To the Editor.
—In the October 28,1992, issue of JAMA, the authors of the new adult, pediatric, and neonatal advanced life support guidelines1 suggest, as postulated by others,2-4 that a catheter should be inserted into an endotracheal tube beyond the distal tip, at which point the administered drug can be instilled deeply into the tracheobronchial tree, possibly ensuring a more effective route of the drug delivery. My concern is that this step, although it seems reasonable, is unnecessary, increases the likelihood of inducing hypoxia, and fails to accomplish the goal of improved drug delivery. Based on a recent review by Prengel et al,5 32 women undergoing elective gynecologic operations were given 2 mg/kg of 2% lidocaine diluted with normal saline, to a total volume of 10 mL. Eight patients received the drug by instilling it directly into the proximal aperture of the endotracheal tube. All other study