CV Module 4

Question 1

Cardiovascular Disease
- An estimated _______(1) American adults (1:3) have one or more types of cardiovascular disease
- _______(2) are > 65 years old
- Estimated _______(3) inpatient cardiovascular operations performed in the U.S.
- Data indicate that the lifetime risk for CVD after age 40 is _______(4) men and _______(5) women
- CVD kills twice as many women as _______(6) does!
- _______(7) > Caucasians
- Biologic systems and mechanistic pathways genetically associated with _______(8) adverse events

Answer 1

Answers:

1. 79,400,000
2. 37,500,000
3. 6,363,000
4. 2:3
5. 1:3
6. breast cancer
7. African Americans
8. perioperative

Question 2

Patient Assessment
- The anesthetic evaluation includes the cardiac history, particularly the cath report, thallium stress test, echo, and _______(1).
- Critical information includes left main disease or equivalent, poor distal targets, ejection fraction, _______(2), presence of aneurysm, pulmonary hypertension, valvular lesions, and congenital lesions.
- Ask your patient, “How is your angina manifested?” If a patient’s angina is experienced as shortness of breath, or nausea, or _______(3), you need to be able to link that symptom to possible myocardial ischemia.
- Limit the things that cause angina such as _______(4)
- Does the EKG reveal _______(5), conduction abnormalities?
- Concerns re: Cath report include an _______(6) > 18 mm Hg, EF < 4 or a CI < 2.0 L/min/m^2
- _______(7)
- Does the CXR reveal cardiomegaly, pulmonary congestion, pulmonary edema, pleural effusion and “Kerley B” lines (thin, linear pulmonary opacities caused by fluid or cellular infiltration into the interstitium of the lungs).

Answer 2

Answers:
1. ECG
2. LVEDP
3. heartburn
4. self-moving to OR table
5. ischemia/infarct
6. LVEDP
7. Patient is coming in compromised

Question 3

HTN
- DM
- CIGARETTE SMOKING – determine whether pulmonary HTN is due to primarily pulmonary or cardiac factors
◦ Are they even a good candidate for this procedure if they are still _______(1)?

CAROTID ARTERY DISEASE – may require higher systemic arterial pressures
- RENAL DYSFUNCTION – pre-existing renal insufficiency is the most common cause of postoperative renal failure
- Does the past medical history include COPD, TIA, stroke, cerebral vascular disease, renal disease (CRI is an _______(2) risk factor), and/or hepatic insufficiency.
- Is the COPD being treated?
- Does the patient have allergies?
- Has the patient previously received protamine during vascular or cardiac surgery? (Why is this _______(3)?)

Answer 3

Answers:
1. smoking
2. independent
3. important

Question 4

Findings Suggestive of Ventricular Dysfunction

• Tachycardia (severe CHF)
• Engorged neck veins
• Apical impulse displaced laterally
• S3 S4
• Rales
• Pitting edema
• Pulsatile liver (CHF, tricuspid regurgitation)
• Ascites

Patient Assessment - Blockers

• Look specifically for anti-_______(1) medications; consider the synergism between calcium channel and beta blockers.
• Patients should _______(2) their anti-anginal therapy throughout the hospitalization.
• If a patient is on a beta blocker, calcium channel blocker, nitrate, and/or ACE inhibitor, they should _______(3) that drug throughout the perioperative period.

Answer 4

Answers:
1. anginal
2. continue
3. continue

Question 5

Physical Assessment

• Airway
• BBS: wheezing? pneumonia? COPD?
• Cardiac: Do they have a murmur? Are they in failure?
• Abdomen: _______(1), obesity
• LABS: CBC, PLT, Lytes, BUN, CR, Glu, PT, PTT, PFA
• CXR: cardiomegaly? tumors? pleural effusions?
• ECG: critical information includes the presence of a LBBB. If a pulmonary artery catheter is planned, remember patients with ______(a) can develop third degree block with PA catheter placement.
  
  • What can _______(2) your PA Catheter?
  • How does LBBB _______(3) PA Catheter? It can turn into a complete block
• Have they had a recent MI? Do they have resting ischemia? Where are their ST-T changes?
• PFTs and ABGs: are they going to become a respiratory cripple?
  
  • Are they going to be _______(4) tracked? Aka Extubated within the first hour
• Height & Weight – drug calculations and hemodynamics
• Airway assessment
• Neck – landmarks for jugular vein cannulation; assess for bruits (carotid disease)
• Heart – murmurs?
  
  • S3 indicates _______(5)
  • S4 indicates _______(6)
  • “Click” indicates _______(7)
  • PMI heard laterally indicates _______(8)
  • Precordial heave, lift indicates _______(9), wall motion abnormal

Answer 5

Answers:
1. ascites
a. LBBB
2. effect
3. affect
4. fast
5. elevated LVEDP
6. decreased compliance
7. MVP prolapse
8. cardiomegaly
9. hypertrophy

Question 6

Patient Assessment

• Lungs – rales, rhonchi, wheezing
• Vasculature – peripheral pulses sites for venous and arterial access
• Take BP on both arms…Why?
  
  • Large difference in _______(1) indicates _______(2) disease
• Abdomen – pulsatile _______(3)?
• Extremities – peripheral _______(4)
• Nervous system – cognitive _______(5)?

Patient Interview

• Tell the patient about the a-line, the PA catheter, and post-op ventilation.
• Patients having cardiac surgery have serious and frequent complications including: MIs, CVAs, neuropsychiatric effects, transfusions, pneumonia and _______(6).

Answer 6

Answers:
1. pressure
2. more severe
3. liver
4. edema
5. deficits
6. death

Question 7

Pre-op Medications

• These patients are scared. They understand there is real risk with this surgery.
• They will become ischemic with stress.
  
  • At least ______(a) of the patients develop ischemic even with adequate premedication.
  • Consider oxygen administration.
  • Consider diazepam 10 mg po (one hour prior) or midazolam 2 – 5 mg iv in the holding area.
• Anxiolytics – midazolam 2-5 mg depending on age, level of consciousness, cardiovascular state and level of anxiety
• +/- Opioids (fentanyl 25-50 mcg)
• Frail patient with severe valvular dysfunction – ______(b) sedation
• ______(c) – use extreme caution with pre-medication.
• Barash with preop CPB
  
  • Contrary to common belief, there is a potential long-term benefit of ACE inhibitors provided that dosing is adjusted so that hypotension is _______(1).
  • On the other hand, the protracted hypotension encountered on bypass and associated with poor outcome has been associated with preoperative β-blockers or calcium channel blockers

Monitoring

• ______(d) – should be placed first according to _______(2)
• EKG- leads ______(e) (inferior leads & right coronary distribution)
• V4-V5 – anterior myocardium (left anterior descending)
• Lead I and aVL for the lateral LV myocardial walls (_______(3))
• Run a strip before induction, ST segment analysis

Answer 7

Answers:
a. 40%
b. lighter
c. Severe aortic stenosis
1. avoided
d. Pulse oximeter
2. barash
e. II, III and aVF
3. circ

Question 8

EKG Lead Placement

Monitoring

• Temperature – urinary bladder or PAC
• Arterial blood pressure – _____(a) arterial lines most common _______(1), brachial could be used (harvesting radials?)
• Site of surgery dictates placement of arterial line

Arterial Line

• Arterial line – ______(b) radial preferred for CABG. (Harvesting radial artery)
• However, with descending thoracic aorta, the _______(c) radial is used because the left subclavian artery may be included in the proximal aortic clamp.
  
  • (Note: following CPB, the radial artery pressure can be 30 mm Hg _______(2) than central aortic pressure (due to peripheral dilation or vasoconstriction); gradient in BP usually disappears within 45 minutes bypass separation.)
• Sudden or transduced BP may represent _______(3)
• Re-zero the transducer especially before separating from CPB
• Confirm patency of the catheter and transducer system
• Avoid potentially dangerous medication _______(4)

Answer 8

Answers:
a. radial
1. femoral
b. left
c. right
2. lower
3. error
4. errors

Question 9

CVP and PAC

• Central circulation access is mandatory for infusion of cardio active drugs
• Right atrial or CVP is critical whenever right ventricular dysfunction is suspected.
• Relationship between right atrial pressure and LV filling is less predictable, especially with pulmonary HTN or reduced LV compliance
• PAC – measurement of wedge – better index of LV filling, CO, calculation of stroke volume, SVR
• ______(a) is an even better measure – provides an estimation of the heart’s volume.
• Check for history of carotid endarterectomy prior to insertion of _______(1).
• History of Left Bundle Branch Block?
• Chest tubes? Pneumothorax? Thoracotomy intended?

PA catheters

• Most bypass cases have standard monitors + an a-line, and a PA-catheter. Some data suggests PA catheters offer little additional information.
• The placement of PA catheters must be done with incredible skill to prevent injury to other structures. With no proven benefit, all risk must be reduced.
• Guide use of pharmacologic and mechanical interventions
  
  • PCWP as an index of LV filling
  • CO
  • calculation of derived hemodynamic indices (e.g., SVR)
• Usually placed routinely, but sometimes limited to:
  
  • severe LV dysfunction
  • pulmonary hypertension
  • reduced LV compliance
  • combined procedures (e.g., _______(2)/valve)
  • prolonged intraoperative time (cardiac reoperations or use of bilateral _______(3))

Answer 9

Answers:
a. TEE
1. central line
2. CABG
3. IMAs (Internal Mammary Arteries)

Question 10

PA Catheters

• Placed before or after induction of anesthesia
• Early insertion determination of baseline hemodynamic values
• After induction avoid anxiety, discomfort, and possible HTN
• Can migrate with cardiac manipulation & acute changes in preload
• Risk of permanent wedge and possible pulmonary artery rupture
• Pull the catheter back a few cm prior to CPB
• Insertion:
  
  • VT
  • VF
  • RBBB
  • may precipitate CHB with pre-existing _______(1)
• Infection
• Pulmonary Artery Rupture
• Avoid “overwedging”
• Minimize the number of balloon inflations
• Withdraw PAC when initiating CPB

PAC placement is most commonly performed by observing the pressure waves as the catheter is floated from the CVP position through the right heart chambers and into the pulmonary artery.

Answer 10

Answers:
1. LBBB (Left Bundle Branch Block)

Question 11

The anatomic position of a PAC in the PA. The dashed line positions the inflated balloon in the “wedged” position. PA, _______(1); Alv, _______(2); PCap, _______(3); PV, _______(4); I, II, and III characterize the relationship of _______(5) and _______(6) as described by West. (The bottom of the figure shows a _______(7) correlation of vascular pressures.)

The normal central venous pressure (CVP) trace. _______(8), electrocardiogram.

