Reanimation

• Ventilation:

In the 19th century, less effective measures for indirect ventilation through chest compressions such as Sylvester's arm movements were used, some of which were still taught until the 1970s (Ziegenfuß 2007).

The Austrian physician Peter Safar, together with D G Greene, developed the technique of modern respiratory resuscitation in the 1950s (Litzberski 2025).

• Cardiac massage:

Böhm first used external cardiac massage for poisoning with chloroform in 1874 and König performed it successfully in Göttingen in 1892. However, it was subsequently forgotten (Düben 1972).

It was not until 1960 that external cardiopulmonary resuscitation using chest compressions was published by Kouwenhoven, Jude and Knickerbocker. This was a milestone in modern medicine (Scholz 2017).

The combination of ventilation and cardiac massage was first recommended by P. Safar in 1961 (Ziegenfuß 2007),

In 1972, the European Resuscitation Council (ERC) published the first evidence-based European guidelines for the prevention and treatment of circulatory arrest and life-threatening emergencies. The last amendment dates from 2025 (Guidelines 2025).

Resuscitation is the attempt to revive a patient who is suffering from circulatory and/or respiratory arrest (Antwerpes 2025).

A distinction is made in resuscitation between "Basic Life Support" (BLS) and "Advanced Life Support" (ALS). For more details, see "General information" (Antwerpes 2025).

• Basic Life Support (BLS):

BLS can be performed by any layperson as well as by emergency paramedics and emergency physicians (Antwerpes 2025).

If a cardiovascular arrest occurs in a public place, resuscitation should ALWAYS be initiated without a clear advance directive or clear medical exclusion criteria. In hospital, however, possible scenarios can be discussed beforehand (Zumbrunn 2025).

CRP should be carried out for at least 30 minutes, and even up to an hour in the event of hypothermia caused by accidents (Herold 2025).

After recognizing a circulatory arrest, both the emergency medical services and an emergency physician should be notified (Herold 2025).

The basic measures of CPR consist of:

- C = Chest compression

- A = Airway

- B = Breathing (Herold 2025)

The BLS include:

• Determining the level of consciousness:

Loud response, shaking the body, rubbing the knuckles of a clenched fist over the sternum (Pelz 2016).

• Checking the breathing:

Any residual gasping should not be misinterpreted as sufficient breathing. However, breath control can be difficult even for experienced rescuers, so resuscitation should be started as soon as there is no pulse (Schwab 2015).

• Cardiac massage:

First, chest compressions should be started on as hard a surface as possible. This involves compressing the lower half of the sternum with a compression depth of approx. 5 - 6 cm, the frequency should be between 100 - 200 / min (Herold 2025).

Chest compression can also be performed mechanically, whereby the compression depth of the ram can be adjusted (Ziegenfuß 2007).

• Ventilation:

For mouth-to-mouth ventilation, the patient's head should be hyperextended and the chin raised. The nasal opening should be closed with the fingers. Then exhale into the patient's lungs for approx. 1 second until the chest rises visibly (Ziegenfuß 2007).

For endotracheal intubation, the pause in chest compressions should be < 5 sec (Herold 2025).

The subsequent HDM: ventilation rate in adults should be 30: 2, with no pause in chest compressions during ventilation (Herold 2025). For children, the frequency is 15:2 and for infants 3:1 (Secchi 2009).

The rescuers should be changed every 2 minutes if possible (Herold 2025).

If mouth-to-mouth resuscitation is rejected for psychological or infection prevention reasons, only chest compressions are permitted (Herold 2025).

The patient should not be touched during the AED cardiac rhythm analysis (Herold 2025)

• Advanced measures after ECG analysis (Advanced Life Support = ALS)

A distinction is made here between

- a. pulseless ventricular tachycardia, ventricular fibrillation or ventricular flutter and

- b. Asystole and electromechanical dissociation

a. Pulseless ventricular tachycardia, ventricular fibrillation or ventricular flutter:

• Immediate defibrillation at the highest energy level required
• If this is unsuccessful, the same cycle of CPR should be repeated for 2 minutes, followed by defibrillation at the highest energy level. If unsuccessful again, an alternative patch position may be considered.
• Establish venous access without interrupting HDM. If venous access cannot be achieved, create intraosseous access.
• If a defibrillatable rhythm still cannot be achieved, a maximum of 1 mg adrenaline(adrenaline 10 µg /kg [2025 guidelines]) plus 9 mg NaCl should be administered intravenously.
• If the rhythm can be defibrillated, 1 mg adrenaline should be administered after the 3rd defibrillation. This therapy should be repeated every 3 - 5 minutes. In the case of intraosseous access, additional rinsing with 20 ml isotonic solution is required.
• If VF or polymorphic VT is still present after 3 defibrillations, a maximum of 300 mg amiodarone should be administered intravenously(amiodarone 5 mg /kg [Guidelines 2025]). After 5 defibrillations and continued VF or polymorphic VT, re-inject 150 mg amiodaroneonce (Herold 2025). For further medication, see also "Internal therapy"
• Intubation and ventilation: If the interruption of HDM does not last longer than 5 seconds, the patient can be intubated at an early stage. As an alternative to intubation, a supraglottic breathing aid can also be used (Herold 2025)
• The measurement of CO2 in the exhaled air, known as capnography, is recommended to check the correct position of the endotracheal tube. The ventilation rate should be 10/min.
• The resuscitation itself is carried out under high oxygen levels. After successful resuscitation, SpO2 values should be limited to normal values between 94-96%. Hyperoxemia should be avoided at all costs after the return of spontaneous circulation (Herold 2025).
• Blood glucose should also be monitored regularly and kept within the normal range. Hypoglycemia should be avoided at all costs (Herold 2025).

