Technically, hypoxemia is also known as low oxygen. However, it is usually defined as oxygen saturation that is below 94% (or below 88%) measured without chronic lung disease. In most patients who die from acute COVID-19, the initial illness progresses subclinically and is sometimes accompanied by "silent hypoxia," which typically leads to pneumonia within two weeks, followed by acute respiratory distress syndrome. Many hospitalized patients with acute COVID-19 experience severe hypoxia, low oxygen, silent hypoxia, and whether they need oxygen supplementation, all of which are independent predictors of worsening COVID-19. Novel prognostic tools indicate the importance of early recognition of hypoxia and the timely and aggressive management of complex physiological causes.
Household pulse oximeters have been used in primary care facilities for a long time.
Pulse oximeters are generally used to monitor chronic lung disease and heart failure. Bulk purchases can save a lot of costs. Although not everyone can understand or operate them, they are relatively simple and easy to use. Finger pulse oximeters are usually accurate and reliable, although they have built-in oxygen sensors that work similarly to standard finger oxygen saturation meters, but they are not permitted for medical use.
The pulse oximeter reading should be measured on warm fingers.
The patient should maintain an upright (sitting) position. The instrument should be stabilized for one minute before confirming the reading. Cold surroundings, low blood pressure, insufficient blood volume shock or heart failure causing poor blood flow, and tattoos, nail polish or false nails when the patient is lying flat can cause incorrect low readings. The reading of anemia, sickle cell disease, and other hemoglobin disorders may also be too low.
A study of hospitalized patients found that black or brown-skinned people were three times more likely than white-skinned patients to experience silent hypoxia, meaning that the pulse oximeter reading was in the normal range while arterial blood gas levels were hypoxic. In 11.7% of black or brown-skinned patients, and 3.6% of white-skinned patients, the oximeter gave inaccurate readings. However, other authors found that in darker-skinned populations, the inaccuracy of pulse oximeters was mainly related to saturation levels below 90%, which is basically below the level that triggers hospital referral.
To conduct home monitoring, some empirical rules are proposed to mitigate skin color differences. First, make sure that the patient uses a oximeter with a quality mark, as cheap products sold directly to the public may not be as accurate. Second, consider the deviation from the patient's own baseline. Third, pay special attention to the overall assessment of the patient, rather than just relying on the pulse oximeter reading. Finally, for patients with darker skin tones, regardless of race, be prepared to take action on any readings below the normal range.