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Ventilation during cardiopulmonary resuscitation remains understudied with current guideline recommendations for the treatment relying on low level evidence and expert opinion. The aim of this doctoral project was to explore ventilation during cardiopulmonary resuscitation, both in the experimental and clinical setting.

Study I investigated whether a suction cup on a mechanical chest compression device intended to assist chest recoil affected the haemodynamics and ventilation in an experimental porcine model. No difference in EtCO2, as a measurement of cardiac output, or ventilation could be found, although the suction cup increased the coronary perfusion pressure.

In study II, ventilation parameters, haemodynamics, blood gases and lung injuries were compared between ventilation during continuous chest compressions and ventilations given during a pause of the chest compressions (30:2) in an experimental porcine model. Continuous chest compressions were associated with higher peak inspiratory pressure, lower EtCO2 and PaCO2. No differences were found with regards to lung injuries between the groups.

Study III aimed to develop and test a novel algorithm designed to extract accurate ventilation parameters from ventilation waveform signals, gathered during experimental CPR, in the presence of chest compression artefacts in the signal, that otherwise interferes with the parameter extraction. The algorithm was tested with a pneumotacography device and with mechanical ventilators giving ventilation parameters with known values. The algorithm deviated only slightly from the ventilator settings and outperformed the standard software of the pneumotachograph.

Study IV was an observational multicentre study that aimed to describe ventilation parameters during cardiopulmonary resuscitation. Patients were included from five sites, four out of hospital and one in hospital. Included in the study were 241 patients and 28120 ventilations. The ventilations were heterogenous and varied with airway modality and ventilation mode. Bag-valve-mask ventilations were associated with large levels of leakage and asynchronous ventilations with endotracheal tubes with high airway pressures. No obvious signs of hyperventilation were found.

Future research on cardiopulmonary resuscitation should when possible include measurements of ventilation, in order to deduce if the varying ventilation parameters affects outcomes and to decide optimal ventilation strategies for survival.