Unusual Pre-oxygenation Techniques and Transorbital Fibre-optic Intubation

Extensive maxillo-facial surgery can create significantly complex airway anatomy. We present the case report of a 31-yrs-old female presenting for elective day case surgery. She had a past medical history of Asperger Syndrome and T4 N0 spindle cell sarcoma of the left maxilla for which she had a left orbital exenteration and maxillectomy and left-sided neck dissection in 2004 with no anaesthetic complications. This was accompanied with post-operative radiotherapy which had left her with severe radiation trismus. Her American Society of Anaesthesiologists (ASA) grade was II and airway assessment found that she had moderate neck flexion and extension with a thyromental distance of 6.5 cm. However, mouth opening was restricted to less than 1 finger and there was no mandibular protrusion. Her nasal passages were collapsed and distorted externally. Her prosthetic eye was removed and pre-oxygenation was achieved using a DuoDERM dressing (ConvaTec Inc.) to occlude her left orbital cavity to prevent any air leak. Due to her level of autism, and documented evidence of previous easy facemask ventilation, it was agreed that an awake fibreoptic intubation would neither be required nor appropriate. Given the unfamiliarity with her abnormal oral and nasal airway anatomy we utilized a flexible fibre-optic scope to perform an asleep transorbital intubation to secure a definitive airway for surgery. This impossible oral access presents a challenge to the anaesthetist putting restrictions on the function of any laryngoscope. Fibre-optic intubation was first described in 1967 and is the gold standard approach for the anticipated difficult airway. The fourth National Audit Project (NAP4), which examined airway complications in the United Kingdom, identified a number of cases where awake fibre-optic intubation may have been beneficial over the chosen technique. Structurally unusual airways often require some unconventional initiative but this cannot replace thorough pre-operative planning and communication to prioritize patient safety.