Answer 11

Answers:
1. pulmonary artery
2. alveolus
3. pulmonary capillary
4. pulmonary vein
5. P_alveolar
6. P_arterial and P_venous
7. progressive
8. ECG

Question 12

CVP and EKG Waves
- P wave – depolarization of _______(1).
- QRS complex – depolarization of _______(2).
- T wave – repolarization of _______(3).
- A wave – atrial _______(4).
- C wave – tricuspid valve elevation into _______(5).
- X wave – downward movement of contracting right _______(6).
- V wave – back pressure wave from blood filling right _______(7).
- Y wave – ______(a) valve opens in early ventricular _______(8).

CVP Waveforms
- Atrial Fibrillation — _______(9) waves absent.
- Resistance to RA emptying — large _______(10) waves due to:
- Tricuspid Stenosis
- RV hypertrophy
- Pulmonary HTN
- Low RV compliance
- Large or prominent v waves due to:
- ______(b) regurgitation
- RV ischemia or failure
- Constrictive pericarditis or cardiac tamponade
- RV papillary muscle ischemia & TR

Answer 12

Answers:
1. atria
2. ventricles
3. ventricles
4. contraction
5. RA (Right Atrium)
6. ventricle
7. atrium
a. tricuspid
8. diastole
9. a
10. a
b. Tricuspid

Question 13

Mixed Venous Oximetry → Oximetric PAC
- Reflected intensity of light identifies the saturation of blood surrounding the tip of the PAC.
- ______(a) – total tissue O2 balance
- Ability to continuously monitor balance between O2 delivery and consumption.
- Normal is _______(1)% (denotes tissue extraction).

Low SVO2
- decreased CO
- increased oxygen consumption
- ______(b) arterial oxygen saturation
- ______(c) hemoglobin (Hb) concentration

Continuous Cardiac Output
- Microcomputer continuously computes CO based on changes in blood temperature
- Potential to identify acute changes in ventricular function

Answer 13

Answers:
a, SVO2
1. 75
b. decreased.
c. decreased.

Question 14

This SVO2 recording in a post-CABG demonstrates the effects of shivering and its treatment, and the relationship between SVO2, cardiac output (CO), and metabolic rate (SvO2).
*______(a), a long acting muscle relaxant, used to eliminate shivering and improve SvO2.

Cardiopulmonary Bypass Machine (CBM)
- Extracorporeal circulation or _______(1) machine.
- Device does the work of the heart and lungs when the heart is stopped for a _______(2).
- Operated by _______(3).

Extracorporeal Membrane Oxygenation (ECMO)
- Initially used to describe long-term extracorporeal support that focused on the function of _______(4).
- In some patients, the emphasis shifted to _______(5) removal, and the term extracorporeal carbon dioxide removal was coined.
- Extracorporeal support was later used for postoperative support in patients following _______(6). Other variations of its capabilities include treatment of PPHN.
- With all of these uses for extracorporeal circuitry, a new term, extracorporeal life support (ECLS), has come into _______(7) to describe this technology.

Answer 14

Answers:
a. Pancuronium
1. heart-lung
2. surgical procedure
3. Perfusionists
4. oxygenation
5. carbon dioxide
6. cardiac surgery
7. vogue

Question 15

CNS Dysfunction
- Etiology believed predominantly due to emboli
- Air
- Atheroma
- Particulates
- Incidence of CVA S/P CABG (__________(1))
- 1% < 64 years old
- 5 to 9% >65 years old
- _________(2) subtle cognitive deficits (microemboli)
- Improves over initial 2 to 6 months
- _________(3) have residual impairment
- Risk Factors
- advanced age (>__________(4))
- preexisting cerebrovascular disease
- e.g., carotid artery stenosis
- Should check for carotid U/S
- history of prior CVA
- PVD
- ascending aortic atheroma
- diabetes
- duration of CPB
- intracardiac procedure
- (e.g., valve replacement)
- excessive warming during and following CPB
- perfusion during CPB
- Difficult to monitor during CPB & no standard criteria
- Cerebral protection is limited
- Hypothermia
- _________(5) cerebral metabolic rate
- prolongs ischemic tolerance
- Nagelhout
- Hepatic BF and enzymatic activity are reduced — reduced clearance of drugs
- Myocardial protection is enhanced
- CNS is protected

Resume normothermia towards the end of bypass prior to unclamping.
- Increased risk of CNS dysfunction when:
- ______(6)
- during ______(7)
- ______(8) ventricular ejection

Answer 15

Answers:
1. macroemboli
2. 60-70%
3. 13 to 39%
4. 70 years
5. ↓ (decreased)
6. Unclamping
7. rewarming
8. initial

Question 16

BIS Monitoring
- Falsely ______(a) BIS values during cardiac surgery
- Barash: Targeting an end-tidal concentration of the inhaled agent between _______(1) and _______(2) MAC is as effective as maintaining a BIS value between _______(3) and _______(4).
- Attributed to interference from:
- _______(5) head rotation
- _______(6)
- _______(7)

Answer 16

Answers:
a. high
1. 0.7
2. 1.3
3. 40
4. 60
5. pump
6. pacemakers
7. hypothermia

Question 17

Anesthesia Technique
- It has not been demonstrated that one form of anesthesia is obviously better than any other with one exception:
- ______(a) inductions have been demonstrated to cause pulmonary hypertension and myocardial ischemia.
- ______(b) is the only anesthetic not recommended for patients with known coronary disease.
- There is also ______(c) (MS 1 mg subarachnoid) but safety data for this technique is limited.
- Thoracic Epidural Anesthesia (TEA) is successfully used in other countries to include India.
- No one “ideal” anesthetic for patients with CAD
- extent of pre-existing myocardial dysfunction
- pharmacologic properties of the drugs
- Barash:
- Opioids — lacks myocardial depression, stable HD state, and reduces HR
- Sufentanil and remifentanil — rapid extubation
- New research morphine is cardioprotective and _______(1)
- VA
- Which VA is the most potent coronary vasodilator? Isoflurane
- Desflurane and sevoflurane have the fastest recovery of all volatile anesthetics
- increase in sympathetic activity and myocardial ischemia in patients anesthetized with desflurane as the sole anesthetic agent
- Nitrates
- Nitroglycerin (TNG) is the drug of choice for the treatment of _______(2).
- Angina only on heavy exertion & good LV function
- Benefit of ↓ MVO2 (myocardial oxygen consumption) with volatile-based technique
- Severe CHF
- Choose technique with less myocardial depressant effect
- Avoid precipitating overt heart failure
- Factors to consider
- degree of ventricular dysfunction
- difficult airway
- length of surgery (“fast track”)

• Varying intensity of surgical stress and sympathetic response
  
  • intubation
  • incision
  • sternotomy
  • pericardiotomy
  • manipulation of the aorta

Answer 17

Answers:
a. Desflurane
b. Desflurane
c. high dose spinal narcotic
1. anti-inflammatory
2. acute myocardial ischemia

Question 18

CVOR Set-up
- Arrive extra early. Help the anesthesia technician set-up the room.
- Standard room set up for GA to include a non-depolarizing muscle relaxant, atropine, _______(1), ephedrine, norepinephrine (syringe and infusion ready), dopamine (infusion ready), calcium chloride, heparin (30,000 units drawn up, probably more), lidocaine and epinephrine.
- Anesthesia machine (Routine machine check).
- Airway
- Difficult airway anticipated? Gather special equipment
- Circulatory access
- Catheters for peripheral and central intravenous and arterial access
- Intravenous _______(2) and infusion tubing and pumps
- Fluid warmer with high volume tubing available
- Patient preparation includes at least one large bore IV.
- Place the a-line at the ______(a) radial artery since the left side will be occluded by the retractor for the IMA
- Right IJ _______(3) (or single lumen internal catheter, ‘SLIC,’ pronounced ‘slick’) and PA catheter.
- Five-lead _______(4)

Answer 18

Answers:
1. glycopyrrolate
2. fluids
a. right
3. chords
4. ECG

Question 19

CVOR Set-up
- Arrive extra early. Help the anesthesia technician set-up the room.
- Standard room set up for GA to include a non-depolarizing muscle relaxant, atropine, glycopyrrolate, ephedrine, neosynephrine (syringe and infusion ready), dopamine (infusion ready), calcium chloride, heparin (30,000 units drawn up, probably more), lidocaine and epinephrine.
- Anesthesia machine (Routine machine check).
- Airway
- Difficult airway anticipated? Gather special equipment
- Circulatory access
- Catheters for peripheral and central intravenous and arterial access
- Intravenous _______(1) and infusion tubing and pumps
- Fluid warmer with high volume tubing available
- Patient preparation includes at least one large bore IV.
- Place the a-line at the ______(a) radial artery since the left side will be occluded by the retractor for the IMA
- Right IJ _______(2) (or single lumen internal catheter, ‘SLIC,’ pronounced ‘slick’) and PA catheter.
- Five-lead _______(3)

CVOR Set-up cont.
- The surgeons can cause profound ______(b) with cardiac manipulation.
- If the pressure suddenly drops or PVC’s develop, look at what they are doing before you give a drug to treat episodic hypotension.
- If you give a drug because of hypotension caused by the surgeons and then they let go of the heart, the pressure will sky rocket.
- You may need to hand ventilate during some parts of the dissection.

Pre-induction measurements:
- If you put a PA catheter in prior to induction, you have indicated that you need it for patient management.
- You should therefore measure and record SAP, HR, CVP, PAP, PAO, and CO prior to anesthetic induction.
- You can _______(4) the patient during this time and free up one hand by using the mask strap to hold the mask in place.

Answer 19

Answers:
1. fluids
a. right
2. chords
3. ECG
b. hypotension
4. denitrogenate

Question 20

Pre-induction measurements:
- If you put a PA catheter in prior to induction, you have indicated that you need it for patient management.
- You should therefore measure and record SAP, HR, CVP, PAP, PAO, and CO prior to anesthetic induction.
- You can _______(1) the patient during this time and free up one hand by using the mask strap to hold the mask in place.

Pre-bypass hemodynamics:
- Maintain the blood pressure within _______(2) of baseline ward pressure.
- Heart rates between _______(3) limit myocardial oxygen consumption demand.

Bypass hemodynamics:
- Maintain the MAP between _______(4) during the cold period of bypass (cross clamp on) and between _______(5) during warm bypass (cross clamp off).
- Exceptions include patients with carotid vascular disease or chronic renal insufficiency who may need _______(6) pressures (60-80 mmHg) for the entire pump run.

