Saturation of arterial blood. Saturation of blood with oxygen and factors of its development. Types and methods of pulse oximetry

When the amount of carbon dioxide begins to prevail over oxygen, the condition is accompanied by the following symptoms:

• fast fatiguability;
• inability to focus on anything.

In the opposite situation, when oxygen saturation is greater than necessary, negative signs are also observed:

• headache;
• excessive sleepiness;
• fatigue.

This condition occurs in persons who have experienced oxygen deficiency for a long time, and then spent a long period in nature.

Lifestyle decides how well the human body will be saturated with oxygen. If a person leads a sedentary image, rarely happens in the fresh air, then the level of saturation will become low, which poses a threat to health.

As it was written above, saturation is considered as a percentage and displays the degree of blood oxygen saturation. How is this analysis done?

It is called "pulse oximetry" because this test uses a pulse oximeter.

This is an unusual test where blood is analyzed without taking a sample. The device is applied to the ear or finger, and then the built-in device is launched, which reads the data and reorganizes the result in percentage terms.

The lack of oxygen in the blood is due to:

• a decrease in the amount of hemoglobin;
• failure of the lungs (pneumonia, asthma);
• violation of respiratory functionality (apnea - unintentional suspension of breathing, dyspnea - a feeling of lack of air);
• pathologies of the heart;
• blood circulation disorders;
• stay in the mountains.

FROM
symptoms of reduced saturation:

• frequent dizziness;
• lethargy, general weakness;
• low pressure;
• dyspnea.

When the body is saturated with a sufficient amount of oxygen, the performance of all organs and systems improves significantly. Metabolic processes are accelerated, and a person begins to feel good. If a person assumes that he has a lack of oxygen, then it is worth changing his lifestyle.

The human body functions normally only if blood saturated with oxygen circulates in it. With a deficiency of this element, hypoxemia occurs, which can be the result of both serious diseases and functional disorders in the body. Timely diagnosis and treatment will help to avoid the complications of this disease, and preventive measures will allow you to never encounter it.

What is hypoxemia

The oxygen that we inhale is necessary for absolutely all tissues, organs and cells of our body. This gas is carried by hemoglobin, an iron-containing element. From the lungs to the blood, oxygen binds with it, resulting in the formation of oxyhemoglobin. This reaction is called oxygenation. When oxyhemoglobin gives oxygen to the cells of organs and tissues, again turning into ordinary hemoglobin, the reverse process occurs - deoxygenation.

1. Saturation of blood with oxygen, or saturation. This indicator is the ratio of oxyhemoglobin to the total amount of hemoglobin in the blood and is normally 96–98%.
2. Oxygen tension in the blood.

Norms of oxygen tension in arterial blood - table

The decrease in oxygen tension in the blood is explained by the fact that with age, different parts of the lungs begin to function unevenly. As a result, the supply of this element to the cells of the body worsens, which leads to many health problems.

A decrease in saturation and oxygen tension in the blood leads to a condition called arterial hypoxemia. Moreover, at first it is the tension that decreases, while the saturation of the blood with oxygen is a more stable value. As a rule, during hypoxemia, the saturation drops below 90%, and the voltage drops to around 60 mm Hg. Art.

Hypoxemia, which is also called oxygen starvation or oxygen deficiency, is the main cause of hypoxia, a condition that is extremely dangerous for the body. Pathology can occur at any age, including during fetal development.

Doctors do not distinguish hypoxemia as a separate disease. It is believed that this condition only accompanies other disorders in the body. Therefore, for normal blood saturation with oxygen, it is necessary to find and eliminate the real cause of the pathology.

Causes of the disease

Medicine knows 5 causes of hypoxemia. They can provoke oxygen starvation both individually and in combination with each other.

1. Hypoventilation of the lung tissue. Various pathologies of the lungs lead to the fact that the frequency of inhalations and exhalations decreases, which means that oxygen enters the body more slowly than it is consumed. Causes of hypoventilation can be airway obstruction, chest injury, inflammatory lung disease.
2. Reducing the concentration of oxygen in the air. Too low oxygen pressure in the environment provokes insufficient oxygenation of the blood. This can happen due to a long stay in a tightly closed unventilated room, while climbing to a great height, or due to force majeure: gas leaks, fire, etc.
3. Atypical shunting of blood in the body. In people with congenital or acquired heart defects, venous blood from its right half enters not into the lungs, but into the aorta. As a result, hemoglobin does not have the ability to attach oxygen, the total content of this element in the blood falls.
4. diffuse disorders. With excessive physical exertion, the rate of blood circulation increases and, accordingly, the time of contact of hemoglobin with oxygen decreases. Because of this, less oxyhemoglobin is formed, and hypoxemia occurs.
5. Anemia. With a decrease in hemoglobin content, the amount of oxygen carried through the tissues of the body also decreases. As a result, cells experience an acute shortage of it, and hypoxemia develops after hypoxemia.

Factors provoking hypoxemia are:

• heart pathology (arrhythmia, tachycardia, heart defects);
• blood diseases (oncology, anemia);
• broncho-pulmonary problems (, lung resection, hemothorax and other diseases that provoke a decrease in the area of ​​\u200b\u200bworking lung tissue);
• a sharp drop in atmospheric pressure;
• excessive smoking;
• obesity;
• general anesthesia.

