Abstract: A flexible medical intubation instrument provided for placement into an animal or human patient comprises a catheter with at least one longitudinally extending lumen or channel. A fixed or slideably removable sensor cable is at least partially contained within the channel, having a sensor for sensing a characteristic or condition. While enabling observations through the sensor channel, the working channel may simultaneously function as a drain or an irrigation duct, a feeding tube, or to provide a passage for the insertion of one or a succession of surgical devices such that the catheter serves as a protective artificial tract or liner as surgical devices are inserted and removed through it in succession so as to minimize tissue trauma.