COVID-19: Doctor suggests ways to detect silent hypoxia
A New Taipei City doctor has suggested ways to test for silent hypoxia, which has been occurring more frequently due to COVID-19 and has no obvious symptoms.
People with the condition do not experience any difficulty breathing, but their blood oxygen levels drop to dangerously low levels, which could be fatal, Linkou Chang Gung Memorial Hospital physician Wu Chang-teng (吳昌騰) wrote on Facebook on Monday.
A normal blood oxygen saturation level is 95 to 100 percent, and levels below 80 percent can result in organ function being compromised, Wu said.
“Doctors in the US have reported treating some COVID patients last year who had levels of about 70 to 80 percent, and some even as low as 50 percent,” Wu said, adding that the patients had not displayed symptoms.
Early testing is important to allow for the timely use of oxygen therapy, and to determine whether invasive or non-invasive therapy is needed, he said.
One way to test the blood oxygen level is using a pulse oximeter, Wu said.
However, some devices are less accurate than others, and if the device measures a saturation level below 90 percent, the reading should be confirmed using another method, he said.
Doctors and nurses can also determine blood oxygen saturation levels through a blood test, which can determine the concentration of all gases in the blood, Wu said.
People using an oximeter can also check for fluctuations in blood oxygen levels with a six-minute walk test, he said.
Blood oxygen levels and heart rate should change with exertion, but if the blood oxygen level drops below 90 percent, or by more than 4 percent, after six minutes of walking, that might be an indication of hypoxia, he said.
新聞來源：https://www.taipeitimes.com/News/taiwan/archives/2021/05/27/2003758130