Tips to avoid artefacts
Nellcor sensors must be used exclusively and positioned
correctly in order to avoid the risk of measuring errors
and tissue damage.
Damaged sensors with exposed electric wires must not
be used – risk of electric shock.
Adhesive strips of the Oxiband OXI-A/N and OXI-P/I
sensors must not be reused: they may not adhere
properly.
The strips must not be stretched unduly.
Never use two strips together, as this may lead to venous
pulsation and failure of the pulse signal.
High intrathoracic pressure, pressure on the thorax and
other consecutive impairments of the venous flow can
lead to venous pulsation with failure of the pulse signal.
The pulse signal may fail in the presence of shock, low
blood pressure, severe vasoconstriction, major anaemia,
hypothermia, arterial occlusion proximal to the sensor and
asystolia.
The sensor must be covered in bright light (e.g. surgical
lamps and direct sunlight), otherwise the pulse signal
may fail or inaccurate results may be obtained.
The sensor should not be positioned on limbs together
with an arterial catheter, sphygmomanometer cuff or
intravascular venous infusion: pulse signal may fail and
measurement becomes inaccurate.
Major concentrations of dyshaemoglobins, such as
carboxyhaemoglobin or methaemoglobin, can make the
measurement inaccurate.
Intravascular dyes, such as methylene blue, may similarly
result in inaccurate measurement.
Electrocautery can impair the measuring accuracy; the
leads and sensor should therefore be positioned as far
away as possible from the electrocautery and its neutral
electrode.
Sensor performance may be impaired if the patient
moves violently, thus leading to inaccurate results. The
sensor should be applied to a different site in such cases
in order to reduce the risk of artefacts due to movement.
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Care
Reassembling system
SpO
2
measurement
Tips to avoid artefacts