ch. 6

Question 1

define how bronchial vasculature affects cardiac output and pulmonary veins?

Answer 1

bronchial vasulation (part of systemic circulation: oxygenated blood to lung tissue)
bronchial venous blood is deoxygenated & drain into pulmonary veins mixing is called anatomical shunt, contribute to 1-2% cardiac output.

Question 2

describe the diffence in resistance b/w pulmonary circulation and systemic circulation

Answer 2

pulmonary: lower resistance 1/10 of systemic blood flow easier than lungs keep capillaries safe& allow proper gas exchange

systemic; push blood to entire blood, systemic arteries are larger and narrower less cpmpliant, longer distance and pushing against gravity so increase pressure and increase resistance.

Question 3

what is the name of the pressure that is essentially equal to the left ventricular end-diastolic pressure

Answer 3

pulmonary capillary wedge pressure(PCWP)
-pressure in left atrium( tells Dr if heart is getting too full or backed up w/blood) increase when heart is having trouble

Question 4

what is the name of the pressure that is commonly used as a clinical indicator of left ventricular function

Answer 4

PCWP

Question 5

what would happen to PCWP in a patient with a stenotic mitral valve

Answer 5

mitral valve narrows left atrium fills w/blood pressure builds up and can not flow into Left ventricle. PCWP elevates

Question 6

why should the balloon of the PAC be left inflated when inserted in the right attrium

Answer 6

decrease risk of cardiac arrythmias, follows direction of blood flow.
R.A–>R.V–>pulomonary artery

Question 7

during the insertion of pulmonary artery catheter, it is observed that the waveform increases in height and that the pressure is about 25/0. where is the catheter probably located?

Answer 7

Right ventrical

R.A=low pressure
R.V= 25/0
P.A= 25/10
wedge is low/steady

Question 8

what is the explanation for the dicrotic notch on the waveform of the PAC

Answer 8

pulmonary valve closing

Question 8

what is the normal value for the PCWP

Answer 8

4-12 mmHg

Question 9

in drawing blood from the proximal channel of pulmonary artery catheter the attempt is to measure which of the following pressures

Answer 9

CVP-central venous pressure

Question 10

what channel of the PAC should be selected to draw blood from if a mixed venous sample is required?

Answer 10

distal port

Question 11

what conditions would cause the PAP to increase

Answer 11

affect lungs: fluid overload or pulmonary hypertension, left heart failure
over 40 mm mercury=COPD
under 40mm mercury= pulmonary embolism

Question 12

what technique is useful in evaluating cardiac output

Answer 12

thermodilution

Question 13

what is the normal value of PVR

Answer 13

1.2mmHg/(L/min) or 96 dyenes/sec/cm-5

Question 14

what is the normal value for systemic vascular resistance (SVR)

Answer 14

8.2 mmHG/ (L/min)
1456 dynes/sec/cm-5

Question 15

in the presence of increased LAP due to inadequate left ventricular pumpin actions,what will be the effect on PVR

Answer 15

The elevated LAP gets pushed back throughout the (blood vessels of the lungs) pulmonary veins, capillaries, and arteries, dilating them and decreasing their vascular resistance

Question 16

increased blood volume would affect pulmonary circulation in what way?

Answer 16

increased blood volume–>more blood into heart (r.side)–>more blood in pulmonary artery–>more blood in lungs–>elevated PAP (fluid build up)

Question 17

which are endogenous substances that produce pulmonary vasodilation

Answer 17

Nitric oxide ( blood vessels lining)-open blood vessels in lungs reduces resistance
acetylcholine, bradykinin, histamine, thrombin, serotonin, adenosine diphosphate (ADP), and some prostaglandins.

