Silent hypoxia is one of the symptoms in which COVID-19 patients have alarmingly low blood oxygen saturation levels, yet they do not show any other symptoms of COVID-19 or breathlessness to identify the hidden danger. The pulse oximeter, a non-invasive device of arterial blood oxygen saturation and pulse rate, can help people to monitor the symptoms at home, and ask for medical care sooner before this deadly symptom kills them. It has been in high demand recently, although it is not always reliable to identify that you are COVID-19 positive or not. But you can consult a doctor if you find any abnormality in the pulse oximeter reading.
It uses light to work out oxygen saturation levels. The probe has a light source on the upper side and a light indicator on the lower side. When a finger is placed on the probe, a part of the light will be absorbed and the rest won’t be. The amount of light that is absorbed depends on the physical properties. And these are used by the pulse oximeter to determine the oxygen saturation. According to the World Health Organization (WHO), oxygen saturation (SpO2) should be between 95% and 100%. If the rate is 94% or less than it, the person needs to be treated quickly. Less than 90% of oxygen saturation is a clinical emergency. The normal perfusion index (PI) ranges from 0.02% to 20% showing weak to strong pulse strength.