Compression injury in CPR? Four tips to help you cope easily

Since the invention of chest compressions in 1960, this technique has been widely used by doctors around the world as one of the core techniques of cardiopulmonary resuscitation, saving countless lives.

However, heart compressions can sometimes cause injury to the patient. Once the injury occurs, it will cause great harm to both the patient and the doctor. Research into heart compressive injury is both important and imperative.

Compression injuries include sternal fractures, rib fractures, cardiac and pericardial injuries, hemopneumothorax, lung, liver, spleen, and gastrointestinal injuries

Cardiopulmonary resuscitation (CPR) for more than 10 minutes may result in fractured ribs and damaged internal organs. Injuries from heart compressions are sometimes inevitable, sometimes less than 10 minutes, and can result in a fracture even at the first compressions.

In my 26 years of pre-hospital emergency work, I have personally performed hundreds of cardiopulmonary resuscitation (CPR) for patients. According to a rough review, about 20 times or more of the patients' sternum and costal cartilage were crushed when the heart was pressed. It is believed that every clinician who is often engaged in first aid and resuscitation has the same feeling that compressive injury is inevitable.

Once compression injury occurs, it will affect the quality of resuscitation, and literature [2] reported that severe injury caused by compression sometimes even the direct cause of death. In addition, compression injury may give a handle, causing doctor-patient disputes and even litigation.

Although in the vast majority of cases, the death of the patient is caused by the primary disease and has nothing to do with the compression injury, because the patient is a non-medical personnel, it is impossible to truly understand the cause of death of the patient, and sometimes litigation is inevitable.

Root cause: analysis of the cause of cardiac compression injury

After the advent of cardiac compressive surgery, medical personnel in different countries have different understanding and application of its basic techniques and techniques. For this reason, American heart association (AHA), international liaison committee for resuscitation (ILCOR) and other organizations have issued several guidelines for cardiopulmonary resuscitation over the years, and improved measures have been proposed each time [3], standardizing the methods of cardiopulmonary resuscitation [4]. Still, compression injuries continue to emerge. Why?

The injury of heart pressure mainly comes from the force exerted by the palm of the compressor on the chest wall of the patient. Does this mean that the design of heart pressure is wrong?

As a rule of thumb, if the design is correct, there will be no compression damage. The authors concluded that the design of heart compressions was fine. So what's the problem? The factors related to compression injury are as follows:

1. Pressing method

Press action is rough, kneading type press especially the impact type press easy to cause fracture. [5] in addition, the press is the most easy to mistake: the vertical 90 ° heart pressure also is the main reason that lead to harm.

2. Press the area

One of the core contents of cardiac compression is that the operator only touches the chest wall of the patient with the palm root (figure 1), which can avoid pressing hands on the weak costal cartilage on both sides (figure 2). At this time, the force released by the compression is completely absorbed by the sternum and evenly distributed, thus avoiding the occurrence of injury.

However, in practice, compressors cannot always ensure that the palmar root does not deviate from the sternum. Sometimes it may be unconsciously pressed on the outside of the sternum. If it is accidentally pressed on the weak costal cartilage, xiphoid process or upper abdomen, it may cause injury.

FIG. 1 manipulation: palmar root only touches chest wall

Partial pressure

Since compression requires only the palmar root of the pincher to touch the patient's chest wall, this increases the pressure at the pressure point.

According to the calculation, when the adult patients are resuscitation, pressing can generate 30 ~ 50 kg of pressure, and all these forces will be concentrated in the limited contact area of the palm root (about 30 cm2), so that the smaller area on the chest wall of the patient will bear greater pressure. Moreover, these pressures are poured into the chest wall of patients in a very short time (0.25 s ~ 0.3 s note) and repeated.

In particular, if the palmar heel plane of the compressor cannot be parallel to the chest wall of the patient, the pressure will be concentrated on the ulnar small head of the operator's ulnar wrist joint to form a point (about 3 cm2), which will increase the pressure and cause injury to the chest wall of the patient.

It can be seen that the sternum or costal cartilage in the range of 3 ~ 20 cm2 was impacted continuously for a long time with a force of 30 ~ 50 kg and a frequency of 0.6 s, so it was difficult to avoid damage.

Note: the frequency of cardiac compressions is 100 to 120 times /min, that is, every 0.5-0.6s, and the ratio of compressions to relaxation is 1:1. Therefore, half of the compressions in the period of 0.5-0.6s are for relaxation. Therefore, the time for downward compressions is 0.25-0.3s.

