Principles Final Flashcards
Risk Factors of CAD
- genetics
- diet
- environment
- hypertension
- smoking
- diabetes
(3) Factors increasing myocardial oxygen demand
wall tension, contractility, and heart rate
(4) Factors affecting myocardial oxygen supply
coronary blood flow
diastolic time
oxygen saturation
myocardial oxygen extraction
Which part of the heart is most vulnerable to ischemia?
left ventricular subendocardium
(3) methods for monitoring Ischemia
ECG, pulmonary artery catheter, and TEE
(3) disadvantages of using Agents with CAD
- myocardial depression
- systemic hypotension
- lack of post-op analgesia
drug of choice for coronary vasospasms
Nitroglycerin
Nitroglycerin
treats coronary vasospasm
- venodilator
- decreases venous return and filling pressures
Phenylephrine
increases myocardial oxygen requirements, but increases coronary perfusion pressure
Verapamil
CCB for treating SVT
Normal pulmonary wedge pressure
12
(above 18 is too high)
How would you treat decreased BP and increased PCWP in a patient with CAD?
phenylephrine, NTG and an inotrope
An ejection fraction less than ____ indicates myocardial dysfunction
0.4
LVED pressure greater than _____ indicates myocardial dysfunction
18 mmHg
“LAMPS” before CPB
- Labs
- ACT and HCT
- Anesthesia
- Monitor
- BP, CVP, and PACWP
- Patient
- Support
(7) Components of Cardiopulmonary Bypass
- circuit
- oxygenator
- pump
- heat exchanger
- primer
- anticoagulants
- myocardial protection
In CPB, blood is drained form the _____ and returned to the ____
right atrium
ascending aorta
(2) Types of CPB Oxygenators
bubble and membrane
(3) Types of CPB Pumps
roller, centrifugal, and pulsatile
CPB primer decreases HCT to ____
< 30%
ACT goal during CPB
> 400 seconds
Hypothermia during CPB
10 - 15 oC
Systemic BP decreased to _____ before aortic cannulation during CPB
80 - 100 mmHg
(reduces risk of aortic dissection)
Most likely cause of neurologic injury after CPB
emboli
(with hypotension being a contributing cause)
Laboratory tests during CPB
- ACT
- HCT
- ABG
- potassium
- glucose
Monitoring during CPB
- BP
- CVP
- ECG - flat line
- urine output
- temperature
Why should mixazolam be given before rewarming?
high risk of awareness
5 - 10 mg
dose of Protamine
1 mg/100 units of Heparin
- administer slowly
- double check with surgeon
- Check ACT before giving
Intra-aortic balloon pumps ___ before systole to ____ afterload and ____ during diastole to ____ coronary blood flow
Intra-aortic balloon pumps deflate before systole to decrease afterload and inflates during diastole to increase coronary blood flow
(3) Side effects of Protamine
hypotension, allergic reaction, and pulmonary hypertension
normal Mitral valve area
4 - 6 cm2
Normal Aortic valve area
2.5 - 3.5 cm2
mitral stenosis area
< 1 cm2
aortic stenosis area
< 0.75 cm2
Murmur in Mitral stenosis
rumblic diastolic
Murmur in aortic stenosis
systolic ejection murmur
(right upper sternal border)
Pathophysiology of Mitral Stenosis
- increased left atrial pressure and volume overload
- impaired blood flow from left atrium to left ventricle
- right ventricular hypertrophy
- pulmonary edema
- increase in left atrial pressure reflected back to pulmonary circulation
most common cause of mitral stenosis
rheumatic fever
Anesthetic considerations in Mitral Stenosis
avoid increased HR or decreased SVR
Dysrhythmia that commonly occurs with Mitral Stenosis
atrial fibrillation
Mitral stenosis has impaired blood flow from _____ to _____
left atrium to left ventricle
(3) Symptoms of Aortic Stenosis
angina, CHF, and syncope
Murmur in mitral regurgitation
holosystolic
(best heard at lower left sternal border)
Murmur in Aortic regurgitation
decrescendo diastolic
(3) symptoms of right heart failure
- hepatic congestion
- peripheral edema
- JVD
Diagnostic methods of Mitral regurge
ECHO and angiogram
Mitral Regurge Treatment
- cardiac glycosides
- hydralazine
- ACE inhibitor
- CHF regimen
mangement goals in Mitral regurge
- small increase in HR
- derease in SVR
Management goals in Aortic Regurgitation
- avoid overzealous fluid
- decrease afterload
- maintain contractility
- slight increase in HR
(4) classic symptoms of CHF