Answer 20

Answers:

1. denitrogenate
2. ±20%
3. 50 and 70
4. 50-60
5. 60-80
6. higher

Question 21

Post-bypass hemodynamics:
- SBP >______(a) mmHg is fine.
- Between 100 and 120 mmHg, everyone will be happy.
- If it is greater than 120 mmHg, the patient is hypertensive and there will be more _______(1).
- Cardiac index 2.0-2.5 L/min
- PA Diastolic < 15 mmHg
- CVP < 5 mmHg.
- If CVP is ever greater than PA-D there is a problem.
- Consider poor calibration or _______(2).

Ischemia:
- Patients have CABG surgery because of myocardial ischemia.
- 40% of patients undergoing CABG surgery have intraoperative episodes of myocardial ischemia.
- Record a 5 lead ECG prior to induction for a _______(3) comparison.
- When the blood flow to myocardium is insufficient, it immediately stops contracting. This process takes 5 to 10 seconds. At 60 to 90 seconds, the ______(b) wave starts to change.
- As revascularization changes, _______(4) may improve

Induction and Intubation:
- Never induce the patient without a surgeon who can put the patient on bypass in the room.
- Never induce without a perfusionist and a pump. They should be able to place the patient on bypass in less than 5 minutes if the patient arrests on induction.
- Take care to avoid hypotension and _______(5).

Answer 21

Answers:
a. 80
1. bleeding
2. right ventricular failure
3. baseline
b. ECG ST-T
4. cardiac tissue
5. hypoxia

Question 22

Baseline ACT and ABG:
- Obtain as soon as possible after induction.
- Remember, the ACT is measured in seconds. Therefore, an ACT of 450 will take _______(1) to result.
- ABGs are typically run via I-Stat and cartridges.

Sternotomy:
- You will let the lungs _______(2) during opening.
- You must disconnect the patient from the ventilator and reconnect after they open the sternum.
- Develop a system to prevent yourself from forgetting to _______(3).
- Do not rely on the alarm as the only reminder.
- Apex:
- _______(4) is most common during this section of surgery in CPBs

IMA dissection:
- The surgeon may want the table tilted to the left and elevated.
- The surgeon may want the tidal volumes _______(5) (and, therefore, you will _______(6) the rate to maintain minute volume) to facilitate the dissection.

Heparinization:
- Do not allow the surgeons to go on bypass without heparinization. If the patient is not heparinized when the clamp is ______(a) on the bypass pump, the pump and oxygenator will clot and the patient will most likely die.
- If the surgeons are placing a cannula in an artery, ask if they want the heparin given. When they ask for heparin, respond with a verbal statement – “heparin has been given.”
- Always use the ______(b) for heparin. Aspirate blood from the line before and after the heparin dose to check to make sure the IV is _______(7).
- Check the ACT a minute or two after the dose.
- Apex:
- ACT should be > _______(8) secs
- Heparin allergy or heparin-induced thrombocytopenia requires alternatives (bivalirudin, hirudin, factor X inhibitor)
- Do not use the same IV to draw the blood that you infused the _______(9).
- Draw an arterial blood sample.

Answer 22

Answers:
1. 7.5 minutes
2. deflate
3. place patient back on ventilator
4. Awareness
5. reduced
6. increase
a. opened
b. central line
7. patent
8. 400
9. heparin

Question 23

Placing the cannulas:
- Monitor TOF and administer a NDMB prior to cannula placement.
- If the patient takes a breath with the atrium ______(a), they can develop a gas emboli and suffer severe injury.
- The small cannula in the aorta should not have any bubbles in it.
- If you see a bubble, tell the surgeons immediately.
- When they put in the aortic cannula there is _______(1); wear eye protection.

HADDSUE – or going on bypass.
- H — ______(b): Always give prior to bypass.
- A — _______(2): Always check before going on bypass (450 seconds)
- D — ______(c): Do you need anything? (i.e., NDMB)
- D — ______(d): Turn off the inotropes, etc.
- S — ______(e): Pull the PA catheter back 5 cm to avoid pulmonary arterial occlusion/rupture.
- U — ______(f): Account for _______(3) urine.
- E — ______(g): Check the arterial cannula for bubbles.

Answer 23

Answers:
a. open
1. splash
b. Heparin
2. ACT
c. Drugs
d. Drips
e. Swan
f. Urine
3. bypass
g. Emboli

Question 24

The Perfusionist:
- Three easy ways for the perfusionist to kill the patient:
- No ______(a) in the oxygenator.
- No ______(b).
- Reservoir runs _______(1).
- If the power goes out, there is a _______(2) crank.
- If a line breaks, you may be asked to help replace it.

Cardioplegia:
- There are lots of types: Cold, Warm, “Warm induction - Cold Maintenance - Warm Reperfusion,” Hot Shot, Crystalloid, Blood, Antegrade, and Retrograde.
- A pediatric cardiac surgeon started a new heart program. Several unexplained deaths occurred in the CVOR; cause of death was determined to be incorrect formulation of cardioplegia mixed by the hospital pharmacy.
- “The best is a _______(3) with a skillful surgeon.”
- Record the “on bypass time,” the “off bypass time,” the “on cross clamp,” and the “off cross clamp” time.
- As the cross clamp time exceeds ______(c), ventricular function deteriorates; as it exceeds 2 hours, it gets worse.
- Apex: Maybe antegrade or retrograde
- Antegrade - introduced in the aortic root — coronary arteries, C/I include in incompetent _______(4) valve
- Retrograde - cannula in the coronary sinus
- Cardioplegia protects myocytes during cross clamp.
- An infusion of Cardioplegia with a high _______(5) solution into the aortic root results in myocardial depolarization, resulting in cessation of electrical & mechanical activity (diastolic arrest).
- This produces electromechanical silence and reduces myocardial oxygen demand (MVO2) by more than ______(d).
- Nagelhout
- ______(e) solution — hypothermia — reduced metabolism of cardiac cells.
- Cardioplegia is indicated when the aortic cross clamp is in place because there is no coronary blood flow at this time.

Answer 24

Answers:
a. oxygen
b. heparin
1. empty
2. hand
3. short cross clamp
c. 1 hour
4. aortic
5. potassium
d. 80%
e. Cold

Question 25

De-airing maneuvers:
- It is difficult to get all of the air out.
- Doppler studies of the middle cerebral artery during bypass demonstrate 50-2000 emboli per case.
- On open ventricle or aortic procedures, the surgeons will have you place the patient in _______(1). They will bump the patient, roll from side to side, stick a needle in the ventricle, aspirate from the aorta, etc. in the hopes of getting out all of the bubbles.
- Observe the TEE. There will be a snowstorm of little bubbles in the ventricle. If you see a large bubble or more than usual, say something.
- The majority of emboli occur on aortic cannulation, cross clamp placement, cross clamp removal, weaning from bypass, and aortic cannula removal.
- It is best not to have high _______(2) levels or overly _______(3) temperatures (>37°C) during any of the embolic times.
- ______(a) of patients suffer subtle neuro-psychiatric changes consistent with multiple small emboli.

Answer 25

Answers:
1. Trendelenburg
2. glucose
3. warm
a. 95%

Question 26

WRMVP: wide receiver most valuable player – or getting off bypass
-______(a): What is the bladder and blood temp?
-______(b): Are they in NSR or do you need to pace? Is the rate adequate?
-______(c): Turn ‘em back on if you turned them off for bypass. Turn back on the alarms.
-______(d): Turn on the ventilator. Easy to forget and you look very stupid.
-______(e): What is the pump flow?

Answer 26

Answers:
a. Warm
b. Rhythm
c. Monitors On
d. Ventilation
e. Perfusion

Question 27

Preparation for CABG:
- Monitors (standard):
- ECG leads (5 lead)
- BP cuff
- Pulse Oximeter
- Neuromuscular blockade monitor
- Temperature probes (nasal, tympanic, bladder, rectal)
- Transducers (arterial, PAP and CVP) calibrated and zeroed
- Cardiac output computer: proper constant inserted
- Anticoagulation (ACT)
- Recorder
- Infusion pumps (make sure plugged in)

• Medications
  
  • Amnestic/benzodiazepine
  • Hypnotic/induction
    
    • Barash:
      
      • Etomidate is favored for induction in patients with limited cardiac reserve, but rarely administered repeatedly or for prolonged periods because of the risk of adrenal dysfunction associated with prolonged use
  • Volatile agent
  • Opioid
    
    • Barash: High dose opioid administration may lead to chest wall and abdominal rigidity
      
      • Counteract with low dose _______(1) prior to opioid adm.
  • Muscle relaxant
  • Heparin (pre-drawn; weight based; generally _______(2) units per kg)

Answer 27

Answers:
1. NDMR
2. 300

Question 28

Medications:
- Cardioactive “sticks”
- phenylephrine/ephedrine
- epinephrine/norepi
- 10% CaCl
- Glycopyrrolate
- nitroglycerin/esmolol
- Infusions:
- Nitroglycerin
- Inotropes (examples: epi, norepi, _______(1))
- Antibiotics

Miscellaneous:
- Pacemaker with battery
- TEE
- Defibrillator
- Compatible blood in operating room
- “Redo” hearts have blood in _______(2)

Induction:
- Smooth induction individualized approach
- Barash: Awake intubation in obese patient may be appropriate
- Avoid:
- coughing / laryngospasm
- truncal rigidity
- hemodynamic responses
- hypotension
- loss of sympathetic tone
- myocardial depression
- hypertension

Answer 28

Answers:
1. primacor (milrinone)
2. room

Question 29

Post-Induction Labs:
- Initial (baseline) set of labs once lines are placed
- ACT
- ABGs
- Hct
- Glucose
- K+, Ca++

Pre-Incision:
- Minimal stimulation
- insertion of a bladder catheter
- temperature probe
- Positioning
- preparing, and draping
- harvesting of artery or vein
- Hypotension often develops BEFORE INCISION
- reduce anesthetic depth
- vaso______(1)
- Observe for ischemia
- Be prepared for stimulation of incision and sternotomy
- Drugs ready to blunt sympathetic response
- Deflate lungs! “Lungs _______(2)”

Answer 29

Answers:
1. pressors
2. down

Question 30

Incision to CPB:
- Anticipate intense surgical stimulation incision and sternotomy
- Hypertension
- Tachycardia
- Ischemia
- Hypotension
- Periods that are less stressful (IMA dissection, vein graft harvest)
- Cardiac manipulation during cannulation
- interfere with venous return or
- episodic ectopic beats, SVT, AF
- Hypotension is desired prior to arterial cannulation
- Check before treating pressure
- Apex: Hypertension can lead to aortic dissection
- SBP < _______(1)
- Critical period
- Continual observation of the surgical field
- Identifying new ischemia
- Treat & notify surgeon
- Communication with surgeon is necessary
- ensure the heart gets a periodic “rest.”

