Math for Perfusion Technology Flashcards
BSA Calculation for Adults
Kg^0.425 x Ht^0.728 x 0.007184
BSA Calculation for Infants (3-30 kg)
1321 + 0.3433 x Kg
Inches into Centimeters
2.54cm/ 1 in
Pounds into kilograms
2.24 lbs/ 1 kg
mmHg into dyne/ cm^2
1330 dyne/cm^2/mmHg
Torr into mmHg
1 Torr/ 1 mmHg
mmHg into kilopascals
27.1 mmHg/ kPa
mmHg into PSI
50.1 mmHg/ PSI
Cardiac Output Equation
CO = HR x SV
Cardiac Index Equation
CO/ BSA (L/min/m^2)
CO/ Kg (ml/min/kg)
Normal Cardiac Index
2.2 - 4.0 L/min/m^2
60-150 ml/min/kg
Stroke Volume Definition
the volume displaced by one beat of the heart or one RPM of a blood propelling device
Ejection Fraction Definition
the fraction of the left ventricular end diastolic volume (EDV) that is ejected stroke volume
Normal Ejection Fraction
40-70%
Ejection Fraction Equation
(SV/EDV) x 100
Tension-Time Index (TTI) Definition
a measure of systemic blood pressure for a given period of elapsed time, expressed as a measure of the adequacy of systemic perfusion pressure - also the Time -Tension Index may be used to express the duration of LV pressure creation magnitude for a period of time
Tension-Time Index Equation
TTI = mABP in mmHg x Elapsed time in minutes x mmHg x min
Left Ventricular Stroke Work Definition
the pressure work that the left ventricle performs to move the stroke volume from the LV end-diastolic pressure up to the mean aortic pressure up to the mean aortic pressure.
SW correlates highly with ______________.
myocardial oxygen consumption
Left Ventricular Stroke Work Index (LVSWI)
(SV/BSA) x (MAP-PCWP) x (0.0136)
Normal Left Ventricular Stroke Work Index (LVSWI)
45-75 gm x m/m^2/beat
Laplace’s Law
a law in physics that in medicine is applied in the physiology of blood flow; under equilibrium conditions the pressure tangent to the circumference of a vessel storing or transmitting fluid equals the product of the pressure across the wall and the radius of the vessel for a sphere and half this for a tube
Blood Flow Calculation for a Roller Pump
BF = RPMs x SV mL blood/ min = revolutions/minx mL / revolution
Calibration
roller pump calibration is begun by setting the roller pump occlusion to assure minimal or known backflow at zero RPM.
