Artificial pulmonary ventilation (ALV): invasive and non-invasive respiratory support

Artificial respiration (AR) is an urgent emergency measure if a person’s own breathing is absent or impaired to such an extent that it poses a threat to life. The need for artificial respiration may arise when providing assistance to those who have received sunstroke, drowned, suffered from electric current, as well as in case of poisoning with certain substances.

The purpose of the procedure is to ensure the process of gas exchange in the human body, in other words, to ensure sufficient saturation of the victim’s blood with oxygen and the removal of carbon dioxide from it. In addition, artificial ventilation has a reflex effect on the respiratory center located in the brain, as a result of which independent breathing is restored.

Mechanism and methods of artificial respiration

Content:

• Mechanism and methods of artificial respiration
• Indications and contraindications
• Preparing for artificial respiration
• Artificial respiration from mouth to mouth
• Artificial respiration from mouth to nose
• How long does artificial respiration last?
• Features of the procedure in children
• Manual methods of artificial respiration
• Hardware artificial respiration methods
• Complications of artificial respiration

Only through the process of breathing does a person’s blood become saturated with oxygen and carbon dioxide is removed from it. After air enters the lungs, it fills the lung sacs called alveoli. The alveoli are pierced by an incredible number of small blood vessels. It is in the pulmonary vesicles that gas exchange takes place - oxygen from the air enters the blood, and carbon dioxide is removed from the blood.

If the body's supply of oxygen is interrupted, vital activity is at risk, since oxygen plays the “first fiddle” in all oxidative processes that occur in the body. That is why, when breathing stops, artificially ventilating the lungs should be started immediately.

The air entering the human body during artificial respiration fills the lungs and irritates the nerve endings in them. As a result, nerve impulses are sent to the respiratory center of the brain, which are a stimulus for the production of response electrical impulses. The latter stimulate contraction and relaxation of the diaphragm muscles, resulting in stimulation of the respiratory process.

Artificially supplying the human body with oxygen in many cases makes it possible to completely restore the independent respiratory process. In the event that cardiac arrest is also observed in the absence of breathing, it is necessary to perform a closed cardiac massage.

Please note that the absence of breathing triggers irreversible processes in the body within five to six minutes. Therefore, timely artificial ventilation can save a person’s life.

All methods of performing ID are divided into expiratory (mouth-to-mouth and mouth-to-nose), manual and hardware. Manual and expiratory methods are considered more labor-intensive and less effective compared to hardware methods. However, they have one very significant advantage. They can be performed without delay, almost anyone can cope with this task, and most importantly, there is no need for any additional devices and instruments, which are not always at hand.

The essence and meaning of cardiac massage

The purpose of cardiac massage is to artificially recreate and replace cardiac activity if it stops. This can be achieved by squeezing the cavities of the heart from the outside, which imitates the first phase of cardiac activity - contraction (systole) with further weakening of pressure on the myocardium, which imitates the second phase - relaxation (diastole).

This massage can be done in two ways: direct and indirect. The first is possible only with surgery, when there is direct access to the heart. The surgeon takes it in his hand and performs a rhythmic alternation of compression and relaxation.

Indirect cardiac massage is called indirect because there is no direct contact with the organ. Compression is applied through the chest wall, as the heart is located between the spine and the sternum. Effective pressure on this area can release about 60% of the blood volume into the vessels compared to self-contracting myocardium. Thus, blood will be able to circulate through the largest arteries and vital organs (brain, heart, lungs).

Indications and contraindications

Indications for the use of ID are all cases where the volume of spontaneous ventilation of the lungs is too low to ensure normal gas exchange. This can happen in many urgent and planned situations:

1. For disorders of the central regulation of breathing caused by impaired cerebral circulation, tumor processes of the brain or brain injury.
2. For medicinal and other types of intoxication.
3. In case of damage to the nerve pathways and neuromuscular synapse, which can be caused by trauma to the cervical spine, viral infections, the toxic effect of certain medications, and poisoning.
4. For diseases and damage to the respiratory muscles and chest wall.
5. In cases of lung lesions of both obstructive and restrictive nature.

The need to use artificial respiration is judged based on a combination of clinical symptoms and external data. Changes in pupil size, hypoventilation, tachy- and bradysystole are conditions that require artificial ventilation. In addition, artificial respiration is required in cases where spontaneous ventilation is “turned off” with the help of muscle relaxants administered for medical purposes (for example, during anesthesia for surgery or during intensive care for a seizure disorder).

As for cases where ID is not recommended, there are no absolute contraindications. There are only prohibitions on the use of certain methods of artificial respiration in a particular case. So, for example, if venous return of blood is difficult, artificial respiration modes are contraindicated, which provoke even greater disruption. In case of lung injury, ventilation methods based on high-pressure air injection, etc., are prohibited.

Invasive ventilation

An endotracheal tube is inserted into the trachea through the mouth or nose and connected to a ventilator.

With invasive respiratory support, the ventilator provides forced pumping of oxygen to the lungs and completely takes over the breathing function. The gas mixture is supplied through an endotracheal tube placed into the trachea through the mouth or nose. In particularly critical cases, tracheostomy is performed - a surgical operation to dissect the anterior wall of the trachea to insert a tracheostomy tube directly into its lumen.

Invasive ventilation is highly effective, but is used only if it is impossible to help the patient in a more gentle way, i.e. without invasive intervention.

Who needs invasive ventilation and when?

A person connected to a ventilator can neither speak nor eat. Intubation is not only inconvenient, but also painful. Because of this, the patient is usually placed in a medically induced coma. The procedure is carried out only in a hospital setting under the supervision of specialists.

