CV Surgery Flashcards
What population is at higher risk for cardiac surgery and why?
Females older than 70, had protective estrogen so diagnosed later
Vasculature much smaller (targets)
What is the best indicator for post operative functional status in cardiac patients?
Ejection fraction
What is the gold standard in determining cardiac functional status?
Cardiac cath, gives a full picture of the coronaries
What interventions are used to decrease cardiac O2 utilization for CV surgery?
Anesthesia
Hypothermia
Electrical silence (cardioplegia)
Emptying the cardiac chambers, especially the LV
What technique is used to maintain adequate perfusion since the blood has a decreased viscosity from hypothermia?
Hemodilution and acceptable perfusion pressure
What two organs are at the most risk for injury from CV surgery?
The brain and kidneys
Why is it important to know if the CV patient has had a history of groin or leg vascular surgery?
These are used as graft sites or cannulation
What is the difference between HIT-1 and HIT-2?
HIT 1 usually not as bad self limiting
HIT2 worse and is cause by an immune mediated response
What drugs can be given if a patient is allergic to heparin?
Low molecular weight heparin or heparinoids
What is heparin resistance?
The need for greater amount of heparin to obtain the desired ACT
What can be given if a patient is heparin resistant?
AT III (in cryo)
What type of EKG should be in place for CV surgery?
5 electrode (7 leads), show two different lead on monitor at a time
Where are alternative sites for the pulse oximeter in CV patients?
Ear, lip or tongue
Where are arterial lines typically placed for CV surgery?
Radial unless using as bypass vessel conduit
What needs to be done before a TEE can be placed?
Empty the stomach
Why is it essential to monitor more than one temperature site during CV surgery?
Each temperature site measures different blood supply (vessel rich, vessel poor)
What are typically the three locations to monitor temperature during CV surgery?
The bladder, esophageal and skin
What should always be checked prior to placing an a-line?
The Allen test, measures collateral circulation to radial and ulnar arteries
At what temperature should the provider never warm the CV patient due to poor neurologic outcomes?
Greater than 37C
Why is the ulnar artery starting to be used more frequently as an arterial line site?
The radial can be used as a graft
Why is it preferred to place a left axillary a line if required compared to a right?
The left lies distal to the aortic arch and great vessels and decrease the risk of cerebral embolization
What two a line sites would resemble the aortic pressure waveforms?
Axillary and Femoral
What invasive monitor is a standard in monitoring CV surgical patients?
Pulmonary artery catheter
What is the most important application of CVP monitoring?
Provide an estimate of the adequacy of circulating blood volume and right ventricular preload
Where is the most common location to place a PAC?
The IJ, it is the most direct route
In what cases will the PAC not estimate LV?
Lung disease or Valve pathology
At what length is the provider expected to be in the RA, RV and the PA?
RA 10
RV 20
PA 30
How might the provider tell from the monitor that they have advanced from the RV to the PA?
The diastolic pressure is higher in the PA
Why don’t we typically wedge in CV surgery?
The catheter gets cold and there is a potential for the balloon to rupture
What pressure can be used in place of the wedge?
PA diastolic = wedge (unless pulmonary HTN and mitral valve function)
What can a wedge pressure of 20 indicate?
Normal compliance when given preload
External pressure
Stiff ventricle
What is the most common arrhythmia from PAC placement?
RV ectopy
Why is it so dangerous to place a PAC in a patient with a LBBB?
RBBB can be caused by PAC placements and then you have a total blockage
What is the most common complication of PAC placement from a subclavian approach?
Pneumothorax
What is the most common mechanical error from PAC placement?
Arterial puncture compared to venous
What is the most common life threatening complication of PAC placement?
Cardiac tamponade
Why are TEEs used?
Helps diagnose underlying mechanisms ascribed to several scenarios (ventricle filling, CO, tamponade, calcifications, thrombus)
What are contraindications to the used of TEE?
Esophageal pathology
If calcifications are found when performing TEE what does that indicate?
That the surgeon should not clamp the aorta because of the risk of breaking off and going to the brain
What are the most important TEE views?
Four chamber view Long axis view Two chamber view Mild short axis Basal short axis
What are specific recommendations for hemodynamics in patients with aortic and mitral stenosis prior to going on pump?
Maintain preload and SVR
HR 50-80 NSR
What are specific recommendations for hemodynamics in patients with aortic and mitral regurgitation prior to going on pump?
Maintain preload
Low SVR
Low HR 60-80 NSR