Answer 30

Answers:
1. 100mmhg

Question 31

CPB:
- Administer Heparin prior to cannulation
- Essential to draw post-heparin ACT
- Will take at least 6 to 7 minutes
- May need to give ______(a) during cannulation
- Once CPB is initiated, no longer need to ventilate lungs
- Disconnect from circuit or Low level PEEP with 100% O2 or mixed with air
- MAP on CPB
- Determined by flow rate and total vascular resistance
- Maintained ~ _______(b) range, may be higher for older patients
- By coincidence CPB flow rates are kept at 50-60ml/kg/min as well!
- Barash:
- During the initial minutes of CPB, systemic arterial pressure initially drops to _______(1) as pulsatile flow ceases and the hemodilution effect of the CPB prime becomes apparent
- Everything below is Barash 39-13 (checklist before initiating CPB)
- Laboratory values
- Heparinization adequate (ACT or other method)
- Hematocrit
- Anesthetic Maintenance: supplement with
- amnestics
- opioids
- muscle relaxants
- Nagelhout: In patients undergoing CPB which gas should never be used? _______(2)

Monitors:
- Arterial pressure: initial hypotension and then return
- CVP: indicates adequate venous drainage
- PCWP:- Elevated?: LV distention (inadequate drainage, AI)
- Pull back PAC 1–2 cm
- Patient/field
- Cannula in place
- No kinks or clamps or air locks
- Arterial cannula is free of bubbles
- Face
- Suffusion? inadequate SVC drainage
- Unilateral blanching? _______(3) artery cannulation
- Heart
- Signs of distention (AI, ischemia)

Answer 31

Answers:
a. volume
b. 50 to 60
1. 30 to 40 mmHg
2. Nitrous Oxide
3. innominate

Question 32

Support
- Usually not required
Maintain adequate depth of _______(1)
- IV agents
- _______(2) agents via pump
Anesthetic requirements
- Decreased during _______(3)
- Return toward normal when rewarmed
Continue to monitor
- _______(4) (adequacy of perfusion)
- _______(5) output
- _______(6)+
- _______(7)
- _______(8)
- _______(9)
Continue to watch the surgical field
Monitor for electrical activity in the _______(10)
Should observe that there is _______(11) output in the first 10 minutes
Check _______(12), eyes, and face periodically

Answer 32

Answers:
1. anesthesia
2. Volatile
3. hypothermia
4. ABGs
5. Urine
6. K
7. Glucose
8. Hct
9. ACT
10. heart
11. urine
12. position

Question 33

Acute Renal Failure
- Contributing factors related to _______(1)
- systemic inflammatory response
- loss of pulsatile flow during _______(2)
- hypoperfusion
- Major cause of _______(3) M & M
- Mortality S/P _______(4)
- normal renal function (0.9%)
- acute renal failure (ARF) (______(a)%).
- No strategy, other than maintaining normovolemia, appears to be uniformly effective in preventing postoperative renal _______(5)

Answer 33

Answers:
1. CPB
2. CPB
3. periop
4. CABG
a. 63
5. impairment

Question 34

During CPB
- Laboratory values
- Adequate heparinization? (_______(1) or other method)
- ABGs (uncorrected): is there acidosis? _______(2)
- Hematocrit
- _______(3)+
- _______(4)+
- Ionized _______(5)++
- _______(6)
- _______(7)
- Patient/field
- Conduct of the operation
- Heart: distention, _______(8)
- Cyanosis, venous engorgement, skin _______(9)
- _______(10)
- Support
- Assist adequacy of pump flow
- Anesthetics/vasodilators for hypertension
- Constrictors for _______(11)

Answer 34

Answers:
1. ACT
2. Bicarb
3. Na
4. K
5. Ca
6. Anesthetic
7. Discontinue ventilation
8. fibrillation
9. temperature
10. Movement
11. hypotension

Question 35

During CPB: arterial hypotension
- Monitoring: side port of transducer with pressure line provided from the _______(1)
- Arterial hypotension:
- Inadequate _______(2) return
- Venous cannula:
- malposition, clamp, kink, air _______(3)
- _______(4), hypovolemia
- IVC obstruction
- Table too _______(5)
- Pump:
- poor occlusion, low _______(6)
- Arterial cannula:
- misdirected, kinked, partially clamped aortic _______(7)
- Decreased vascular _______(8):
- anesthetics
- Hemodilution
- Apex → CPB must be primed with Na+ solution/blood
- Causes hemodilution which has the ff. Effects
- Dec. HCT
- Dec. plasma conc. Of drugs and plasma proteins
- Dec. O2 carrying capacity
- Dec. blood _______(9)
- Inc. microvascular flow
- Transducer/monitor malfunction:
- radial artery cannula malpositioned, kinked, _______(10)

Answer 35

Answers:
1. field
2. venous
3. lock
4. Bleeding
5. low
6. flow
7. dissection
8. tone
9. viscosity
10. waveform

Question 36

Venous pressure:
- Transducer higher than atrial _______(1)?
- True obstruction to chamber drainage? (CVP right, PCWP or LA left heart)
EEG
Adequate body _______(2):
- Flow and _______(3)? Acidosis? Mixed venous blood oxygen saturation?
Temperature
Urine _______(4)

Answer 36

Answers:
1. level
2. perfusion
3. pressure
4. output

Question 37

Cardiopulmonary Bypass
- Cannulas
- tubing to drain blood & return blood and other fluids
- Venous: RA & IVC
- Apex:
- Drains by _______(1)
- Causes airlock when air enters the venous line
- Arterial: ascending aorta, femoral, axillary arteries
- Barash: placement depends if _______(2)/intracardiac
- Nonintracardiac uses _______(3) “dual stage cannulas”
- Gets blood from Right atrium, coronary sinus, and IVC most often
- Intracardiac/ “single-stage” cannula
- Snared at Superior and inferior venae cavae
- Reservoirs
- collection of solutions
- Oxygenator
- gas exchange
- Apex - Which increases the risk of cerebral air embolism?
- Bubble oxygenator > membrane oxygenator
- Pumps
- Circulates blood to CPB machine and back to patient
- Hand cranks in case of power failure
- Apex - 2 kinds of pumps
- ______(a) pump: more traumatic to rbc, more likely to _______(4) air if reservoir runs dry, moves flow forward regardless of arterial load (has an occlusion point)
- ______(b) pump: less trauma to rbc, less risk of air embolism, lack occlusion point (may cause _______(5) in high afterload patients)
- Centrifugal is preferred

Answer 37

Answers:
1. gravity
2. nonintracardiac
3. multiforifice
a. Roller
b. Centrifugal
4. entrain
5. regurgitation

Question 38

Drainage of venous blood
- “Dual Stage” large-bore cannula in the right atrium RA & IVC (CABG/Aneurysm)
- “Single Stage” ______(a) open cardiac heart procedures bloodless field (valve/PFO)
Rate of venous drainage is either passive or vacuum-assisted
- proper placement & adequate diameter cannulas
- intravascular volume status, and
- pressure gradient (height of RA above the venous reservoir)
If poor venous drainage
- adjustment of cannulas
- raising the height of OR table
- _______(1)
From venous reservoir to the oxygenator/heat exchanger unit
- warmed/cooled (separate heat exchanger for cardioplegia)
- oxygenated & CO2 removed
Oxygenated blood returned to the arterial circulation via a large “arterial” cannulas
Prolonged CPB results in time-dependent destruction of blood elements
- _______(2)
- platelet destruction
- Microemboli
- Seldom observed with CPB times that are <_______(3) minutes

Answer 38

Answers:
a. SVC and IVC
1. Suction
2. hemolysis
3. 90

Question 39

Pulsatile Blood Flow
- Native pattern of blood flow in the human body
- CPB pumps do not deliver physiologically significant pulsatile blood flow
- Implicated in causing
- renal dysfunction
- production of ischemic metabolic byproducts
- Apex: BF is not pulsatile, rely on _______(1)

Priming Solution
- Fluid used to fill CPB tubing (~ 1500 to 2000 ml) aka Prime
- Crystalloids solutions (osmolarity and electrolytes) ~500ml
- _______(a) (to decrease postoperative edema) ~25 grams
- ______(b) (to promote diuresis) ~25 grams
- Electrolytes (_______(2) due to citrate in transfused blood)
- Corticosteroids (anti-inflammatory effects)
- Heparin (maintain safe level of anticoagulation)
- _______(3) units (for the circuit)
- c.__ (5 grams)=hemostatic/antifibrinolytic agent
- Sodium Bicarb (25 mEq)
- Blood (as needed)

Answer 39

Answers:
1. MAP
a. Albumin
b. Mannitol
2. Ca++
3. 10,000
c. Amicar

Question 40

Dilutional Anemia
- Decreased O2-carrying capacity
- Hct 17% usually well tolerated
- higher Hct may ↑ risk of renal and neurologic consequences
- Barash: For CPB _______(1)is well tolerated
- Offsets changes in blood viscosity due to hypothermia
- May improve systemic flow
- Usually used with lung transplants (ex: if HBG = 15, decrease to ~11-12 to transport oxygen to tissues via decreased _______(2))

Answer 40

Answers:
1. 22%
2. viscosity

Question 41

Surgical
- Aortic manipulations
- Minimally invasive approach
- Bank blood utilization
- Duration of _______(1)

Techniques
- _______(2)/centrifugal
- _______(3)/closed circuits
- Surface coatings
- _______(4) filtration

Perfusion
- _______(5)
- Shed blood management
- Circuit prime volume
- Beating heart techniques

Pharmacology
- _______(6)
- Aprotinin
- Epo

Inflammation
Initiators
- Systemic cytokine signaling and complement system activation
- Expression of cell adhesion molecules
Effectors
- Margination of neutrophils, monocytes, and platelets
- Release of granule _______(7)

Organ failure
- Brain
- Lungs
- Kidney
- Heart

Inflammatory response is _______(8) during CPB.

