Pulse oximetry is a non-invasive and simple method to measure the oxygen saturation level (SpO2) of your blood. It is a vital tool in medical settings, useful in assessing the respiratory function of patients. Here’s a beginner’s guide to understanding how it works and its significance:

What is Pulse Oximetry?

1. Basic Concept: Pulse oximetry uses a small device, called a pulse oximeter, typically attached to a fingertip, toe, or earlobe. It estimates how much oxygen your blood is carrying as a percentage of the maximum it could carry. This is important because it shows how effectively your blood is being oxygenated.
2. How It Works: The device emits light wavelengths through your skin to the blood vessels. Oxygenated and deoxygenated blood absorb light differently. The oximeter calculates the ratio of red light (which oxygenated blood absorbs) to infrared light (absorbed by deoxygenated blood) and then computes the SpO2 level.

Understanding the Readings

1. Normal SpO2 Levels: A normal reading usually falls between 95% to 100%. Values below 90% are considered low and can indicate a need for medical intervention.
2. Pulse Rate: Alongside SpO2, the device also displays the pulse rate, which is the number of heartbeats per minute. This is helpful in monitoring the overall cardiac health of a patient.

Applications of Pulse Oximetry

1. Monitoring Respiratory Conditions: It’s crucial in monitoring conditions like COPD (Chronic Obstructive Pulmonary Disease), asthma, and other lung diseases.
2. During and After Surgery: It helps in monitoring oxygen levels during and after surgical procedures, especially when patients are under sedation or anesthesia.
3. Fitness and Altitude: Athletes, especially those training at high altitudes, use pulse oximeters to monitor their oxygen level, ensuring they are properly acclimatizing.

Limitations and Considerations

1. Inaccuracies: Factors like movement, nail polish, skin thickness, and poor circulation can affect accuracy.
2. Not a Substitute for Medical Advice: While pulse oximetry is a helpful tool, it is not a substitute for professional medical advice or diagnostic testing.
3. Environmental Factors: Extreme light conditions and use of certain artificial nails or nail polish can interfere with readings.

Pulse oximetry is a valuable tool for quick and easy monitoring of blood oxygen levels, offering critical insights into respiratory and cardiac health. However, it’s important to understand its limitations and ensure that it is used alongside other medical advice and diagnostics.