Mindray BeneView T8, Operation Manual

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Monitoring SpO
2
8-5
8.5.4 Monitoring SpO
2
and NIBP Simultaneously
When monitoring SpO
2
and NIBP on the same limb simultaneously, you can switch [
NIBP
Simul
] on in the [
SpO2 Setup
] menu to lock the SpO
2
alarm status until the NIBP
measurement ends. If you switch [
NIBP Simul
] off, low perfusion caused by NIBP
measurement may lead to inaccurate SpO
2
readings and therefore cause false physiological
alarms.
8.5.5 Sat-Seconds Alarm Management
The Sat-Seconds feature is available with the Nellcor SpO
2
module to decrease the likelihood
of false alarms caused by motion artifacts. To set the Sat-Seconds limit, select [
Sat-Seconds
]
in the [
SpO2 Setup
] menu and then select the appropriate setting.
With traditional alarm management, high and low alarm limits are set for monitoring oxygen
saturation. During monitoring, as soon as an alarm limit is violated, an audible alarm
immediately sounds. When the patient % SpO
2
fluctuates near an alarm limit, the alarm
sounds each time the limit is violated. Such frequent alarm can be distracting. Nellcor’s
Sat-Seconds alarm management technique is used to reduce these nuisance alarms.
With Sat-Seconds alarm management, high and low alarm limits are set in the same way as
traditional alarm management. A Sat-Seconds limit is also set. The Sat-Seconds limit controls
the amount of time that SpO
2
saturation may be outside the set limits before an alarm sounds.
The method of calculation is as follows: the number of percentage points that the SpO
2
saturation falls outside the alarm limit is multiplied by the number of seconds that it remains
outside the limit. This can be stated as the equation:
Sat-Seconds= Points × Seconds
Only when the Sat-Seconds limit is reached, the monitor gives a Sat-Seconds alarm. For
example, the figure below demonstrates the alarm response time with a Sat-Seconds limit set
at 50 and a low SpO
2
limit set at 90%. In this example, the patient % SpO
2
drops to 88% (2
points) and remains there for 2 seconds. Then it drops to 86% (4 points) for 3 seconds, and
then to 84% (6 points) for 6 seconds. The resulting Sat-Seconds are:
% SpO2 Seconds Sat-Seconds
2× 2
＝
4
4× 3 ＝ 12
6× 6
＝
36
Total Sat-Seconds
＝
52