4. Chest wall compliance and sternal and rib compression resistance

Compliance refers to flexibility. When the chest wall of the patient has a strong compliance, the chest wall can be dispersed and resolved by timely deformation, so as to avoid compression damage.

However, the chest wall compliance of the elderly, some women and emaciated patients is poor, and the brittleness of costal cartilage increases and the flexibility decreases. In addition, the whole body bone of some patients is decalcified and loose, which reduces the compressive ability of the sternum and ribs. When pressure comes, it cannot be defused by timely and appropriate deformation to deal with injuries caused by pressure.

Sometimes even if the operator's hand is not detached from the patient's sternum, excessive pressure can cause direct damage to the sternum and ribs. I believe that experienced emergency doctors have a profound understanding of this, the older patients, the more prone to compression injury.

5. Heart pressure time

The damage done by pressing is cumulative. The longer the compression, the greater the possibility of injury to the chest wall tissue, and the greater the possibility of deviation of the palm of the resuscitator from the patient's sternum, the more likely it is to cause injury.

For a long time, it is not uncommon for our medical staff to carry out invalid resuscitation for a long time under the strong demand of patients' families. Although there is no hope for the patient to survive (such as cardiac arrest in patients with end-stage disease), the family members still require the medical staff to carry out prolonged resuscitation, which is also an important cause of compression injury.

In the final analysis, the main causes of cardiac compression injury are improper manipulation of the operator during resuscitation, failure to consistently meet the guideline of not deviating from the sternum, individual factors of the patient and prolonged compression. These four factors may work alone or may add up to cause injury.

Coping skills: clinical management of compressive injury

1. Use correct pressure

Strengthen heart press operation training and assessment, avoid rough press, kneading dough type press, impact type press vertical 90 ° of the heart and the press; Pressure must adjust and control their emotions, emotional impulse and instability will lead to abnormal pressure; Press hard according to the patient's condition.

2. Reduce the pressure on the chest wall

The main measures to reduce the pressure are to change the palmroot contact into full-palm contact when pressing the chest wall of the patient, use the pressure device for resuscitation, and change the one-way pressure into two-way pressure, etc.

1) change the palmar root contact to full-palmar contact when pressing the chest wall

The operator does not need to lift the palm root when pressing, but USES the whole palm to press, can make pressing operation technique becomes simple and natural so, can make palmar bosom contact area expands 1 ~ 2 times again, make pressure reduces 1 ~ 2 times at the same time. Since compressors do not always meet the technical requirements for palm-root compressions set out in the guidelines, this should be changed.

Stress is applied to the sternum and both ribs to minimize damage. When operating, make sure that the whole palm is forced evenly. If the pressure is concentrated on a certain point of the palm accidentally, local pressure may be too high and damage may occur. (note: this method is only for reference and scientific research)

2) resuscitate with pressure apparatus

The commonly used clinical compressive devices include cardiopulmonary resuscitation machine and heart pump, etc. The characteristics of these devices are that the diameter of the compressive contact point is between 12 and 15 cm, and the compressive force area is approximately equal to 113 ~ 177 cm2, which is 4 ~ 6 times of the palm-root compressive area. Increasing the contact area of pressure disperses the pressure force and reduces the damage, so it is very safe [6-7].

In addition, a heart pressure plate may be manufactured and used to extend the area of compression contact. The structure consists of a handle that rotates in all directions and a circular plate with a diameter of 12 ~ 15 cm. When pressing, the first responder holds the pressing handle to press (figure 3), which increases the pressing area.

3) change one-way press to two-way press

The resuscitator is located at the top of the head of the patient. One hand is placed on the chest of the patient and the other hand is placed on the relative position of the patient's back. Then the arms are closed and the palms of the two hands are pressed with relative force.

In this way, the patient's chest wall can be changed from unidirectional force to bidirectional force. By dividing the pressure equally between the patient's chest and back, the pressure can be reduced by four to six times.

In addition, another advantage of this method is that, due to the effect of gravity (earth attraction) in lateral lying position, the anteroposterior diameter of patients' chest wall increases when they are not pressed, exceeding the thickness in supine position, while the anteroposterior diameter of patients' chest wall decreases obviously when pressed.

In this way, under the combined action of compression and relaxation, the range of motion of the chest wall of the patient is significantly higher than that of the supine cardiac compression, so that the negative pressure of the patient's chest during the relaxation period increases, and the cava produces greater sucking force, increasing the amount of cardiac blood return, and thereby increasing the cardiac output, increasing the possibility of successful resuscitation.