Answer 41

Answers:
1. CPB
2. Roller
3. Open
4. Selective
5. Ultrafiltration
6. Steroids
7. proteases
8. SIGNIFICANT

Question 42

Systemic Anticoagulation
- Heparin prevents thrombosis of the CPB circuit (Barash: Anticoagulant of Choice)
- A polyionic mucopolysaccharide (more of a _______(1) thing though)
- Peak onset - 5 minutes
- Half life - 90 minutes
- Contact of blood with the circuit initiates the coagulation cascade
- Binds to and potentiates activity of Antithrombin III
- Inhibits ______(a) and prevents formation of fibrin clot via intrinsic and extrinsic pathways
- Barash mention the ff in particular
- factors IX, Xa, XIa, XIIa
- kallikrein and plasmin
- Deficiency of Antithrombin III can be corrected with _______(2)
- Usually give AT3 first (from pharmacy); remember, if you give AT3, you have to give more heparin.
- Heparin
- administered through central line
- always confirm that you can aspirate the line!
- Initial dose of ______(b) U/kg (EXAM-KNOW YOUR DOSE)
- let circulate 3 to 5 minutes before drawing ACT
- ACT must be at least 480 seconds before CPB is initiated
- (most institutions use at least 400 to _______(3) seconds)
- Additional heparin administered, if necessary

Answer 42

Answers:
1. pareira
a. thrombin
2. FFP
b. 400
3. 480

Question 43

If allergic to heparin, may consider administering _______(1) infusion while on bypass, depending upon the facility.
- No reversal
- Turn off the infusion ~______(a) minutes before coming off the pump.

ACT
- Tube containing diatomaceous earth or kaolin, warmed and rotated
- Time for clot formation (______(b) seconds for CPB) - According to Barash
- Nagelhout:
- Normal ACT is ______(c) seconds
- Safe is ≥______(d) for CPB
- Reasons for a heparinized patient to have decreased ACT <400
- Presence of _______(2) decreases effectiveness
- ______(e) deficiency → infuse 2 unit of _______(3)

Measure heparin levels
- Known amount of protamine added until clot formation in the shortest amount of time is determined
- Based on neutralization ratio of protamine to heparin
- (1 mg protamine for ______(f) U heparin)

PTT not used
- Will not get clot formation at heparin levels that are far below safe levels for CPB

Answer 43

Answers:
1. argatroban
a. 45
b. 480
c. 70-110
d. 400
2. nitroglycerin
e. Antithrombin III
3. FFP
f. 100

Question 44

Heparin Induced Thrombocytopenia
- Mild → transient ↓ _______(1) count
- Severe → auto-immune mediated ↓ platelet count
- Formation of antigenic heparin compounds (anti-PF4)
- ______(a) platelets in the face of endothelial injury
- Platelet clumping and microvascular thrombosis
- Heparin alternatives
- Defibrinogenating agents
- Ancrod (From pit viper venom)
- Factor X inhibitors
- Direct thrombin inhibitors
- Hirudin (From leech saliva)
- _______(2)

Blood Conservation
- Intraoperative autologous whole blood donation
- Obtained before heparin & reinfused following CPB
- RBCs, platelets, coagulation factors
- Barash: C/I
- preoperative anemia
- unstable angina/high-grade left main coronary artery disease
- aortic stenosis

Answer 44

Answers:
1. platelet
a. Activate
2. Bivalirudin

Question 45

Scavenging and re-infusing shed blood
- Washing and removal of serum
- High Hct (as much as _______(1))
- No _______(2) or coagulation factors
- Can contribute to _______(3)
- Barash C/I
- _______(4)
- _______(5)
- Topical hemostatic agents

Ultrafiltration
- Hemoconcentration during _______(6)
- ↓ free water and circulating inflammatory mediators
- ↑ concentration of _______(7), _______(8), and coagulation factors

Antifibrinolytics (epsilon-aminocaproic acid “EACA”)
- Binds to _______(9) — prevent ability to bind at lysine residues of fibrinogen — prevent lysis of fibrin clots
- Give loading dose followed by infusion
- _______(10) load followed by an infusion of 25mg/kg/hr
- Give after _______(11)

Aprotinin
Naturally occurring ______(a)
Reoperations, ASA, anticipated major blood loss
Risk of anaphylaxis—give test dose
Renal failure and ↑ 30 day mortality
Indefinitely suspended from market by FDA

Answer 45

Answers:
1. 70%
2. platelets
3. Dilutional Coagulopathy
4. Infection
5. Malignancy
6. rewarming
7. RBCs
8. platelets
9. plasminogen
10. 50mg/kg
11. heparin
a. fibrinolytic

Question 46

Myocardial Protection

• Intermittent hyperkalemia due to cold cardioplegia
  
  • Injected into coronary arteries or veins to induce diastolic electrical arrest
  • Barash: 2 types
    
    • _______(1) cardioplegia solution is injected via the aortic root following aortic cross-clamp which then follows the normal anatomic flow of blood into the native coronaries
      
      • In patients with severe coronary artery disease or AI, _______(1) cardioplegia may provide inadequate myocardial protection due to an incompetent AV
    • _______(2) cardioplegia is employed for myocardial protection by placing a catheter inside the coronary sinus.
      
      • bypasses obstructed coronaries and achieves greater myocardial protection.
• Moderate systemic hypothermia (passive or active)
  
  • _______(3) metabolic rate and O2 consumption
  • preservation of high-energy ______(a) substrates
  • _______(4) neurotransmitter release
  • (______(b) degrees C = - 50% in metabolic rate)

Answer 46

Answers:
1. Anterograde
2. Retrograde
3. ↓ (decrease)
a. phosphate
4. ↓ (decrease) excitatory
b. 28

Question 47

Re-Warming

• Patient gradually rewarmed to ______(a) degrees
  
  • Barash: A gradient of _______(1) is maintained between the patient and the perfusate to prevent formation of gas bubbles, and blood temperature should be less than _______(2).
• Top-off anesthetics to prevent awareness
  
  • 2nd most common time for rewarming, what is the first? _______(3)
• Aortic cross clamp removed
  
  • Heart is _____(b) to beat
  • Might need defibrillation
    
    • internal paddles _______(4) Joules
    • may need to pace
• Inflate the lungs recruit alveoli
• Check labs in preparation for separating from CPB
• Nagelhout: If patient gets hypotensive how should BP be treated?
  
  • Fluid status —> _______(5)
  • Phenylephrine
  • Ca++/Mg++
  • Blood

Answer 47

Answers:
a. 37
1. 4° to 6°C
2. 37°C
3. sternotomy
b. permitted
4. 20 to 30
5. TEE

Question 48

Coming off Bypass

• Laboratory values
  
  • Hematocrit
  • ABGs
  • K+ and Ionized Ca++
  • Glucose
• Anesthetic/Machine
  
  • Lung compliance: evaluate (hand ventilation)
  • Lungs are ventilated (manual or mechanical)
  • Vaporizers: turn on before separation of CPB
  • Alarms: on
• Transducers recalibrated and zeroed
  
  • Arterial and filling pressures
• Recorder (if available)
• Patient/field
  
  • LOOK AT THE HEART!
  • De-aired: → check lead II, _______(1)
  • Contractility, size, rhythm
  • LV vent clamped/removed, caval snares released
  • Bleeding: no major sites (grafts, suture lines, LV vent site)
• Support as needed

Answer 48

Answers:
1. TEE

Question 49

Coming off Bypass

1. Prior to separation from _______(1)
   
   • _______(2)
   • Dry surgical field
2. Acceptable _______(3) values
3. Adequate pulmonary _______(4)
4. Ventilation of the _______(5)
5. Adequate heart rate and _______(6)
   
   • _______(7) (pacing, defibrillation, cardioversion)
6. Venous _______(8) occluded incrementally
7. Sufficient pump volume is _______(9) while bypass flow is slowly ↓
8. Cardiac function & need for drugs _______(10)
   
   • _______(11) and TEE data
   • _______(12)
9. Will need to continually _______(13) especially upon closing the chest
   
   • Barash Checklist

PLEASE STUDY TABLE 39-15
(ChatGPT cant generate flashcards out from it)

Answer 49

Answers:
1. CPB
2. Normothermic
3. laboratory
4. compliance
5. lungs
6. rhythm
- pharmacologically
7. cannulas
8. transfused
9. assessed
- hemodynamic
- EKG
10. assess

Question 50

Weaning from cardiopulmonary bypass. While on cardiopulmonary bypass (CPB), the venous return to the heart is diverted from the right atrium (RA) to the CPB reservoir. The drainage is _______(1) (by gravity). From the venous reservoir, the blood is “ventilated,” CO2 is removed, and O2 is added, and then returned to the patient, usually into the _______(2) but occasionally via the _______(3) or axillary arteries. During weaning from CPB, the venous return to the CPB is reduced by gradually occluding the venous cannula, directing more of its contents to the _______(4) and _______(5). LV, left ventricle.

General approach to termination of cardiopulmonary bypass (CPB). TEE, _______(6); MAP, mean arterial pressure; CO, cardiac output.

Answer 50

Answers:
1. passive
2. aorta
3. femoral
4. right heart
5. lungs
6. transesophageal echocardiographic

Question 51

Weaning from cardiopulmonary bypass
While on cardiopulmonary bypass (CPB), the venous return to the heart is diverted from the right atrium (RA) to the CPB reservoir. The drainage is _______(1) (by gravity). From the venous reservoir, the blood is “ventilated,” CO2 is removed, and _______(2) is added, and then returned to the patient, usually into the aorta but occasionally via the _______(3) or axillary arteries. During weaning from CPB, the venous return to the CPB is reduced by gradually occluding the venous cannula, directing more of its contents to the _______(4) and _______(5). LV, left ventricle.

General approach to termination of cardiopulmonary bypass (CPB). TEE, transesophageal echocardiographic; MAP, mean arterial pressure; CO, cardiac output.

Algorithm for the diagnosis and treatment of hemodynamic abnormalities at termination of cardiopulmonary bypass. CO, cardiac output; SVR, systemic vascular resistance; vasc, _______(6); IABP, intra-aortic balloon pump; LVAD, left ventricular assist device; CVP, central _______(7); RV, right ventricle; NO, nitric oxide; PGI2, prostacyclin.

