What is the oxygen concentration for respiratory failure?

It depends on the decay.

Specific symptoms and types to determine the concentration of oxygen used:

1. Continuous oxygen supply at low flow

Controlling the concentration of oxygen therapy can be selected according to the patient's condition, mild hypoxemia.

No cyanosis. SAO2 50%, PAO2 50mmHg, PACO2 50mmHg), the general oxygen concentration can be 24% 28%;

For moderate hypoxemia (cyanosis is obvious, SAO2 is about 80%, PAO2 is 30mmHg), the oxygen concentration should be 28%;

Severe hypoxemia (severe cyanosis, SAO2 60%, PAO2 30 mmHg) can be given at 28% to 35%.

2. High concentration intermittent oxygen supply

Oxygen is inhaled through a mask with a breathing valve device, and the oxygen flow rate is generally 6 8 l min; Patients with severe hypoxia and no carbon dioxide retention need to inhale oxygen at a high concentration (50%), but the inhalation time should not be too long, usually 12 hours, and alternate inhalation with low concentration, otherwise it can lead to lung damage and oxygen toxicity.

Presents with pulmonary edema.

Congestion and consolidation further affect respiratory function, so intermittent alternating oxygen is necessary.

It is suitable for cardiopulmonary resuscitation and acute respiratory failure.

Such as respiratory, cardiac arrest, ARDS, acute toxic respiratory depression, and patients with refractory heart failure.

Type 1 exhalation failure is only hypoxia, which should be 35%-45% of oxygen concentration at a high concentration, and type 2 hypoxia with carbon dioxide retention should be low concentration less than 35% continuous oxygen supply.

For type 2 respiratory failure, oxygen therapy concentrations are used.

Acute or chronic???

The 30% concentration machine is also known as the oxygen-rich concentration oxygen generator, we call the oxygen concentration below 50% concentration called oxygen-enriched, oxygen-rich is harmless to the human body, will not produce oxygen poisoning, oxygen dependence, mainly used for health preservation.

90% concentration oxygen concentrator is also known as medical oxygen machine, 90% concentration oxygen machine can not inhale oxygen for a long time, long-term inhalation of 90% concentration will produce oxygen dependence, only in the case of long-term oxygen inhalation recommended by doctors, it can be used, or if you have severe emphysema, asthma, pulmonary heart disease, etc., inhale 90% concentration of oxygen, but you should also pay attention to control the time of oxygen inhalation.

The conventional oxygen concentration refers to the concentration of oxygen inhaled into the alveoli, that is, the concentration inhaled into the lungs, not the concentration of the oxygen source.

Medical definition: the oxygen concentration (specifically the concentration of oxygen in the alveoli) is less than 30%, which is a low concentration; The oxygen concentration is between 30% and 50%, which is the medium concentration; A concentration of oxygen above 50% is considered a high concentration. Inhalation of high concentration of oxygen, with a concentration of more than 50%, may cause oxygen poisoning for 2 consecutive days; Inhaled oxygen concentrations above 80% can lead to oxygen toxicity within 12 hours.

The reasonable oxygen concentration, which is also most consistent with the oxygen exchange in the alveoli, is 24%-33%. Therefore, it is recommended that the flow rate of both ** and health care should not exceed 5L per minute, and the purpose of finding a reasonable oxygen concentration (flow) is to take into account factors such as economic costs, if the flow rate per minute can fully achieve the purpose of **.

If you adjust the concentration to oxygen per minute, the effect is the same, but 1 liter of oxygen per minute is wasted, and if the oxygen concentration is not enough, it will have no effect. Therefore, at the beginning of oxygen inhalation, it is necessary to find a suitable oxygen concentration for the user under the guidance of a doctor.

For the effect of oxygen concentration, we need to understand the relationship between the typical oxygen output flow rate and the oxygen concentration taken up. In medicine, when the output gas flow concentration is approximately 100%, the oxygen absorption concentration when using a nasal oxygen tube is -21+4 output gas oxygen flow (l min).

The content of medical oxygen in the oxygen concentrator generally stipulates that the oxygen concentration is 90% (V v), which means that when using the oxygen concentrator, the oxygen concentration will be lower than the corresponding value in the table. If the oxygen concentration is less than 25%, oxygen therapy has no value; Toxicity occurs if the oxygen concentration is higher than 60% and lasts longer than 24 hours. Therefore, it is recommended that home oxygen therapy buy a 2L-5L oxygen concentrator to achieve the effect of adjuvant **.

According to the user's condition, we should give oxygen according to our own physical condition in the process of oxygen therapy and health care, and if necessary, we can go to the hospital for hypoxia testing.

The purpose of oxygen** is to increase the oxygen concentration or partial pressure of oxygen in the alveoli and improve the body's hypoxic state.

Therefore, the amount of oxygen per unit time (oxygen flow) or the concentration of oxygen in the alveoli is one of the important factors that determine the effect.

The control of the absorbed oxygen concentration plays an important role in correcting hypoxia.

The oxygen concentration below 25 is similar to the oxygen content in the air (the concentration of oxygen in the air is 21), and it has no value.

Oxygen toxicity occurs when the oxygen concentration is higher than 70 and lasts for more than 1-2 days.

Most hypoxic patients should give oxygen to 2-4 liters per minute (2-4 compartments of the oxygen flow table).

In this way, the oxygen concentration can reach 29-37.