b. Asystole and electromechanical dissociation:

• CPR for 2 min and subsequent administration of 1 mg adrenaline every 3 - 5 min i.v. (as for ventricular fibrillation).
• If this is unsuccessful, transthoracic electrical stimulation should be used as pacemaker therapy.
• 50 mmol sodium bicarbonate should be administered in case of circulatory arrest due to hyperkalemia or overdose of tricyclic antidepressants
• The use of thrombolytics should be considered if there is an urgent suspicion of pulmonary embolism. CPR should then be continued.
• If the cause of the circulatory arrest is a myocardial infarction/acutecoronary syndrome (ACS), prompt percutaneous coronary intervention is recommended (Herold 2025)

Termination of resuscitation

Resuscitation measures should be continued for at least 30 minutes, in the case of hypothermia even > 1 hour (Herold 2025). If an embolism is suspected, a resuscitation duration of 60 - 90 min is even recommended (Schwab 2015).

If an underlying infaust disease is known, premature termination may be advisable (Schwab 2015).

In the case of ventricular fibrillationand pulseless ventricular tachycardia, once resuscitation has begun, it should be continued for as long as this rhythm persists. If the rhythm degenerates into asystole or pulseless electrical activity (PEA), this should be regarded as a bad sign. Pupil width and pupil response, on the other hand, have no prognostic significance, contrary to previous claims (Schwab 2015).

Post-resuscitation treatment

After successful resuscitation, the following target values should be aimed for:

▪ SaO2 94-98%

▪ PaO2 10-13 kPa

▪ etCO2 (end-tidal CO2) 4.7-6.0 kPa

▪ MAP (mean arterial blood pressure) 60-65 mmHg

▪ Temperature ≤ 37.5 °C (2025 guidelines)

In Europe, around 84 out of every 100,000 people suffer a cardiovascular arrest every year (Zumbrunn 2025). In the western world, cardiovascular death is the most common cause of death and is the first manifestation of previously unrecognized heart disease in around 55% of cases (Herold 2025).

The average age of patients is 67 years (plus/minus 17 years), of whom around 65% are male (Herold 2025).

There are many causes that lead to resuscitation. These include in particular:

• Cardiovascular causes in approx. 60 % of cases
• Unknown causes in 15 %
• Respiratory causes in 14 %
• Trauma in 3 %
• Pulmonary artery embolism between 2 - 5 %
• Rare causes such as electrolyte disturbances, tension pneumothorax, aortic dissection, acute bleeding (Girndt 2022)

Patients with sudden loss of consciousness and abnormal breathing patterns should be resuscitated immediately (Girndt 2022).

Complications caused by the resuscitation measures include:

• Rib fractures with injuries to the lungs and/or heart
• sternal fracture
• Liver injury
• Spleen injury
• Aortic and/or cardiac rupture
• Pericardial effusion
• Gastric hyperinflation (Herold 2025)
• Pneumothorax
• Gastric rupture (Secchi 2009)

Emergency medication in the event of resuscitation is:

• Adrenalin: 1 mg every 3 - 5 min i. v. or intraosseous
• Amiodarone: 300 mg i.v. once, 150 mg i.v. if repeated, followed by continuous infusion at 900 mg / 24 h
• Lidocaine: 1.0 - 1.5 mg / kg bw i.v., maximum dosage 3 mg / kg bw
• Magnesium: 2 g 50% magnesium sulphate solution i. v. for hypomagnesemia, intoxication with digitalis and torsade de pointes tachycardia
• Sodium bicarbonate: 50 ml sodium bicarbonate 8.4% only in case of prolonged resuscitation, if pH< 7.1 and BE < -10 mmol/l
• Calcium: 2 - 4 mg / kg bw i.v. in case of hypocalcemia, hypokalemia or intoxication with calcium antagonists
• Thrombolytics such as urokinase in case of suspected pulmonary embolism for 60 - 90 min while continuing CPR
• Lipid emulsion 20 %: in case of intoxication by local anesthetics 1.5 ml / kg bw as a bolus, then 0.1 ml / kg bw / min over a period of 30 min or 0.5 ml / kg bw / min over a period of 30 min (Schwab 2015)

Rescue services in Germany attempt around 55,000 resuscitations per year. However, 74.3% of these die shortly before or after reaching the hospital. But even after reaching the hospital, the prognosis remains serious, as the 1-year survival rate is only 7.7% worldwide (Zumbrunn 2025).

The chances of successful resuscitation after primary circulatory arrest are significantly better than after secondary circulatory arrest, as in secondary circulatory arrest the organs are usually already severely hypoxic (Secchi 2009).

If defibrillation is started immediately after the onset of ventricular fibrillation (e.g. in the intensive care unit), it can be successful in up to 95% of cases. For every minute that defibrillation is delayed, the chances of survival are reduced by 10% (Herold 2025).

Within a hospital (IHCA) between 15-34% of those affected survive a cardiac arrest, outside (OHCA) only around 10%. Among the survivors, around 22.9% of IHCA patients ultimately die from severe neurological damage and around 67.7% of the OHAC group. In patients who survive the first year after such an incident, up to 83.3% have a good neurological outcome (Zumbrunn 2025).

In OHCA cases under 50 years of age, a clinically relevant pathogenic variant in a gene that is probably associated with sudden circulatory arrest was identified in up to 25% of cases (Guidelines 2025).

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