Pulse oximetry is a noninvasive monitoring technique used to estimate the measurement of arterial oxygen saturation (SpO2) of hemoglobin. Oxygen saturation is an indicator of the percentage of hemoglobin saturated with oxygen at the time of the measurement. The reading, obtained through pulse oximetry, uses a light sensor containing two sources of light (red and infrared) that are absorbed by hemoglobin and transmitted through tissues to a photodetector. The amount of light transmitted through the tissue is then converted to a digital value representing the percentage of hemoglobin saturated with oxygen.


Steps

1. Select the appropriate pulse oximeter that fits your needs. Several different types of pulse oximeters are available. The most popular are portable handheld and fingertip pulse oximeters.
2. Plug oximeter into grounded wall outlet if the unit is not portable. If the unit is portable, ensure sufficient battery charge by turning it on before using.
3. Wash hands. This will reduce transmission of microorganisms and body secretions.
4. Place the probe onto your finger or earlobe, and turn the oximeter on. Adequate arterial pulse strength is necessary for obtaining accurate SpO2 measurements.
5. Your oxygen saturation level and pulse rate are displayed in seconds on a lighted display screen. A range of 95% to 100% is generally considered normal. If your oxygen level drops below 85% you should seek medical attention.
6. Print out readings, and/or download them onto a computer if your oximeter has this capability.

Tips

• Portable systems have batteries and are dependent on proper level of battery charge. When system is used in the portable mode, always check battery capacity.
• If the oximeter sensor fails to detect a pulse when perfusion seems adequate, excessive environmental light (overhead examination lights, phototherapy lights, infrared warmers) may be binding the light sensor. Troubleshoot by reapplying the sensor or shielding the sensor with a towel or blanket.
• Your oxygen level will vary depending on many things. Whether you smoke, do drugs, exercise, swim, etc. are all variables in why your oxygen level may vary.
• Don't worry if your oxygen level is not at 100%! Very few people's oxygen level is actually at 100%.

Warnings

• Anything that absorbs light may cause false-low readings and should be removed (Dried blood, Nail polish).
• Never apply the pulse oximeter sensor on a finger of an arm that is using an automatic blood pressure cuff. Blood flow to the finger will be cut off whenever the cuff inflates.
• The most common cause of inaccurate SpO2 readings is movement.