Calculations

Question 1

How do you estimate heart rate from ECG tracing?

Answer 1

300 divided by the number of large boxes between R waves

Question 2

What is the pulse pressure?

Answer 2

Systolic pressure minus diastolic pressure

Question 3

What is the formula for MAP?

Answer 3

Systolic + (diastolic x2)/3

Question 4

What is the formula for cardiac output using the Fick equation?

Answer 4

Cardiac Output (QT)=Oxygen consumption (VO2)/C(a-v)O2 X 10

Question 5

What is the formula for cardiac output using the stroke volume equation?

Answer 5

Qt= H.R. X stroke volume

Change to liters

Question 6

What is the cardiac index formula?

Answer 6

CI= cardiac output or (QT)/body surface area or (BSA)

CI will be about half of QT

Question 7

What is the formula for systemic vascular resistance (SVR)

Answer 7

SVR=MAP-CVP/QT

Multiplied by 80 to get dynes

Question 8

What is the formula to determine pulmonary vascular resistance (PVR)

Answer 8

PVR=MPAP-PWP/QT

MULTIPLY BY 80 TO GET DYNES

Question 9

What is the formula to determine pack year history?

Answer 9

Packs per day X # of years smoked

Question 10

How do you determine cerebral perfusion pressure?

Answer 10

CPP=MAP-ICP