dyspnea, fatigue, fluid retention, and edema
decompensated fluid retention due to CHF may manifest as:
- pulmonary rales
- JVD
- peripheral edema
- ascites and hepatomegaly
- S3 gallop
Acute treatment of CHF
- optimize preload and afterload
- dobutamine, milrinone, and amrinone
- vasodilators
- acute beta blockers
(3) causes of CHF
- weakening of heart muscle
- stiffening of heart muscle
- disease that increase oxygen demand
Patients recieving ____ valves are required to begin anti-coagulaiton therapy
mechanical
CVP may significantly _____ LVEDP
(in aortic valve replacement)
underestimate
anticoagulation for mechanical valves should be started ___ days post-op
2 - 3
aortic stenosis generally has a ____ prognosis than aortic regurge
better
Total Cardiopulmonary Bypass
all venous return from superior and inferior vena cava and coronary sinus is drained
- PA and systemic pressure tracings are non-pulsatile
Partial Bypass
some of the blood return is still pumped by the ventricles
- example: femorofemoral bypass
Keep HCT higher than ____ during priming for CPB
18-20%
(3) Common priming solutions
Normosol, albumin, and mannitol
PA and CVP should be ___ during CPB
low or near zero
urine output rate during CPB
1 mL/kg/hr
Duing CPB, maintain MAP between ____ to ensure adequate tissue perfusion
50 - 100 mmHg
Treatment of Hypotension during CPB
increase flow rate
phenylephrine
How do you treat hypertension during CPB?
inhalational agents via pump
(do not lower pump flow rate)
_____% of normal cardiac output is usually enough to maintain tissue oxygenation
70
normal pump flow
50 - 70 mL/kg/min
Do you give muscle relaxants during CPB?
yes
- prevents diaphragmatic movement and shivering
How does CPB affect muscle relaxants?
- requires more
- reduces renal excretion
- prolonged onset
Normal mixed venous oxygen tension should be _____ during CPB
40 - 45 mmHg
How do you preserve myocardium during CPB?
cardioplegia and hypothermia
Components of Cadrioplegia
- potassium
- magnesium
- THAM or bicarbonate
- steroids, calciu, and insulin
- nitroglycerin
Aorta may be cross-clamped for ____ without perfusion
60 - 120 minutes
At what temperature can patients be weaned from CPB?
37 oC esophageal/naso
35oC rectal/bladder
How do you defibrillate the heart internally during CPB?
DC at 5 - 10 joules
platelet function returns to normal ____ hours post CPB
2 - 4 hours
Thrombocytopenia is more common with ____ oxygenators
bubble-type
What is the most common cause of bleeding post CPB?
platelet dysfunction
Laboratory tests for termination of CPB
- HCT 20-25%
- potassium 4 - 5.5
- ionized calcium 1.1 - 1.2
- mixed venous oxygen more than 70%
IABP is used when LVEF is predicted to be less thatn ___
25%
If LVEF is between 25 - 35%, which inotropic drug should be used?
milrinone
Mechanism of action of protamine/heparin
heparin is a strong aid
(protamine a strong base)
(3) Types of Protamine reaction
- I - systemic hypotension from rapid injection
- II - anaphylactic or anaphylactoid
- III - catastrophic pulmonary vasoconstriction with sytemic hypotension
How do you treat hypotension after protamine administration?
rapid volume infusion and vasoconstrictors
Bystolic
beta blocker
Lamisil
treats fungal infections
Lipitor
treats high cholesterol
Transvalvular gradient
greater than 50 mmHg represents significant aortic stenosis
Gingko
increases blood flow through atherosclerotic vessels
(may increase bleeding)
Aortic stenosis represents obstruction to ______ tract
left ventricular outflow
Pathophysiology of Aortic Stenosis
- concentric hypertrophy of LV
- decreased ventricular compliance
(contractility and ejection fraction usually maintained)
Hemodynamic goals of aortic stenosis
- adequate volume
- maintain SVR, HR and normal rhythm
- maintain contractility
Hemodynamic goals of Aortic Regurge
- adequate preload
- increase HR
- decreased afterload
Risks associated with cannulation of vein during PAC
bleeding, infection, air embolism
Risks associated with floating PA catheter
arrhythmias, PA rupture, failure to wedge
What should be done before sternal splitting?
additional narcotics and lung deflation
What are some causes of hypotension during CPB?