1. Rate and Rhythm: Adjust, Pace if Needed
2. Fill the Heart: Partially Occlude the Venous Line – Observe TEE
3. Allow Ejection: Decrease the Arterial Flow from the CPB
4. Measure MAP

Normal or Elevated
5. Occlude Venous Line
6. Stop Arterial Pump when Heart Seems Appropriately Full

Low
5. Stay on Partial CPB
6. Readjust Ventricular Volume
7. Medications
8. Readjust Ventricular Volume, Drugs
9. Wean Off CPB

Estimate Filling Pressures and Measure CO

Answer 51

Answers:
1. passive
2. O2
3. femoral
4. right heart
5. lungs
6. vascular
7. venous pressure

Question 52

Post-Bypass
- Decannulation
- Transient atrial or junctional dysrhythmias
- Unexpected bleeding from atrial or aortic suture lines may require rapid transfusion
- Protamine administration
- Reversal of heparin after removal of the venous cannulae
- Arterial cannula remains in order to give volume from the pump
- “Drying up”
- Arterial cannula removed when bleeding is controlled
- Chest closure
- after bleeding is under control
- sometimes not well tolerated
- Continued vigilance for new ischemia (________(1) Nitroglycerin, CCB, papaverin)
- may indicate a correctable problem with the grafts
- adequacy of valvular repair or replacement assessed by ________(2)

Answer 52

Answers:
1. SPASMS!
2. TEE

Question 53

Reversal of Anticoagulation
- Protamine — neutralize heparin
- Heparin-Protamine: Cationic protamine reverses anionic heparin by a _______(1) interaction
- Dose = fixed ratio of protamine to heparin
- _____(2) mg/kg
- automated protamine titration
- Adequate reversal assessed
- repeated ACT measurements and the appearance of the surgical field
- Immediate and delayed anaphylactic response
- increased airway pressure
- ↓ SVR
- systemic hypotension
- skin flushing
- Increased incidence of reactions sensitized to Protamine
- previous ______(3)
- hemodialysis
- cardiac surgery
- ______(4) insulin
- ______(5)
- allergy to ______(6)
- Hypotension with rapid injection
- Displacement of ______(7) from mast cells, similar to MSO4
- Idiosyncratic, catastrophic pulmonary vasoconstriction — Barash MOST DEVASTATING Complication
- Barash: mediated by release of thromboxane and C5a anaphylatoxin.
- ↓ CVP, ↓ LAP, ↑ PAP
- RV distention & failure
- Treatment with RAPID administration (when started)
- Test dose & slow administration (announce when started)

Answer 53

Answers:
1. simple acid-base
2. 2 to 4
3. cardiac catheterization
4. NPH
5. vasectomy
6. fin fish
7. histamine

Question 54

Post-Bypass Bleeding
- Persistent oozing following heparin
- inadequate surgical hemostasis
- reduced platelet count or function (cannot identify with ACT)
- insufficient dose of protamine
- dilution of coagulation factors
- “heparin rebound” (rare)
- Adequate hemostasis is obtained — chest is closed
- Sometimes see transient ↓ BP
- usually responds to volume infusion
- hypotension persists — _______(1) chest
- cardiac tamponade
- kinked graft

Answer 54

Answers:
1. reopen

Question 55

During Skin Closure
- Prepare for orderly, unhurried transfer of the patient
- Continue to monitor closely
- _______(1)
- Hemodynamics
- titrate infusions/ adjust pacemaker as necessary
- Equipment for transport
- additional syringes with emergency cardiac medications
- equipment for airway management
- transport monitor
- _______(2)

Answer 55

Answers:
1. EKG
2. pacemaker

Question 56

Post-Operative Complications
- Postoperative Re-exploration (“Bring Back”)
- within the first _______(1) hours
- _______(2) of cases
- *Nagelhout and Barash say 4-5%
- Indications:
- persistent bleeding
- anticipate possible ++ transfusions (PRBCs, FFP, Platelets, etc.)
- possibility of CPB
- cardiac ______(3)
- unexplained poor cardiac performance
- Nagelhout
- Persistent bleeding
- Excessive blood loss
- Cardiac Tamponade — low Cardiac Output
- HD instability

Answer 56

Answers:
1. 24
2. 4 to 10%
3. tamponade

Question 57

Cardiac Tamponade
- Tamponade
- Increased intrapericardial pressure, whilst distending (transmural) pressure (intracavitary pressure—extracavitary pressure) is actually decreased.
- Intracardiac pressures deceptively _______(1)
- do not reflect actual volume status
- Cardiac chamber collapse
- ______(a) in diastole most likely to be compressed
- Limited SV CO depends on HR
- Compensatory peripheral vasoconstriction & tachycardia
- Risk of ischemia due to tachycardia and ↓ _______(2)

PLEASE STUDY FIGURE 60-37 ECHOCARDIOGRAM

Answer 57

Answers:
1. elevated
a. atria and RV
2. CPP (Coronary Perfusion Pressure)

Question 58

Cardiac Tamponade
- Clinical Signs
- dyspnea
- orthopnea
- ______(a)
- paradoxical pulse “_________(1)”
- ______(b)
- decreased U/O
- Abnormally large decrease in SBP and pulse wave amplitude during inspiration. Normal fall in pressure is less than 10mmHg. More than _______(2) drop, referred to as PP.
- Intubated & Sedated
- hemodynamic deterioration
- signs of low-output failure
- Serial chest films
- progressive mediastinal widening
- Nagelhout: 3 vessel can be compressed d/t mediastinoscope
- Innominate artery (I nominate the Right carotid and subclavian arteries!)
- Compression may lead to compromised _______(3)
- Monitor with right arm -_______(4) cath.

• Transthoracic echocardiography or TEE
  
  • diastolic collapse of the RA and RV and/or LV
• Anesthesia further depresses cardiac function
  
  • preserve compensatory mechanisms
  • sustain forward flow
• Serious hemodynamic compromise avoid:
  
  • arterial and venous vasodilators
  • myocardial depressants
• ______(c)+/-
  
  • sympathomimetic effects, may help preserve HR & BP
  • may induce hypotension if under maximal sympathetic stress

Answer 58

Answers:
a. tachycardia
1. pulsus paradoxus
b. hypotension
2. 10mmHg
3. cerebral blood flow
4. pulse oximeter or radial artery
c. Ketamine

Question 59

Pain Management
- Goal of early awakening and extubation
- Severe pain due to sternal fracture and retraction
- Standard practice — IV opioids followed by oral pain medications
- Other modes of treatment:
- Intrathecal administration of opioids
- Nonsteroidal anti-inflammatory agents
- Epidural analgesia

Intra-Aortic Balloon Pump (IABP)
- Used to support inadequate left ventricular function.
- ↓ myocardial O2 demand & ↑ O2 supply
- Do not hesitate to suggest if there is difficulty weaning from bypass.
- Mechanical support device
- 25 cm “sausage-shaped” balloon and a 90 cm vascular catheter
- Made of nonthrombogenic polyurethane
- usually placed via the femoral artery where the distal tip lies below the left SC artery and proximal to _______(1)
- Synchronized “_________(2)” where blood volume moves “counter” to normal flow
- Balloon is inflated during diastole
- ↑ aortic diastolic pressure (diastolic augmentation) leads to ↑ CPP proximally and enhances forward flow
- Apex: corresponds with _______(3) on aortic pressure wave form
- Balloon is deflated during _____(a)
- LV ejects against lower diastolic pressure (systolic unloading) resulting in reduced MVO2 and lower AEDP
- Apex: corresponds with ______(b) wave on EKG
- The physiologic effects of intra-aortic balloon pump (IABP) counterpulsation.
- The IABP is isolelectric during _______(4), every other beat (rate: ______(c)).
- The arterial systolic pressure is ______(d) after IABP augmentation (compare beats 2 and 4 with beats 1 and 3).
- The diastolic arterial pressure is ______(e) during IABP inflation (*). The flow through the aortic valve (approximate _______(5)) as demonstrated with pulsed wave Doppler echocardiography shows the increased forward flow after stroke volume as demonstrated with pulsed wave Doppler echocardiography shows the increased forward flow after augmentation (beats 2 and 4). ECG, electrocardiogram

Answer 59

Answers:
1. (above) the renal arteries.
2. counterpulsation
3. dicrotic notch
a. systole
b. R
4. diastole
c. 1:2
d. decreased
e. augmented
5. stroke volume

Question 60

Intra-Aortic Balloon Pump (IABP)
- Proper timing of deflation necessary to maximally off-load the LV
- control heart rate and suppress atrial and ventricular dysrhythmias
- Myocardial function often improves
- systemic perfusion and vital organ function are preserved
- assist ratio is gradually weaned
- Complications
- ischemia distal to insertion site
- direct trauma to the vessel
- arterial obstruction
- thrombosis
- aortic perforation
- balloon rupture
- platelet destruction & thrombocytopenia
- Apex:
- Indications
- Cardiogenic shock
- MI
- Intractable angina
- Difficult separation from CPB
- C/I
- Severe A.___
- Sepsis
- Severe B.___
- _______(1)

Answer 60

Answers:
A. AI
B. PVD
1. Descending aortic disease

Question 61

Ventricular Assist Device
- A transportable centrifugal pump that can be used as a bridge to transplant or to allow recovery of severely stunned myocardium.
- Heart unable to meet systemic metabolic demands despite maximal pharmacologic therapy & IABP
- Pumps blood and bypasses either the LV or RV
- Indications:
- Intraoperative myocardial dysfunction that is reversible; temporary “stunning” of the myocardium survival 20 to 30%
- Apex: “Bridge to Recovery”
- Chronic heart failure: hemodynamic support prior to heart transplantation
- Pearl: use _______(1) for VAD
- Apex: Volume helps to avoid Suction event
- Where low preload + high pump speed = LV gets sucked into LV cavity → inflow cannula occlusion
- LVAD: tip of LV (apex) is outflow, inflow is _______(2)
- Apex: Dependent upon
- LV preload
- Pump Speed
- Pressure gradient across the pump (Afterload)
- RVAD: tip of RV is outflow, inflow is _______(3)
- Barash: Pearls
- The ______(a) is exquisitely sensitive to changes in afterload and a failing RV will not “fill” the left side of the heart and therefore limit LVAD output.
- Low to normal PVR is especially important in patients with an LVAD.
- Apex: Pearls
- Long-term coagulation = no regional
- Most common cause of death is _______(4), GI bleeding is common

Answer 61

Answers:
1. volume
2. aorta
3. PA (Pulmonary Artery)
a. RV
4. sepsis

Question 62

Minimally Invasive Techniques
- Avoid effects of CPB
- Aortic manipulation & cross-clamping thought to be associated with lower stroke rates, especially with _______(1)
- Lower rate of complications associated with sternotomy, scarring, infection, brachial plexus palsy, _______(2)
- MIDCAB (minimally invasive direct CA bypass)
- IMA to LAD
- Initially, left thoracotomy using one-lung ventilation
- OPCAB (off-pump coronary artery bypass)
- Robotic Surgery
- Percutaneous valve repair/replacement (increasingly done in the cardiac cath lab)
- Approaches — limited exposure & surgical difficulty
- parasternal and inframammary incisions
- “mini-thoracotomies”
- Partial sternotomy
- OPCAB
- via a sternotomy but no CPB
- special retractors and stabilization devices
- intracoronary shunts and sutureless anastomotic devices
- Changes in surgical technique have forced changes in anesthetic technique
- Shorter-acting agents that facilitate early extubation rather than the “traditional high-dose opioid” technique
- “Lull” while on CPB replaced by need to constantly monitor hemodynamics and intervene rapidly
- changes occur rapidly
- may be catastrophic during cardiac manipulation
- exposure often requires positioning of the heart that is associated with hypotension and ischemia

Answer 62

Answers:
1. elderly
2. Requires ~ 4 to 8-week recovery period

Question 63

Standard monitors may not be useful in detecting ischemia
- Positioning and retraction of the heart low-amplitude EKG with axis deviation
- ST-T wave changes may be obscured or falsely minimized
- Pain control using systemic opioids and nonsteroidal agents such as ketorolac (in patients without renal insufficiency)
- local infiltration of the surgical incision
- regional techniques (anticoagulation may be a concern)
- thoracic epidurals
- neuraxial narcotics

______(1) may not be beneficial because
- Heart obscured by laparotomy pads or being lifted out of the chest
- May be unreliable in detecting regional wall motion changes

Direct observation of the heart and communication with the surgeon are critical
- Immediate access to cardiac pacing and cardioversion
- Right coronary lesions bradycardia, atrial dysrhythmias, and heart block
- Left-sided coronary lesion ventricular dysrhythmias and hemodynamic collapse

May need IABP or conversion to full CPB

Short-term improved outcomes following OPCAB
- lower length of ICU stays
- decreased utilization of hospital resources
- decreased incidence of atrial fibrillation.