In addition, hypoxemia often occurs in newborns due to oxygen deficiency in the mother's body during pregnancy.

Symptoms of hypoxemia

Hypoxemia in the early stages is characterized by the following features:

• rapid breathing and heartbeat;
• lowering blood pressure;
• pale skin;
• dizziness;
• apathy, weakness and drowsiness.

All these symptoms indicate that the body is trying to compensate for the lack of oxygen, forcing a person to be less active. If measures are not taken to eliminate oxygen deficiency, hypoxemia will progress and the following symptoms will appear:

• cyanosis (cyanosis of the skin);
• dyspnea;
• tachycardia;
• cold sweat;
• swelling of the legs;
• dizziness and loss of consciousness;
• deterioration of memory and concentration;
• sleep disorders;
• tremor of hands and feet;
• respiratory and cardiovascular failure;
• emotional disturbances (euphoria alternating with stupor).

External manifestations of hypoxemia largely depend on the factors that provoked it. For example, if this condition is caused by pneumonia, it will be accompanied by a cough and fever. With hypoxemia provoked by anemia, dry skin, hair loss and loss of appetite will be observed.

In addition, the symptoms of this condition may vary depending on the age and characteristics of the organism.

Hypoxemia in children

In childhood, hypoxemia develops much faster and more aggressively. This happens for two reasons:

1. A child's body consumes more oxygen than an adult: babies need 6 to 8 ml of oxygen per 1 kg per minute of breathing, while adults need only 3–4 ml.
2. Adaptive mechanisms in children are poorly developed, so their body immediately reacts violently to a lack of oxygen.

It is necessary to start diagnosing and treating babies immediately after the first symptoms of hypoxemia are detected. Otherwise, serious complications can develop, up to the death of the body.

Hypoxemia in a newborn baby can be determined by the following symptoms:

• irregular breathing;
• apnea (stop breathing);
• cyanosis;
• inhibition of the sucking reflex;
• weak cry or its absence;
• decreased muscle tone;
• lack of physical activity.

Hypoxemia in newborns requires emergency medical attention, as it can provoke brain hypoxia and even death. If at the same time the baby was diagnosed with intrauterine growth retardation, then his body has been experiencing a chronic lack of oxygen for a long time.

If hypoxemia has developed in an older child, it is necessary, first of all, to check his cardiovascular system. Most often, the lack of oxygen is provoked by congenital heart disease. Such a child is characterized by emotional instability (anxiety and aggression are replaced by apathy), cyanosis of the skin and rapid breathing.

Children with heart defects sometimes have characteristic seizures when the baby squats and breathes rapidly. In this position, the outflow of blood from the legs increases, which improves well-being.

In adolescence, one of the causes of hypoxemia may be smoking. When a change in skin color, shortness of breath and general weakness in a teenager, it is necessary, first of all, to check the oxygen content in the blood.

Pathology in pregnant women

During pregnancy, the normal saturation of the mother's blood with oxygen is very important. In the case of oxygen starvation, not only the woman suffers, but also her unborn child, so pregnant women need to carefully monitor their well-being. Factors that provoke hypoxemia in women carrying a baby include:

• heart disease;
• pathology of the broncho-pulmonary system;
• anemia
• kidney disease;
• diabetes;
• smoking (both active and passive);
• constant stress;
• neglect of walks in the fresh air;
• pathology of pregnancy.

If the expectant mother has hypoxemia, her baby will develop a similar condition over time. Oxygen deficiency provokes fetal hypoxia and fetoplacental insufficiency, which leads to placental abruption, premature birth and miscarriages.

Fetal hypoxemia

The expectant mother may suspect hypoxemia in the fetus by its behavior: the number of movements decreases and their character changes, and sometimes there are pains in the lower abdomen.

When these alarming phenomena appear, a pregnant woman should immediately go to the doctor. An experienced gynecologist may suspect hypoxemia already at the stage of listening to the fetal heartbeat, and the ultrasound procedure will make it possible to draw a conclusion about the general condition of the child. Based on these examinations, a decision is made on treatment and, possibly, urgent delivery.

Interestingly, the saturation and tension of oxygen in the blood of the fetus differ from those of an adult. And if for a pregnant woman a decrease in voltage by 1 mm Hg. Art. almost imperceptibly, then the fetus will already experience mild hypoxia.

Saturation and tension of oxygen in the blood of the fetus - table

Diagnostics

Doctors make the diagnosis of "hypoxemia" based on the patient's complaints, the data of his visual examination, as well as the results of the following diagnostic methods:

1. A blood gas test that measures the oxygen tension in the blood after treatment.
2. Electrolyte blood test, with which you can determine the presence of chronic hypoxemia.
3. A general blood test that gives an idea of ​​​​the content of hemoglobin.
4. Pulse oximetry - measurement of oxygen concentration in the blood using a special device
5. X-ray of the lungs, which allows to exclude broncho-pulmonary diseases.
6. Electrocardiogram and ultrasound of the heart, giving an idea of ​​the work of the heart and the presence of its defects.

