Sir,In 1975, Ring, Adair, and Elwyn (RAE) described a new design for endotracheal tubes, for use in surgeries of the head and neck, particularly in the pediatric age group. The RAE tube has a preformed bend that fit into the contour of the face and helps position the circuit away from the surgical field. One of the reported disadvantages of the RAE tube is the increased chances of an endobronchial intubation,[1] since the length of the tube distal to the bend is fixed and does not allow for inter-patient morphologic variations. The tubes are available in both cuffed and uncuffed variants. The Murphy's eye was designed to allow gas to pass , should the bevel of the tube be occluded by the wall of the trachea or by any other obstruction. The uncuffed RAE tubes {Sheridan,Hudson Respiratory Inc. “Hudson RCI”, Teleflex Medical, USA and Mallinckrodt (Athlone, Ireland)} are provided with two Murphy's eyes for enhanced patient safety and ostensibly to ventilate the left lung in the event of an endobronchial intubation. However, as shown in Figure 1 the eyes are too close to serve the purpose. We had two cases of inadvertent endobronchial intubation with RAE tube and fiberoptic bronchoscopy revealed both the Murphy's eyes to be in the left main stem bronchus. Weiss et al.,[2] described the need for improvement in cuffed preformed pediatric tracheal tubes and also elaborated that uncuffed preformed tracheal tubes were more at risk of inadvertent endobronchial intubation than cuffed preformed tracheal tubes. We propose a change in the design of the uncuffed RAE tube, i.e. sitting the upper (proximal) eye a little higher to serve the aforementioned purpose.
Figure 1
Proposed change in the location of the upper Murphy's eye in the uncuffed RAE tube
Proposed change in the location of the upper Murphy's eye in the uncuffed RAE tube
Figure 1