A case of a nasogastric tube knotting around a tracheal tube: detection and management.

Numerous complications of gastric tube insertion have been reported (1–7). Few, however, have involved the entanglement of gastric and tracheal tubes (8–10). In our report of a nasogastric (NG) tube knotted around a tracheal tube, prompt detection and adequate management averted airway compromise. Case Report A 72-yr-old, ASA physical status II, female patient with an intraabdominal mass was admitted for exploratory laparotomy. Under general anesthesia and with muscle relaxation, a 7.5-mm inside diameter cuffed Murphy-eye orotracheal tube (Hi/Lo; Mallinckrodt Medical, St. Louis, MO) was easily placed with direct laryngoscopy and secured at the 2-cm mark at the upper incisors. A size 8.0 oral airway (Cath-Guide Airway; Hudson RCI, Temecula, CA) was inserted. Mechanical ventilation was initiated, and the surgical procedure commenced. With the patient’s head flexed, a lubricated 16F gastric tube (Argyle Salem Sump; Sherwood Medical, St. Louis, MO) was blindly inserted via the right naris, but resistance during advancement was felt. The oral airway was removed, and the NG tube was pulled back 2–3 cm and then re-advanced with forward displacement of the larynx. When gastric fluid could not be aspirated, two unsuccessful attempts at withdrawing the NG tube were made. Resistance was felt during withdrawals, and the tracheal tube was noted to move in tandem with the NG tube. A knot was palpated around the tracheal tube in the oropharynx and confirmed under direct vision laryngoscopy. Peak airway pressure remained between 18 and 20 cm H2O. A normal capnographic wave form was present, and oxygen saturation ranged between 98% and 100%. As the knot was judged inaccessible to cutting, tracheal extubation and reintubation were considered. The proximal end of the NG tube was cut at the naris. With its cuff deflated, the tracheal tube was advanced into the trachea until the cut end of the NG tube was visible in the mouth. The tracheal tube and the knotted NG tube were then withdrawn from the mouth en bloc. Upon examination, the NG tube was found tightly knotted around, but not strangulating, the tracheal tube just below the 17-cm mark. The knot was measured approximately 20 cm from the tip of the NG tube (Figure 1). The patient’s trachea was reintubated, and another NG tube was uneventfully inserted through the left naris. Figure 1: After extubation, the cut nasogastric tube knotted around the tracheal tube near the 17-cm mark (Insert). Note the tight square knot which did not result in complete strangulation of the tracheal tube lumen.Discussion Knotting of gastric tubes has been reported among the complications of gastric tube placement (2), but knotting of gastric tubes around tracheal tubes is rare. To our knowledge, only three other cases have been reported in the English language literature (8–10). As in the present case, they all involved blind insertion of Salem sump tubes, either orally or nasally. However, the previous cases resulted in either unintentional tracheal extubation during orogastric tube removal (8) or strangulation of the tracheal tube lumen and airway obstruction with repeated manipulations of the gastric tube (9,10). In the case reported here, the two failed attempts to withdraw the NG tube with concomitant motion of the tracheal tube alluded to the possibility of entanglement, as previously mentioned in one case report (10). Various options dealing with this complication include cutting the knot under direct vision laryngoscopy (9), leaving the knotted gastric tube in place until tracheal extubation is performed, and immediate tracheal extubation and reintubation (10). Factors influencing the choice of options include 1) the possibility of threatening airway obstruction, 2) the ease of intubation and accessibility of the airway, 3) the urgency of gastric emptying, and 4) the location of the knot. Our management was based on a number of considerations. First, the surgical procedure required a patent NG tube for intra- and postoperative gastric decompression. Second, the knot was deemed inaccessible to cutting or manual unknotting. Finally, because the initial intubation was recent and easy, we decided to extubate and reintubate the trachea. The predisposing factors causing gastric tube knotting are not well understood. However, in intubated, anesthetized patients in the supine position, the impaction of the gastric tube on the piriform sinuses and arytenoid cartilages (11), the posterior tilt of the intubated larynx, and the cuffed tracheal tube itself can interfere with the advancement of the gastric tube (12,13) and may cause it to curl and coil within the pharynx. Attempts to withdraw the curled or coiled gastric tube may cause a loop to tighten into a knot. It is conceivable that knotting of gastric tubes might be prevented by the same maneuvers designed to facilitate their placement, such as forward displacement of the larynx (12), lateral neck pressure (11), chilling the gastric tube, inserting a Fogarty catheter through a suction port of the gastric tube to increase its rigidity, lubrication, direct guidance of the tube with two fingers in the mouth, and use of Magill forceps with direct laryngoscopic visualization (7). Although a rare complication, gastric tube knotting around a tracheal tube should be suspected when, during withdrawal of the gastric tube, resistance is felt and concurrent motion of the tracheal tube is noted. The urgency of management depends on the presence or absence of airway compromise, the relative risks of tracheal extubation and reintubation, the necessity of gastric decompression, and the accessibility of the knot.