These methods can detect oxygen deficiency in the blood in adults, children and infants. To determine fetal hypoxemia, the following methods are used:

• counting the number of fetal movements;
• listening to the heartbeat: in the presence of pathology, a rapid rhythm alternates with a slow one;
• Ultrasound: discrepancy between the size and weight of the fetus and the gestational age is evidence of a lack of oxygen;
• dopplerometry: starting from the 18th week of pregnancy, ultrasound of the vessels makes it possible to diagnose pathologies of the blood flow of the umbilical cord and placenta;
• amnioscopy, or visual examination of the fetal bladder: if the waters turn out to be cloudy or green - this is evidence that the baby is suffering in the womb, an urgent delivery is necessary.

Sometimes an additional test is performed, with the help of which they find out how the fetal heart rate reacts to its own movements. Normally, this figure should increase by 10-12 contractions.

Treatment of hypoxemia

If the cause of hypoxemia is clear (climbing too high, the consequences of a fire or carbon monoxide poisoning, a long stay in a stuffy room), it is necessary to provide the victim with access to fresh air with a normal oxygen content: open a window or inhale. After that, you can make a decision to go to the hospital.

With moderate or severe hypoxemia, the patient needs urgent hospitalization and careful diagnosis. If the patient cannot breathe on his own, he is intubated, connected to a ventilator (artificial lung ventilation), and other resuscitation actions are performed.

Newborns with intrauterine hypoxemia also often experience respiratory arrest. Such babies are artificially ventilated, and if the child begins to breathe on his own, he is placed in an incubator, where heated humidified oxygen is supplied. At the same time, important general and biochemical blood parameters are constantly monitored, and the work of the heart and lungs of the baby is also monitored.

The acute form of hypoxemia develops in the following cases:

• edema of the lung tissue;
• asthma attack;
• pneumothorax (collapse of the lung);
• inhalation of water or a foreign body.

In the event of acute hypoxemia, it is necessary to promptly provide the victim with medical assistance. The mouth must be cleared of water, saliva, mucus and foreign bodies. You should also exclude the retraction of the tongue. If breathing and heartbeat are absent, this is an indication for immediate chest compressions and mouth-to-mouth artificial respiration.

Chest compressions and artificial respiration can save a person suffering from acute hypoxemia

In hospitals, artificial lung ventilation is used to exit from acute conditions. After intubation of the trachea, the patient is connected to the equipment and they try to restore the ability to breathe on their own.

Medical therapy

Medicines to eliminate hypoxemia are selected depending on the cause that caused this pathology. The following groups of medicines are most often used:

• means for the regulation of redox processes: Cytochrome C, Mexidol, Actovegin, Sodium hydroxybutyrate;
• medicines to prevent diseases of the lungs and heart: Nitroglycerin, Dexamethasone, Isoket, Papaverine, Benzohexonium, Furosemide;
• drugs to lower the blood viscosity index: Heparin, Warfarin, Sinkumar, Pentoxifylline;
• vitamins for general strengthening of the body: C, PP, vitamins of group B;
• solutions for infusion therapy that improve blood circulation: Infezol, glucose solution, saline.

If hypoxemia is accompanied by additional pathologies, other drugs may be prescribed. So, with anemia, iron preparations are indicated, and with pneumonia - antibiotics.

Medicines - photo gallery

Warfarin lowers blood viscosity Infezol improves blood circulation Nitroglycerin is prescribed for heart disease Cytochrome C takes part in the processes of tissue respiration

Physiotherapy

The maximum effectiveness of treatment is achieved with the simultaneous administration of appropriate drugs and the use of physiotherapeutic methods. Inhalation is used to quickly saturate the blood with oxygen. Oxygen therapy is carried out using a mask or nasal catheter. It is necessary to saturate the blood with oxygen until the saturation rises to 80-85%.

Attention! Over-oxygenation can lead to heart problems, so oxygen saturation and tension must be constantly monitored.

Through inhalation, drugs can be introduced into the body that help eliminate oxygen starvation. As a rule, a nebulizer is used for this purpose. With its help, you can inject the desired drug into the blood and lungs, due to which attacks that make breathing difficult are quickly stopped.

Traditional medicine

Herbs and fruits have long been used by traditional healers to combat various diseases, including hypoxia and its consequences. The following plants are considered effective natural antihypoxants.

1. Hawthorn. Hawthorn fruits normalize blood pressure and have a beneficial effect on the cardiovascular system. Boil 1 liter of water and pour boiling water over 2 tbsp. l. hawthorn berries. Infuse the drink in a thermos for 8 hours. Drink 4 times a day for half a glass.
2. Calendula. Calendula infusion is extremely useful for heart problems. Pour 2 tsp. flowers 500 ml of boiling water and leave the drink to infuse for about an hour. Then strain the infusion and drink 3 times a day for half a glass.
3. Black currant. These berries are used to increase hemoglobin levels. Grind 300 g of currants with 300 g of sugar, add 600 g of buckwheat flour and mix well. The resulting mixture, take 1 tbsp. l. 3-4 times a day.
4. Black chokeberry. Mash the mountain ash in a mortar, put it on a fine sieve and squeeze out the juice. Take the resulting drink 3 times a day, 1 tbsp. l.
5. Ginkgo biloba. For making tea 1 tsp. crushed dry leaves of the plant, pour 200 ml of boiling water. After 5-10 minutes, the drink is ready to drink. The course of treatment is 1 month, and you can drink no more than 2-3 cups per day.
6. Arnica mountain. Arnica flowers (about 20 g) pour a glass of boiling water and insist in a water bath for 15 minutes. After the liquid has cooled, strain it and drink 50-60 ml three times a day half an hour before meals. Carefully monitor the dosage: if the dose is exceeded, arnica infusion can have a toxic effect on the body.
7. Horsetail. Pour 1 tsp. dry herbs with a glass of boiling water. After an hour, the infusion can be consumed. Drink it warm 2-3 times a day. Horsetail infusion is contraindicated in people suffering from inflammation of the kidneys.

