Mindray Accutorr 7, Руководство оператора

Страница: 81 / 200

Accutorr 7 Operator’s Manual 7 - 5
7.5.6 Sat-Seconds Alarm Management
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 alarms can be distracting.
Nellcor’s Sat-Seconds alarm management technique is used to reduce these nuisance
alarms.
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 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:
After approximately 10.9 seconds, a Sat-Second alarm would sound, because the limit of
50 Sat-Seconds would have been exceeded.
Saturation levels may fluctuate rather than remaining steady for a period of several
seconds. Often, the patient % SpO
2
may fluctuate above and below an alarm limit, re-
entering the non-alarm range several times. During such fluctuation, the monitor
integrates the number of %SpO
2
points, both positive and negative, until either the Sat-
Seconds limit is reached, or the patient %SpO
2
re-enters the non-alarm range and
remains there.
% SpO
2
Seconds Sat-Seconds
2× 2= 4
4× 3= 12
6× 6= 36
Total Sat-Seconds= 52