gradual/incremental occlusion of the venous cannula}*
• _{CPB circuit starts directing more volume to heart and lungs}*

Question 63

_{DISCONTINUATION OF BYPASS}

T/F: The bypass flows will gradually decrease until the pump is completely off

Answer 63

True

Bypass flow is initially decreased by 50%

Question 64

_{DISCONTINUATION OF BYPASS}

Ongoing evaluation cardiac function will occur by

Answer 64

Direct visualization of heart filling and contractility

TEE

Hemodynamics

Question 65

_{DISCONTINUATION OF BYPASS}

In adjusting blood pressure, what must be considered first?

Answer 65

Remember volume from CPB machine can be given back to patient

Optimizing preload is a goal

Question 66

_{DISCONTINUATION OF BYPASS}

After safely weaned off bypass and Once the surgeon and anesthesia provider are satisfied, what happens next

Answer 66

Venous Decannulation

Venous cannula will be clamped and removed

Venous line removed 1st

Blood in the venous system will be drained by gravity into the venous reservoir, and then transfused via the aortic cannula

Question 67

_{DISCONTINUATION OF BYPASS}

Commonly seen arrythmia during decannulation:

Answer 67

Atrial/junctional rhythm

Disappear when cannula is out

Question 68

_{DISCONTINUATION OF BYPASS}

After venous decannulation, why does the Arterial cannula remain?

Answer 68

For continued transfusion of pump contents

Question 69

_{DISCONTINUATION OF BYPASS}

After Venous Decannulation and Once all blood in the reservoir is transfused, Drop SBP less than 100 mmHg again or MAP less than 60mmHg. Why?

Answer 69

To allow for the Aortic/Arterial cannula to be removed

Aortic/Arterial Decannulation

Question 70

_{DISCONTINUATION OF BYPASS}

After Aortic/Arterial Decannulation, Heparin reversed by protamine; at which Dose?

Answer 70

1 mg of Protamine per 100 units of heparin

given SLOWLY through peripheral site

Question 71

_{DISCONTINUATION OF BYPASS}

After Aortic/Arterial Decannulation and Heparin reversal by protamine, when should a repeat ACT be obtained?

Answer 71

Repeat ACT 3-5 minutes after administration

Assess surgical field for bleeding

Question 72

_{POST CARDIOPULMONARY BYPASS - PROTAMINE}

Mechanism of action:

Answer 72

Positively-charged protein molecule derived from salmon sperm

Binds the negatively charged heparin AND inactivates anticoagulant effect

Question 73

_{POST CARDIOPULMONARY BYPASS - PROTAMINE}

Why should Protamine be administered slowly?

Answer 73

Because its administration causes

Histamine release by lungs

Which results in vasodilation & hypotension

Question 74

_{POST CARDIOPULMONARY BYPASS - PROTAMINE}

Anaphylactic/anaphylactoid reaction that follows its administration during bypass surgery is well known

Manifested as:

Answer 74

IGE mediated venodilation: ↓cardiac filling pressures,

↓ SVR = hypotension

↑Pulmonary vascular resistance (↑PIP)

Question 75

_{POST CARDIOPULMONARY BYPASS​ - PROTAMINE}

Population at greatest risk of allergic reaction from Protamine due to antibodies include?

Answer 75

Presensitization from prior administration

^{(Prior cardiac surgery/catheterization)}

Previous hemodialysis

NPH insulin

Vasectomy

Fish allergy

Question 76

_{POST CARDIOPULMONARY BYPASS}

After bypass, the assessment of adequate control of bleeding should continual; Paying close attention to

Answer 76

Chest tube volumes & Hemodynamics

Question 77

_{POST CARDIOPULMONARY BYPASS}

Whys is Chest closure an important phase for vigilance for new ischemia for the anesthesia provider?

Answer 77

Increase in intra-mediastinal pressure could cause

↓systemic venous return leading to transient ↓BP

Potential kinking or occlusion of new graphs

Question 78

_{POST CARDIOPULMONARY BYPASS}

Why must anesthesia pay close attention to the EKG during Chest closure?

Answer 78

To make sure No new ischemia forms

Question 79

_{POST CARDIOPULMONARY BYPASS}

Why is a post closure TEE needed?

Answer 79

To make sure that there is no changes observed

Question 80

_{POST CARDIOPULMONARY BYPASS}

Transport to SICU when? Accompanied with what supplies?

Answer 80

When hemodynamically stable

Accompanied with Lifepak, Ambu bag with 100% O2, emergency drugs

Question 81

_{FAILURE TO WEAN FROM BYPASS}

Common causes for failing to wean from bypass include

Answer 81

Left ventricular dysfunction

Right ventricular dysfunction

^{(Nitric oxide, Hyperventilation)}

Unrecognized ischemia

Valvular dysfunction

Question 82

_{FAILURE TO WEAN FROM BYPASS}

In cases of “failing to wean from bypass” where the pt is relatively hemodynamically stable, which can be started for support?

