Hall Ch11 Flashcards
What type of patients should receive antibiotic prophylaxis for infective endocarditis?
Pts undergoing selected dental procedures with prosthetic valves, previous infective endocarditis, congenital heart disease, heart transplant with valvulopathy
Most sensitive indicator of left ventricular myocardial ischemia
Wall motion abnormalities on echocardiogram
2500 cc/min of oxygen consumption equates to how many METs?
10 METs. 1 MET equals energy expended during 1 minute of rest
Common reason for pulmonary artery pressure to suddenly increase during CPB
Distal migration of pulmonary artery catheter into a wedge position. Another reason is inadequate ventricular venting leading to ventricular distension
During CPB, facial or scleral edema is a sign of
Malposition of venous cannula
During CPB, unilateral facial blanching is a sign of
Improper positioning of aortic cannula
How does transposition of great vessels affect inhalation induction?
Slower than normal
How does transposition of great vessels affect IV induction?
Faster than normal
Fontan procedure (anastomosis of right atrial appendage to pulmonary artery treats which congenital cardiac defects?
Tricuspid atresia, pulmonary atresia, pulmonary stenosis, hypoplastic left heart
Tissue metabolic rate is reduced by how much for each degree body temperature is lowered?
5-8% for every degree of body temp lowered. CPB
Effective deflation of IABP occurs when?
Just before ventricular systole or midpoint of QRS complex
Effective inflation of IABP occurs when?
Immediately after closure of aortic valve or after T wave
Effects of afterload reduction on Tetralogy of Fallot
Increases right to left shunt which worsens systemic hypoxemia
Afterload reduction is beneficial for which cardiac conditions?
Aortic insufficiency, mitral regurgitation, congestive heart failure, patent ductus arteriosus
Protamine is a compound isolated from?
Fish sperm
Dose of protamine to reverse heparin
1.3 mg of protamine for each 100 units of heparin
Administering protamine to pt who hasn’t received heparin results in?
Anticoagulant effect by binding to platelets and soluble coagulation factors. Hypotension if given rapidly because of histamine release.
3 factors that determine myocardial O2 demand from most to least important
Heart rate > afterload > preload
Pulsus paradoxus is sign of
Cardiac tamponade, severe airway obstruction, RV infarction. (Inspiratory fall in SBP > 10 mmHg)
Pulsus parvus (diminished pulse wave) and pulsus tardus (delayed upstroke) are signs of
Aortic stenosis
Pulsus alternans (alternating smaller and larger pulse waves) is a sign of
Severe LV dysfunction
Bisferien pulse (pulse waveform with 2 systolic peaks) is a sign of
Significant aortic regurgitation
Drugs that can be administered down ETT?
ALONE: Atropine, Lidocaine, Oxygen, Naloxone, Epinephrine. Vasopressin too
Amiodarone is what class of antidysrhythmic?
Class 3, prolongs action potential and repolarization
Amiodarone metabolism
Liver
Amiodarone half life
58 days
Amiodarone excretion
Bile
Lidocaine is what class of antidysrhythmic?
Class 1B
Lidocaine metabolism
Liver
Lidocaine excretion
Urine 90%
Lidocaine half life
1-8 hrs
Antidysrhythmic drug that may cause hypothyroidism or hyperthyroidism
Amiodarone, a benzofurane derivative with similar chemical structure to thyroxine
Equation for SVR
SVR = 80 * ((MAP-CVP)/CO)
Beta 2 stimulation effects include…
Relaxation of vascular, airway, and uterine smooth muscle tone. Glycogenolysis Gluconeogenesis Insulin secretion Renin secretion
Which volatile agent causes the most direct myocardial depression?
Halothane
What is halothane’s effect on SVR?
Unchanged
What is halothane’s effect on heart rate?
Decrease in heart rate.
MC form of inherited long QT syndrome
Romano Ward
Treatment for Romano Ward (long QT)
Left stellate ganglion block which shortens QT interval and temporarily abolishes the imbalance between right and left sides of the sympathetic nervous system that may play a role in the etiology of the syndrome
Why is left stellate ganglion block used to treat long QT syndrome?
Long QT syndrome is thought to be caused by a left greater than right sympathetic activity so left stellate ganglion block will balance the activity
What percent of cardiac output is dependent on atrial kick?
25%
An arterial waveform with 2 systolic peaks is a sign of what cardiac disorder?
Severe aortic regurgitation. 2nd peak is a reflected pressure wave from the periphery
Which volatile anesthetic provides most stable hemodynamics for hypertrophic cardiomyopathy
Halothane
What type of induction would provide most stable hemodynamics for tetralogy of Fallot?
Ketamine, which maintains SVR and minimizes right to left shunt
Under max stress, how much cortisol is produced per day?
150 mg
Normal resting myocardial O2 consumption
8-10 mL/100g/min or 10% of total body consumption of O2
Normal resting coronary artery blood flow
75 mL/100g/min or 225-250 mL/min or 4-5% of cardiac output
Known risk factors for pulmonary artery rupture with PA catheter
Elderly Anticoagulation Hypothermia (stiffens catheter) Migration Prolonged wedge time
Why are IDDM pts at risk of allergic rxn to protamine with certain types of insulin?
These pts have been exposed to protamine which is in some types of insulin like NPH and PZI
Half life of heparin
1.5 hrs
Medication that inhibits breakdown of adenosine so dose of adenosine should be reduced
Dipyridamole
The reason for measuring both bladder and PA catheter temperature
Helps evaluate adequacy of rewarming after CPB
Best TEE view to monitor myocardial ischemia
Transgastric mid papillary left ventricular short axis view
Most frequent initial rhythm in a witnessed sudden cardiac arrest
Ventricular fibrillation
Mechanism of action of milrinone
PDE3 inhibitor
Non immune HIT is which type?
Type I, transient and clinically insignificant
Mechanism of action of hirudin
Direct thrombin inhibitor
HIT type 2 is where a complex is formed consisting of?
Antibody, heparin, and platelet protein factor 4. This complex bonds to endothelial cells which then stimulate thrombin production
Mechanism of action of clopidogrel
Noncompetitive irreversible inhibition of ADP receptor P2Y12.
Type of WPW rhythm that is amenable to rate control
Narrow complex tachycardia, conduction is orthodromic (conduction passes through AV node)
Type of WPW rhythm that is NOT amenable to rate control
Wide complex tachycardia, antidromic conduction. Rx is procainamide
Procainamide is what class of antidysrhythmic
Class 1A, used to treat antidromic wide complex tachycardia in WPW patient
What to do if pacemaker is set to DOO mode at 70 bpm and under GA the patient’s native HR increases to 85?
Give beta blocker to avoid R on T phenomenon.
Main advantage of milrinone over amrinone in long term use is lack of what side effect?
Thrombocytopenia
Dromotropy
Conduction of impulses along conduction tissue
Bathmotropy
Muscular excitation in response to a stimulus
Lusitropy
Myocardial relaxation or diastole
At what lung volume is pulmonary vascular resistance the least?
FRC
Cardiac risk factors for elective noncardiac surgery
High risk surgery CHF Ischemic heart disease Cerebrovascular disease IDDM Creatinine > 2mg/dL