Kinking of the Pilot Tube Prevents Inflation of the Cuff

Abstract

To the Editor: We are writing to describe an endotracheal intubating event that has not been previously described in the literature. A 23-year-old male (178 cm/64 kg) was scheduled for repair of an open right mandible body fracture and left condylar fracture sustained in a fall. His past medical history was significant only for asthma in childhood, but he was asymptomatic and was not taking medication. Examination of the airway was remarkable for <1-cm incisor distance and the presence of loose molars as had been shown on radiograph. Awake fiberoptic nasotracheal intubation was planned. The left naris was topically anesthetized in the operating room with 0.45% tetracaine solution, and awake nasotracheal intubation proceeded uneventfully (8.0 nasal RAE, 28 cm at naris, 2 cm above carina). The cuff of the nasotracheal tube was filled with 7 cm of air without any apparent difficulty. IV anesthetic induction proceeded without event. With initiation of positive pressure ventilation, there was a large discrepancy between delivered tidal volumes and expiratory volumes. This air leak was present despite the pilot balloon being full and tense. Attempts to add additional volume to cuff encountered unexpectedly high resistance. Approximately 5 cm3 of air could be withdrawn from the pilot balloon; however, attempts to add additional volume to the cuff again encountered high resistance. Inspection of pilot balloon and valve did not reveal any abnormality. A fiberoptic bronchoscope was passed per os into the trachea external to the nasotracheal tube (NTT) and demonstrated that the cuff was completely deflated. At that point, the NTT was carefully backed out of the naris to 26 cm (tip remained in the trachea) at which point the entirety of the pilot balloon tubing could be examined (Fig. 1). The pilot balloon tubing was acutely kinked at its connection with the NTT and wrapped one-half turn around the NTT, effectively inhibiting flow of air to the tracheal cuff. Unkinking of the pilot balloon tubing quickly corrected the problem. The NTT was then readvanced 2 cm and functioned properly for the duration of the case.Figure 1: Pilot balloon tubing acutely kinked at insertion to nasotracheal tube (NTT) and wrapped one-half turn around the NTT.Carla St. Laurent, MD Daniel Lee, MD, PhD Jonathan Benumof, MD