The Effect of Anaesthesia on Oral Fibreoptic Tracheal Intubation in A Patient of Ankylosing Spondylitis

Airway management in patients with ankylosing spondylitis (AS) is a challenging problem for anaesthesiologists. The fibreoptic intubation (FOI) is designed to assist tracheal intubation for patients with a difficult airway. If we chose to do FOI, our first step is to decide whether to do a fibreoptic intubation with the patient anesthetized or awake. Once we’ve decided on anesthetized or awake, chose either the oral or nasal route. The aim of the study was to report the successful intubation by anesthetized nasal fibreoptic tracheal intubation of an AS patient after the failed intubation by anesthetized oral fibreoptic tracheal intubation because of a difficult airway found, and to discuss the effect of anaesthesia on oral fibreoptic tracheal intubation in patients with AS. One patient with chronic, severe AS were evaluated preoperatively and had features associated with a difficult direct laryngoscopy. Awake oral fibreoptic intubation was recommended to the patient. Patients were kept in supine position, with their head and neck supported on pillows. We performed the necessary preparations for difficult airway and intubation. First, we attempted awake fibreoptic orotracheal intubation. When a gap was observed between the epiglottis and posterior pharyngeal wall and wanted to further advance the instrument into the gap, Patient was unable to cooperate and presented with irritable cough. So, we decided to perform anesthetized oral fibreoptic tracheal intubation. Following sufficient preoxygenation, patients received i.v. sufentanil at 0.4μg/kg, propofol at 2mg/kg, and rocuronium at 1mg/ kg. Ninety seconds after the rocuronium administration, Fibreoptic bronchoscopy was attempted again. However, although anaesthesia provided skeletal muscle relaxation, but oropharyngeal and laryngeal muscle relaxation resulted in upper airway collapse. The upper airway collapse made fibreoptic visualization of the glottis difficult. After multiple attempts with oral fibreoptic laryngoscopy failed, nasal fibreoptic intubation was then performed with the jaw thrust manoeuvre. Fibreoptic laryngoscopy confirmed the glottis rapidly. Intubation was accomplished successfully with a 6.5 endotracheal tube lubricated with lidocaine gel. Surgery proceeded uneventfully, and the postoperative course was uncomplicated. Awake oral fibreoptic intubation was ideal and safe to secure airway in severe AS patients, but an anesthetized oral fibreoptic tracheal intubation could be difficult to do that. Anesthesia decreased muscle tone in upper airway, especially at the level of the soft palate and the epiglottis. As the depth of general anesthesia increases, upper airway narrowing occurs throughout the entire upper airway but is most pronounced in the hypopharynx at the level of the epiglottis. Thus, making fibreoptic visualization of the glottis difficult. Anesthesia also prevented the patient from inspiring deeply, which could help locate the laryngeal inlet. In this situation, we might have to resort to nasal fibreoptic tracheal intubation. So do not do oral fibreoptic intubations on anesthetized patients with AS. Nasal fibreoptic intubation was more successful and easier than the oral approach in anesthetized patients with AS.