These plants have vasodilating and antioxidant properties, thin the blood and help the body overcome oxygen starvation. The use of phytotherapy is advisable in combination with traditional medicine. It is impossible to cure severe forms of hypoxemia with herbs alone.

Attention! Before using medicinal plants, you should consult a doctor. Many herbs have contraindications, and dosages often need to be selected individually, depending on the severity of hypoxemia and concomitant diseases. Hawthorn berries normalize blood pressure and have a beneficial effect on the cardiovascular system Calendula officinalis is useful for heart problems
Chokeberry is used as an antispasmodic, vasodilator, hematopoietic Blackcurrant increases hemoglobin levels
Horsetail increases the overall tone of the body

Complications and prevention

An acute lack of oxygen in the blood often has an unfavorable prognosis, since the vital centers of the body - respiratory and cardiac - are affected. The cessation of breathing in the absence of timely medical care entails the death of the brain and the death of the whole organism. However, mechanical ventilation and competent follow-up therapy often bring people back to life.

Mild and moderate forms of hypoxemia are treated quickly and successfully. With delayed therapy, the following complications may occur:

• convulsions;
• encephalopathy;
• myocardial hypoxia;
• arrhythmia;
• pulmonary edema;
• breathing problems (shortness of breath, irregular breathing).

With intrauterine fetal hypoxemia, complications arise:

• intrauterine growth retardation;
• pathological and premature birth;
• delayed physical and mental development after birth;
• the death of a child in the womb, during childbirth or immediately after birth.

With simple preventive measures, hypoxemia can be prevented. For this you need:

• timely diagnose diseases of the respiratory and cardiovascular systems;
• include more fresh fruits, vegetables and juices in the diet;
• in the autumn-winter period, take vitamin and mineral complexes;
• every day to walk in the fresh air for at least 2 hours;
• practice breathing exercises (diaphragmatic breathing);
• engage in feasible physical activity (brisk walking, running, swimming);
• to exclude smoking (including passive).

Hypoxia and oxygen starvation of cells - video

Hypoxemia is a rather serious pathology and the first sign of impending hypoxia. Ignoring the symptoms of a lack of oxygen in the blood leads to many complications and even death. However, this condition can be prevented if pathologies of the heart and lungs are detected in time, as well as prevention of oxygen starvation. Pregnant women should be especially careful about their health, because hypoxemia can develop not only in them, but also in the fetus, which, as a rule, leads to sad consequences.

Thanks

The site provides reference information for informational purposes only. Diagnosis and treatment of diseases should be carried out under the supervision of a specialist. All drugs have contraindications. Expert advice is required!

What is pulse oximetry?

• With anesthesia. During the operation, the patient is unconscious and cannot complain about the deterioration. Pulse oximetry gives objective data without his participation. The anesthesiologist can monitor the depth of anesthesia and, if necessary, support vital processes. This is especially important in complex and risky operations.
• During operations on the limbs. Operations on limbs are often accompanied by temporary occlusion of blood vessels to prevent severe bleeding. The pulse oximeter is attached to the finger and allows you to control blood circulation. Too little oxygen saturation can lead to tissue death, which can lead to complications.
• When transporting patients. The conventional pulse oximeter is portable and does not take up much space, so it is convenient to use it to monitor the condition of patients during their transportation. Many ambulances, airplanes and medical helicopters are equipped with pulse oximeters.
• In reanimation. In the postoperative period and in severe life-threatening diseases, patients are in intensive care. Pulse oximetry in these departments is carried out continuously ( for several days or more). In addition, devices are used to alert medical personnel when a patient's vital signs are declining.
• With some diseases of the lungs and heart. With a number of lung pathologies and heart diseases, there are problems with saturating the body with oxygen. Pulse oximetry helps to determine the severity of the disease and choose the right treatment tactics. In addition, it can be used to quickly diagnose asthma attacks, sleep apnea ( respiratory arrest) and other pathologies that manifest themselves in the form of seizures.
• With carbon monoxide poisoning and oxygen treatment. For a number of diseases, patients are prescribed treatment with a mixture of gases with a high oxygen content ( the mixture is inhaled through a mask). This allows you to quickly increase the concentration of oxygen in the blood. Pulse oximetry determines the effectiveness of such treatment and allows you to understand when the patient's condition will return to normal.
• in the preparation of athletes. In this case, pulse oximetry is not performed for medical reasons. Professional athletes are healthy, but this study allows us to improve the quality of their training. Coaches and doctors monitor blood oxygen saturation during extreme exercise and make the necessary adjustments to the training methodology.

What indicators reflect pulse oximetry? ( saturation, SpO2, etc.)

