GE CARESCAPE, User Manual

Page: 203 / 548

Pulse oximetry
WARNING
Many factors may cause inaccurate readings and alarms,
decreased perfusion, and or low signal strength:
●
Interfering substances:
￭
Carboxyhemoglobin may erroneously increase SpO
2
reading.
￭
Methemoglobin (MetHb) usually represents less than 1%
of the total Hb, but in the case of methemoglobinemia
that can be congenital or induced by some IV dyes,
antibiotics (such as sulphas,) inhaled gases etc. this
level increases sharply and thus can cause inaccuracies
in the SpO
2
reading.
￭
Intravascular dyes (such as indocyanine green,
methylene blue, etc.)
●
Physiological characteristics:
￭
Cardiac arrest
￭
Hypotension
￭
Shock
￭
Severe vasoconstriction
￭
Severe anemia
￭
Hypothermia
￭
Venous pulsations
￭
Darkly pigmented skin
￭
Ventricular septal defects (VSDs)
●
Environmental conditions:
￭
Excessive ambient light
￭
Electrical interference
￭
Electrosurgery
￭
Defibrillation - May cause inaccurate reading for a short
amount of time.
￭
Excessive patient/sensor motion. Artifact can simulate
an SpO
2
reading, so that the monitor fails to sound an
alarm. In order to ensure reliable patient monitoring, the
proper application of the probe and the signal quality
must be checked at regular intervals.
●
Sensor placement:
￭
Incorrect sensor placement - prolonged monitoring or
incorrect sensor application can cause skin irritation or
impaired circulation. It is recommended that you check
the probe site every four hours (more frequently for poor
perfusion or for neonates). Refer to the instructions
supplied with the sensor.
￭
Sensor placement on the same extremity as a blood
pressure cuff, arterial catheter or intravascular line; or
arterial occlusion proximal to the sensor.
￭
Poor sensor fit.
￭
Do not allow tape to block the sensor light emitter and
detector.
2062971-001 CARESCAPE Modular Monitors 203