Pulse oximeter is used for monitoring
**Core Concept**
Pulse oximetry is a non-invasive method used to continuously monitor the oxygen saturation of hemoglobin and heart rate in the blood. It measures the absorption of light by hemoglobin and oxyhemoglobin in the arterial blood, allowing for real-time assessment of oxygenation status.
**Why the Correct Answer is Right**
Pulse oximeters work by emitting light of two different wavelengths (typically 660 nm and 940 nm) through a translucent site, usually a finger, toe, or earlobe. The ratio of absorbed light at each wavelength is used to calculate the oxygen saturation of hemoglobin (SpO2). This value is then displayed on the pulse oximeter screen, allowing healthcare professionals to monitor the patient's oxygenation status and make informed decisions about ventilation, oxygen therapy, and other interventions. The device also measures heart rate, providing a comprehensive picture of the patient's cardiovascular status.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the use of pulse oximeters.
**Option B:** While electrocardiography (ECG) is used to monitor heart rate, it does not measure oxygen saturation.
**Option C:** Blood gas analysis is a laboratory test used to measure oxygen and carbon dioxide levels in arterial blood, but it is not a real-time monitoring device like a pulse oximeter.
**Clinical Pearl / High-Yield Fact**
Pulse oximeters can be affected by several factors, including motion artifact, poor perfusion, and the presence of nail polish or other substances that absorb light. It is essential to choose a suitable monitoring site and maintain good technique to ensure accurate readings.
**Correct Answer: B. Oxygen saturation and heart rate.**