Unit 2-2

Question 1

Cardiac output (co)

Answer 1

determined by heart rate and stroke volume (sv times hr, divided by 100)-amount of blood ejected by the left ventricle into the aorta in 1 minute, normal is 4-8L/min

Question 2

Stroke volume is affected by

Answer 2

preload, afterload, and contractility

Question 3

Cardiac index

Answer 3

co divided by bsa

Question 4

preload

Answer 4

EDp-what is returned to the heart at the end of diastole is used to estimate volume

Question 5

Cvp normal

Answer 5

5-12 or 2-6

Question 6

afterload

Answer 6

Resistance heart must overcome to eject blood to the vascular

Question 7

Indicators of lv afterload

Answer 7

svr, arterial pressure

Question 8

increased afterload results in

Answer 8

decreased sv, co, and increases o2 demand*

Question 9

contractility

Answer 9

Strength of contraction
Not directly measured
Can be altered by meds

Question 10

Hemodynamic monitoring

Answer 10

Look at mentation, uop, capillary refill, skin, etc. to make sure correlates with hemodynamics
Identify trends
Provides immediate information
Aids in diagnosis, minimizes complications/dysfunction, treat disorders, evaluates therapies

Question 11

Components of hemodynamic monitoring system

Answer 11

Invasive catheter
High-pressure non-compliant tubing
The transducer (and stopcocks)
A pressurized flush system
Bedside monitoring system

Question 12

Components of validating accuracy of hemodynamic monitoring

Answer 12

Patient positioning
Zeroing the transducer
Leveling the air-fluid interface to the phlebostatic axis
Assessing dynamic responsiveness

Question 13

Pulmonary artery pressure monitoring

Answer 13

Also called swan ganz or shortened to swan

Question 14

Thermodilution pa catheters

Answer 14

ability to obtain pa pressures and co measurement became the gold standard to which all new hemodynamic monitors are compared

Question 15

Pulmonary artery pressure monitoring-Purpose/indications

Answer 15

monitors pressures in the right atrium, right ventricle, pulmonary artery, distant branches of the pulmonary artery, measure co, blood samples

Question 16

Cather inserted

Answer 16

subclavian, jugular, of femoral VEIN
Inflated balloon “flows” through vein & heart chambers
Final placement in PA
“Lumens” each open into various chamber of the heart
Tip or “distal” lumen opens in PA

Question 17

proximal lumen

Answer 17

blue, rt atrium, measures rt atrium pressure, CO, fluid/bolus

Question 18

distal lumen

Answer 18

yellow, pulmonary artery, measure PAWP

Question 19

Pulmonary Artery Pressure

Answer 19

Systolic 15-30/Diastolic 5-13, Mean 9-18
Increased values define pulmonary hypertension
Diastolic pressure = LVEDP (preload)

Question 20

Pulmonary Artery Occlusion Pressure

Answer 20

AKA – Wedge pressure: PCWP
Normal is 6-12 mmHg
Eliminates PVR
Estimates the LV preload or LV volume at end of diastole (LVEDP)

Question 21

Pawp (paop)

Answer 21

Reflects left atrial and left ventricular pressures (measures left ventricular filling pressures)
Normal 6-12 mmHg

Question 22

Pawp (paop) measuring

Answer 22

Use max of 1-1.5 ml air
Inflate while watching monitor
Inflate only until waveform dampened
Leave inflated maximum of 5-10 seconds
Deflate immediately after obtaining reading

Question 23

Assessment of swan ganz

Answer 23

Connections
Stopcocks
Dysrhythmias

Question 24

complications of swan ganz

Answer 24

Pneumothorax
Ventricular arrhythmias
Pulmonary artery rupture or perforation (rare)
Infection
Tissue infarction distal to catheter

Question 25

Cardiac output/cardiac index

Answer 25

Monitored in hemodynamically unstable patients
Normally increases with exercise
Decreased in shock states and heart failure

Question 26

Thermodilution cardiac output

Answer 26

Room temperature set volume is injected quickly and smoothly in the proximal port
Injectate mixes with the blood and passes into the right ventricle
Thermistor in the catheter senses the change in blood temperatures as it passes the catheter tip in the pulmonary artery
Temperature over time is calculated and then CO and ci are determined

Question 27

Continuous cardiac output

Answer 27

Based on same principle as the intermittent measurement
A special catheter for the monitor that has a filament near the distal end that delivers pulses of energy at intervals and warms the blood in the right ventricle
Temperature change is detected by the thermistor at the end of the catheter
Computer interprets the temperature change and averages the co over last 60 seconds

Question 28

Continuous cardiac output

Answer 28

Patients can be positioned supine with HOB at 45 degrees versus flat for intermittent readings, a negative is if the body temperature is greater than 40-43C the filament heats to a maximum of 44C, also does not reflect acute changes in CO.

Question 29

Noninvasive cardiac output

Answer 29

Nicom
Edm
Co derived from arterial pulse contour analysis that is comparable to PA catheter method-ie Picco, flo trac and lidco

Question 30

Invasive arterial bp monitoring

Answer 30

Continuous readings
Immediate evaluation
Indicated for:
Critically ill patients where bp changes are anticipated
Continuous infusions of vasoactive drugs
Acute htn or hypotension
Respiratory failure
Shock
Neurolgoic injury
Multiple blood gases are needed

Question 31

Abp monitoring errors

Answer 31

Transducer not “zeroed”
Stop cock “closed”
Transducer position
Catheter malfunction

Question 32

Abp monitoring complications

Answer 32

Distal ischemia
Arterial thrombosis
Embolism
Infection
Hemorrhage
Accidental drug injection
Damage to artery

Question 33

Central venous pressure

Answer 33

Can be obtained through central venous line
Pressure gives indication for volume status or right ventricular preload
Must use ij or sc to obtain
complications are related to insertion