Test 3 Flashcards
Definition of MAP
The cuff pressure at which amplitude of oscillations is the highest
What are size requirements for BP cuff?
Bladder width should be 40% of extremity Bladder length should be 80% of extremity
As BP cuff moves peripherally, SBP _________ and DBP _________.
SBP increases DBP decreases
For every 1 inch change in level of BP cuff in relation to the heart, how much does the pressure change?
1 inch=2 mm Hg change So elevated above heart 1 inch, will read 2 mm Hg lower than actual P. Lower 1 inch below heart, will read 2 mm Hg higher than actual P.
Which positions are contraindicated for use of a calf BP?
Sitting or reverse Trendelenburg; BP will read normal but will be much lower at level of heart and patient is at high risk for cerebral ischemia.
T/F Abnormal artery flow after removal of A-line is a frequent occurrence.
True. May take 30-70 days to normalize.
How to decrease risk associated w/ A lines? (4)
Low catheter to artery size ratio Continuous saline infusion at 2-3 mL/hr Minimize flushing Use aseptic technique
How to assess adequate perfusion on ipsilateral hand as A-line is present?
Pulse oximetry to assess continuous perfusion on ipsilateral finger.
Where is the phlebostatic axis?
4th ICS, mid anteroposterior level
Why do we place the transducer at the level of the ear in a sitting position?
This is the location of the Circle of Willis and measures arterial pressure at the base of the brain.
As the pulse moves peripherally, the arterial waveform becomes __________
distorted
The dicrotic notch on the A line aligns with what ECG event?
The end of the T wave. It signals end systole and closure of aortic valve; the IABP also inflates during this mark as this is when diastole is beginning.
The frequency of the arterial system should be higher/lower than the artery for proper function?
Higher. Adding extra tubing, stopcocks, and air in the tubing can decrease the frequency of the system making it unreliable and overdamped. If you increase the frequency of the system, this could lead to underdamping.
What are some physiological causes of underdamped Arterial line tracings?
Poor vascular compliance Severe hypothermia Some dysrhythmias *Can overestimate BP by 15-30 mmHg and amplify artifact*
What is an optimum square wave test?
1-2 oscillations before return to tracing Underdamped: >2 Overdamped: <1
Which lung zone should the PAC be in? What does this mean?
Zone 3 PA>PV>Palv The zones are gravity dependent changes in V/Q in the lung. Zone 3 means that pulmonary arterial pressures are higher than venous, which are higher than pulmonary alveolar pressures. These zones change with patient position so a seated pt Zone 3 is in the lung bases but a patient lying down it will be the posterior lung fields.
Which factors increase CVP?
Transducer below phlebostatic axis VSD Hypervolemia RV failure Pericarditis Tamponade Pulmonic stenosis TR/stenosis PEEP
How do you put a patient in Durant’s position?
Left lateral decubitus and Trendelenburg
Which patients would benefit from IJ CVC over SC?
Those w/ coagulopathy would benefit from IJ b/c can hold pressure over site; those with lung disease/injury d/t increased risk of pneumo.
What is the Fabian test?
Connecting tubing to the CVC prior to threading catheter to ensure venous cannulation. The blood is allowed to fill the tubing and then held up against gravity-arterial blood will flow up the tubing column but venous blood will flow downward or stay static.
Entry into RV from RA is indicated by?
Rapid rise in SBP, from 0-8 to 20-30 mm Hg
Entry into the PA from the RV is indicated by?
Rapid rise in DBP; from 0-8 to 8-15, as well as the appearance of a dicrotic notch that was absent in the RV.
Where is cold injectate introduced during thermodilution?
Right atrium…it is measured at the tip of PAC for T change
What is the gold standard for measuring CO?
Thermodilution w/ PAC
