<qa>  What is the tidal volume of the airborne ambulance in Oslo?On the anesthesiologist manned ambulance in Oslo ventilation volumes during CPR will be controlled with a ventilator, the tidal volume varied in random order between 500, 700 and 100 ml, and the volumes be measured continuously as will the impedance between the defibrillator electrodes. In case of failed CPR, the patient will be declared dead. Thereafter the lungs will be ventilated with 700 ml followed by removal of the endotracheal tube, placement of an endotracheal tube in the esophagus and ventilation of this tube, again with monitoring of the impedance. 