The author has successfully rescued a 9-year-old girl with prolonged cardiac arrest due to drowning by this method, and the patient recovered completely without any sequelae [8]. Although this method is more laborious than conventional compressions, it is still worth trying. (note: this method is only for reference and scientific research)

3. Gradually increase the depth of pressure

Theoretically, the greater the compression depth, the more cardiac output. Therefore, the 2015 guideline update raised the cardiac compression depth to "5 ~ 6 cm".

However, the guidelines did not take into account that simply increasing the depth of compression could easily cause chest wall injury. Clinicians must consider this when resuscitating, because once injury occurs and litigation occurs, patients do not Sue guidelines, only hospitals and doctors.

However, the guidelines did not take into account that simply increasing the depth of compression could easily cause chest wall injury. Clinicians must consider this when resuscitating, because once injury occurs and litigation occurs, patients do not Sue guidelines, only hospitals and doctors.

Therefore, when we start to press, we should first control the depth of pressure at about 1 ~ 2 cm, and let the patient's chest wall gradually adapt to this state of pressure, and then gradually increase the depth of pressure, and find the feeling while pressing, until the maximum depth that the patient can tolerate.

This is especially true when cardiopulmonary resuscitation (CPR) is administered to the elderly, women, and thin patients. It is suggested that the depth of compression should be measured by the "degree of chest deformation" proposed by he zhongjie, and relevant studies should be carried out.

Set scientific deadlines

Set a scientific compression time limit and avoid prolonged useless compression. It is common for patients with no hope of survival to undergo prolonged and useless CPR at the urging of their families. Constant pressure is not only unscientific but also dangerous.

This not only wastes precious first aid resources, but also consumes the physical strength of medical staff without any reason. It is also easy to cause resuscitation injury. Once pressing injury occurs, it may become the fuse of doctor-patient dispute. Therefore, it is necessary and imperative to establish scientific compression time reference index.

According to the 2010 guidelines, basic life support conditions for the termination of cardiopulmonary resuscitation in adult patients with out-of-hospital cardiac arrest are: [9] : the emergency medical staff or rescuers did not witness when the patient suffered from cardiac arrest; After three rounds of cardiopulmonary resuscitation (CPR) and automatic external defibrillator (AED) analysis, there was no restoration of autonomic circulation. No AED. China should also carry out research on the indication of termination of resuscitation, and formulate a scientific reference time for giving up resuscitation for the reference and implementation of emergency workers.

Before the introduction of our guidelines, for patients who have completely lost the possibility of survival, if the emergency responders cannot stop the cardiac compressions for a while due to various reasons, the compressions should be appropriately reduced to avoid injury. This is to protect the patient, but also to protect the cardiopulmonary resuscitation doctors themselves.

The author is feng geng, chief physician of Beijing emergency medical center.

Photo source: 123rf.com.cn legitimate photo library

References:

[1] Kouweuhoven WB, Jude JR., Knickerbocker CG, et al. Closed chest massage[J]. JAMA, 1960 Jul 9, 173: 1064-1067.

[2] cui lijuan, yi xufu, feng junshuang. Discussion on cardiopulmonary resuscitation related injuries [J]. Clinical misdiagnosis and mistreatment, 2012, 25(2): 95-97.

[3] note: without the original author. Emergency cardiac care committee and subcommittees American heart association guidelines for cardiopulmonary resuscitation and Emergency cardiac care Ⅸ: Disappointing effectiveness of communitywide emergency cardiac care[J]. JAMA 1992, Oct 28; 268:2289-2295.

[4] Berg RA, Hemphill R, Benjamin S, et al. Part 5: Adult Basic Life Support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care [J]. Circulation, 2010, Oct 19; 122: S685 - S705.

[5] hu huiying, zhong shizhen. Effects of chest compressions in cardiopulmonary resuscitation and research progress [J]. China emergency medicine, 2006(12): 52-54.

[6] tao yijiang, Chen jianrong, wang shixiang, et al. The application of the ram cardiopulmonary resuscitation machine in the rescue of 9 cases of cardiopulmonary resuscitation [J]. China critical care emergency medicine, 2001, 13(3):176.

[7] zeng yan, zhou chaohong. An analysis of the advantages of cardiopulmonary resuscitation device in the application of first aid in Utstein mode [J]. Modern preventive medicine, 2011, 38 (13): 2675-2676.

Chinese journal of emergency medicine, 2004, 13(8):517. (in Chinese with English abstract)

[9] Morrison LJ, Kierzek G, Diekema DS, et al. Part 3: Ethics: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care [J]. Circulation, 2010, Oct 19; 122: S665 - S675.

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