Chem/physics In Anesthesia

Front 1

What are the values for normal CO and CI?

Back 1

CO= 4-7 L/min
CI= 2.5-4 L/min/meter squared

Front 2

What is the normal value for CVP or RAP?

Back 2

0-5 torr or cm of water

Front 3

What is a normal RVP? (right ventricular pressure)

Back 3

30 systolic, 5 diastolic

Front 4

What is a normal PAP? (pulmonary artery pressure)

Back 4

30 systolic, 10 diastolic, <20 mean

Front 5

What is a normal PAWP or PAOP?

Back 5

<20 mean

Front 6

What is a normal LAP? (left atrial pressure)

Back 6

<12 mean

Front 7

What is a normal LVP? (left ventricular pressure)

Back 7

140 systolic, 12 diastolic

Front 8

What is the mean blood pressure value below which autoregulation is lost?

Back 8

60

Front 9

What is the calculation for MAP?

Back 9

1/3PP +DBP

(SBP-DBP)/3 +DBP

Front 10

What is the calculation for LaPlace's Law for a sphere?
(Physics of LV contraction)

Back 10

P=2T/R

P=pressure at outlet
T=tension of wall
R=radius of wall

Front 11

Regarding the equation T=PR, at a constant pressure in the vessel or outlet of LV, the tension in the wall _________ with increased radius.

Back 11

Increases

Front 12

How is an arterial waveform different in a more peripheral site (such as dorsalis pedis) from a more central site (such as in the brachial artery)?

Back 12

The waveform is higher and sharper; waveforms become higher and sharper more peripherally.
(doesn't necessarily mean change in pressure)

Front 13

In spontaneous respirations, inspiration ________ intrathoracic pressure and therefore ________ CO and BP.

Back 13

DECREASES intrathoracic pressure; INCREASES CO and BP

Front 14

With PPV, on inspiration, intrathoracic pressure is ________ and therefore CO and BP is ________.

Back 14

Intrathoracic pressure is INCREASED;
CO and BP is DECREASED

Front 15

The calculation for SVR is:

Back 15

[(MAP-CVP) x80] /CO

Front 16

Normal SVR is:

Back 16

900-1500 dynes/sec/cm-5

Front 17

What are some factors that can decrease SVR?

Back 17

Vasovagal syncope, bacteremia/sepsis, anesthetics

Front 18

What are some factors that can decrease CO?

Back 18

Decreased venous return, MI, myocarditis, tamponade, valvular disease, CHF, PPV, PEEP

Front 19

What are some factors that increase CO?

Back 19

Exercise, SNS stimulation, septic shock, Nipride, any increase in metabolism (fever, thyrotoxicosis)

Front 20

BP is dependent on what two factors?

Back 20

Cardiac Output and SVR

Front 21

In septic shock, what happens to the values of PCW, MAP, SVR and CI?

Back 21

Decreased PCW, MAP, and SVR
Increased CI

How is this treated?

Hint 21

Increase circulating volume and use pressors

Front 22

In Cardiogenic shock, what happens to the values of PCW, MAP, SVR, and CI?

Back 22

Increased PCW and SVR
Decreased MAP and CI

How is this treated?

Hint 22

Careful optimization of circulating volume, diuretics, vasodilators, and inotropes

Front 23

In hemorrhagic shock, what happens to the values of PCW, MAP, SVR, and CI?

Back 23

Increased SVR
Decreased MAP, CI, and PCW

How is this treated?

Hint 23

Volume loading

Front 24

What are the sound markers called in manual non-invasive blood pressure?

Back 24

Korotkoff sounds

Front 25

If non-invasive blood pressure cuff is too wide, you will get a falsely _____ reading. If non-invasive blood pressure cuff is too narrow, you will get a falsely _____ reading.

Back 25

too wide- falsely low reading
too narrow-falsely high reading

Width and length of cuff bladder should be what percents of arm circumference?

Hint 25

width-40%
length-80%

Front 26

What's the best artery choice for invasive BP monitoring?

Back 26

Radial

Which arteries are considered last resort?

Hint 26

Femoral or brachial
(because of no collaterals)

Front 27

What factors may change the accuracy of your transducer in your invasive BP monitor?

Back 27

Change in temperature, patient repositioning, passage of time

Front 28

Invasive BP transducer should be re-zeroed when:

Back 28

-Temp. changes >5 degrees C
-At least every 4 hours
-Before critical reading
-Whenever reading is questionable

Front 29

When checking flow of arteries for radial art-line placement, what test is utilized when testing of both ulnar and radial arteries are tested?