The indicators recorded by pulse oximeters have the following features:

• Saturation of blood with oxygen. Saturation of peripheral blood with oxygen is also called saturation and is denoted by SpO2. This indicator is very important, as it indicates problems with breathing and cardiac activity almost immediately ( in the process of verification), before there are indirect signs of lack of oxygen - blue ( cyanosis) skin and mucous membranes, changes in heart rate, subjective discomfort in the patient.
• Pulse rate. The pulse rate reflects the heart rate, but does not always coincide with it one hundred percent ( i.e. electrocardiography and pulse oximetry data may differ). This is due to the different elasticity of the vessels, the property of their walls to partially absorb the pulsation, and possible blockage of the vessel lumen. However, the pulse oximeter in any case indirectly reflects the work of the heart and helps to suspect some disorders. To reliably determine the pulse rate during pulse oximetry, the device must correctly read the data for at least 15 to 20 seconds.

Pulse oximeters used in hospital conditions ( resuscitation, operating room, etc.) are often "built into" more complex devices and equipped with a wider range of functions. They register the same indicators, but in combination with other devices, computers provide more complete information about the patient's condition ( heart rate, respiratory rate, etc.).

The norm of pulse oximetry in adults, children and newborns

Normal heart rate at different ages:

• newborns and children under 2 years old - 110 - 180 beats per minute;
• children 2 - 10 years old - 70 - 140 beats per minute;
• teenagers ( over 10 years old) and adults - 60 - 90 beats per minute.

Saturation of arterial blood with oxygen in the norm should always be above 95%. Lower rates are typical for various diseases, and the lower the rate, the more severe the patient's condition. An oxygen saturation of less than 90% is considered life threatening and these patients require urgent medical attention.

Saturation of venous blood with oxygen is measured much less frequently and does not have such great practical significance. Its rate is 75% and above.

Which doctor prescribes and performs pulse oximetry?

The following doctors usually prescribe pulse oximetry:

• anesthesiologists ( enroll) ;
• resuscitators;
• pulmonologists ( enroll) ;
• phthisiatricians ( enroll) ;
• surgeons ( enroll) ;
• therapists ( enroll) and etc.

Conducting pulse oximetry does not require special skills or special training. As a rule, the patient and equipment are prepared by nurses and paramedics familiar with the instructions. The doctor can conduct a study on his own if there is a risk of a rapid deterioration in the condition. For example, in the operating room, an anesthesiologist monitors the performance of a pulse oximeter.

Do I need special patient preparation before pulse oximetry?

Conditional patient preparation for pulse oximetry includes the following recommendations:

• Do not use stimulants. Any stimulants ( narcotic drugs, caffeine, energy drinks) affect the functioning of the nervous system and internal organs. If taken before the procedure, pulse oximetry will provide objective information, but the state of the body will change as the effect of stimulants weakens.
• To give up smoking. Smoking immediately before the procedure can affect the depth of inspiration, heart rate, vascular tone. These changes will cause a decrease in blood oxygen saturation, which will be reflected by pulse oximetry.
• Refusal of alcohol. A single drink of alcohol will not greatly distort the data of pulse oximetry. But if the patient regularly drank alcohol in the days before the procedure, it will affect the functioning of the liver. The liver is responsible for the production of many blood components and enzymes. Thus, the result of pulse oximetry will be somewhat distorted.
• Do not use hand creams or nail polish. In most cases, the pulse oximeter sensor is attached to the finger. The use of various hand creams can affect the "transparency" of the skin. The light waves that are supposed to determine the saturation of the blood with oxygen may encounter an obstacle, which will affect the result of the study. Nail polishes ( especially blue and purple) and completely make the finger opaque to light, and the device will not work.
• Eat normally. Overeating or fasting on the eve of the study can somewhat distort the results, as more of these or other substances will appear in the blood. It is best to eat normally before the study so that the result can be interpreted as a normal state of the body.

Does pulse oximetry hurt?

Thus, the patient is in a comfortable position and does not experience pain or any discomfort. This allows pulse oximetry even for small children and newborns. For them, there are special designs of sensors with soft pads so that the sensor does not rub delicate skin even during prolonged examination.

How long does pulse oximetry take?

The most commonly used monitoring observation) of the patient's condition for a long time. The pulse oximeter records data on how the patient's vital signs changed during the night, day or under certain conditions.

The procedure can last several hours or more in the following cases:

• during a surgical operation;
• during transportation of the patient;
• in the postoperative period or in severe patients in intensive care;
• throughout the night if necessary to detect sleep apnea attacks ( respiratory arrest);
• during an attack of bronchial asthma to objectively determine the severity of the disease;
• within a day or more to register attacks of other diseases ( at the discretion of the attending physician).

Can I do my own pulse oximetry at home?

To obtain reliable data, it is enough for the patient to follow the instructions in the instructions for the device. If the patient has additional questions regarding the interpretation of the results, it is better to contact a specialist. If the pulse oximeter at home gives saturation ( oxygen saturation) less than 95%, you should immediately consult a doctor.

What is a pulse oximeter?

To obtain reliable results when using a pulse oximeter, you must adhere to the following recommendations:

• The right choice of research site. It is advisable to perform pulse oximetry in a room with moderate lighting. Then bright light will not affect the operation of photosensitive sensors. intense light ( especially red, blue and other colors) can significantly distort the results of the study.

