sideration of various surgical procedures, 1 a comprehen sive approach should include attention to all pot~ntial contributing factors such as obesity, alcohol, nasal airway obstruction, therapy of congestive heart failure. Most pa tients with severe obstructive sleep apnea who were rou tinely managed in the past with a tracheostomr can now be successfully treated using nasal continuous positive airway pressure (CPAP).3 However, the combined im mediate and long-term failure rate with nasal CPAP mea sures 25% to 40 %,4,5 and other than a tracheostomy, there are few viable alternatives with established value. Z Transtracheal oxygen (IT O~, which was originally de veloped for patients with chronic pulmonary disease, 6,7 may also be an effective treatment for some patients w!th sleep-disordered breathing including severe obstructive sleep apn ea. The advantages of IT 0 2, relate to the smaller size of the catheter compared with a standard tracheostomy (Fig I), which permits insertion on an out oatient basis and fewer complications. We have used IT )2 in sleep apnea patients in whom nasal CPAP therapy .vas either intolerable or unsuccessful. Polysomnogra ohy was used in all of these cases to document the type 1nd severity of sleep-disordered breathing, to adjust the flow of oxygen, and to verify the adequacy of tr.eatment. In addition, five patients with severe obstructive sleep apnea were systematically studied in order to compare IT O2 to more traditional therapies, ie, nasal CPAP and O2 via nasal cannula. Due to the limited number of studies performed to this point,8'10 the precise mechanisms of action and the indi cations for IT O 2 in this disorder have not been com pletely elucidated. In this article w.e will dis~uss ~he su~ gical technique and the hypothetI~al phYS.lOlogiC bas.ls and summarize some of our expenence WIth IT O2 10 patients with sleep-disordered breathing.