GE HEALTHCARE B20, User'S Reference Manual

Page: 196 / 320

B40/B20 Patient Monitor
11-14
Arrhythmia detection
Safety precautions
Warnings
•
LOSS OR DETERIORATION OF ARRHYTHMIA DETECTION -Automated arrhythmia analysis
programs may incorrectly identify the presence or absence of an arrhythmia. A physician
must therefore interpret the arrhythmia information in conjunction with other clinical
findings. Please take special note of the following ECG waveform conditions:
− Noisy waveforms. Noisy portions of ECG waveforms are typically excluded from
analysis. The exclusions are necessary to reduce the occurrence of inaccurate beat
interpretations and/or rhythm alarms. If the excluded noisy portions of the ECG
waveform contain true arrhythmia events, those events may remain undetected by
the system.
−
Beat amplitude and duration. Accurate detection and interpretation of beats
becomes increasingly difficult as the amplitude and/or duration of those beats
approach the design limits of the analysis program. Thus, as beats become
extremely wide or narrow, or especially as beats become small, arrhythmia
interpretation performance may degrade.
− Other morphology considerations. Automated arrhythmia detection algorithms are
designed fundamentally to detect significant changes in QRS morphology. If an
arrhythmia event is present and does not exhibit a significant change from the
patientís predominant morphology, it is possible for those events remain
undetected by the system.
•
SUSPENDED ANALYSIS - Certain conditions suspend arrhythmia analysis. When
suspended, arrhythmia conditions are not detected and alarms associated with
arrhythmias do not occur.The messages which alert you to the conditions causing
suspended arrhythmia analysis are: 'Arrhythmia Paused', ‘Leads off’ and ‘Patient
discharged’.
•
Always monitor ECG for arrhythmia detection purposes. HR calculated from pulsatile
SpO
2
waveform may differ significantly from ECG HR measured values. Users should be
aware that the “SpO2 probe off” and “No SpO2 pulse” technical alarms escalate no higher
than a Medium priority.
•
Artifact and arrhythmia paused alarm - The artifact and arrhythmia paused alarm
indicates that the system is no longer monitoring ECG and there may be no Tachy or
Brady alarms.
NOTES:
•
Since the arrhythmia detection algorithm sensitivity and specificity is less than 100%,
sometimes there may be some false arrhythmias detected and also some true
arrhythmia events may not be detected. This is especially true when the signal is noisy.
•
If QRS amplitude is low, the monitor might not be able to calculate HR and false Asystole
may occur.
•
During the learning phase of the algorithm, arrhythmia detection may not be available. As
a result, the patient condition should be closely monitored during the learning phase and