Hemodynamics #6

Question 1

Cardiac index

Answer 1

Make CO relative to body size
CI = CO / BSA
Normal: 2.5-4.2 LPM

Question 2

Normal SV

Answer 2

60-135 ml

Question 3

Stroke volume and ejection fraction

Answer 3

SV - 2/3 end diastolic volume

• thus normal ejection fraction (EF) - 67%
• EF >55% is ok

Question 4

How do we decrease preload?

Answer 4

Vasodilators (immediate)
Morphine (immediate)
Diuretics (fast)
Ace inhibitors (slow)

Question 5

How is preload increased?

Answer 5

Monitored by CVP or PCWP 
Fluids (immediate)
Vasoconstrictors (typically fast)
-Levophed (arterial)
-neosynephrine (venous side)

Question 6

Cardiac output

Answer 6

HR x SV

Normal is 4-8 LPM

Question 7

Normal PVR

-PVR increases & decreases

Answer 7

50-250 dynes
Decrease with dehydration & RV failure
-increased w/ anything that causes pulmonary HTN

Question 8

Normal SVR

-Increases & decreases

Answer 8

800-1200 dynes

• decreases w/ dehydration, distributive shock, vasodilators (Nitroprusside, low dose dopamine, nitro)
• increase w/ IHSS, HTN, vasoconstrictors, shock states.

Question 9

IHSS

Answer 9

Idiopathic Hypertrophic Subaortic Stenosis.

-fat septum - hypertrophic cardiomyopathy => fat septum will not allow aortic valve to open => LV cannot clear

Question 10

Medications to decrease afterload

Answer 10

• Nitroprusside (nitrate donor) - nitric oxide most potent vasodilator
• fenoldopam (corlapam) - dopamine agonist / vasodilate mesenteric
• nifedipine (procardia), nicardipine (Cardene) Ca channel blockers
• dobutamine (Dobutrex) - B2 / B1 agonist
• nesirtide (natrecor) RAA inhibitor, synthetic BNP

Question 11

Medications to increase afterload

Answer 11

• Dopamine - A1 agonist (high doses) / significant beta activity as well
• Phenylephrine (Neo-synephrine) pure A1 agonist, will not Improve pump problems.
• norepinephrine (Levophed) A1 agonist above 2 mcg/min, don’t use with pump problems.
• epinephrine A1/B1/B2

Question 12

Dopamine robs:

Answer 12

Robs preload, decreases diastolic filling time, increases myocardial oxygen demand.

Question 13

Contractility increases by which actions?

Answer 13

• sympathetic stimulation
• increases calcium levels (IV Ca considered especially w/ trauma)
• cardiac glycosides (digitalis)
• B1 agonists (dobutamine (#1), epinephrine)

Question 14

Contractility is decreased by which mechanisms?

Answer 14

Electrolyte abnormality
-primary four: potassium, Magnesium, phosphorous, calcium

Hypoxia,

Acidosis
-correct shock states, oxygenation, bicarbonate

Question 15

1 cause of dampened waveform (hypodynamic)

Answer 15

Air in the line

Question 16

Advanced line monitoring priorities

Answer 16

1. PA Cath (for risk of inadvertent wedge & embolism)
2. A-lines
3. CVP