Hamilton G5 - Introduction; F.1 Introduction

624074/07 F-3
F.1 Introduction
WARNING
• A pulse CO-oximeter should be considered an
early warning device. As a trend towards
patient hypoxemia is indicated, blood samples
should be analyzed by laboratory instruments
to completely understand the patient’s condi-
tion.
•SpO
2
is empirically calibrated to functional arte-
rial oxygen saturation in healthy adult volun-
teers with normal levels of carboxyhaemo-
globin (COHb) and methaemoglobin (MetHb). A
pulse oximeter can not measure elevated levels
of COHb or MetHb. Increases in either COHb or
MetHb will affect the accuracy of the SpO
2
measurement.
– For increased COHb: COHb levels above normal
tend to increase the level of SpO
2
. The level of
increase is approximately equal to the amount
of COHb that is present.
NOTE:
High levels of COHb may occur with a seemingly
normal SpO
2
. When elevated levels of COHb are
suspected, laboratory analysis (CO-oximetry) of a
blood sample should be performed.
– For increased MetHb: The SpO
2
may be
decreased by levels of MetHb of up to
approximately 10% to 15%. At higher levels of
MetHb, the SpO
2
may tend to read in the low-
to mid-80s. When elevated levels of MetHb are
suspected, laboratory analysis (CO-oximetry) of
a blood sample should be performed.