KUALA LUMPUR: The Covid-19 pandemic has sparked a sudden interest in pulse oximeters, a medical device that allows people to check their oxygen saturation levels.
Health experts said while it could help alert a person with Covid-19 on when to seek medical care, there is no need for people who are young, healthy and have no symptoms to buy one.
Professor Datuk Dr Awang Bulgiba Awang Mahmud, who is the Science, Technology and Innovation Ministry's Covid-19 Epidemiological Analysis and Strategies Task Force chairman, said the device was not a necessity unless one intends to monitor Covid-19 patients in isolation.
He said while there was no harm in buying one, the oximeter must conform to certain standards, and care must be taken when interpreting the readings.
"Not everyone is conversant with the use of oximeters and how to interpret the readings together with other signs and symptoms of hypoxia," he told the New Straits Times.
A pulse oximeter is an electronic device that clips onto a finger to measure heart rate and oxygen levels in the red blood cells — the device is usually used to monitor patients with lung disease.
The device started flying off store (and online) shelves when people learned that Covid-19 could cause blood oxygen levels to drop dangerously, even when one had no symptoms — a condition called "silent hypoxia" (or happy hypoxia).
According to the Malaysian Pharmacists Society, there was an increase in enquiries on pulse oximeters, and sales of those devices were particularly strong in April and May.
On Thursday, Singapore's Temasek Foundation announced that it would be giving one oximeter to every household so people could monitor their blood oxygen levels regularly.
Asked if Malaysia should follow suit, Dr Awang Bulgiba, who is an epidemiologist, said the benefits of providing such devices versus other priorities in this pandemic management were unclear.
"I am not sure about the feasibility and the cost-benefit of providing each household in Malaysia with an oximeter as we have millions of households to cover," he added.
He also noted that there were limitations in the accuracy of home pulse oximeters.
A study had found that pulse oximeter results might not be as accurate for people with darker skin, where their oxygen levels were sometimes reported to be higher than they really were.
Manipal University College Malaysia community and occupational medicine Professor Dr G. Jayakumar said pulse oximeters should be considered for home use as an added precaution, rather than a must-have device.
"There is debate among doctors on the need for a pulse oximeter at home. The World Health Organisation guidelines advocates pulse oximeters for home use in symptomatic patients who are not hospitalised.
"However, some Covid-19 patients show no signs of respiratory distress, such as shortness of breath (silent hypoxia). In this case, pulse oximeters are helpful in detecting a change in a patient's oxygen saturation level that would otherwise go unnoticed."
Dr Jayakumar said patients must be trained on how to use the device. They need to understand that pulse oximeters could not save lives if medical attention was not sought at the right time.
"Finger pulse oximeters are generally accurate and reliable. Devices with evidence of a quality standard such as ISO 80601-2-61:2017 are preferred. Most smartphone oximeters are unreliable and are discouraged.
"People planning to use pulse oximeters need to obtain advice from a medical professional to know the baseline level of these devices," he said.
"The American Lung Association prescribes a level between 95 and 97 per cent oxygen saturation as a normal level. A level below this range will need medical consultation, and under 90 per cent would be a reason to seek immediate medical attention at the emergency unit."
University of Malaya Medical Centre Public Health Medicine Specialist Associate Professor Dr Rafdzah Ahmad Zaki had earlier said that Covid-19 patients should monitor their blood oxygen levels continuously using a pulse oximeter to prevent happy hypoxia.
Pantai Hospital Kuala Lumpur consultant respiratory physician Dr Helmy Haja Mydin had said the device could be useful for Covid-19 patients.
"It will be useful (for them) to keep an eye on the oxygen levels, but I wouldn't urge people to buy without the need for it," he said.