Workings of a Pulse Oximeter

Recently an article was published in the edition of ‘The Hindu’ on July 19, 2020. Divya Kala Bhavani, the contributor, observed, “People with COVID-19 often need oxygenation support.

Therefore, Pulse Oximeter, a staple for many doctors, has become something of a necessity for the layperson. Oximeters have been flying off the shelves for many households’ first aid kits, largely because they are non-invasive, low-cost, easy to use, and effective at detecting hypoxemia (low blood oxygen levels).” More than a month later the device is flying-off the shelves in no time.

She adds further, “There are two important readings: the pulse rate, recorded as beats per minute (60 to 100 is the safe range); and the oxygen saturation of haemoglobin in arterial blood, the reading of which is recorded as SpO2). Normal readings range from 95% to 100%; anything less, and the user should get medical assistance from a doctor. If your oximeter has alarms, atypical readings will set them off.” On a number of occasions while serving our members, we at Porosh, have first-hand experience that timely medical intervention based on oximeter readings saved a few seniors’ lives.

“The mechanism clips onto the user’s forefinger, though some oximeters have been known to be clipped onto one’s big toe or even the ear, depending on the model. According to the World Health Organization’s Pulse Oximetry Training Manual, one must use the oximeter with patience. Once clipped on, it requires about 10 seconds to get an accurate reading,” Divya contends. “One cannot use the pulse oximeter as a sole detector for any respiratory issues. It is only meant to give readings for a small time interval. When buying an oximeter, one must be wary of the brand names.”

There are oximeters selling on e-commerce platforms that will work for a month at most before giving out, and may cost as much as about ₹2,000.

Role of Vitamin D in combating Covid 19

On June 20, 2020 a research paper by Nurshad Ali on “Role of vitamin D in preventing of COVID-19 infection, progression and severity” was published in the Journal of Infection and Public Health (Elsevier). In that paper he observed, “Little is known about the protective factors of this infection. Therefore, preventive health measures that can reduce the risk of infection, progression and severity are desperately needed.” Thus, Ali alluded to the impact of preventive health maintenance for reducing the risk and impact of Covid 19 and not its amelioration. It is in this context the role of vitamin D has been analyzed.

He went on to add, “Several studies demonstrated the role of vitamin D in reducing the risk of acute viral respiratory tract infections and pneumonia. These include direct inhibition with viral replication or with anti-inflammatory or immunomodulatory ways. In the meta-analysis, vitamin D supplementation has been shown as safe and effective against acute respiratory tract infections. Thus, people who are at higher risk of vitamin D deficiency during this global pandemic should consider taking vitamin D supplements to maintain the circulating 25(OH)D in the optimal levels (75–125 nmol/L).” Although researchers are yet to ascertain the extent of vitamin Ds ability to fight Covid 19 yet it seems vitamin D supplementation is a safe and effective source to fight ‘acute respiratory tract infections.’

Ali observes, “Indeed, supplementation of vitamin D with doses up to 100 μg/day is safe for adults, and many expert groups now suggest supplementation in older people, although at lower levels than it. A study reported that intake of vitamin D supplement at 100–250 μg/day over 6 weeks increases the baseline serum concentration of 25(OH)D from 2 to 3 folds, respectively, without any adverse health effects.” It is interesting to note that recommendation for vitamin D dosage depends on an individual’s age (& also ethnicity). Hence, doctor’s advice becomes all the more important before taking recourse to vitamin D supplementation.

The research paper concluded that although in the randomized trials and meta-analysis, vitamin D supplementation has been shown to have protective effects against respiratory tract infections yet more randomized ‘controlled’ trials and large-scale cohort studies are still necessary to test this hypothesis.

Limitations of medicine

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The idea for this week’s blog came from a book - Man, The Unknown - authored by Alexis Carrel. He was a French surgeon and biologist who was awarded the Noble Prize in Medicine in 1912 for pioneering vascular suturing techniques. Although the book was published in 1935 (& a best seller then) yet some of the profound truths shared by him are relevant even today.

In the chapter on Remaking of Man he made the following observation, “There are, as we know, two kinds of health, natural, and artificial. Scientific medicine has given to man artificial health, and protection against most infectious diseases. It is a marvelous gift. But man is not content with health that is only lack of malady and depends on special diets, chemicals, endocrine products, vitamins, periodical medical examinations, and the expensive attention of hospitals, doctors, and nurses.

He wants natural health, which comes from resistance to infectious and degenerative diseases, from equilibrium of nervous system. He must be constructed so as to live without thinking about his health. Medicine will achieve its greatest triumph when it discovers the means of rendering the body and mind naturally immune to disease, fatigue, and fear. In remaking modern human beings we must endeavor to give them the freedom and happiness engendered by the perfect soundness of organic and mental activities.” (pp. 289-290).

We are aware that in the modern times medicine has made rapid strides in addressing issues pertaining to the degeneration of the body. However, in the process, the health of the mind has been largely neglected maybe because its workings remain beyond the defined boundaries of laboratory experiments. As a consequence, we are witnessing, globally, sharp rise in health issues pertaining to the mind. During the pandemic it has become all the more evident. Hence, there is a growing realization that holistic living should comprise more than adequate dose of ‘medicine’ for the mind as well in the form of mental drills like meditation, breathing exercises, yoga and a renewed quest for finding meaning in life rather than chasing mundane goals defined in terms of power, position and asset-heaviness.

Therefore, instead of waiting for the invention of a magic pill to be popped-up for achieving natural ‘immunity against disease, fatigue, and fear’ we should start the journey on our own in the right earnest.