Invasive ventilation is highly effective, but intubation involves placing the patient in a medically induced coma. In addition, the procedure is associated with risks.

Traditionally, invasive respiratory support is used in the following cases:

• lack of effect or intolerance of NIV in the patient;
• increased drooling or production of excessive sputum;
• emergency hospitalization and the need for immediate intubation;
• coma or impaired consciousness;
• possibility of respiratory arrest;
• presence of trauma and/or burns to the face.

How does an invasive ventilator work?

The operating principle of devices for invasive ventilation can be described as follows.

• For short-term mechanical ventilation, an endotracheal tube is inserted into the patient's trachea through the mouth or nose. For long-term mechanical ventilation, an incision is made in the patient's neck, the anterior wall of the trachea is dissected, and a tracheostomy tube is placed directly into its lumen.
• A breathing mixture is delivered through a tube into the lungs. The risk of air leakage is minimized, so the patient is guaranteed to receive the right amount of oxygen.
• The patient's condition can be monitored using monitors that display breathing parameters, the volume of supplied air mixture, saturation, cardiac activity, and other data.

Features of equipment for invasive ventilation

Equipment for invasive ventilation has a number of characteristic features.

• Completely takes over the breathing function, i.e. actually breathes instead of the patient.
• It requires regular checking of the serviceability of all valves, because... The patient’s life depends on the performance of the system.
• The procedure must be supervised by a doctor. Weaning the patient from the ventilator also requires the participation of a specialist.
• Used with additional accessories - humidifiers, cough cleaners, spare circuits, suction units, etc.

Preparing for artificial respiration

Before performing expiratory artificial respiration, the patient should be examined. Such resuscitation measures are contraindicated for facial injuries, tuberculosis, polio and trichlorethylene poisoning. In the first case, the reason is obvious, and in the last three, performing expiratory artificial respiration puts the person performing resuscitation at risk.

Before starting expiratory artificial respiration, the victim is quickly freed from clothing squeezing the throat and chest. The collar is unbuttoned, the tie is undone, and the trouser belt can be unfastened. The victim is placed supine on his back on a horizontal surface. The head is tilted back as much as possible, the palm of one hand is placed under the back of the head, and the other palm is pressed on the forehead until the chin is in line with the neck. This condition is necessary for successful resuscitation, since with this position of the head the mouth opens and the tongue moves away from the entrance to the larynx, as a result of which air begins to flow freely into the lungs. In order for the head to remain in this position, a cushion of folded clothing is placed under the shoulder blades.

After this, it is necessary to examine the victim’s oral cavity with your fingers, remove blood, mucus, dirt and any foreign objects.

It is the hygienic aspect of performing expiratory artificial respiration that is the most delicate, since the rescuer will have to touch the victim’s skin with his lips. You can use the following technique: make a small hole in the middle of a handkerchief or gauze. Its diameter should be two to three centimeters. The fabric is placed with a hole on the victim’s mouth or nose, depending on which method of artificial respiration will be used. Thus, air will be blown through the hole in the fabric.

Fundamentals of resuscitation techniques

The success of resuscitation largely depends on the time elapsed from the moment of circulatory arrest to the start of resuscitation.

The basis of measures to increase the survival rate of patients with circulatory and respiratory arrest is the concept of the “chain of survival”. It consists of a number of stages: at the scene, during transport, in the hospital operating room, in the intensive care unit and in the rehabilitation center. The weakest link in this chain is the effective provision of basic living standards at the scene. The outcome largely depends on it. It should be remembered that the time during which you can count on successful restoration of cardiac activity is limited. Resuscitation under normal conditions can be successful if started immediately or in the first minutes after the onset of circulatory arrest. The basic principle of resuscitation at all stages of its implementation is the provision that “resuscitation should prolong life, and not prolong death.” The final results of resuscitation largely depend on the quality of resuscitation. Errors in its implementation can subsequently be layered on the primary damage that caused the terminal condition.

The indication for resuscitation measures is a state of clinical death. Among the main causes of clinical death requiring resuscitation, the leading ones are: sudden circulatory arrest, airway obstruction, hypoventilation, apnea, blood loss and brain damage. Clinical death is the period between life and death, when there are no visible signs of life, but life processes are still ongoing, making it possible to revive the body. The duration of this period at normal body temperature is 5–6 minutes, after which irreversible changes develop in the tissues of the body. Under special conditions (hypothermia, pharmacological protection), this period is extended to 15-16 minutes.

Signs of clinical death are:

1. Arrest of blood circulation (lack of pulsation in the main arteries);

2. Lack of spontaneous breathing (no chest excursions);

3. Lack of consciousness;

4. Wide pupils;

5. Areflexia (no corneal reflex and pupillary reaction to light):

6. Appearance of the corpse (pallor, acrocyanosis).

When carrying out resuscitation, there are 3 stages and 9 stages. The symbolic abbreviation of resuscitation measures - the first letters of the English alphabet - emphasizes the fundamental importance of methodical and consistent implementation of all stages.

Stage I - basic life support. Consists of three stages:

A (airway open) - restoration of airway patency;

B (breath for victim) - emergency artificial ventilation and oxygenation;

C (circulation his blood) - maintaining blood circulation.

Stage II - further life support. It consists of restoring independent blood circulation, normalizing and stabilizing blood circulation and breathing parameters. Stage II includes three stages:

D (drug) - medications and infusion therapy;

E (ECG) - electrocardioscopy and cardiography;

F (fibrillation) - defibrillation.

Stage III - long-term maintenance of life in the post-resuscitation period. It consists of post-resuscitation intensive care and includes the stages:

G (gauging) - state assessment;

H (human mentality) restoration of consciousness;

I - correction of organ dysfunction.

