The study investigates the influence of three types of ventilation mode by using Bi-Level positive airway pressure (pinsp 20 mbar, PEEP 5, AF 10/min) with two different types of ventilators ( Medumat vs. MeduVENT ), Continuous positive airway pressure (PEEP 5, AF 10/min, ASB 10) and Chest Compression Synchronized Ventilation (pInsp = 30 vs. 60 mbar; respiratory rate = chest compression rate, PEEP 5) with regard to achieving a sufficient tidal volume and the tightness of various supraglottic airway devices (laryngeal mask, i-Gel-laryngeal mask, laryngeal tube) and endotracheal intubation.

The European Resuscitation Council (ERC) guidelines for cardiopulmonary resuscitation (CPR) recommend uninterrupted chest compressions and continuous ventilation as soon as a patient is endotracheally intubated or a supraglottic airway (SGA) is positioned.

Recently, SGAs have been adopted by emergency medical services worldwide as the primary tool for airway management during CPR. SGAs offer limited protection against aspiration compared to endotracheal intubation (ETI) and may increase the risk of aspiration. A new ventilation mode (Chest Compression Synchronized Ventilation [CCSV]) is now available for resuscitation with uninterrupted chest compressions.

The study investigates the influence of three types of ventilation mode by using Bi-Level positive airway pressure with two kind ventilators (pinsp 20 mbar, PEEP 5, AF 10/min), Continuous positive airway pressure (PEEP 5, AF 10/min, ASB 10) and Chest Compression Synchronized Ventilation (pInsp = 30 vs. 60 mbar; respiratory rate = chest compression rate, PEEP 5) with regard to achieving a sufficient tidal volume and the tightness of various supraglottic airway devices (laryngeal mask, i-Gel-laryngeal mask, laryngeal tube) and endotracheal intubation.

Gender, age, height and weight are documented (external post-mortem examination). The respective body donor is randomly assigned to a group. The grouping determines the order in which the means of airway management (SGA, ETI) are used.

Initial airway management is performed with an ETI with blockage of 40 mmH2O). The body donor is then bronchoscoped. A gastric tube is placed and the pressure probe to be used is calibrated if necessary. Positive pressure ventilation (pInsp = 35 mbar, positive end-expiratory pressure (PEEP) = 12 mbar, frequency = 10 min-1) is performed for 2 minutes to recruit the lungs. Vt is documented.

Mechanical cardiopulmonary resuscitation (CPR) is then performed for minutes (4 cycles) using the mechanical chest compression device in accordance with ERC 2015. Ventilation pressure and flow curves are continuously recorded by the respirator (Medumat Standard² and MeduVENT by the company Weinmann GmbH). Leaks are detected via the automatically initiated ventilation curves, measured and recorded by the ventilator. Ventilation takes place for 4 minutes with CPAP ASB, 4 minutes in BIPAP mode with Medumat, 4 minutes with MeduVENT and 4 minutes in CCSV mode with an pinsp of 30 and 4 minutes with 60 mbar . At the end of the cycle, the body donor is intubated with one of the remaining airway devices, and the lungs are recruited again and mechanical CPR is performed again for 20 minutes using the 3 ventilation modes. All in all the time durance of CPR for one donor will be 100 minutes by using all four airway devices.

Inclusion Criteria:

• more than 18 years of age

Exclusion Criteria:

• Adult respiratory distress syndrome (ARDS)
• Severe lung or thoracic injuries
• Pneumothorax
• Abnormal airways
• Tracheostoma
• severe aspirations