Spco General Description; Spmet General Description; Pleth Variability Index - (Pvi) General Description; Low Perfusion - Masimo SET Rainbow SET Rad-57 Operator's Manual

O v e r v i e w
1

SpCO General Description

Pulse CO-Oximetry is a continuous and non-invasive method of measuring the levels of carbon
monoxide concentration (SpCO) in arterial blood. It relies on the same basic principles of pulse
oximetry (spectrophotometry) to make its SpCO measurement. The measurement is obtained by
placing a sensor on a patient, usually on the fingertip for adults and the hand or foot for infants. The
sensor connects either directly to the Pulse CO-Oximetry instrument or through an instrument patient
cable. The sensor collects signal data from the patient and sends it to the instrument. The Rad-57
displays the calculated data as percentage value for the SpCO, which reflect blood levels of carbon
monoxide bound to hemoglobin.

SpMet General Description

Pulse CO-Oximetry is a continuous and non-invasive method of measuring the levels of methemoglobin
concentration (SpMet) in arterial blood. It relies on the same basic principles of pulse oximetry
(spectrophotometry) to make its SpMet measurement. The measurement is obtained by placing a
sensor on a patient, usually on the fingertip for adults and the hand or foot for infants. The sensor
connects either directly to the Pulse CO-Oximetry instrument or through an instrument patient cable.
The sensor collects signal data from the patient and sends it to the instrument. The Rad-57 displays
the calculated data as percentage value for the SpMet.

Pleth Variability Index - (PVI) General Description

The Pleth Variability Index (PVI) is a measure of the dynamic changes in the perfusion index (PI) that
occur during the respiratory cycle. The calculation is accomplished by measuring changes in PI over
a time interval where one or more complete respiratory cycles have occurred. PVI is displayed as a
percentage (0-100%).

Low Perfusion

It has been suggested that at extremely low perfusion levels, Pulse CO-Oximeters can measure
peripheral saturation, which may differ from central arterial saturation. This "localized hypoxemia" may
result from the metabolic demands of other tissues extracting oxygen proximal to the measurement site
under conditions of sustained peripheral hypoperfusion. (This may occur even with a pulse rate that
correlates with the ECG heart rate.)
CAUTION:
IF LOW PERFUSION IS FREQUENTLY INDICATED, FIND A BETTER-PERFUSED MONITORING
SITE. IN THE INTERIM, ASSESS THE PATIENT AND, IF INDICATED, VERIFY OXYGENATION
STATUS THROUGH OTHER MEANS.
1-6
Rad-57 Signal Extraction Pulse CO-Oximeter Operator's Manual