In this manual, we will examine in detail only the first stage of resuscitation measures (A, B, C), leaving the remaining stages and stages for detailed study in subsequent courses.

So, stage A is the restoration of airway patency. When emergency conditions occur, the patency of the airways is often impaired due to the retraction of the tongue, which covers the entrance to the larynx and air cannot enter the lungs. In addition, in an unconscious patient there is always a danger of aspiration and blockage of the respiratory tract by foreign bodies and vomit.

To restore airway patency, it is necessary to perform a “triple airway maneuver”:

1) throwing back (hyperextension) of the head,

2) moving the lower jaw forward,

3) opening the mouth. To do this, with the II-V fingers of both hands, grab the ascending branch of the patient’s lower jaw near the auricle and push it forward (up) with force, shifting the lower jaw so that the lower teeth protrude in front of the upper teeth. During this manipulation, the anterior muscles of the neck are stretched, due to which the root of the tongue is raised above the back wall of the pharynx.

If the airways are obstructed by a foreign body, the victim should be placed in a lying position on his side and 3-5 sharp blows should be given with the lower part of the palm in the interscapular area. The oropharynx is cleaned with a finger, trying to remove the foreign body, then artificial respiration is attempted. If there is no effect, an attempt is made to restore the airways using the Greimlich maneuver - forced pressure on the abdomen. In this case, the palm of one hand is applied to the stomach in the midline between the navel and the xiphoid process. The second hand is placed on top of the first and presses on the stomach with quick movements up the midline. After ensuring airway patency, the next stage of resuscitation begins.

Stage B - artificial respiration. Artificial respiration is the injection of air or an oxygen-enriched mixture into the patient’s lungs, performed without or with the use of special devices, that is, temporary replacement of the function of external respiration. The air exhaled by a person contains from 16 to 18% oxygen, which allows it to be used for artificial respiration during resuscitation. It should be noted that in patients with respiratory and cardiac arrest, pulmonary tissue collapses, which is greatly facilitated by chest compressions. Therefore, it is necessary to provide adequate ventilation during cardiac massage. Each insufflation should take 1-2 seconds, since with a longer forced insufflation, air may enter the stomach. Insufflation must be done sharply and until the patient’s chest begins to rise noticeably. In this case, the victim exhales passively, due to the increased pressure created in the lungs, their elasticity and the mass of the chest. Passive exhalation should be complete. The respiratory rate should be 12-16 per minute. The adequacy of artificial respiration is assessed by periodic expansion of the chest and passive exhalation of air.

Technically, artificial ventilation of the lungs can be carried out by artificial respiration “mouth to mouth”, “mouth to nose”, artificial respiration through an S-shaped air duct and with the help of a mask and an Ambu bag. The most accessible and common method in prehospital intensive care is the simple method of mouth-to-mouth artificial respiration (Fig. 49 d, e, f). To do this, you need to pinch the patient’s nose with one hand, take a deep breath, press your lips tightly around the patient’s mouth (to the lips and nose of newborns and infants) and blow in air until the chest rises to the maximum. While blowing air, monitor the patient’s chest; it should rise when air is blown in. If the patient's chest rises, it is necessary to stop insufflation, lower the patient's mouth and turn his face to the side, giving the victim the opportunity to make a full passive exhalation; when the exhalation ends, take the next deep breath. First, two inflations of the lungs are made, each lasting 1-2 seconds. Then the pulse in the carotid artery is determined; if there is a pulse, repeat the inflation of the lungs - in adults there is approximately one inflation every 5 seconds (12 per minute); for children - one every 4 seconds (15 per minute); in infants - every 3 seconds (20 per minute) - until adequate spontaneous breathing is restored. Artificial respiration is performed at a frequency of 10-12 times per minute (once every 5-6 seconds).

Auxiliary ventilation is used against the background of preserved independent but inadequate breathing in the patient. Simultaneously with the patient's inhalation, additional air is injected through 1-3 respiratory movements. The inhalation should be smooth and correspond in time to the patient’s inhalation. It should be noted that restoring spontaneous breathing quickly restores all other functions. This is due to the fact that the respiratory center is the pacemaker for the brain.

Stage C – maintaining blood circulation. After circulatory arrest for 20–30 minutes, the heart’s automaticity and conductivity functions are preserved, which makes it possible to restore its pumping function. Regardless of the mechanism of cardiac arrest, cardiopulmonary resuscitation must be started immediately to prevent the development of irreversible damage to body tissues (brain, liver, heart, etc.) and the onset of biological death. The main purpose of cardiac massage is to create artificial blood flow. It should be understood that cardiac output and blood flow created by external cardiac massage are no more than 30% of normal and only 5% of normal cerebral blood flow. But, as a rule, this is enough to maintain the viability of the central nervous system during cardiopulmonary and cerebral resuscitation, provided that sufficient oxygenation of the body is achieved within several tens of minutes. At the prehospital stage, only indirect, or closed, cardiac massage is used (i.e., without opening the chest). Sharp pressure on the sternum leads to compression of the heart between the spine and sternum, reducing its volume and ejecting blood into the aorta and pulmonary artery, i.e. it is an artificial systole. At the moment the pressure stops, the chest expands, the heart takes on a volume corresponding to diastole, and blood from the vena cava and pulmonary veins enters the atria and ventricles of the heart. The rhythmic alternation of compressions and relaxations to some extent replaces the work of the heart, i.e., one of the types of artificial circulation is performed. The technique of performing indirect cardiac massage is as follows. The patient is placed on a hard, flat horizontal surface on his back (Fig. 50). Carrying out chest compressions on an armored bed does not make sense - the patient must be laid on the floor. Conductive massage

is located on the side of the patient and places his palms (one on top of the other) on the lower third of the sternum above the base of the xiphoid process by 2 - 3 cm.

