Blue Book Flashcards
aneurysm definition
expansion of the wall of a blood vessel
what is an aneurysm caused by
atherosclerosis: build up of plaque on the inside of an artery hypertension injury infection marfan's syndrome pregnancy
aneurysms of the aorta may rupture immediately causing what?
loss of systemic blood flow volume and pressure
dissection definition
tear in the layers of the aortic wall causing blood to flow between the layers of the aorta
how is arterial blood pressure ideally monitored in an aortic arch repair
left radial art line and femoral line
why is the left radial used and not the right?
the right may be compromised by the clamping on the ascending aorta since the right radial arises from vessels off the innominate arty which is often too close to affected area
when there is a dissecting thoracic aortic, what may become obstructed coming off the aorta?
cerebral, coronary, renal and peripheral vessels
what will you see if there is a dissection during cardiac surgery?
the arterial perfusion line pressure may rise immediately and then possibly fall as the dissection extends
describe debakey’s classification of thoracic aortic dissections
Type 1: begins in the ascending aorta just above the aortic valve and extends into the descending aorta
type 2: includes the ascending aorta only
type 3: originates distal to the left subclavian artery and involves the descending aorta only
what the device that is used to monitor the oxygen saturation in both sides of the brain?
cerebral oximeter
what can the cerebral oximeter help the perfusionist measure?
indirect assessment of the cerebral blood flow
what are some “cons” of the clamp and go method for descending thoracic and thoracoabdominal aneurysms?
- kidneys, liver, and gastrointestinal regions are not perfused
- left ventricle must eject against a clamped aorta, which can increase after load of the left ventricle (blood left in the ventricle after ejection)
- anterior spinal artery syndrome
Temperatures of _____ degrees C and below are thought to cause cessation of the brain’s electrical activity and provide optimal protection
15 degrees C
Some research shows that hyperglycemia in circulatory arrest patients may cause damage to the central nervous system. Therefore, what should be give to the patient?
Insulin should be given if blood glucose levels rise too high prior to circulatory arrest
what other drugs are given to patients undergoing circulatory arrest?
sodium Pentothal: causes the brain’s electrical activity to decrease
forane: barbiturate effect on the brain (sedative or sleep-inducing drug)
A temperature gradient less than __ should be maintained during rewarming. Why?
less than 8 degrees.
More oxygen is held in solution in cold blood, and warming the patient to rapidly may cause micro bubbles
mild temperature
32-37
moderate temperature
28-31
deep temperature
18-28
profound temperature
0-18
if the patient is 32 degrees C, what should the arrest period be?
under 10 min
if the patient is 28 degrees C, what should the arrest period be?
10-15 min
if the patient is 18 degrees C, what should the arrest period be?
16-45 min
if the patient is under 18 degrees C, what should the arrest period be?
46-60 min
what is a pulmonary embolism and what can it cause?
embolism may be a blood clot, fat, air or debris
result in circulation to a lung being stopped or compromised
in patients who are rapidly deteriorating from pulmonary embolism, what surgery might be done?
pulmonary embolectomy
what are indicators that a patient may need emergency surgery to remove embolus?
- arterial pO2 less than 60 mmHg
- systolic blood pressure less than 90 mm Hg
- urine output less than 20 cc an hour
what are the most common problems that occur during pregnancy?
valvular disorders
when is the safest period for the mother and the fetus for the surgery to be performed?
second trimester
why is the first trimester dangerous for surgery?
the embryo is easily injured by hypoxemia, drugs, and other factors
why is the last trimester dangerous for surgery?
premature labor can occur
also, the blood volume of the fetus and the output directed to the uterus is at its greatest
does heparin cross the the placental barrier?
NO
heparin does not cross the placenta
what anticoagulant does?
Coumadin
if a mitral valve is necessary, what valve must be used on the pregnant patient?
porcine valves that do not require anticoagulants
why are pregnant patients not cooled?
because the fetal heart rate would decrease and uterine contractions may be precipitated by rewarming
what is the BPM that the fetus must stay in range of when on bypasss?
60 BPM
what are the flows on a pregnant patient?
- flows are maintained high
- cardiac index of 3 to 3.2 L/min/M sq may be necessary to ensure the fetal heart beat is kept above 60 BPM
what should the mother’s blood pressure be kept at to provide optimal flow to the uterus?
65 mmHg
what should be used to increase the pressure while on bypass for a pregnant patient?
epinephrine
what drugs should not be used on bypass? and why?
neosynephrine and levarterenol
these drugs are alpha agonists and can compromise blood flow to the uterus
what drug should be used for hypertension on a pregnant patient?
hydralazine
what drug should NOT be used for hypertension on a pregnant patient? and why?
sodium nitroprusside
cyanide toxicity possible and its effect of the fetus
what are cold agglutinins or cryoproteins?
antibodies that work on the antigens found on the surface of red blood cells that cause complement activation and red blood cells to clump at low temperatures and break down
what antibody class are usually the one where the agglutination is significant?
IgM
if a patient must be cooled to temperatures that may cause a reaction, what is necessary?
plasmapheresis
if cold cardioplegia is desired for a cold agglutinins patients, what type should be used?
plain crystalloid
what is cannulation for a hypothermia patient?
femoral artery and femoral vein
what should the setup of the circuit be for hypothermia patients?
- half of heparin should be circulated in the pump prime if the ability of the patient to circulate the heparin is in question
- ultrafiltrator is used to control volume status and because of the possibility of ensuing renal failure
- oxygenator will help the patient if they may be in an acidotic state
- temperature of the priming solution should be near the patient’s core temperature when bypass is initiated
how fast should hypothermia patients be warmed?
rewarmed at a rate of 4 degrees an hour to ensure adequate recovery time and uniform rewarming
what should be done when a hypothermia patient starts fibrillating during rewarming?
cardioversion should be attempted when the core temperature has reached 32 C
what is the goal when performing CPB on Jehovah’s Witness patient?
strict blood conservation
autotransfusion, ultrafiltration, and return of the chest tube output
what should be taken into consideration when setting up a pump for Jehovah’s Witness patient?
- minimizing the pump circuit and priming volume
- blood is returned to patient in a continuous loop by connecting cell save or chest tube directly in line to an IV site for direct infusion
what drugs can be given to manage blood?
hespan or dextran may be given as plasma expanders
