Can one less finger save your life when doing nail art? Doctor: It's true!

Recently, the Department of Emergency Medicine of the Second Hospital of Zhejiang University

Deputy Chief Physician Lu Xiao

A health alert was posted on social media:

Friends who love nail art remember

Leave yourself a "life-saving finger"

It is reported

The emergency room often sees female patients who have had their nails done

And they're measuring oxygen saturation

It is easy to encounter undetectable

or inaccurate values

Why does nail art make oximeters "fail"?

Let's take a look!

Dr. Lu said the cause was related to a female patient he had previously seen. This is a young girl in her twenties who was taken to the emergency room in a coma. "At that time, I wanted to measure her blood oxygen saturation, but it turned out that she had nails on both hands and feet, and it was the kind with a drill, and she couldn't pull it off, and the oximeter couldn't detect it at all (note: it couldn't measure the value)." Vital signs were later tested with an ear-clip oximeter before further treatment was possible.

"Blood oxygen saturation is an important indicator of the amount of oxygen in the blood and is essential for assessing human health." Dr. Lu said that when the patient is in a coma or under anesthesia after surgery, doctors use an oximeter to monitor the patient's blood oxygen saturation, which is an indirect measurement method, and the patient's vital signs are judged through the blood oxygen saturation, so as to detect and deal with potential health problems in time.

Actual measurement: Nail art with diamonds does not display values

Basic manicure measurements may not be accurate

Can nail art cause oximeter to malfunction? Some media have conducted self-tests with household finger pulse oximeters.

The blood oxygen saturation value was 98% when measured on the index finger of a female colleague who did not have a manicure.

Two more colleagues who did a non-sticky diamond model and only applied light-colored nail polish gel manicures were selected, and the index finger and ring finger were measured respectively, and the blood oxygen saturation was 98%.

Measuring the ring finger of a regular undiamond nail colleague shows an oxygen saturation of 98%

Finally, the thumb and index finger of the nail art colleague with diamonds were measured, and the value of the thumb could not be displayed, and the value of the index finger was 86%.

When measuring the thumb of a colleague sticking a drill on a diamond model, the data cannot be displayed

When measuring the index finger of the same colleague without a drill, the oxygen saturation was 86%

The emergency room often sees female college students with nail art

Ear clip-on oximeters for children "emergency work"

Wang Yan, head nurse of the emergency center of the Qiantang branch of Zhejiang Provincial Hospital of Traditional Chinese Medicine, said that the emergency room often receives female college students who have done nail art, and it is indeed easy to encounter undetectable or inaccurate blood oxygen saturation measurements.

"We use a medical oximeter in the emergency room, which is a little different from the home one. Usually receive patients who do nail art, the style with drills cannot be monitored because of the impact on light transmission, and the general nail glue oil can be measured, but the results may be inaccurate. ”

Wang Yan introduced that Zhejiang Provincial Hospital of Traditional Chinese Medicine purchased an ear clip oximeter 6 years ago. At that time, the purpose of introducing the ear clip type oximeter in the department was originally for the convenience of children, because children's fingers are easy to move, and it is difficult to insist on reading data from the instrument. "In the practical application of the ear clip-on oximeter, in addition to children, it also plays an important role in the monitoring of our other patients, including female patients with manicures."

How does an oximeter measure oxygen saturation?

The basic principle is the reflection or transmission of light

Why does nail art make oximeters "fail"? This is closely related to the principle of oximeter measurement of blood oxygen saturation.

Before we get into the principle, let's take a look at hemoglobin. Hemoglobin is a special protein in the red blood cells of human blood that carries oxygen, and hemoglobin is divided into oxyhemoglobin (HbO2) and deoxygenated hemoglobin (Hb). Blood oxygen concentration = oxyhemoglobin/total hemoglobin.

How do you measure the ratio of two types of hemoglobin? This depends on the little detective "absorbance". Absorbance is like the "difficulty index" of light passing through matter, and the more difficult it is, the less light it will pass through. These two types of hemoglobin have different sensitivities to light of a particular color. Under red light (660nm wavelength), oxyhemoglobin is like a "transparent person", while deoxygenated hemoglobin is a "master of light absorption". But when it comes to infrared light (around the 915nm wavelength), the opposite is true. This is the main reason why oxyhemoglobin tends to appear red in daylight conditions and deoxyhemoglobin has a dark purple color.

It is reported that the principle of color measurement of oximeter relies on the basic physical phenomenon of light reflection or transmission. Combined with the different absorbance of two different hemoglobins for different wavelengths, the difference in the number of two hemoglobins was distinguished, and then the blood oxygen saturation data was calculated.

Why does nail art affect oximeter measurements

According to the relevant R&D personnel of the home finger oximeter test, the reason why nail art will affect the measurement results of the oximeter can be analyzed from three main angles:

1. Light absorption and reflection

Certain colors of nail polish (especially dark colors like blue and black) can strongly absorb or reflect light. This means that light that is supposed to penetrate the skin and be absorbed by the bloodstream may be blocked or reflected by nail polish, resulting in inaccurate readings. Even light-colored nail polish can contain tiny particles or other components that can scatter light and reduce the amount of effective light reaching the sensor, which in turn can affect measurement accuracy.

2. Physical barriers

Nail polish forms a physical barrier that prevents light from interacting directly with the blood vessels under the nail bed. This barrier effect can lead to weakened or distorted signals, making it difficult for oximeters to obtain accurate readings.

3. Temperature changes

In rare cases, some types of nail polish may slightly alter their optical properties under certain conditions, such as exposure to high temperatures, but this is not a major factor.

Love beauty and health at the same time

Doctors recommend leaving a "life-saving finger" or wearing armor

"In addition to nail art people, people with dyes and paint residues on their skin, as well as people with particularly thick skin and poor peripheral nerve circulation, are often prone to inaccurate oximeter interpretation results." Dr. Lo mentioned that the measurement of blood oxygen saturation is incorrect, which will directly mislead the doctor's judgment and affect the patient's treatment effect.

Nowadays, girls love beauty, and it has become a habit to get regular nail art. "Many young girls who come to the emergency department today have this problem, and they often find that they can't measure their oxygen saturation when they need to check their blood oxygen saturation. Many nail articures require professional instruments to disassemble, and our doctors and nurses are not easy to disassemble, so follow-up treatment has become a problem. ”

Dr. Lo advises women to consider their own health needs while pursuing beauty. Keep at least one original armor or wear a wearing armor (which can be removed at any time) in case of an accident that cannot be examined, which will affect subsequent rescue and treatment.

Comprehensive: Youth Zhejiang, the Second Hospital of Zhejiang University, Zhejiang Medical Online, Hangzhou Daily, News Square

Source: Jiangsu Communist Youth League