You should pay attention to the fact that not the entire palm is located on the sternum, but only its proximal part in close proximity to the wrist (Fig. 51). Indirect cardiac massage itself consists of rhythmic (80 per minute) pressure on the patient’s sternum. In this case, the sternum should drop by at least 5–6 cm.

You should pay attention to the fact that in order to perform a massage correctly, the arms should be almost completely straightened at the elbow joints and pressure on the sternum should be applied with the entire mass of the torso. Many guidelines recommend starting chest compressions with a single strong blow to the patient’s sternum, since fibrillation is often the cause of impaired myocardial contractility and a precordial blow can stop the arrhythmia.

The actual sequence of actions during cardiopulmonary resuscitation is as follows. Option I – resuscitation is carried out by one person:

• if the victim is unconscious, his head is thrown back as much as possible, supporting his chin so that his mouth is slightly open. If necessary, the lower jaw is advanced. If injury to the cervical spine is suspected, moderate head tilting is used only to maintain airway patency. Check for spontaneous breathing (listening and feeling the flow of air at the victim’s mouth, nose, observing the excursion of the chest);
• if the victim is not breathing, perform two deep inflations of the lungs (the chest should rise). Each inflation is performed relatively slowly for 1-2 seconds, then pause to allow a complete passive exhalation;
• palpate the pulse in the carotid artery (5-10s). If a pulse is present, continue ventilation at a rate of about 12 inflations per minute in adults (one inflation every 5 seconds), 15 inflations per minute in children (about 4 seconds) and 20 inflations per minute (one every 3 seconds) in infants;
• if there is no pulse, begin chest compressions;
• carry out 15 compressions of the sternum with a frequency of 80-100 per 1 min. After 15 compressions, two inflations of the lungs are made and continue to alternate 15 compressions on the sternum with two inflations of the lungs;
• the sternum is pressed to the spine by approximately 4-5 cm in adults, 2.5-4 cm in young children and 1-2 cm in infants. The recovery of spontaneous pulse is checked every 1-3 minutes.

Option II – resuscitation is carried out by two people:

Those resuscitating should be on opposite sides of the victim to make it easier to change roles without interrupting resuscitation.

• if the victim is unconscious, the resuscitator (performing ventilation) tilts his head back;
• if the victim is not breathing, the first resuscitator performs two deep lung inflations;
• checks the pulse in the carotid artery;
• if there is no pulse, the second resuscitator begins compression of the sternum with a frequency of 80-100 per minute, the first resuscitator performing ventilation performs one deep inflation of the lungs after every 5 compressions of the sternum; while the lungs are being inflated, the second resuscitator makes a short pause;
• then continue alternating 5 pressures on the sternum with one inflation of the lungs until an independent pulse appears.

Signs of the effectiveness of the massage are the narrowing of previously dilated pupils, the disappearance of pallor and a decrease in cyanosis, pulsation of large arteries (primarily the carotid) in accordance with the frequency of the massage, and the appearance of independent respiratory movements. Indirect cardiac massage is not stopped for more than 5 seconds; it should be carried out until spontaneous heart contractions are restored, ensuring sufficient blood circulation. An indicator of this will be the pulse detected in the radial arteries and an increase in systolic blood pressure to 80-90 mm. Hg Art. The absence of independent heart activity with undoubted signs of the effectiveness of the massage is an indication for continued resuscitation. Carrying out a cardiac massage requires sufficient endurance; It is desirable to change the massager every 5-7 minutes, carried out quickly, without disturbing the rhythm of the heart massage.

Artificial respiration from mouth to mouth

To perform artificial respiration using the mouth-to-mouth method, the person who will provide assistance must be on the side of the victim’s head (preferably on the left side). In a situation where the patient is lying on the floor, the rescuer kneels. If the victim's jaws are clenched, they are forced apart.

After this, one hand is placed on the victim’s forehead, and the other is placed under the back of the head, tilting the patient’s head back as much as possible. Having taken a deep breath, the rescuer holds the exhalation and, bending over the victim, covers the area of ​​his mouth with his lips, creating a kind of “dome” over the patient’s mouth. At the same time, the victim’s nostrils are pinched with the thumb and index finger of the hand located on his forehead. Ensuring tightness is one of the prerequisites for artificial respiration, since air leakage through the victim’s nose or mouth can nullify all efforts.

After sealing, the rescuer quickly, forcefully exhales, blowing air into the airways and lungs. The duration of exhalation should be about a second, and its volume should be at least a liter for effective stimulation of the respiratory center to occur. At the same time, the chest of the person receiving assistance should rise. If the amplitude of its rise is small, this is evidence that the volume of air supplied is insufficient.

Exhaling, the rescuer unbends, freeing the victim's mouth, but at the same time keeping his head thrown back. The patient should exhale for about two seconds. During this time, before taking the next breath, the rescuer must take at least one normal breath “for himself”.

Please note that if a large amount of air enters the patient's stomach rather than the lungs, this will significantly complicate his rescue. Therefore, you should periodically press on the epigastric region to empty the stomach of air.

Artificial respiration from mouth to nose

This method of artificial ventilation is carried out if it is not possible to properly unclench the patient’s jaws or there is an injury to the lips or oral area.

The rescuer places one hand on the victim’s forehead and the other on his chin. At the same time, he simultaneously throws back his head and presses his upper jaw to the lower. With the fingers of the hand that supports the chin, the rescuer must press the lower lip so that the victim’s mouth is completely closed. Taking a deep breath, the rescuer covers the victim’s nose with his lips and forcefully blows air through the nostrils, while watching the movement of the chest.