High-flow oxygen should be given with caution and is generally reserved for patients with severe hypoxia, a partial pressure of oxygen at 30 mm Hg, and no carbon dioxide retention.

For critically ill patients with acute hypoxia, such as acute left heart failure, severe shock, etc., high-flow oxygen is given 4-6 liters for a minute, and the oxygen concentration reaches 37-45%, and the time should not exceed 15-30 minutes, and if necessary, each skin is searched for 15-30 minutes before use.

For patients with chronic respiratory insufficiency, hypoxia and carbon dioxide retention, high-flow oxygen inhalation should be prohibited, and continuous low-flow oxygen should be used to compensate for the lack of oxygen.

Because the sensitivity of the respiratory center to carbon dioxide retention in the body is reduced, the respiratory center mainly relies on the hypoxic oxygen ** aortic body and carotid sinus slow chemoreceptors to maintain breathing through reflexes.

At this time, if the patient is given high-flow oxygen, the hypoxic state is relieved, and the effect of reflex ** breathing in the aortic body and carotid sinus is weakened or disappears, which can make apnea or shallow, and aggravate the condition.

Please take a closer look!

In respiratory failure, the lowest concentration of inspired oxygen is an oxygen saturation of less than 75%. Arterial blood analysis in respiratory failure: PAO2 less than 60 mmHg, with or without PACO2 greater than 50 mmHg.

It is better for ordinary people to have an oxygen saturation above 95, but there are also special ones, such as lung disease, altitude sickness, etc. If it is below 90 for a long time, it should be in a state of hypoxia. However, it should be determined according to the patient's condition and other special circumstances, if the patient is now recommended to be sent to a regular comprehensive examination at home, such as already following the doctor's advice.

If it is a young person, when the SPO2 measured non-invasively at the peripheral vascular end is less than 96%, it should be paid attention to! The elderly have low SPO2 due to peripheral vascular obstruction due to various reasons, which does not indicate the blood oxygen status of the whole body. The doctor will take a blood sample for testing.

Normal arterial oxygen saturation is about 95 97% and mixed venous oxygen saturation is about 75%. The normal oxygen content of the human body is about 90%. The higher the oxygen content in the blood, the better the person's metabolism.

Of course, high blood oxygen content is not a good phenomenon, the blood oxygen in the human body has a certain saturation, too low will cause insufficient oxygen supply to the body.

The low-flow oxygen intake is 1 2 l min, the medium-flow oxygen intake is 2 4 l min, the high-flow oxygen intake is 4 6 l min, and the oxygen concentration is converted to 21 4 l oxygen flow rate l min.

Under normal circumstances, the body's oxygen reserves are very limited, each liter of oxygen is only enough for the body to consume for 3-4 minutes, so the body must continuously obtain oxygen from outside the body. Hypotonic hypoxia results in inadequate oxygen delivery due to a decrease in the partial pressure of oxygen in the arterial blood, which reduces the oxygen content.

Bloody hypoxia is due to the decrease in the amount or nature of hemoglobin, which reduces the oxygen content of the blood or the release of oxygen from hemoglobin, which leads to the impaired oxygen supply.

If you breathe 105ml of oxygen at a time, the amount of gas you breathe is 10ml kg of body weight.

An adult breathes more than 20,000 times on a dry day, inhales 15-20 cubic meters of air, consumes about kilograms of oxygen, and exhales about kilograms of carbon dioxide in the carbon ruler.

The reason why the oxygen concentration formula is 21 and 4 is that 21 is the concentration of oxygen in the air, and the latter is calculated according to the concentration formula, which has no specific meaning.

Inhaled oxygen is the inhalation of oxygen. It is a commonly used method in clinical practice, and oxygen therapy is mainly a method to alleviate hypoxia. Appropriate oxygen inhalation is used to correct hypoxia, improve the level of arterial oxygen partial pressure and oxygen saturation, and promote metabolism, which is one of the important methods to assist a variety of diseases.

Oxygen inhalation is used to correct hypoxia, improve the level of arterial blood oxygen partial pressure and oxygen saturation, and promote metabolism, which is one of the important methods to assist a variety of diseases. Such as respiratory failure, chronic bronchitis, cerebrovascular disease, coronary heart disease. Patients with no obvious clinical hypoxia symptoms may also have oxygen debt, or they may have abnormal microcirculation metabolism, so they may need to inhale oxygen for blind travel.

For example, patients before and after certain surgical operations, patients with hemorrhagic shock, patients with poor fetal heart sounds or prolonged labor during childbirth, etc.

Hazards of oxygen inhalation:

It should be understood that if you do not follow the doctor's instructions to blindly and unrestricted oxygen inhalation, high-concentration "oxygen therapy" can cause complications, at this time, it will inhibit breathing, oxygen toxicity will occur, retrosternal discomfort and pain will occur, aggravation during inhalation, coughing, dyspnea, etc. Under normal circumstances, healthy people do not suffer from hypoxia, and the oxygen delivered to the tissues of the body always exceeds the oxygen consumption of the tissues.

The atmosphere contains about 20% oxygen, this value is relatively constant, air pollution only adds some impurity particles, does not affect the concentration of oxygen in the air, even in densely populated areas are enough for people's needs. In addition, for the human body, oxygen cannot be stored, and the ability of human hemoglobin to carry oxygen is also limited, so oxygen inhalation cannot increase arterial blood oxygen and improve brain oxygen output, and oxygen can only play a placebo role.