Answer 82

Inotropic agents

(Epi, Dopamine, Dobutamine)

Question 83

_{FAILURE TO WEAN FROM BYPASS}

In cases of “failing to wean from bypass” where the pt is relatively hemodynamically stable, and the pt is unresponsive to (Epi, Dopamine, Dobutamine), which drug could be added?

Answer 83

Milrinone

Question 84

_{FAILURE TO WEAN FROM BYPASS}

In cases of “failing to wean from bypass”, the surgeon may elect to resume full bypass while trouble shooting the problem occurs. Which drug should you remember to redose in this situation?

Answer 84

Heparin

Followed by rechecking ACT, and ABG for lab irregularities

Question 85

_{FAILURE TO WEAN FROM BYPASS}

In cases of “failing to wean from bypass”, which mechanical circulatory device might the surgeon opt to place while the pt is rested on bypass?

Answer 85

Intra-aortic balloon pump counterpulsation (IABP)

Question 86

_{FAILURE TO WEAN FROM BYPASS - IABP}

Describe how the IABP works?

Answer 86

The IABP Assist a beating/ejecting heart

It’s a synchronized counter pulsation

Does not pump blood, but rather

Augments diastolic BP and coronary blood flow after closure of the aortic valve

Question 87

_{FAILURE TO WEAN FROM BYPASS - IABP}

How is Diastolic augmentation acheived?

Answer 87

Balloon infaltes during Diastole, just after the dicrotic notch

↑AoDP = ↑coronary perfusion pressure

Enhances forward flow distally

Question 88

_{FAILURE TO WEAN FROM BYPASS - IABP}

Balloon is deflated during

Answer 88

Systole, resulting in

Afterload reduction

LV ejects against a ↓ systemic diastolic pressure

Question 89

_{FAILURE TO WEAN FROM BYPASS - IABP}

T/F: IABP is the ONLY method that ↓MVO2 & ↑myocardial O2 supply

Answer 89

True

Question 90

_{FAILURE TO WEAN FROM BYPASS - IABP}

Where is the IABP inserted? Where are its proximal and distal tips positioned?

Answer 90

Inserted into femoral artery

Guided to the correct position using the TEE

Distal tip: Below L subclavian artery

Proximal tip: Rests above renal arteries

The anesthesiologist will tell the surgeon when the balloon is in the correct position

Question 91

_{FAILURE TO WEAN FROM BYPASS - IABP}

To acheive successful counter pulsation, the balloon triggering must be timed to the pt’s

Answer 91

Cardiac cycle

This can be done by using either the pt’s EKG, the arterial wave form, or the intrinsic pump rate

Question 92

_{FAILURE TO WEAN FROM BYPASS - IABP}

Usually triggering of the balloon occurs with which EKG wave?

Answer 92

R-wave

Question 93

_{INTRAAORTIC BALLOON PUMP}

Typically after surgery, the IABP is initiated with an Assist ratio of

Answer 93

1:1

Question 94

_{INTRAAORTIC BALLOON PUMP}

As the pt’s cardiac function improves, he will be weaned from the pump; decreasing the ratio to

Answer 94

1:2, 1:3 ….

Question 95

_{INTRAAORTIC BALLOON PUMP}

Complications:

Answer 95

Arterial obstruction

Aortic perforation/dissection

Balloon rupture

Displacement of the balloon pump, occluding the subclavian artery or renal arteries

Ischemia distal to site of balloon insertion

Thrombosis

Platelet destruction/thrombocytopenia

Question 96

_{POST CARDIOPULMONARY BYPASS}

Often post-bypass Complications include

Answer 96

Post bypass bleeding

Persistent oozing is not uncommon following heparin reversal

Question 97

_{POST CARDIOPULMONARY BYPASS}

Typical causes of oozing is following heparin reversal

Answer 97

Inadequate surgical hemostasis

Reduced platelet count function

Insufficient dose of protamine

Dilutional coagulopathies

Heparin rebound

Question 98

_{POST CARDIOPULMONARY BYPASS​}

Bring backs (reexploration) within 24 hr d/t

Answer 98

Persistent bleeding

Excessive blood loss

Unexplained poor CO

Cardiac tamponade

Question 99

P_{OST CARDIOPULMONARY BYPASS​}

What percentage of of cardiac cases require postop reexploration, usually within 24 hr?

Answer 99

4-10%

Question 100

_{CARDIAC TAMPONADE}

When does it occur?

Answer 100

When is increase in fluid in the pericardial sac

Normally houses about 15-30mL of fluid

Question 101

_{CARDIAC TAMPONADE}

The increase in fluid causes an impairment in

Answer 101

Diastolic filling of the ventricle

Question 102

_{CARDIAC TAMPONADE}

Why is CO decreased?

Answer 102

Due to decreased stroke volume

Question 103

_{CARDIAC TAMPONADE}

How is CVP affected by cardiac tamponade?