After artificial inspiration is completed, you need to free the patient's nose and mouth. In some cases, the soft palate may prevent air from escaping through the nostrils, so when the mouth is closed, there may be no exhalation at all. When exhaling, the head must be kept tilted back. The duration of artificial exhalation is about two seconds. During this time, the rescuer himself must take several exhalations and inhalations “for himself.”

How long does artificial respiration last?

There is only one answer to the question of how long ID should be carried out. You should ventilate your lungs in this mode, taking breaks for a maximum of three to four seconds, until full spontaneous breathing is restored, or until the doctor appears and gives other instructions.

At the same time, you should constantly ensure that the procedure is effective. The patient's chest should swell well, and the facial skin should gradually turn pink. It is also necessary to ensure that there are no foreign objects or vomit in the victim’s respiratory tract.

Please note that due to the ID, the rescuer himself may experience weakness and dizziness due to a lack of carbon dioxide in the body. Therefore, ideally, air blowing should be done by two people, who can alternate every two to three minutes. If this is not possible, the number of breaths should be reduced every three minutes so that the person performing resuscitation normalizes the level of carbon dioxide in the body.

During artificial respiration, you should check every minute to see if the victim’s heart has stopped. To do this, use two fingers to feel the pulse in the neck in the triangle between the windpipe and the sternocleidomastoid muscle. Two fingers are placed on the lateral surface of the laryngeal cartilage, after which they are allowed to “slide” into the hollow between the sternocleidomastoid muscle and the cartilage. This is where the pulsation of the carotid artery should be felt.

If there is no pulsation in the carotid artery, chest compressions in combination with ID should be started immediately. Doctors warn that if you miss the moment of cardiac arrest and continue to perform artificial ventilation, it will not be possible to save the victim.

Sudden cardiac arrest on the street: what to do before the ambulance arrives?

Resuscitation measures are carried out after establishing a state of clinical death, the main signs of which are: absent breathing and heartbeat, unconsciousness, dilated pupils, lack of response to external stimuli. To reliably determine the severity of the situation, it is necessary to determine the following indicators of the victim:

• check the pulse in the carotid arteries of the neck at the jaw angle - when the pressure drops to less than 60-50 mm Hg. Art. the pulse on the radial artery of the inner surface of the hand is not detected;
• examine the chest, check for spontaneous breathing movements;
• approach the victim’s face to check breathing, determine inhalation and exhalation (air movement assessment);
• pay attention to the color of the skin - cyanosis and severe pallor appear when breathing stops;
• check consciousness - lack of response to stimuli indicates coma.

Cardiopulmonary resuscitation according to the new standards is carried out only in two cases. You should start performing CPR only after determining your pulse and breathing.

If the pulse is clearly detected for 10-15 seconds and atonal breathing is disturbed with episodes of convulsive sighs, artificial respiration is required. To do this, you need to take 10-12 breaths “mouth to mouth” or “mouth to nose” over the course of a minute. While waiting for an ambulance, you need to measure your pulse every minute; if it is absent, CPR is indicated.

If spontaneous breathing and pulse fail, a set of resuscitation measures is indicated strictly according to the algorithm.

Consciousness testing is carried out according to the following principle:

1. Address the victim loudly. Ask what happened and how he feels.

2. 
   If there is no response, use painful stimuli. Pinch the top edge of the trapezius muscle or apply pressure at the base of the nose.

3. If there is no reaction (speech, twitching, attempts to defend yourself with your hand) - there is no consciousness, you can move on to the next stage.

Breath test:

1. Tilt your head back (holding it by the back of your head and chin) and open your mouth. Inspect it for foreign bodies. If they are there, remove them.
2. Bend towards your face and for 10 seconds. check your breathing. You should feel it with your cheek and hear and see the movements of your chest. Normally, 2-3 breaths are sufficient.
3. If there is no breathing or only 1 breath is felt (which can be considered its absence), we can assume the cessation of a vital function.

In such a case, it is necessary to call an ambulance and begin performing resuscitation measures in case of cardiac and respiratory arrest.

Features of the procedure in children

When performing artificial ventilation for babies under one year of age, the mouth-to-mouth and nose technique is used. If the child is older than one year, the mouth-to-mouth method is used.

Small patients are also placed on their back. For babies under one year old, place a folded blanket under their back or slightly raise their upper body, placing a hand under their back. The head is thrown back.

The person providing assistance takes a shallow breath, seals her lips around the child’s mouth and nose (if the baby is under one year old) or just the mouth, and then blows air into the respiratory tract. The volume of air blown in should be less, the younger the patient. So, in the case of resuscitation of a newborn, it is only 30-40 ml.

If a sufficient volume of air enters the respiratory tract, chest movement occurs. After inhaling, you need to make sure that the chest drops. If you blow too much air into your baby's lungs, this can cause the alveoli of the lung tissue to rupture, causing air to escape into the pleural cavity.

The frequency of insufflations should correspond to the breathing frequency, which tends to decrease with age. Thus, in newborns and children up to four months, the frequency of inhalations and exhalations is forty per minute. From four months to six months this figure is 40-35. In the period from seven months to two years - 35-30. From two to four years it is reduced to twenty-five, in the period from six to twelve years - to twenty. Finally, in a teenager aged 12 to 15 years, the respiratory rate is 20-18 breaths per minute.

Emergency assistance from the medical team: what is the algorithm of action?

To provide emergency care in case of sudden cardiac arrest, a special cardiology team arrives on site, whose task is to carry out advanced resuscitation measures and immediately transport the patient to the hospital. It works according to a protocol that includes the following sequence of actions:

1. Checking vital signs and making a diagnosis. For this purpose, a wider arsenal of equipment is used, including an electrocardiograph. It is necessary to exclude other causes of clinical death, such as bleeding or blockage.