limited pump flow, aortic dissection, and low peripheral resistance
(3) types of burns
thermal, eletrical, and chemical
Most common type of burn
thermal
second degree burn
blisters
third degree burn
burn through dermis
(insensitive)
Pulmonary complications of burns within 24 hours
CO poisoning, inhalational injury, and edema
pulmonary complications days to weeks after burn injury
pneumonia, atelectasis, and pulmonary emboli
Problems with cabon monoxide poisoning
- tissue hypoxia
- left shift of oxy-hemoglobin curve
- cardiovascular depression
- cytochrome inhibition
Intial cardiovascular effects of burns
- hypovolemia
- depressed myocardial function
- increased blood viscosity
- release of vasoactive substances
Problems with renal function due to burns
- decreased function and GFR
- increased ADH
- acute renal failure
- hemoglobinuria and myoglobinuria
How are hemoglobinuria and myoglobinuria treated?
fluid resuscitation and alkalinization with bicarb
then osmotic diuretics
Rule of 9’s
A. Head and Neck 9%
B. Arms 9% each
C. Anterior chest 9%
D. Posterior chest 9%
E. Abdomen 9%
F. Lower Back 9%
G. Legs 18% each
H. Perineum 1%
(2) formulas used for fluid resuscitation in burn patients
Parkland and Brooke
Parkland forumla
LR 4 mL/kg/% BSA burn
- 50% given in first 8 hours
- after 24 hours, use colloids
Common procedures in burn patients
- escharotomies
- burn excision and skin graft
- reconstruction
- tracheostomy
Drug resposnes in burn patients
- increased opioid requirement
- prolonged duration in those that need liver
- albumin bound drugs will have a prolonged effect
Most common complication following massive transfusion
dilutional thrombocytopenia
After how many PRBC will a patient need FFP and platelets?
12 units - FFP
20 units - platelets
What causes a hemolytic transfusion reaction?
ABO incompatibility
- Kell, Kidd, Lewis, and Duffy antigens
- hemolysis takes place in either extravascular or intravascular space
Signs and symptoms of hemolytic transfusion reaction in patient under GA
- hypotension
- hemoglobinuria
- diffuse bleeding
- oliguira leading to renal failure
Signs and symptoms of hemolytic transfusion reaction in awake patient
- fever, chills, nausea
- hypotension
- tachycardia
- restlessness
- flused and dyspneic
Types of Blood transfusion reactions
- febrile non-hemolytic (most common)
- hemolytic and delayed hemolytic
- allergic urticarial
What is the treatment for febrile non-hemolytic transfusion reaction?
- acetaminophen, NSAIDS
- antihistamines
- leukocyte depleted blood products
What lab value abnormalities would you expect in a patient with DIC?
- Prolonged PT and PTT
- Reduced platelet count
- Reduced fibrinogen level
- Elevated fibrin degradation products
Citrate
anticoagulant used in stored blood products
- can cause hypocalcemia and dysrhythmias
TRALI
non-cardiac pulmonary edema occuring within 6 hours of transfusion
- related to antibodies to leukocytes
- resolves within 96 hours
- treat with oxygen, mechanical ventilation, and support of BP and CO
Shunt
phenomenon that occurs when portion of venous return of one circulation (pulmonary or systemic) is redirected back to arterial outflow of the same circulation
(3) Types of Shunt
simple, bidirectional, and complex
Left to Right shunt
pulmonary venous directed towards pulmonary arterial system
Potential problems of L-to-R shunt
- hypotension
- pulmonary edema
- increased PVR
Right to Left Shunt
systemic venous return directed to systemic arterial outflow
- bypasses the lungs
- results in arterial oxygen desaturation
(5) Lesions characterized by excessive pulmonary blood flow
- atrial septal defects
- ventricular septal defects
- atrioventricular septal defects
- truncus arteriosus
- hypoplastic left heart
(4) lesions characterized by inadequate pulmonary blood flow
- transposition of great vessels
- tetralogy of fallot
- tricuspid atresia
- total anomalous pulmonary venous return
Marfan’s Syndrome
disorder of connective tissue
Symptoms of Marfan’s
- lens dislocation
- aortic dissection, myocardial ischemia, and arrhythmias
- restrictive lung disease
- tall stature, joint hypermobility, and hernias
Preoperative preparation for Marfan’s
- antibiotics for SBE
- BB
- reduce risk of aortic wall tension
airway concerns in Marfan’s
- high arched palate
- potential cervical instability
- potential for TMJ dislocation
Lifespan of tissue valve
12 - 15 years
Advantage and Disadvantage of mechanical valves
lasts forever
require anticoagulation for remainder of life
In a mitral valve replacement, the heart is opened through the _____
left atrium
In mitral stenosis, avoid increases in ____
PVR and tachycardia