Advantages of traditional CABG
- a still bloodless field
- allows for a better anastomosis and long-term graft patency
- studies have refuted this argument

No consensus as to the superiority of CABG versus OPCAB
- studies show equal long-term graft patency
- no definite improvement in neurological outcome with _______(2)

Answer 63

Answers
1. TEE
2. OPCABG

Question 64

Off-pump coronary artery bypass (OPCAB)
- Reduced need for blood transfusions
- Reduced risk of bleeding, stroke and kidney failure
- Potential for reduced _____(1) problems
- The invention of the octopus and starfish have made it easier, safer, and practical for most CABG operations to be done off pump.

Answer 64

Answer
1. psychomotor and cognitive

Question 65

OPCAB
- The Octopus and Starfish are retractors, which use suction to stabilize the heart.
- The Octopus system “sucks up” the myocardium with two little arms. The arms then separate slightly to tighten the area and reduce motion.
- The Starfish is a retractor used for lifting and moving the heart with a suction cup shaped like a “Y.”
- These retractors improve hemodynamics during stabilization.
- Consider an anesthetic that _______(1).
- Have the perfusionist available.
- The patient will be anticoagulated just as for a CABG with extracorporeal circulation (Heparin 300 U/kg).
- Consider prophylaxis for arrhythmias.
- After the surgeon has retracted the heart, placed the stay sutures and the stabilizer, load the patient with volume (hespan/hextend) and maintain the pressure with vasoconstrictors.
- Try to avoid _____(a) as an increased HR makes the _______(2) more difficult.
- Adjust the ventilator to reduce motion (______(b) tidal volumes with ______(c) rate).
- Have a plan to lower the heart rate even more if necessary (esmolol, adenosine). If the heart rate is irregular or too low, consider atrial pacing.

• Do not use ______(d) when asked to increase the heart rate because they are hard to undo when the surgeon changes his mind.
• Be ready for re-perfusion arrhythmias when the stay sutures are released.
• Reverse the heparin gently.
• The dose of protamine may be reduced because of the lack of damage to the platelets.
  
  • Check the ACT 1/3 and 2/3 of the way through the case to avoid _______(3).

Aortic Diseases
- Aortic Dissection
- Intramural Hematoma
- Thoracic Aortic Aneurysm
- Aortic root
- Ascending aorta
- Aortic arch
- Descending aorta
- (Definitely know the different types, where they’re occurring, how far the travel)

Figure 62-10 The DeBakey classification of dissecting aneurysms of the aorta. Type I has an intimal tear in the ascending aorta with dissection extending down the entire aorta. Type II has an intimal tear in the ascending aorta with dissection limited to the ascending aorta. Type III has an intimal tear in the proximal descending thoracic aorta with dissection either limited to the thoracic aorta (type IIIA) or extending distally to the abdominal aorta or aortoiliac bifurcation (type IIIB).

(Adapted from DeBakey ME, Beall AC Jr, Cooley DA, et al: Dissecting aneurysms of the aorta. Surg Clin North Am 46:1045-1055, 1966.)

Figure 62-9 The Crawford classification of thoracoabdominal aortic aneurysms is defined by anatomic location and extent of involvement. Type I aneurysms involve all or most of the descending thoracic aorta and the upper abdominal aorta; type II aneurysms involve all or most of the descending thoracic aorta and all or most of the abdominal aorta; type III aneurysms involve the lower portion of the descending thoracic aorta and most of the abdominal aorta; and type IV aneurysms involve all or most of the abdominal aorta, including the visceral segment.

(Adapted from Crawford ES: Thoracoabdominal and supra-renal abdominal aortic aneurysm. In Ernst CB, Stanley JC [eds]: Current Therapy in Vascular Surgery. Philadelphia, BC Decker; 1987, pp 96-98.)

Answer 65

Answers:
1. lowers the heart rate
a. tachycardia
2. anastomosis
b. smaller
c. increased
d. glycopyrrolate or atropine
3. over-dosing

Question 66

Apex: Crawford Classification System

Thoracoabdominal Aneurysm involvement | Classification (Crawford) | Definition (Descending Thoracic Aorta) | Definition (Abdominal Aorta)
— | — | — | —
Type I | All or most | Upper only
Type II | All or Most | Most
Type III | Lower only | Most
Type IV | none | most

Which type is most likely to lead to paraplegia and renal failure? Type II d/t stopping perfusion of the artery of adamkiewicz

Which are the most difficult to repair because they involve the thoracic and abdominal aorta? Type II and III

Causes of Aortic Diseases
- Acquired
- HTN
- inflammation
- deceleration trauma
- iatrogenic factors
- Genetic
- Bicuspid aortic valve
- Inherited connective tissue disorders such as ______(1)

Mechanism
- Cystic Medial Degeneration
- disappearance of smooth muscle cells
- degeneration of elastic fibers
- Higher wall stress → aortic dilatation and aneurysm formation
- intramural hemorrhage (considered a precursor to acute dissection)
- aortic dissection (tear in the aortic intima)
- Rupture

Answer 66

Answer
1. Marfan syndrome and Ehlers-Danlos syndrome

Question 67

Dissection vs Aneurysm
- Aortic dissection is an intimal tear, which creates another pathway within which the blood runs, like a false lumen between layers of the aortic wall.
- Aortic aneurysm is a weakening of the wall and formation of an “outpouching” of the aortic wall.

Apex: Based on law of ______(1)

Acute Aortic Dissection
- Rapid development of intimal flap separating true and false lumens
- Spreads antegrade or retrograde from the intimal tear
- Malperfusion syndromes
- Aortic Insufficiency
- Tamponade
- Barash definition:
- Aortic dissection is caused by a tear in the aortic intima and media, which propagates proximal and distally, creating a false lumen within the aortic media.
- When the false lumen involves aortic vessels, it causes malperfusion of vital organs (brain, spinal cord, abdominal organs)

Answer 67

Answers
1. Laplace

Question 68

Risk Factors

• Usually, occurs in the _______(1) or _______(2) decade of Life
  
  • Men > Women
  • _______(3)
  • Apex: _______(4)
• In younger patients
  
  • Inherited connective tissue disorders (_______(5) and _______(6))
  • _______(7) aortic valve
  • Prior surgery

Presenting Complaint

• Pain is the most common complaint
  
  • Ascending aorta → _______(8)
    
    • Severe _______(9) (type A)
  • Descending aorta → _______(10) (type B)
• _______(11) is an ominous sign
  
  • Cardiac tamponade
  • Cerebral hypoperfusion
• Barash:
  
  • Rupture of the false lumen into the pericardium can cause cardiac tamponade
  • interference with the AV may cause _______(12).
• Apex: Triple A Rupture
  
  • _______(13)
  • _______(14)
  • _______(15) Abdominal Mass

Answer 68

Answers:

1. fifth
2. sixth
3. HTN
4. Smoker
5. Marfan syndrome
6. Ehlers–Danlos syndrome
7. Bicuspid
8. chest pain
9. neck or chest pain
10. back or abdominal pain
11. Syncope
12. AI
13. Hypotension
14. Back pain
15. Pulsatile

Question 69

Additional Symptoms

• Atypical symptoms mimic
  
  • _______(1)
  • _______(2)
  • vascular embolization
  • abdominal pathology
• Pulse and/or BP variation
  
  • impaired blood flow to an _______(3) or _______(4)

_________ induced by original dissection or propagation of the dissection

Mortality

• Acute ascending aortic dissection
  
  • mortality 1 to 2% per hr after symptom onset
  • without surgery mortality exceeds 50% in 1 month
• Uncomplicated descending aortic dissections
  
  • 30-day mortality of _______(5)
  • may be managed medically or with _______(6) placement

Answer 69

Answers:

1. stroke
2. myocardial infarction
3. organ
4. limb
5. 10%
6. stent

Question 70

Acute Aortic Dissection

• Surgical emergency
  
  • Large bore IV access
  • Invasive pressure monitoring
  • TEE (Best Diagnostic)
  • Barash:
    
    • _______(1) of the ascending aorta (type A) has a mortality rate of _______(2) per hour after onset of symptomatology and is a true surgical emergency.
    • An aortic dissection distal to the left subclavian artery is called type B, has a 30- day mortality of _______(3), and may be managed medically or with insertion of a scaffold (_______(4)).
• Ascending Aorta
  
  • prevent aortic rupture
  • pericardial tamponade
  • ameliorate concomitant _______(5)
  • implantation of composite graft in the ascending aorta with possible re-implantation of the coronary arteries
  • Anesthetic Management:

Answer 70

Answers:

1. Acute aortic dissection
2. 1% to 2%
3. 10%
4. stent
5. AI

Question 71

Table 39-9 Acute Aortic Dissection: Hemodynamic Goals

Parameter | Goal | Comment
— | — | —
Preload | ↓ | If acute _______(1); (must ↑ further in tamponade)
Afterload | ↓ | With anesthetics, analgesics, arterial dilators (nitroprusside, nicardipine); keep systolic BP <100–120 mmHg
Contractility | Maintain or ↑ | Titrate myocardial depressants carefully
Rate | ↓ to <60–80 bpm | Use β-blocker; ensure contractility is adequate
Rhythm | | Control ventricular response (if atrial fibrillation present)
MVO₂ | | Compromised if aortic dissection involves coronary vessels
CPB | | Alternate site of inflow (arterial) cannulation, deep hypothermic circulatory arrest possible if cerebral vessels are involved

↑, increased; ↓, decreased; _______(2), aortic insufficiency; BP, blood pressure; bpm, beats per minute; MVO₂, myocardial oxygen consumption; CPB, cardiopulmonary bypass.

