"After troubleshooting the instrument and inserting the needle into the vein by mistake, the patient found that the changes in SAO2 were seriously inconsistent with SO2. The reason for the difference between the two is that SAO2 is the percentage of oxygen content and oxygen capacity, and its value is correlated with AO2 within a certain range. ”

"It is based on this principle that the blood gas analyzer calculates the actual SAO2 value by measuring the AO2 in the blood. ”

"SO2 is measured by photoplethysmography based on the principle that different wavelengths of light will decay differently when they pass through arterial blood. ”

Wu Mian began to talk about the basic principles of blood oxygen saturation determination, and several veteran anesthesiologists were confused.

Although the monitor has been used for decades, they only know how to use it, and they really don't know the principle of specific construction machinery.

"There's really no way to explain this in plain language. Wu Mian also saw the confusion of several directors, and he immediately said, "When it comes to the principles of mechanical engineering...... By the way, did everyone study medical devices when they were in school?"

"Teacher Wu, no. Several people shook their heads.

"Then I'll try to keep it simple. Wu Mian couldn't help it, so he hesitated and said.

In fact, what he said before was about the principles of medicine, and it was difficult for ordinary people to understand, just like when talking about the principles of medical devices, the reactions of several directors were the same.

"One side of the pulse oximetry monitoring probe simultaneously emits infrared light with a wavelength of 660 N, and oxidized hemoglobin and reduced hemoglobin absorb different amounts of light, so the oxygen saturation is measured and displayed on the monitor's machine. ”

"Based on this difference, the photosensor on the other side of the probe measures the intensity of infrared and red light after passing through the tissue, uses spectrophotometry to measure the absorption of infrared and red light, and then converts the ratio to SO2. ”

"Differences in SAO2 and SO2 assays lead to a mismatch between the two in severe hypoxemia in this case, which can lead to false elevations of SO2 in the following situations. ”

"First, there is an increase in carboxyhemoglobin in the blood. The absorbance of carboxyhemoglobin and oxyhemoglobin is similar, while the pulse oximetry can only distinguish between oxyhemoglobin and hemoglobin, and cannot exclude carboxyhemoglobin, so it will cause a high value of SO2. ”

"Second, methemoglobinemia, can also cause this to happen.

Patients with methemoglobinemia have a larger absorption coefficient of red and infrared light, and their absorption coefficient at 660 HB is higher than that of hemoglobin and oxyhemoglobin.

Therefore, if the actual arterial oxygen saturation is low, the SO2 reading will be falsely high, and conversely, the SO2 reading will be falsely low. ”

"Thirdly, patients with severe anemia may also experience a similar situation......

"Fourth ......"

"Fifth ......"

"Sixth ......"

"Twelfth, Hereditary fetal hemoglobinemia ......"

"Based on Lao Ren's medical history, I think that this patient is more likely to have hereditary fetal hemoglobinemia, and I recommend that he be checked after postoperative recovery. However, it is estimated that the patient will refuse, after all, it has no effect. ”

Everyone including Dean Zhao was dumbfounded, and they looked at Wu Mian in a daze, with dew.

In particular, Director Liu witnessed all the process at the scene. At the time, I thought it was some kind of supernatural event. However, when Mr. Wu said this, he found that there were more than a dozen diseases that could induce the situation that the blood oxygen saturation monitored on the monitor did not match the actual oxygen concentration.

Is this the gap between the average practitioner and the top practitioner?

As for hereditary fetal hemoglobinemia, several people have never heard of it.

Originally, I thought that Wu Mian was just shaking his wit, but he talked about more than a dozen possibilities, and after listening to it, the clinicians present were all in a cold sweat.

There is a saying in the clinic - if nothing happens, it is less surgery.

Looking at it now, this sentence is really the experience summed up by the predecessors.

In the past, it was thought that Wu Mian relied on Mr. Lao to become the editorial board member of the latest edition of "Diagnostics", but now everyone understands that Mr. Wu is a person with real and great skills.

In such a rare situation, which has not been encountered by several directors who have been on the battlefield for a long time, Mr. Wu talked eloquently, from medicine to medical equipment, and then back to diagnosis, and also cited more than a dozen diseases that can lead to this abnormal situation......

It's really speechless.

Without contrast, there is no harm.

Everyone present felt like one critical hit after another hit hit was coming out of their heads, and the health bar had been cleared in an instant.

Only Ren Haitao listened attentively, seeing what he meant, if the conditions permitted, he would definitely take a small book and write down everything that Teacher Wu said.

After Wu Mian finished speaking, Ren Haitao continued to ask about the criteria for the diagnosis of hereditary fetal hemoglobinemia.

"Old Ren, let's go back and talk about it. Wu Mian said with a smile, "Let's have a plane in the afternoon, and we'll go back after dinner." ”

"Oh, good. Ren Haitao had some regrets, and everyone could see his unwillingness.

This person is really an idiot, and there are not many people who are obsessed with technology now. Dean Zhao looked at Ren Haitao curiously, thinking to himself that this anesthesiologist named Ren Haitao has such a low EQ, where did Mr. Wu draw the baby?

But fortunately, Ren Haitao is here, and the person who changes the "clever" point will not care at all. After all, under the circumstances at that time, there was no evidence to prove that the patient had a problem, everything was quiet, and who knew that the patient was already on the edge of life and death.

Teacher Wu is interesting, and the person he found is also very interesting, Dean Zhao opened a bottle of wine with a smile, and poured a glass for Wu Mian first, and then a glass for Ren Haitao.

The demonstration operation went smoothly, the cooperation between the two hospitals went smoothly, and the piggybacking solved a medical hidden danger, and a patient who may have hypoxic brain death was "fished back", and the meal was very happy.

Wu Mian was also good at dancing at the wine table, chatted happily with Dean Zhao, and finalized the next cooperation plan.

"Teacher Wu, your level is really high, I would like to give you a drink. Director Liu raised his glass and saluted Wu Mian with a glass of wine.

"You're welcome. Wu Mian said with a smile, "It's not at any level, it's all clinically beaten, it's normal." ”

"Uh......" Director Liu was a little puzzled, is Mr. Wu really talking about clinical beating, which is directly related to age. Mr. Wu is not yet 30, why does he say that?

"Director Liu, sit down. Wu Mian took a sip of wine and said, "When I was an intern in college, I encountered something in the gastrointestinal endoscopy room. ”