Back 29

Allen's Test

What test is utilized if only ulnar artery flow is tested?

Hint 29

Modified Allen's Test

Front 30

What is necessary for these tests to take place regarding the patient?

Back 30

Patient must be conscious to perform clenching of hand.

What test is utilized if the patient is unconscious and the flow is checked via pulse oximeter?

Hint 30

Modified-modified Allen's test

Front 31

What causes a Dichrotic notch on the arterial wave form?

What does it indicate?

Back 31

Caused by aortic valve closure

Indicates good wave form

Front 32

What level should the invasive BP transducer be placed?

Back 32

Phlebostatic axis
(4th intercostal space, midaxillary line)

Where should it be placed in sitting craniotomy cases?

Hint 32

At the level of the Circle of Willis

Front 33

CVP is a good reflection of:

Back 33

Cardiac function and Venous return to the heart.

CVP is also known as:

Hint 33

Right atrial pressure (RAP)
Right ventricular diastolic volume (preload)

Front 34

CVP is a good indicator of right sided cardiac function; when can it be a good indicator of left sided heart function as well?

Back 34

When the patient is healthy and has good heart and lung function.

Front 35

Greatest risk for air embolus occurs in which surgical position?

Back 35

Sitting crani or wound above heart level.

Why?

Hint 35

Crani veins are always stented open and are therefore more susceptible to air emboli.

Front 36

Which waves in the CVP waveform are positive and indicate increased pressure?

Back 36

A, C, and V waves

Which indicate a decrease in pressure and are therefore negative waves?

Hint 36

X and Y waves

Front 37

In the CVP waveform, the a wave indicates what?

Back 37

Increased atrial pressure during RIGHT ATRIAL CONTRACTION.

Front 38

In the CVP waveform, the c wave represents what?

Back 38

CLOSING OF THE TRICUSPID VALVE during ventricular contraction.

Front 39

In the CVP waveform, the v wave represents what?

Back 39

Increased pressure when BLOOD FILLS RIGHT ATRIUM.

Front 40

What do the two negative waves, x and y represent?

Back 40

X represents the drop in arterial pressure during ventricular systole

Y represents opening of the tricuspid valve during diastole when blood flows into right ventricle.

Front 41

What happens to the CVP wave in atrial fibrillation?

Back 41

a waves will be absent

In atrioventricular disassociation, a waves will be dramatically increased.

What are these increased waves called?

Hint 41

Cannon waves

Front 42

What happens to the CVP wave in the instance of tricuspid regurgitation?

Back 42

The C wave and X wave will be replaced with a large positive wave
(because of regurg. when blood is flowing back into the right atrium during ventricular contraction)

Front 43

What happens to the CVP wave in the instance of Cardiac tamponade?

Back 43

All pressures will be elevated and Y wave will be nearly absent.

Front 44

What are some contraindications to central venous catheter use?

Back 44

-Previous carotid endarterectomy on ipsilateral side as catheter
-Tricuspid valve vegetation
-Renal cell tumor extension to right atrium

Front 45

What are some contraindications to PA catheter use?

Back 45

-Wolff-Parkinson-White syndrome
-Ebstein's malformations
-Complete left BBB

Front 46

PCWP measures what?

Back 46

-indirectly measures left ventricular end diastolic pressure (LVEDP)

Front 47

What are instances where PCWP overestimates LVEDP?

Back 47

-Chronic Mitral Stenosis
-PEEP
-Left atrial myxoma (primary heart tumor)
-Pulmonary Htn

Front 48

What are instances where PCWP underestimates LVEDP?

Back 48

-Stiff left ventricle
-LVED pressure > 25 mmHg
-Aortic insufficiency

Front 49

What technique does the PAC use to measure CO? How does it work?

Back 49

Thermodilution-cool fluid injected into right atrium passes tip of PAC in pulm. artery & detects temp. change.

The degree of temperature change in the fluid is ________ proportional to the cardiac output.

Hint 49

Inversely;

Increased blood flow/CO= minimal temp. change

Decreased blood flow/CO=pronounced temp. change

Front 50

How do you calculate PVR?

Back 50

[(PA-PCWP) x 80] / CO

What is a normal range for this value?

Hint 50

100-300 dynes/sec/cm-5

Front 51

When observing the CVP waveform, CVP ________ with spontaneous inspiration and _________ slightly with PPV inspiration.

Back 51

CVP decreases with spontaneous insp. and CVP increases with PPV insp.

Patients on PEEP > 7.5 may also have elevated CVP.

Why is this?

Hint 51

This is from artifact due to the central line placement being in the thorax.