Answer 71

Answers:

1. AI
2. AI

Question 72

Apex: Aortic Dissection Classification: DeBakey and Stanford

Classification | Definition
— | —
Stanford | Type A: A for Ascending Aorta involvement
Type B: B for Boo no ascending aorta involvement
DeBakey | 1 - tear in ascending aorta + dissection in entire aorta
Type 1 | 2 - tear in ascending aorta + dissection only in _______(1)
Type 2 | 3 - tear in proximal _______(2) aorta with:
Type 3 | 3a - limited to thoracic aorta
Type 3a | 3b - for belly → thoracic and abdominal aorta
Type 3b |

Which of these classifications is considered a surgical emergency? DeBakey A.____ and Stanford _______(3)

Answer 72

Answers:

1. ascending aorta
2. descending
   A. 1 or 2
3. Stanford A

Question 73

Thoracic Aortic Aneurysm

• Most asymptomatic at the time of diagnosis
  
  • Aortic Root
  • Ascending Aorta
  • Aortic Arch
  • Descending Aorta
• May be associated with _______(1)
  
  • (diastolic murmur or heart failure)
• Large may cause local mass effect due to compression
  
  • _______(2) (cough)
  • _______(3) (dysphagia)
  • _______(4) (hoarseness)

Surgical Treatment

• Diagnosed
  
  • contrast-enhanced CT and magnetic resonance angiography (MRA)
• Surgery indicated
  
  • ascending aneurysms >_______(5) cm
  • descending aneurysms >_______(6) cm
  • risk for rupture ↑ abruptly diameter = 6 cm
• Aortic Root Aneurysm with _______(1)
  
  • Composite graft with a prosthetic AV sewn into it
  • _______(1) is due to ______(a) dilation
  • valve-sparing procedure (preservation of the native AV cusps)

Answer 73

Answers:

1. AI
2. trachea
3. esophagus
4. recurrent laryngeal nerve
5. 5.5
6. 6
   a. aortic root

Question 74

Aortic Arch Aneurysm
- Requires ______(a)
○ Risk of neurologic damage
▪ Global ischemic _______(1)
○ Embolization of atherosclerotic debris
- _______(2) protection
○ Profound hypothermic circulatory arrest
○ Cerebral Perfusion
▪ Retrograde (via a _______(3) cannula)
▪ Antegrade (direct cannulation of _______(4) vessels)

Descending Aortic Aneurysm
- Endovascular stent/graft may be placed via transluminal approach
- Surgical repair associated with postoperative _______(5) due to interruption of spinal cord blood supply (13 to 17%)
- Spinal Cord protection for surgical repair (artery of _______(6))
○ cerebrospinal fluid drainage (lumbar drain)
○ reimplantation of critical spinal arteries
○ distal aortic perfusion LA-left femoral artery bypass circuit
○ intraoperative epidural cooling
○ somatosensory evoked potentials (SSEPs)

Answer 74

Answers:
a. total circulatory arrest
1. injury
2. Cerebral
3. superior vena cava
4. cerebral
5. paraplegia
6. adamkiewicz

Question 75

Surgical Risks
- Aortic aneurysm surgery requires clamping of the aorta. This reduces blood & O2 supply to the spinal cord.
- Tissue damage can lead to partial or incomplete paralysis of lower limbs (paresis) and paraplegia (paralysis of legs & lower part of body).
- This is frequently _______(1).
- The CSF pressure (CSFP) increases during clamping, further decreasing the perfusion pressure of the spinal cord.
- As more of the blood supply to the spinal cord is interrupted, the likelihood of paraplegia is increased. Various treatments are used to reduce the ischemic insult to the spinal cord, including CSF drainage.
- Apex: Spinal Cord Circulation
○ Posterior Spinal Arteries
▪ Post ⅓ of spinal cord
■ 2 arteries (posterior radicular and vertebral)
○ Anterior Spinal Artery
▪ Anter ⅔ of spinal cord
■ 1 anterior spinal artery (anterior radicular + vertebral)
○ Artery of Adamkiewicz
▪ 6-8 paired radicular arteries
▪ Supplies anterior spinal cord in _______(2) region
▪ Originates: Left Side (______(a))
● 75% of population: T8-12
● 10%: L1 - L2
- Anterior Spinal Artery Syndrome (Beck’s Syndrome)
○ Lower Extremity: _______(b) — r/t corticospinal tract
○ Bowel and Bladder dysfunction
○ Loss of _____(c) sensation — r/t spinothalamic tract
○ *Touch and proprioception are preserved
- Draining CSF from lumbar region may lessen CSF pressure, thereby improving blood flow to the spinal cord & reducing the risk of ischemic spinal cord injury.

Answer 75

Answers:
1. irreversible
2. thoracolumbar
a. T11-12
b. Flaccid paralysis
c. temperature/pain

Question 76

Anesthetic Technique
- Preservation of cardiac function is vital, especially in descending aneurysms using a “clamp-and-go” method because of great fluctuations in afterload and hemodynamic instability.
- Neurologic integrity, particularly in aortic arch or descending aneurysms, may require drainage of CSF to augment spinal cord perfusion pressure (SCPP).
- 10 mL are drained at a time
- CSF pressure (CSFP) is continuously monitored
- Keep CSFP ~15 or less
- SCPP = ______(1)
- Apex: Spinal Cord protection
- Moderate hypothermia (______(2) degrees C) → reduce O2 consumption
- CSF drainage
- Perfusion is dependent on pressure gradient between anterior spinal artery and CSF pressure
- More drainage → reduce CSF pressure → increased pressure gradient
- Avoid ______(3)
- During cross clamping, MAP: ______(4) mmhg
- SSEP and MEP monitoring
- SSEP monitors _____(5) cord
- Do not use NMBs with MEPs
- Partial CPB (Left atrium to femoral artery)
- Drugs - Corticosteroids, Ca++ blockers, Mannitol

Answer 76

Answers:

1. MAP – CSFP
2. 30 - 32
3. hyperglycemia
4. 100
5. posterior

Question 77

Blood Supply to the Spinal Cord

Figure 62-12 Diagram of the blood supply to the spinal cord showing the anterior and posterior radiculomedullary branches seen in a lateral view. The primary blood supply to the thoracolumbar portion of the spinal cord is derived from the artery of Adamkiewicz; it originates via direct _______(1) usually branches off the _______(2) in the T9 to T12 region.

(From Djindjian R: Arteriography of the spinal cord. Am J Roentgenol Radium Ther Nucl Med 107:461-478, 1969.)

Answer 77

Answers:
1. arterial connections
2. aorta

Question 78

Systemic Hemodynamic Response to Aortic Cross-Clamping

Figure 62-5 Systemic hemodynamic response to aortic cross-clamping. Preload (asterisk) does not necessarily increase with infrarenal clamping. Depending on splanchnic vascular tone, blood volume can be shifted into the splanchnic circulation, and preload will not increase. AoX, aortic cross-clamping; ( \uparrow ) art, arterial resistance.

(Adapted from Gelman S: The pathophysiology of aortic cross-clamping. Anesthesiology 82:1026-1060, 1995.)

1. ( \uparrow ) Preload*
2. ( \uparrow ) Catecholamines (and other vasoconstrictors)
3. ( \uparrow ) Impedance to Ao flow
4. Active venoconstriction proximal and distal to clamp
5. ( \uparrow ) R art
6. ( \uparrow ) Afterload
7. ( \uparrow ) Coronary flow
8. ( \uparrow ) Contractility
9. If coronary flow and contractility increase
10. ( \uparrow ) CO ( \downarrow )
11. If coronary flow and contractility do not increase

Answer 78

Answers:
1. Increased
2. Increased
3. Increased
4. Increased
5. Increased
6. Increased
7. Increased
8. Increased
9. Increased cardiac output decrease
10. Increased
11. Remains the same

Question 79

Hemodynamic Changes During Cross-Clamping

After Clamp Placement:
1. Venous Return: Blood volume shifts _______(1) to clamp
2. Cardiac Output: Depends on _______(2) reserve
3. MAP: Increase in _______(3) & SVR
4. SVR: Mechanical effect of clamp, _______(4) release, RAAS activation
5. PAOP: Depends on venous return (depends on CV reserve)
6. LV Wall Stress: Increase in _______(5) and afterload
7. MVO2: Increase in preload, wall stress & _______(6)
8. Coronary Blood Q: Increase in AoDBP
9. Renal Blood Q: Even with infrarenal clamp (>30 min increase risk ARF)
10. Total Body VO2: Decrease in O2 delivery distal to clamp → anaerobic metabolism
11. SvO2: Total body VO2 (less O2 consumed so more is left over)

After Clamp Removal:
12. Venous Return: Central hypovolemia & _______(7) leak
13. Cardiac Output: Reduced preload & _______(8)
14. MAP: Decrease in preload & SVR
15. SVR: Washout of anaerobic metabolites → _______(9)
16. PAOP: Lactic acidosis → increase in PVR
17. LV Wall Stress: Decrease in preload & afterload
18. MVO2: Decrease in preload & afterload (if PAOP → increase PVR & decrease MVO2)
19. Coronary Blood Q: Decrease in AoDBP
20. Renal Blood Q: Depends on MAP
21. Total Body VO2: Cells distal to clamp receive O2 → aerobic metabolism
22. SvO2: Total body VO2 (more O2 consumed so less is left over)

Answer 79

Answers:
1. proximal
2. CV (cardiovascular)
3. preload
4. Catecholamine
5. preload
6. afterload
7. capillary
8. contractility
9. vasodilation

Question 80

Left Heart Bypass (“Partial Bypass”)
- Bypassing left heart LA/LV & aorta to repair _______(1).
LA to Femoral Artery
○ nonpulsatile retrograde aortic perfusion
○ does not perfuse the excluded _______(2) segment
■ Blood is removed from the LA
■ advanced distal to the aortic _______(3) site
- Ameliorates LV _______(4).
○ reduces LV preload and _______(5).
- Bypass flow depends on adequate _______(6).
Too high flow hypotension
○ Unlike CPB ↑ flow will ↑ _______(7).

Rate Pressure Product (RPP)
- The RPP is an indicator of the oxygen requirements of the _______(8).
- Intraoperative tachycardia can cause myocardial ischemia by increasing myocardial oxygen demand. Controlling the _______(9) rate significantly reduces the risk of perioperative myocardial events.
- RPP = SBP x HR (Maintain < _______(10))

Answer 80

Answers:
1. aneurysm
2. aortic
3. interruption
4. stress
5. afterload
6. preload
7. MAP
8. heart
9. heart
10. 12,000