Philips Avalon FM20, Instructions For Use Manual

Page: 10 / 221

1 Introduction
10
Confirm Fetal Life Before Using the Monitor
Fetal monitoring technology available today is not always able to differentiate a fetal heart rate (FHR)
signal source from a maternal heart rate (MHR) source in all situations. Therefore, you should confirm
fetal life by independent means before starting to use the fetal monitor, for example, by palpation of fetal
movement or auscultation of fetal heart sounds using a fetoscope, stethoscope, or Pinard stethoscope.
If you cannot hear the fetal heart sounds, and you cannot confirm fetal movement by palpation,
confirm fetal life using obstetric ultrasonography. Continue to confirm that the fetus is the signal
source for the FHR during monitoring.
Be aware that:
•
a MHR trace can exhibit features that are very similar to those of a FHR trace, even including
accelerations and decelerations. Do not rely solely on trace pattern features to identify a fetal
source.
• Fetal Movement Profile (FMP) annotations on a fetal trace alone may not always indicate that the
fetus is alive. The body of a deceased fetus can move and cause the monitor to annotate fetal body
movements.
Here are some examples where the MHR can be misidentified as the FHR.
•
When using an ultrasound transducer:
– It is possible to pick up maternal signal sources, such as the aorta or other large vessels.
– Misidentification may occur when the MHR is higher than normal (especially when it is over
100 bpm).
• When using a fetal scalp electrode:
– Electrical impulses from the maternal heart can sometimes be transmitted to the fetal monitor
through a recently deceased fetus via the spiral scalp electrode cable, appearing to be a fetal
signal source.
– The recorded MHR (and any artifact) can be misinterpreted as a FHR (especially when it is
over 100 bpm).
• When Fetal Movement Profile (FMP) is enabled:
FMP annotations in the absence of fetal life may be a result of:
– Movement of the deceased fetus during or following maternal movement.
– Movement of the deceased fetus during or following manual palpation of fetal movement
(especially if the pressure applied is too forceful).
– Movement of the ultrasound transducer.
– The ultrasound transducer detecting a maternal movement source, such as the mother
coughing.
See also the chapters “Monitoring FHR and FMP Using Ultrasound” on page 95 and “Monitoring
FHR Using DECG” on page 137.
To reduce the possibility of mistaking the MHR for FHR, it is recommended that you monitor both
maternal and fetal heart rates. The monitor's cross-channel verification (CCV) facility can help by
automatically detecting when a MHR coincides with a FHR. For further details, see “Cross-Channel
Verification” on page 97.