[Seeking an ideal protocol for the stability of blood gases during general anesthesia for bronchosopies]

During general anesthesia for bronchoscopy, hypoxemia is a major risk, especially in patients with a severe intrapulmonary shunt. With the technique of apnea in pure oxygen, after one hour denitrogentation, and with an intake of 50 liters of oxygen per minute through the bronchoscope, the PaO2 was greater than 400 mm of Hg, but hypercapnia and acidosis occurred. To compensate the latter, five minute sessions of apnea, alternating with two minutes of jet hyperventilation, nevertheless, have the disadvantage of producing a Ventrui phenomena at the proximal end of the bronchoscope, hence a fall in FiO2 which was dangerous in these high risk patients. The authors propose a method so that the Venturi phenomenon, which cannot be prevented, occurs in pure oxygen.