• Correct positioning of the patient. The main requirement during pulse oximetry is the static position of the patient. It is advisable to carry out the procedure lying on the couch with a minimum number of movements. Fast and abrupt movements can cause the sensor to move, reduce its contact with the body and distort the result.
• Turning on and powering the device. Some modern pulse oximeters turn on automatically after putting on the probe. In other models, the device must be turned on by yourself. In any case, before using the pulse oximeter, you need to check the charge level ( for models with accumulators or batteries). The study can take quite a long time, depending on the information that the doctor wants to receive. If the device is discharged before the end of the procedure, it will have to be repeated.
• Attaching a sensor. The pulse oximeter sensor is attached to the part of the body specified in the instructions. In any case, it must hold well so that it does not accidentally fall when the patient moves. Also, the sensor should not pinch the finger too hard or tighten the wrist.
• Correct interpretation of results. The pulse oximeter gives the results in a form understandable to the patient. Usually this is the heart rate and the level of oxygen saturation in the blood. However, only the attending physician can correctly interpret the result. He compares the indicators with the results of other studies and the patient's condition.

Currently, portable pulse oximeters can be purchased by almost every patient at home. This acquisition is best agreed with the attending physician. It is not always necessary for it. More often, these devices are purchased for the treatment or care of seriously ill people at home. A pulse oximeter may also be needed if there are difficulties in transporting the patient. Most modern ambulances are equipped with special models.

What are pulse oximeters?

The main advantages that are found in different models of pulse oximeters are:

• Indication of the limits of the norm. Most modern pulse oximeters can determine the normal range themselves. It is displayed on the screen next to the patient's readings. In some cases, the numbers on the screen may turn red if vital signs are falling.
• Sound signal. Some devices are equipped with a special sensor that reacts to a decrease in blood oxygen saturation and notifies you by giving a sound signal. This allows doctors to quickly respond to the problem.
• Portability. Pulse oximeters can be stationary ( for hospitals) and portable ( for home use and ambulances).
• Data processing. Most pulse oximeters display data in the form of numbers on the monitor. However, some can print a graph of changes over time, which is very convenient in case of a long study.
• Compatibility with other devices. Pulse oximeters used in intensive care settings in hospitals are built into or connected to more sophisticated life support machines. "Home" portable devices do not have such a function.

Pulse oximeter sensors ( finger, adult, child, etc.)

All pulse oximeter sensors are connected by a flexible wire to the pulse oximeter itself. Here the data is processed and presented in a convenient form ( usually on the screen in the form of numbers or a graph).

There are the following types of sensors for pulse oximetry:

• Clips. Such sensors resemble a clothespin in shape, which is usually fixed on the index finger or earlobe of the patient. This type is well suited for adults and adolescents when the patient is observed for a short time. Wear a clip when you need a long measurement ( several hours or more) is inconvenient, since it can shift during movements, distorting the results of the study.
• Flexible silicone sensors. Such sensors are more often used during the procedure in newborns. They are usually attached to the lateral side of the leg, since the fingers are too small for examination, and it is difficult to fix the sensor well on them. In addition, silicone nozzles do not cause discomfort to the child.
• Silicone sensors for adults. Such sensors are used when long-term monitoring is required ( more than 3 - 4 hours). They are well fixed and do not cause inconvenience or discomfort. Depending on the model, the sensor can be designed for a certain finger diameter ( for example, the instructions indicate - with a finger thickness of 9 to 12 mm). This parameter must not be neglected, otherwise the device will not illuminate the thickness of the finger tissues, and the result of the study will be distorted.
• Ear clip. Such sensors differ in shape from clips on fingers. As a rule, they have convenient latches ( like an earpiece), allowing them to be well fixed on the auricle. At the same time, the light elements are arranged so as to shine through the earlobe. Ear clips are used for a long study, when the patient is engaged in daily activities, and it is simply not possible to fix the clip on the finger.

Some clinics use disposable pulse oximetry sensors, which is more hygienic for patients. There is no fundamental difference in obtaining results. Disposable sensors are made separately for each model of the device.

Where can I attach the pulse oximeter sensor?

In the case of reflected pulse oximetry, there are more opportunities, since the sensors can be fixed on a flat area of ​​the skin. Doctors are more likely to place such sensors on the extremities, where there are difficulties with blood circulation. In other words, the place of fixation can be almost anything, provided that there is a good vascular network there.

Technique, principle and algorithm of pulse oximetry

The amount of oxygen in the blood is measured as follows. In erythrocytes ( red blood cells) contains hemoglobin - a substance capable of attaching oxygen atoms.
In a healthy body, one hemoglobin molecule is able to attach 4 oxygen molecules. In this form, it is carried to organs and tissues with arterial blood. In venous blood, the amount of dissolved oxygen is less, since some of the hemoglobin molecules are "occupied" with the transfer of carbon dioxide from the tissues to the lungs.

With pulse oximetry, the method of selective absorption of light waves determines the amount of oxygen attached to hemoglobin in arterial blood ( in the form of oxyhemoglobin). To do this, the tissues "shine through" so that the waves are absorbed by the capillaries. The most accurate data, respectively, will be in those areas where the circulatory network is denser.

