The purpose of this study was to compare the Oxylator EM-100, a ventilator with a fixed flow and working pressure of 25 to 50 cm H(2)O, with a bag-valve device with respect to safety, efficiency, and efficacy when used by professionals. We conducted a prospective, controlled, caregiver-blind single center study. Induction was followed by ventilation with a bag-valve device oxylator in manual and automatic modes. Steps were repeated under hypnosis, after muscle relaxation with mask, and with an endotracheal tube. Forty patients, aged 48.8 +/- 13.5 years weighing 50 to 111 kg were studied. Airway management was consistently better with the bag-valve (P <.0001). Normocapnia was maintained with the bag-valve in 88%, oxylator (manual) in 73%, but only 14% of cases in automatic mode with tidal volumes of 1200 mL and more. This device was associated with the potential for rapid hyperventilation in patients when used by professionals. Simplicity of airway management was not improved.