Edwards HemoSphere

C
197
Appendix
Equations for Calculated Patient
Parameters
This section describes the equations used to calculate continuous and intermittent patient parameters displayed on the
HemoSphere advanced monitor.
NOTE Patient parameters are calculated to more decimal places than are displayed on the
screen. For example, a screen CO value of 2.4 may actually be a CO of 2.4492. Conse-
quently, attempts to verify the accuracy of the monitor's display using the following
equations may produce results that are slightly different from the data computed by the
monitor.
For all calculations that include SvO
2
, ScvO
2
will be substituted when the user selects
the ScvO
2
.
Subscript SI = Standard International Units
Table C-1 Cardiac and oxygenation profile equations
Parameter Description and formula Units
BSA Body Surface Area (DuBois formula)
BSA = 71.84 x (WT
0.425
) x (HT
0.725
) / 10,000
where:
WT – Patient Weight, kg
HT – Patient Height, cm
m
2
CaO
2
Arterial Oxygen Content
CaO
2
= (0.0138 x HGB x SpO
2
) + (0.0031 x PaO2) (mL/dL)
CaO
2
= [0.0138 x (HGB
SI
x 1.611) x SpO
2
] + [0.0031 x (PaO
2
SI
x7.5)] (mL/dL)
where:
HGB – Total Hemoglobin, g/dL
HGB
SI
– Total Hemoglobin, mmol/L
SpO
2
– Arterial O
2
Saturation,%
PaO
2
– Partial Pressure of Arterial Oxygen, mmHg
PaO
2
SI
– Partial Pressure of Arterial Oxygen, kPa
mL/dL
Status = Released Printed Date: 2018-01-16 Released Date: 2017-09-14