| 摘要 |
A laryngeal mask airway is described which is fitted with an evacuation or drainage tube which passes through the back of the mask and terminates concentrically within an inflatable-cuff formation at the distal end of the mask. In the case of a laryngeal mask which relies on an inflatable ring to establish a seal around the laryngeal inlet, the inflatable-cuff formation results from sealed passage of the evacuation tube through the distal region of the inflatable ring, the distal end of which is centrally apertured and reentrantly folded into sealed junction with the distal end of the tube. When the mask is inflated, its distal end establishes a cuff, sealing the tube against the upper oesophageal sphincter. In the presently preferred embodiment, an auxiliary inflatable cuff is carried at the back side of the mask and, when inflated, establishes a cushioned reference between the evacuation tube and the posterior wall of the pharynx, enabling more effective sealing of the mask to the laryngeal inlet and of the drainage cuff to the oesophageal sphincter, in the circumstance of negative pressure applied to the evacuation tube. |