Answer 103

Increased CVP

Question 104

_{CARDIAC TAMPONADE}

In response to decreased Diastolic filling of the ventricle, the circulation will increase systemic pressures and pulmonary venous pressures to

Answer 104

Prevent collapse of the cardiac chamber

This result in an Equalization of diastolic pressures throughout the heart

RAP = RVEDP = LAP = LVEDP

Question 105

_{CARDIAC TAMPONADE}

Why is the y descent abolished on the CVP waveform during cardiac tamponade?

Answer 105

Because the y descent correlates with the opening od the tricupsid valve and filling of the ventricle

But since there is an impairement in atrial emptying and diastolic filling, the y wave disapears

Question 106

_{CARDIAC TAMPONADE}

Reflexive sympathetic activation accompany cardiac tamponade?

Answer 106

Increased HR and contractility to maintain CO

Increased SVR to support BP

Question 107

_{CARDIAC TAMPONADE}

Why do pts in cardiac tamponade have a fast HR? Why shouldn’t you slow it down?

Answer 107

SINCE SV IS FIXED, CARDIAC OUTPUT BECOMES DEPENDENT ON HR

SO THESE PATIENTS WILL HAVE A fast HR

DON’T SLOW IT DOWN! YOU WILL DRASTICALLY REDUCE their CO

Question 108

_{CARDIAC TAMPONADE - Clinical Presentation}

CARDIAC TAMPONADE can either be chronic or acute

When associated with cardiac surgery, it is Acute. What’s its clinical presentation?

Answer 108

Sudden decrease in BP

Tachycardia

Tachypnea

Question 109

_{CARDIAC TAMPONADE - Clinical Presentation}

Besides Hypotension, Tachycardia and Tachypnea, what are other clinical signs of cardiac tamponade?

Answer 109

Beck’s triad

^{Low BP, JVD, muffled heart sounds}

Orthopnea

Narrowed pulse pressure

Question 110

_{CARDIAC TAMPONADE - Clinical Presentation}

Pulsus paradoxus is very similar to “Systolic pressure variation”. What causes it?

Answer 110

Occurs as a result of accumulation of fluid to the point where the pericardium can no longer distend

This is also known as “ventricular interdependence”

Ventricular interdependence during ventilation, when volume increases on one side of the heart, it also decreases on the other side

So what occurs during inhalation is that it causes a 10mmHg or more drop in systolic BP

Cyclic inspiratory decrease in SBP > 10mmHg with inspiration

Question 111

_{CARDIAC TAMPONADE - Clinical Presentation}

Electrical alternans can be seen with cardiac tamponade. What is it?

Answer 111

It’s the Cyclic alteration in magnitude of P wave, QRS, and T wave as a result of a fluid filled cavity

Question 112

_{CARDIAC TAMPONADE - Clinical Presentation}

In cardiac tamponade, TEE is invaluable in diagnosing?

Answer 112

Diastolic compression or collapse of RA and RV

Leftward displacement of ventricular septum

Left sided collapse rarely seen d/t thickness of LV and posterior position of LA unless effusion very large

Question 113

_{CARDIAC TAMPONADE - Clinical Presentation}

On TEE, interventricular septum flattening could be seen as:

Answer 113

RV compressing, LV filling

Question 114

_{CARDIAC TAMPONADE - Clinical Presentation}

T/F: Collapse of LA occurs with large effusions only

Answer 114

True

Question 115

_{CARDIAC TAMPONADE - Anesthetic Considerations}

How is pericardial effusion evacuated In pts with severe hemodynamic compromise?

Answer 115

Bedside => Pericardiocentesis/xiphoid drainage

OR =>Pericardial window or Re-exploration

Re-exploration is the primary option in the immediate post op phase

Reopen median sternotomy for post-bypass patients

Question 116

_{CARDIAC TAMPONADE - Anesthetic Considerations}

What’s the “rule of tumb” in the management of cardiac tamponade?

Answer 116

Fast, Forward, and Tight/Full

Maintain a high sympathetic tone until tamponade relieved

Optimize preload

Question 117

_{CARDIAC TAMPONADE - Anesthetic Considerations}

What should you avoid in the he management of cardiac tamponade?

Answer 117

Anything that will reduce venous return and ultimately CO

Avoid induction phase because it can precipitate severe hypotension/cardiac arrest

Avoid Bradycardia and vasodilators

Avoid Positive pressure ventilation if possible

Avoid Large tidal volumes, coughing, straining

Avoid Increased SVR

Question 118

_{CARDIAC TAMPONADE - Anesthetic Considerations}

T/F: Typically, as seen in the immediate post op phase, they may still be intubated, and the induction phase can precipitate severe hypotension/cardiac arrest

Answer 118

True

Use a slow inhalation induction technique in these pts, with added vasopressors

Question 119

_{CARDIAC TAMPONADE - Anesthetic Considerations}

Keep tidal volume to a minimum and compensate for the reduced tidal volume by:

Answer 119

Increasing the respiratory rate

Question 120

_{CARDIAC TAMPONADE - Anesthetic Considerations}

Which drug should you use as temporary inotrope and and for chronotropy?

Answer 120

Epinephrine (5-10ug)