Question 18

on which group of pts has NO2 been especially beneficial in treating pulmonary hypertension

Answer 18

newborns

Question 19

which of the following is the most important chemical factor causing pulmonary vasoconstriction

Answer 19

low aveolar oxygen pressure PAO2
PAO2 less than 60-70mmHg-> hypoxic pulmonary vasoconsrtiction (HPV)
*not enough 02 in lungs->vessels in lungs narrowing

Question 20

in the presence of a normal PaO2, how long does the pH need to get before a significant increase in PVR is present

Answer 20

pH<7.25

Question 21

what is the PaO2 at which the maximal vasoconstrictive response when the pH is 7.40

Answer 21

PaO2<60-70mmHG

Question 22

what will inhibit HPV

Answer 22

*nitric oxide&prostacyclin
*alpha blockers&B-stimulants
*increase left atrial pressure

Question 23

in which conditions is the HPV response often diminished

Answer 23

acute lung injury (ALI)
*burn smoke inhalation
*acute respiratory distress syndrome(ARDS)
*ventilator induced lung injury (VILI)

Question 24

what is an alternative to inhaled N02 for lowering PVR

Answer 24

prostacyclin sildenafil (Viagra) nitroprusside nitroglycerin

Question 25

monitoring of a patient with PAC reveals an elevated PAP due to left heart failure. which therapies will be specifically directed at decreasing the PAP

Question 26

what happened to zone 1 under positive pressure ventilation

Answer 26

pressure in alveoli>pressure of the pulmonary arties+pulmonary veins *blood is restricted & ventilation occurs w/out perfusion (alveolar deadspace)

Question 27

which maneuvers can monentarily raise alveolar pressure, creating zone 1 conditions

Answer 27

*valsalva, exhaling against a closed glottis, blowing through a wind instrument, or coughing -mechanical ventilation ? -blood loss or vasodilation?

Question 28

in the presence of exercise, the increased cardiac output and PAP will recruit which zones

Answer 28

convert zone 1 zone 2 to zone 3

Question 29

what is the name of the force tending to move fluid into the capillary

Answer 29

oncotic pressure

Question 30

what are causes of pulmonary edema

Answer 30

*increase hydiostatic pressure *increase capillary permeability *lymphatic insufficiency *decrease of plasma oncotic pressure

Question 31

what is a good example of a condition that causes edema associated with high PCWP

Answer 31

left sided heart failure, mitral valve stenosis

Question 32

which conditions are associated with pulmonary edema due to increased hydrostatic pressure?

Answer 32

left ventricular failure, fluid overload, mitral stenosis

Question 33

which conditions are associated with cardiac pulmonary edema

Answer 33

mitral valve disease, left sided heart failure

Question 34

*card added normal values

Answer 34

CVP: 2-6mmHg PAP: 25/10 sys: 20-30 dys:8-12 Mean PAP: 10-22mmHg PCWP: 4-12mmHG QT: 4-8L/min

Question 35

*card added CVP PAP PCWP QT HPV PVR

Answer 35

CVP-central venous pressure-how full heart is w/blood before pumps PAP-pulmonary artery pressure- how hard heart is pushing blood in the lungs PCWP-pulmonary capillary wedge pressure- pressure in the left atrium QT-cardiac output- how much blood the heart is pumping every minute HPV- hypoxic pulmonary vasoconstriction O2 to lungs vessels narrow PVR-pulmonary vascular resistance-resistance that vessels pose to blood flowing through pulmonary circulation. (tight or open blood vessels are in lungs)

Question 36

*card added how to measure the following PCWP PAP CVP

Answer 36

pcwp-measure w/ balloon inflated distal port PAP- measure w/ balloon deflated distal port CVP-measure w/ proximal channels

Question 37

*card added pulmonary arties pulmonary veins Heart: Righ vs Left

Answer 37

Pulmonary arties-carry deoxygenated blood to lungs pulmonary veins-carry oxygenated blood back to the heart. R:recieves deoxygenated blood-R.A->R.V->lungs L:recieves oxygenated blood from lungs-L.A->L.V->pumps blood to rest of body