Pulse Oximeters: a simple device in the battle against Covid-19
The advice to anyone displaying symptoms of coronavirus is to self-isolate, treat the symptoms with the like of paracetamol or ibuprofen and, if necessary, contact the NHS 111 telephone number for advice. A high temperature, and a new, continuous cough are the main, but not the only symptoms. The government advises anyone with symptoms to self-isolate until the temperature returns to normal, getting lots of rest and make sure not to get dehydrated. The cough however can continue for some time after the infection is over.
Most people with coronavirus experience only relatively mild symptoms. It is clear however that others experience truly unpleasant symptoms – like the worst flu ever, some have said; like razor blades in my chest, said others – and a small minority have symptoms severe enough that hospital admission becomes necessary. Those who find the virus most problematic often become breathless, as they struggle to get enough oxygen into their blood, and it is this shortness of breath that is often an indication that the sickness may be getting more serious. If not treated, viral pneumonia can result, and we know that the government has been concerned that the NHS could be overwhelmed, with too few ventilators available to save lives.
Writing in The New York Times, (and reported in The Times), New Hampshire doctor, Richard Levitan, explained that “We are just beginning to recognise that Covid pneumonia initially causes a form of oxygen deprivation we call ‘silent hypoxia’ – ‘silent’ because of its insidious, hard-to-detect nature”. The danger comes, he has said, by the fact that people’s brains are working normally, and their body has accommodated what turn out to be scarily low levels of oxygen levels.
The monitoring of blood oxygen levels, to get early warning of problems, has become an important weapon in the fight against the virus. In order for this to happen, Dr Levitan suggests, people could monitor themselves by means of simple technology, called a pulse oximeter. The public, he says, should think of an oximeter, a simple clip put on the finger that measures your oxygen level, in the same way they do a thermometer. And, just as a very high temperature measured by a thermometer would be a spur to call the GP surgery, so low oxygen levels recorded by an oximeter should prompt anyone to seek medical advice. Pulse oximeters, he says, have helped save two friends of his, while in Germany, which has the lowest death rate in Europe, Covid patients are visited each day and their oxygen levels checked.
The report in The Times quotes Professor Babak Javid, consultant in infectious diseases at Cambridge University Hospitals, who says that “Many of the features of Covid are strikingly reminiscent of other lung infections that interfere with the ability of the lungs to oxygenate the blood”. This may not be apparent in previously fit people, so the pulse oximeter is best used in such instances after mild exercise. Even walking for a few minutes would place enough demand for oxygen from the lungs that blood oxygen levels fall dramatically.
Through all of this, Dr Levitan remains hopeful, telling CBS News: “What we are learning about this disease is it attacks primarily through one pathway, and that’s the lungs. We know when it is going to attack. It is going to attack between five to 10 days after infection. … And we know we have a way to detect it earlier, and that way is by close monitoring of pulse oximetry.”