Short nasal tracheal tubes

Abstract

We wish to draw attention to a problem with Mallinckrodt uncuffed nasal tracheal tubes. During an inpatient dental list, we were unable to pass a Mallinckrodt size 6.0 uncuffed nasal RAE through a patient's vocal cords because the tube was too short, even though it was an appropriate size, and despite an adequate view at laryngoscopy. Figure 4 demonstrates the comparative lengths of three size 6.0 nasal tracheal tubes. The upper two are manufactured by Mallinckrodt and demonstrate the significant difference in length between the cuffed and uncuffed versions, 24 and 18 cm at the nose, respectively. For comparison, an uncuffed size 6.0 Portex nasal tracheal tube is included, which has the length expected if you apply the formula age/2 + 14.5 cm. In our case the patient was 10 years old, requiring an expected nasal tube length of 19.5 cm, which is significantly more than the uncuffed Mallinckrodt tube allows. Figure 5 illustrates the respective size 7.0 Mallinckrodt nasal tubes with a cuffed Portex Blue Line nasal tube for comparison, again demonstrating the same problem. We are unable to explain why such a discrepancy should exist between manufacturers of preformed nasal tracheal tubes. It appears that the uncuffed Mallinckrodt tracheal tubes are consistently too short. No harm came to our patient as the problem was recognised, and the airway secured satisfactorily with an alternative tube; however, we feel that this situation led to increased morbidity as a result of incorrect tube placement and repeat nasal intubation