RESUMO
Some patients may be impossible to intubate due to anatomical or pathological obstruction of the airway, and conventional methods of ventilation cannot be employed. One of us (J.H.) has successfully applied transtracheal ventilation in such an emergency. Under the circumstances it was not possible to measure the adequacy of ventilation by this method using arterial blood gas studies. A laboratory experiment using dogs was therefore devised. Five dogs acting as their own control were alternately ventilated by conventional expired air (mouth to endotracheal tube) (M.E.T.T.) and via a transtracheal cannula and insufflation of room air with a blood pressure cuff inflation bulb. (T.T.V.A.). The result showed an oxygen saturation of more than 80 percent in all cases and no significant difference in pH between the groups. There was a statistically significant differences in PO2 in two dogs (p<0.05) and in PCO2 in three instances )p<0.05). However, the differences in favour of M.E.T.T. did not appear clinically significant, and the quality of T.T.V.A. was certainly sufficient to sustain life for the duration of the experiments (AU)