The pulse oximetry technique includes the following steps:

• the patient is “prepared” for the procedure, explaining what will happen and how;
• on the finger, earlobe or other part of the body ( of necessity) install the sensor;
• the device is turned on, and the actual measurement process begins, which lasts at least 20 - 30 seconds;
• the device displays the measurement result on the monitor in a form convenient for the doctor or patient.

What is fetal pulse oximetry?

This research method is used in neonatology and obstetrics. It requires special equipment, which is not available in all clinics. Fetal pulse oximetry may be needed for certain pregnancy complications, malformations, and other problems.

Errors during pulse oximetry

The most common mistakes made during pulse oximetry are:

• the presence of nail polish;
• wrong sensor attachment ( weak fixation, poor contact with tissues);
• some blood diseases that were not known prior to the start of the study);
• patient movements during the study;
• use of sensors of the wrong model ( by age, weight, etc.).

Interpretation and interpretation of pulse oximetry results

Types and methods of pulse oximetry

Computer pulse oximetry

• Ability to save data. The computer is able to store in memory information about measurements for a certain time. This is necessary, for example, for daily pulse oximetry. In addition, according to the stored data, the computer can build graphs.
• Elimination of artifacts. Artifacts in pulse oximetry are called distortions that can appear when the sensor is not fixed correctly and a number of other errors. Some instruments can detect such distortions and automatically correct the received data.
• Alarm function. The computer stores data on the rate of saturation and heart rate. If the patient's performance drops significantly, the pulse oximeter will notify you with a special signal. Such models are very convenient for resuscitation or operating rooms, where patients are in serious condition.
• Compatibility with other devices. The computer allows you to connect the pulse oximeter to other medical devices, which may be necessary for more complex diagnostic tests.

Transmission pulse oximetry

Transmission pulse oximetry has become widespread, primarily due to the relatively low cost of the device and the simplicity of the study. All models of pulse oximeters intended for home use are based on the principle of transmission pulse oximetry.

Reflected pulse oximetry

It is most convenient to resort to reflected pulse oximetry in the following cases:

• with long-term observation of the patient;
• in pediatrics and neonatology ( as it is difficult for children to explain that it is impossible to move sharply);
• in the diagnosis of diseases of certain organs ( the sensor is fixed in the area of ​​​​the organ and receive indirect data on blood circulation);
• in fitness centers and in the training of professional athletes.

Reflected pulse oximetry has several disadvantages:

• the possibility of an allergy to the adhesive ( sometimes the sensor is glued to the skin for the duration of the procedure);
• poor skin contact if the sensor was loosely attached;
• the appearance of significant distortions in the case of severe tissue edema;
• the sensor cannot be attached to the skin in some dermatological diseases.

Night pulse oximetry ( respiratory night monitoring)

Night pulse oximetry is almost always performed in specialized departments by sleep doctors. They not only monitor the correct conduct of the procedure ( the correct position of the sensor on the finger), but also provide the necessary assistance if there is a threat to the health of the patient.

Daily pulse oximetry

Daily pulse oximetry can detect abnormalities in the work of the following organs and systems:

• respiratory system ( lungs, trachea, etc.);
• the cardiovascular system ( heart, vessels of the small and large circle of blood circulation);
• hematopoietic system ( low level of red blood cells, their pathological changes);
• some metabolic diseases.

Non-invasive pulse oximetry

Non-invasive pulse oximetry has the following undeniable advantages over invasive:

• the procedure does not require special training and even medical education;
• quickly gives results in real time ( monitoring);
• the procedure is cheap and affordable, as it does not require expensive equipment;
• you can observe the patient at home or during transportation;
• the procedure can continuously last several hours or even days;
• there is no risk of complications or infection of the patient, since there is no direct contact with blood;
• The procedure does not require special preparation of the patient.

Invasive pulse oximetry

Sensor installation location ( vessel) may be different. The limiting factor is the diameter of the artery, since even with the transducer inserted, blood must circulate freely through this vessel. Also, the injection site is chosen depending on the specific pathology or problem ( for example, in an area where, for one reason or another, blood oxygen saturation is reduced). In some cases, sensors are also inserted into large veins.

Most often, sensors for invasive pulse oximetry are located in the following vessels:

• radial artery;
• femoral artery;
• veins of the arms and legs of a sufficiently large diameter.

Currently, invasive pulse oximetry is used exclusively in the intensive care unit or surgical department ( of necessity). Sometimes this method is used in research institutes to obtain more accurate data. In the conditions of ordinary hospital departments, minor errors in non-invasive pulse oximetry do not play a significant role, and the use of an invasive method is simply not justified.

Indications and contraindications for pulse oximetry

What conditions require pulse oximetry?

However, there is a certain range of diseases in which pulse oximetry is a very important diagnostic method. We are talking about pathologies of the cardiovascular and respiratory systems. The fact is that it is these systems that are mainly responsible for saturating the body with oxygen. Accordingly, problems with the heart or lungs more often and faster than other diseases lead to a decrease in the concentration of oxygen in the blood.

Most often, pulse oximetry is performed for the following pathologies:

• respiratory failure ( against the background of various diseases);
• bronchial asthma;
• sleep apnea syndrome;
• carbon monoxide poisoning.