2. 
   Resumption of conductivity of the upper respiratory tract. To ensure maximum oxygen supply, they are intubated.

3. Resuscitation measures are carried out according to the same algorithm as indicated above, but for mechanical ventilation they use breathing masks, an Ambu bag or a ventilator.
4. In the presence of atrial fibrillation or ventricular fibrillation on the ECG, the question of using defibrillation is raised.
5. Drug support is provided by intravenous or intracardiac administration of drugs such as Adrenaline (1 ml 0.1% in 19 ml NaCl 0.9%) and Cordarone (in the presence of arrhythmias, 300 mg IV).

Manual methods of artificial respiration

There are also so-called manual methods of artificial respiration. They are based on changing the volume of the chest due to the application of external force. Let's look at the main ones.

Sylvester's method

This method is most widely used. The victim is placed on his back. A cushion should be placed under the lower part of the chest so that the shoulder blades and the back of the head are lower than the costal arches. In the event that artificial respiration is performed using this method by two people, they kneel on either side of the victim so as to be positioned at the level of his chest. Each of them holds the victim’s hand in the middle of the shoulder with one hand, and with the other just above the level of the hand. Next, they begin to rhythmically raise the victim’s arms, stretching them behind his head. As a result, the chest expands, which corresponds to inhalation. After two or three seconds, the victim’s hands are pressed to the chest, while squeezing it. This performs the functions of exhalation.

In this case, the main thing is that the movements of the hands are as rhythmic as possible. Experts recommend that those performing artificial respiration use their own rhythm of inhalation and exhalation as a “metronome”. In total, you should do about sixteen movements per minute.

ID using the Sylvester method can be performed by one person. He needs to kneel behind the victim’s head, grab his arms above the hands and perform the movements described above.

For broken arms and ribs, this method is contraindicated.

Schaeffer method

If the victim's arms are injured, the Schaeffer method can be used to perform artificial respiration. This technique is also often used for the rehabilitation of people injured while on the water. The victim is placed prone, with his head turned to the side. The one who performs artificial respiration kneels, and the victim’s body should be located between his legs. Hands should be placed on the lower part of the chest so that the thumbs lie along the spine and the rest rest on the ribs. When exhaling, you should lean forward, thus compressing the chest, and while inhaling, straighten, stopping the pressure. The elbows are not bent.

Please note that this method is contraindicated for fractured ribs.

Laborde method

The Laborde method is complementary to the Sylvester and Schaeffer methods. The victim's tongue is grabbed and rhythmically stretched, imitating breathing movements. As a rule, this method is used when breathing has just stopped. The resistance of the tongue that appears is evidence that the person’s breathing is being restored.

Kallistov method

This simple and effective method provides excellent ventilation. The victim is placed prone, face down. A towel is placed on the back in the area of ​​the shoulder blades, and its ends are passed forward, threaded under the armpits. The person providing assistance should take the towel by the ends and lift the victim’s torso seven to ten centimeters from the ground. As a result, the chest expands and the ribs rise. This corresponds to inhalation. When the torso is lowered, it simulates exhalation. Instead of a towel, you can use any belt, scarf, etc.

Howard's method

The victim is positioned supine. A cushion is placed under his back. Hands are moved behind the head and extended. The head itself is turned to the side, the tongue is extended and secured. The one who performs artificial respiration sits astride the victim’s thigh area and places his palms on the lower part of the chest. With your fingers spread, you should grab as many ribs as possible. When the chest is compressed, it simulates inhalation; when the pressure is released, it simulates exhalation. You should do twelve to sixteen movements per minute.

Frank Eve's method

This method requires a stretcher. They are installed in the middle on a transverse stand, the height of which should be half the length of the stretcher. The victim is placed prone on the stretcher, the face is turned to the side, and the arms are placed along the body. The person is tied to the stretcher at the level of the buttocks or thighs. When lowering the head end of the stretcher, inhale; when it goes up, exhale. Maximum breathing volume is achieved when the victim's body is tilted at an angle of 50 degrees.

Nielsen method

The victim is placed face down. His arms are bent at the elbows and crossed, after which they are placed palms down under the forehead. The rescuer kneels at the victim’s head. He places his hands on the victim’s shoulder blades and, without bending them at the elbows, presses with his palms. This is how exhalation occurs. To inhale, the rescuer takes the victim’s shoulders at the elbows and straightens, lifting and pulling the victim towards himself.

Stages of cardiopulmonary resuscitation according to new standards

It is extremely important to follow the correct procedure for resuscitation measures. According to the latest medical protocols, to save the victim it is necessary to adhere to the following algorithm:

• A - ensure airway patency for oxygenation, eliminate blockage of the lumen of the pharynx and trachea;
• B - perform breathing using the “mouth to mouth” or “mouth to nose” method;
• C - restore blood circulation using indirect massage.

Technique and procedure for performing indirect cardiac massage and artificial ventilation of the lungs

1. It is important to maintain safety; before starting CPR, the person must be placed on a rigid, stable and solid surface or floor.
2. After this, tilt your head to the side, open your mouth slightly and make sure that the airway is not blocked. If obstruction is detected, clear the airways using improvised means (handkerchief or napkin).
3. For effective artificial respiration, perform the Safar maneuver - tilt your head back, push your jaw forward and upward, and open your mouth in one movement.
4. If there are signs of a spinal fracture in the neck area, just move your jaw.
5. The resuscitation complex begins with 30 compressions of the sternum, which are performed by one person rhythmically without breaks.
6. To do this, you need to place your right hand with your palm resting on the lower part of the sternum in the center, place your left hand on top of your right hand and interlace your fingers.

