V Series Operating Instructions 15 - 7
Pulse Oximetry (SpO2) Measuring SpO2
15.3 Measuring SpO
2
15.3.1 Taking an SpO
2
 Measurement
1. Select the appropriate sensor for the patient.
2. Attach the SpO
2
 sensor to the patient’s finger or other appropriate site. 
3. Attach the SpO
2
 patient cable to the sensor and plug the other end of the patient cable into the 
SpO
2
 connector (as shown in FIGURE 15-1 on page 15-2). 
4. The SpO
2
 measurement displays when the V 12/V 21 detects that the sensor is connected to 
the patient. A pleth waveform displays to the left of the SpO
2
 digital tile, provided the SpO
2
 
parameter is part of the Display Setup.
CAUTION: Tissue damage or inaccurate measurements may be caused by incorrect 
SpO2 sensor application or use, such as wrapping too tightly, applying 
supplemental tape, failing to inspect the sensor site periodically, or 
failing to position appropriately. Carefully read the sensor directions 
for use, the V 12/V 21 Operating Instructions, and all precautionary 
information before use.
CAUTION: Inaccurate SpO2 measurements may be caused by:
• Incorrect sensor application or use
• Significant levels of dysfunctional hemoglobins, (e.g., 
carboxyhemoglobin or methemoglobin)
• Intra-vascular dyes such as indocyanine green or methylene blue
• Exposure to excessive illumination such as surgical lamps 
(especially ones with a xenon light source), bilirubin lamps, 
fluorescent lights, infrared heating lamps, or excessive ambient 
light. In such cases, cover the sensor site with opaque material
•Venous pulsations
•Electro-surgical interference
• Placement of a sensor on an extremity that has a blood pressure 
cuff, arterial catheter, or intra-vascular line
• Nail polish or fungus
CAUTION: Prolonged and continuous monitoring may increase the risk of skin 
erosion and pressure necrosis at the site of the sensor. Check the SpO2 
sensor site frequently to ensure proper positioning, alignment and skin 
integrity at least every eight (8) hours; with the Adult and Pediatric re-
usable finger sensor, check every four (4) hours; for neonates and 
patients of poor perfusion or with skin sensitive to light, check every 2 - 
3 hours; more frequent examinations may be required for different 
patients. Change the sensor site if signs of circulatory compromise 
occur.
CAUTION: Many patients suffer from poor peripheral perfusion due to 
hypothermia, hypovolemia, severe vasoconstriction, reduced cardiac 
output, etc. These symptoms may cause a loss in vital sign readings.
CAUTION: When cleaning SpO2 sensors, do not use excessive amounts of liquid. 
Wipe the sensor surface with a soft cloth, dampened with cleaning 
solution. Do not attempt to sterilize.