With respiratory ( respiratory) insufficiency

Depending on the degree of blood oxygen saturation, the following types of respiratory failure are distinguished:

• Compensated. With compensated respiratory failure, pulse oximetry will be within the normal range. Other organs deal with minor breathing problems, and the level of oxygen in the blood will drop slightly.
• Decompensated. In decompensated respiratory failure, pulse oximetry will detect a significant decrease in the level of oxygen in the blood. This is an indication for a more intensive treatment regimen ( artificial lung ventilation, etc.).

With COPD ( chronic obstructive pulmonary disease)

With pneumonia ( pneumonia)

With bronchial asthma

For carbon monoxide poisoning

For sleep apnea

Contraindications for pulse oximetry

The only significant contraindication is psychomotor agitation, when, due to nervous or mental disorders, the patient is not aware of what is happening. In this case, it is simply not possible to fix the sensor, because the patient himself rips it off. However, the use of tranquilizers helps to calm the patient and carry out the procedure. A similar situation can occur with convulsionswhen, due to severe trembling in the limbs, the sensor will move, and it is more difficult to obtain reliable data.

What tests and examinations are done with pulse oximetry?

• capnometry;

Spirometry

capnometry

Peakflowmetry

Where can I get pulse oximetry done?

Sign up for pulse oximetry

To make an appointment with a doctor or diagnostics, you just need to call a single phone number
+7 495 488-20-52 in Moscow

+7 812 416-38-96 in St. Petersburg

The operator will listen to you and redirect the call to the right clinic, or take an order for an appointment with the specialist you need.

In St. Petersburg

A slight fluctuation in the level of oxygen saturation in the blood can occur in each person. For a more accurate analysis of changes in this indicator, it would be correct to conduct several measurements. Further in the article we will find out why fluctuations occur, how they are fixed and why it is necessary to control them.

Decrease in the level of O 2 in the blood: causes

The saturation of the blood with oxygen occurs in the lungs. Then O 2 is carried to the organs with the participation of hemoglobin. This compound is a special carrier protein. It is found in erythrocytes - red blood cells. By the level of oxygen saturation, you can determine the amount of hemoglobin that is present in the body in an oxygen-bound state. Ideally, the saturation level should be between 96-99%. With this indicator, almost all hemoglobin is associated with oxygen. The reason for its decrease may be severe forms of diseases of the respiratory and cardiovascular systems. With anemia, it is significantly reduced. In case of exacerbation of chronic heart and lung diseases, there is also a decrease in oxygen in the blood, so it is recommended to immediately consult a doctor.

Colds, flu, SARS, pneumonia, chronic bronchitis affect this indicator and report a severe form of the disease. During the examination, it is necessary to take into account some extraneous factors that affect the decrease in oxygen saturation in the blood and change the parameters. These are the movement of the hands or the trembling of the fingers, the manicure with the presence of varnish in dark tones, the direct hit of the light. Among the factors, it should also be noted the low temperature of the room and nearby objects with electromagnetic radiation, including a mobile phone. All this leads to errors in measurements during diagnosis.

Saturation - what is it?

This term refers to the state of saturation of liquids with gases. Saturation in medicine refers to what percentage of oxygen is contained in the blood. This indicator is one of the most important and ensures the normal functioning of the body. Blood carries the oxygen necessary for proper functioning to all organs. How to determine what saturation is in the blood? What will it give?

pulse oximeter

Blood oxygen saturation is determined by a method called pulse oximetry. The instrument used for this is called a pulse oximeter. For the first time, this technique was applied in medical institutions in the wards. The pulse oximeter became a publicly available tool for diagnosing human health. It has been used even at home. The device is easy to use, so it measures some important indicators for life, including heart rate and saturation. What is this device and how does it work?

The principle of operation of the equipment

The circulation of a significant amount of oxygen in the body occurs in a state associated with hemoglobin. The rest of it is freely carried by blood, which is able to absorb light and any other substances. What is the principle of operation of a pulse oximeter? For analysis, you need to take a blood sample. As you know, many people do not tolerate this unpleasant procedure. This is especially true for children. It is quite difficult for them to explain why saturation is determined, what it is and what is the need for it. But, fortunately, pulseoxometry eliminates such troubles. The study is completely painless, fast and absolutely "bloodless". The external sensor, which is connected to the device, leans against the ear, fingertip or other peripheral organs. The result is processed by the processor and the display shows whether the oxygen saturation is normal or not.

Peculiarities

However, there are a couple of nuances. In the human body, there are two reduced and oxyhemoglobin. The latter saturates tissues with oxygen. The task of a pulse oximeter is to distinguish between these types of oxygen. There are two LEDs in the peripheral sensor. From one emit red light rays, having 660 nm, from the other - infrared, whose wavelength is 910 nm and above. It is because of the absorption of these vibrations that it becomes possible to determine the level of oxyhemoglobin. The peripheral sensor is equipped with a photodetector, which receives light beams. They pass through the tissues and send a signal to the procedural block. Further, the measurement result is displayed on the display, and here you can determine whether the oxygen saturation is normal or there are deviations. The second nuance is the absorption of light only from. This is due to its ability to change its density, doing this simultaneously with changes in blood pressure. As a result, the arterial fluctuates much more. The pulse oximeter distinguishes the light that has passed through the artery.