7. 
   To perform a heart massage, your arms should be straight, not bent at the elbow joints.

8. Perform 100-120 compressions per minute with rhythmic compression of the sternum 5-6 cm deep, until the chest is completely expanded after compression.
9. After 30 compressions, exhale 2 times into the victim’s mouth or nose for 1 second.
10. When breathing using the mouth-to-mouth method, you must close your nostrils with your fingers before exhaling.
11. During two exhalations, you should look at the chest: straightening and lifting indicate correct execution.
12. If the chest does not rise or fall, it is necessary to check whether the airways are passable, and you may need to repeat Safar.
13. During CPR, be sure to check your pulse every 2 minutes. Resuscitate without stopping for up to 30-40 minutes.

Criteria for the effectiveness of activities

With timely assistance, the chance of saving a person increases. To do this, it is important to strictly follow the rules of cardiopulmonary resuscitation. The effective implementation of the CPR complex is indicated by:

• the appearance of a pulse in the carotid arteries - to make sure that the pulse is maintained, cardiac massage can be stopped for 3-5 seconds;
• return of the pupillary reaction to a light stimulus - narrowing indicates an enrichment of oxygenated blood in the brain;
• the appearance of spontaneous breathing with full, steady inhalation and exhalation, without episodes of convulsive inhalations followed by cessation (apnea);
• disappearance of blueness of the skin of the face, lips, hands;

After the heartbeat and breathing are restored, the resuscitation complex is stopped, but the victim must remain in the field of view of the resuscitator until the doctor arrives

Common mistakes in providing assistance

It should be remembered that incorrectly provided first aid often causes more harm than its absence. The following erroneous recommendations and myths are often found on the Internet (the rule of four “NOT”):

1. Do not check your breath with a mirror or feather - you waste time looking for it, the humidity outside may interfere with your breathing, and when using a feather, the wind can interfere with the reliability of the result. In such a situation, you will mistakenly consider the dead person to be alive.

2. 
   Do not check the pupillary reflex - you need to be able to do this correctly and not with the help of a regular flashlight. If a person is alive, too bright light in certain diseases can damage the retina. Finally, there are neurological disorders in which this reflex will not work in a person with preserved vital functions.

3. You shouldn't do a precordial blow. This requires appropriate practice, moreover, this method has not been proven in terms of effectiveness, and in some cases it can cause even greater harm.
4. Do not perform mechanical ventilation without protection (without a film valve) on strangers - there is a high risk of transmission of infection. If the chest does not rise during artificial ventilation, it should be assumed that air is passing into the stomach, or the airways are blocked. In the first case, limit yourself to NMS; in the second, clean your mouth or use the Heimlich maneuver.

Hardware artificial respiration methods

For the first time, hardware methods of artificial respiration began to be used back in the eighteenth century. Even then, the first air ducts and masks appeared. In particular, doctors proposed using fireplace bellows to blow air into the lungs, as well as devices created in their likeness.

The first automatic ID machines appeared at the end of the nineteenth century. At the beginning of the twenties, several types of respirators appeared at once, which created intermittent vacuum and positive pressure either around the entire body, or only around the patient’s chest and abdomen. Gradually, respirators of this type were replaced by air-injection respirators, which had less solid dimensions and did not impede access to the patient’s body, allowing medical procedures to be performed.

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All ID devices existing today are divided into external and internal. External devices create negative pressure either around the patient's entire body or around his chest, thereby inhaling. Exhalation in this case is passive - the chest simply collapses due to its elasticity. It can also be active if the device creates a positive pressure zone.

With the internal method of artificial ventilation, the device is connected through a mask or intubator to the respiratory tract, and inhalation is carried out by creating positive pressure in the device. Devices of this type are divided into portable, intended for work in “field” conditions, and stationary, the purpose of which is long-term artificial respiration. The former are usually manual, while the latter operate automatically, driven by a motor.

Non-invasive ventilation

Over the past two decades, the use of non-invasive mechanical ventilation equipment has increased markedly. NIV has become a generally accepted and widespread tool for the treatment of acute and chronic respiratory failure both in hospitals and at home.

One of the leading manufacturers of medical respiratory devices is the Australian company ResMed

NIV - what is it?

Non-invasive ventilation refers to mechanical respiratory support without invasive access (ie, without an endotracheal or tracheostomy tube) using various known assisted ventilation modes.

The equipment supplies air to the patient interface through a breathing circuit. To provide NIV, various interfaces are used - nasal or oro-nasal mask, helmet, mouthpiece. Unlike the invasive method, the person continues to breathe on his own, but receives hardware support during inspiration.

When is non-invasive ventilation used?

The key to successful use of noninvasive ventilation is recognition of its capabilities and limitations, as well as careful patient selection (diagnosis and patient assessment). Indications for NIV are the following criteria:

• shortness of breath at rest;
• respiratory rate RR>25, participation of auxiliary respiratory muscles in the respiratory process;
• hypercapnia (PaC02>45 and its rapid increase);
• Ph level
• symptomatic lack of positive effect from oxygen therapy, hypoxemia and gas exchange disorders;
• increase in airway resistance by 1.5-2 times the norm.

To perform non-invasive ventilation, the patient must be conscious and able to follow the instructions of the doctors. There must be a clear prospect of stabilizing the patient within several hours or days after the start of respiratory support. Absolute contraindications for NIV are:

• coma;
• heart failure;
• respiratory arrest;
• any condition requiring immediate intubation.

Advantages of NIV

One of the advantages of non-invasive ventilation is the ability to carry out therapy at home.

