NM-286
The case of the interfering nasopharyngeal airway
Roche Rodriguez M, Fiadjoe J, Struyk B, Hsu G
Children's Hospital of Philadelphia, Philadelphia, PA, United states
Tracheal intubation using fiberoptic bronchoscopy (FOB) remains the gold standard for intubating children with difficult airways. Several methods of oxygenating during fiberoptic intubation (FOI) have been described, including using a modified nasopharyngeal airway (NPA). We discuss two cases where a modified NPA interfered with the maneuverability of a contralateral nasal fiberoptic scope.
Patient 1: A 17 year-old female with right hemifacial microsomia and ankylosis of bilateral temporomandibular joints (TMJ) was scheduled for closed release of the ankylosis. During inhaled induction, the patient developed upper airway obstruction that could not be relieved with an oropharyngeal airway because of a limited mouth opening. A NPA was placed in the right nare and connected to the anesthesia circuit. A FOB was inserted into the left nare and a view of the glottis obtained, however,
maneuvering the scope to the glottis proved difficult. The scope passed readily after retraction of the NPA.
Patient 2: A 4 year-old male with past medical history of Hurler syndrome, tracheomalacia, obstructive sleep apnea and C1-C2 stenosis was scheduled for bilateral inguinal hernia repair. After mask induction a modified NPA was placed in the right nare. Nasal FOI via the left nare was attempted with an adequate view of the glottis. However, there was difficulty maneuvering the FOB anteriorly into the glottis. Three attempts at advancing the scope were unsuccessful. On the fourth attempt, it was noted that slight retraction of the NPA improved scope manipulation. The FOB was then easily advanced anteriorly into the trachea.
Discussion: The use of a NPA during the induction of anesthesia may prevent airway obstruction and provide oxygenation during difficult airway management. The NPA can be connected to the anesthesia circuit, allowing for delivery of volatile anesthetics/oxygen and monitoring of end-tidal carbon dioxide. It can also provide apneic oxygenation, delaying the onset of hypoxemia. The interference of nasal FOI by a NPA has not previously been described and may go unrecognized. One study has described the optimal depth of a NPA in infants as 7-8.5cm from the nostril in the first year of life and 8-10cm from the nostril in the second year of life, with the tip in close relation to the epiglottis. One of the 27 intubations performed in the study required NPA retraction by 0.5 cm for the FOB to gain access to the trachea. (1) In the cases we present, we find that a NPA in close proximity to the epiglottis may make it difficult for the FOB to curve acutely into the glottis because the NPA restricts the deflection of the scope proximally. Retraction of the NPA solves this issue. The benefits of a NPA in difficult airway management are well described, however the challenges they may present during FOI merit further study.
1. Holm-Knudsen R, Eriksen K, Rasmussen LS. Using a nasopharyngeal airway during fiberoptic intubation in small children with a difficult airway. Pediatr Anesth 2005; 15: 839–845
2. Metz, S. Perioperative use of the modified nasal trumpet in 346 patients. Br J Anaesth 2004; 92: 694-96
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