Usefulness of a Cook® airway exchange catheter in laryngeal mask airway-guided fiberoptic intubation in a neonate with Pierre Robin syndrome -A case report-
A 3.09 kg, 33-day-old boy with Pierre Robin syndrome was admitted to our hospital for a glossopexy. The patient was born at 39 weeks by C-section and was diagnosed with the syndrome during pregnancy. After birth, the patient showed a micrognathia, retrognathia, and a large tongue. The patient also showed moderate chest retraction with coarse breathing sounds presenting difficulty in maintaining patent upper airway. He was kept in a prone/lateral position under 5 L/min of O2 hood at NICU until the operation.\nIn the operating room, he showed moderate chest retraction after changing the position from prone to supine. Intraoperative monitoring devices such as an ECG, an automatic blood pressure cuff, and a pulse oximeter were applied to the patient. The initial oxygen saturation was 98% in room air and other vital signs (BP: 96/27 mmHg, PR: 161/min, RR: 42/min) were in normal ranges. A mask was applied before induction and the manual ventilation was well maintained with patient's spontaneous ventilation. Premedication with 0.004 mg/kg of glycopyrrolate was given intravenously and anesthesia was induced with gradual increment of sevoflurane concentrations from 2% to 4% with oxygen by mask while also maintaining spontaneous respiration. Brief direct laryngoscopic examination with a curved McIntosh blade (#1) was performed and only the hypopharynx was seen. Classical reusable laryngeal mask airway (LMA) #1, in which two vertically placed bars were removed, was inserted and effective ventilation was assured by chest expansion, auscultation, and EtCO2 monitoring. While pausing the ventilation, ultrathin fiberoptic bronchoscope (FOB) (Olympus ENF type XP, 1.8 mm OD, length: 530 mm, Tokyo, Japan) was passed through the lumen of the LMA and the vocal cords were well visualized. Under the visualization of the vocal cords by the FOB, we passed the Cook® airway exchange catheter (CAEC) (1.6 mm ID, 2.7 mm OD) (Cook Medical Incorporated, Bloomington, IN, USA) through the LMA into the vocal cords. However, passing the CAEC into the vocal cords under the guidance of the FOB repeatedly failed because the CAEC frequently flexed backwards toward the esophagus. At that time, we recognized that the length of an uncuffed ID 3.0 mm endotracheal tube (length: 16 cm) was longer than that of LMA#1 (length: 11 cm). Therefore, through the LMA, the tracheal tube was mounted on the FOB and introduced into the trachea. Successful ventilation was verified by manual ventilation. To prepare for any accidental removal of the tracheal tube while removing the LMA, we inserted the CAEC into the lumen of the tracheal tube. After placing the CAEC in the midtrachea, LMA was carefully removed while tightly holding both the CAEC and tracheal tube simultaneously. Despite this, the endotracheal tube was displaced out of the vocal cords while removing the LMA. By holding the CAEC firmly inside the trachea, the displaced endotracheal tube was easily railroaded over the CAEC under the direct laryngoscopy. After intubation, endotracheal tube position was verified again by auscultation of equal bilateral breathing sounds and EtCO2. During the procedure, anesthesia was maintained with intermittent sevoflurane administration in oxygen (O2: 1 L/min, air: 1 L/min) through the LMA to prevent awakening and desaturation of the patient. The maximum time allowed for the procedure was until the SpO2 decreased lower than 95%. Atracurium 1.5 mg was given intravenously for muscle relaxation and mechanical ventilation was maintained during the operation. The glossopexy was performed and the surgery was successfully completed. The extubation was carried out when the patient was in a completely alert state and the spontaneous ventilation was well maintained without any chest retraction following the extubation. The patient was then transferred to NICU in the supine position under 5 L/min of O2 mask.