Non-invasive ventilation allows you to help a patient with acute or chronic respiratory failure without resorting to endotracheal intubation or tracheostomy. The technique is simpler and more comfortable for the patient. Let us list the main advantages of NIV.

• A respiratory support session is easy to start and just as easy to complete.
• The patient retains the ability to speak, swallow, eat independently, and cough.
• The procedure does not cause complications that are possible with endotracheal intubation and tracheostomy, including mechanical damage to internal organs by the tube, bleeding, swelling of the glottis, infection of the respiratory tract, etc.
• The air passes through the respiratory tract, due to which it is humidified, purified and warmed naturally.
• NIV can be performed at an early stage of the disease, i.e. before the patient's condition becomes critical. This shortens the duration of treatment, reduces the number of complications, and also reduces the risk of readmission.
• In many cases, devices for non-invasive respiratory support can be used not only in a hospital, but also at home.
• There is no “respirator weaning” period after completion of treatment.

Non-invasive conscious ventilation also has some disadvantages and side effects. For example, it is impossible to apply high treatment pressure, because this leads to significant leakage from under the mask. There is no direct access to the respiratory tract, so it is impossible to sanitize it. It is also impossible not to mention the likelihood of aerophagia, aspiration of stomach contents and skin irritation in the areas where the contour is adjacent.

Non-invasive ventilation in CPAP and BIPAP modes

The terms CPAP and BIPAP are often used interchangeably with NIV. These are common methods of non-invasive respiratory support using special portable devices. Many modern ventilators used in intensive care units have the option of CPAP and BIPAP.

Portable respirators are low cost (relative to resuscitation stationary ventilators), and they effectively compensate for even high air leakage. But most often they do not provide advanced monitoring of the patient's condition in real time.

Most resuscitation respirators can operate in CPAP and BIPAP modes. But more often, portable devices are used to provide respiratory support to a conscious patient.

In CPAP (continuous positive airway pressure) mode, the device supplies air under constant positive pressure, and the patient breathes spontaneously (i.e., independently). The method is used in the management of patients with moderate to severe obstructive sleep apnea syndrome (OSA), as well as post-traumatic or postoperative acute respiratory failure.

Bi-level positive airway pressure (BIPAP) devices have a wider range of applications and different mode options. Unlike CPAP, they involve an increase in pressure as you inhale and a decrease in pressure as you exhale. Thanks to this, it becomes possible to use high treatment pressure, but the patient does not experience discomfort in the exhalation phase, overcoming the resistance of the air flow. Two-level ventilation allows you to relieve the respiratory muscles, reduce the respiratory rate and increase the tidal volume. And the presence of auxiliary modes in modern models helps to select the optimal treatment protocol in accordance with the diagnosis and needs of the patient.

CPAP and BIPAP machines to help patients with COVID-19

Over the past few months, the issue of mechanical ventilation has been raised frequently in connection with the COVID-19 pandemic. High demand for ventilators has caused their shortage. The Australian company ResMed, as a manufacturer of medical respirators, is taking the necessary measures to prioritize the production of devices to assist patients with severe respiratory failure. But due to the acute shortage of equipment at the moment, alternative ventilation options, incl. non-invasive respiratory support.

The COVID-19 pandemic has led to a shortage of ventilators. In this regard, primary care for patients with coronavirus infection and symptoms of acute respiratory failure can be carried out using CPAP and BIPAP machines.

CPAP and bipap therapy can be used to provide primary care to patients with COVID-19 who require respiratory support. According to clinical protocols and reports received from clinicians in Italy and China, non-invasive ventilation (including BPAP and CPAP) for patients with COVID-19 is recommended in the following scenarios.

1. To provide respiratory support to patients with respiratory failure who have not yet progressed to more severe hypoxemia.
2. To facilitate extubation and recovery after invasive ventilation.
3. To reduce hospital stays by allowing patients who still require respiratory support and rehabilitation to transition to home care.

NIV cannot replace invasive ventilation in the most severe forms of COVID-19. But this therapy is important when triaging patients in medical institutions. CPAP and BIPAP machines provide supplemental oxygen for less severe cases and reduce dependence on invasive ventilation. In addition, they are relevant for countries where hospital bed capacity turned out to be insufficient during the ongoing pandemic.

The following ResMed brand devices are suitable for home therapy: Lumis series BIPAP devices, as well as the AirCurve 10 CS PaceWave servo ventilator. They can be connected to additional oxygen (up to 15 l/min), as well as a module with a pulse oximetry sensor to monitor blood oxygen saturation.

Long-term use of non-invasive ventilation: benefit or harm

There is an opinion that the longer a patient is on a ventilator, the more difficult it is for him to refuse a respirator. This gives rise to the fear of “forgetting how” to breathe without a device and the fear of suffocation if the device turns off for some reason. But such risks occur only with invasive ventilation, when the device literally breathes instead of the patient. In turn, long-term use of non-invasive ventilation does not cause addiction, because the patient breathes on his own, and medical equipment only helps him with this.

According to research results, long-term non-invasive respiratory support (including at home) can optimize gas exchange, reduce the load on the respiratory system and reduce the risk of subsequent hospitalizations in patients with COPD. One of the advantages of long-term NIV is the ability to provide rest to the respiratory muscles, which are in a state of chronic fatigue.

Long-term use of non-invasive ventilation improves sleep quality and well-being while awake. When NIV is discontinued even for a week, patients with chronic respiratory failure begin to have morning migraines again, shortness of breath appears, and their night saturation also worsens.

NIV for chronic respiratory failure is most often performed at night. First, it increases the total time of respiratory support. Secondly, it helps eliminate nocturnal hypoventilation and episodes of desaturation, which most often occur in the REM phase of sleep.