To prevent an unexpected aftertreatment after surgery by causing a sufficient amount of oxygen to flow and preventing an unexpected force from being applied to a respiratory muscle or a tissue mucosa so as not to cause edema , Making it more difficult for wet bronchus to wet liquid such as hate.A catheter which is inserted into a trachea to secure an airway has a tubular member having a hollow portion formed along an axis P, a tubular member having an opening at a front end surface in a direction of inserting the tubular member into a trachea , An opening 12 that opens the hollow portion 11 to the outside, and an opening 13 that opens to the rear end face 15 in the insertion direction of the tubular member 10 and opens the hollow portion 11 to the outside. The tubular member 10 has a protrusion 17 and a protrusion 18 protruding from the inner wall 10 a of the hollow portion 11 to the hollow portion 11.(FIG.【課題】十分な量の酸素を流すと共に、呼吸筋又は組織粘膜に対して不測の力が加わらないようにすることで、浮腫を生じないようにして、手術後の予期せぬ後遺症を回避し、更に浸出液等の液体を気管支に湿潤し難くすること。【解決手段】気管に挿入されて気道を確保するカテーテル1は、軸Pに沿って形成された中空部11を備える管状部材10と、管状部材10の気管に対する挿入方向の前端面14に開口し、中空部11を外部に開放する開口部12と、管状部材10の挿入方向の後端面15に開口し、中空部11を外部に開放する開口部13と、を有する。管状部材10は、中空部11の内壁10aから中空部11に突出する突出部17及び突出部18を備える。【選択図】図3
