Palatal obturator: Perioperative concerns.

Sir,

A 46-year-old male, weighing 60 kg with diabetes mellitus type II since 10 years was scheduled for debridement of the nasal cavity under general anaesthesia (GA). Patient had undergone surgical procedure for mucormycosis under GA uneventfully one year ago. Systemic examination was unremarkable. The airway examination showed a Mallampati (MMP) class IV [Figure 1a] with mouth opening of 3 cm, thyromental distance of 10 cm and possible anterior mandibular protrusion. Patients blood biochemistry and other routine investigations were acceptable. Patient was kept nil per oral and premedicated with anxiolytics and antacids on the night before and on the morning of surgery while morning dose of insulin was omitted. On the day of surgery blood sugar and electrolytes were within the normal range. In the operating room, a multi parameter monitor (AS5, Datex Ohmeda, Finland) was attached to the patient and after securing intravenous (IV) access, IV glycopyrrolate 0.2 mg and IV fentanyl 120 μg were given. Difficult airway cart was kept ready. GA was induced with IV propofol 120 mg and IV succinylcholine 100 mg was given after confirmation of ability to ventilate the lungs. Oral endotracheal intubation was performed with 8.0 mm cuffed endotracheal tube with Glidescope® (GVL; Verathon Inc., Bothell, WA). During intubation, the posterior end of palatal obturator was visualized. Following correct placement of endotracheal tube, the palatal obturator was removed [Figure 1b]. Rest of the perioperative period was unremarkable.

Figure 1

(a) Airway examination of patient shows a mallampati grade IV. (b) The palatal obturator after removal

Palatal obturator is a prosthetic device and is indicated in patients with cleft palate, traumatic injuries and tumours of palate.[12] Palatal obturator consists of an acrylic plate and retention clasps of orthodontic wire, which covers a fistula of the palate. It serves to restore speech, mastication, deglutition and aesthetics.[12] Successful obturation depends on the volume of the defect, tissue retention available around the cavity and development of muscular control.[34] It must be as light as possible as its weight may act as a dislocating force.[3] The palatal obturator can cause anaesthetic complications including airway obstruction, inability to pass endotracheal tube due to dislodgement of prosthesis, limitation of the space for a laryngoscope and a traumatic intubation.

According to recent practice guidelines for management of the difficult airway, video-assisted laryngoscopy can now be used as an initial approach to intubation in patients in non-emergent pathway with difficult airway.[5] We administered succinylcholine considering uneventful previous anaesthetic exposure of the patient and MMP class IV being the only predictor for difficult airway and rest of the airway examination also being normal.[5] The difficult airway cart with other alternative intubation devices were however kept ready.

The absence of symptoms of regurgitation of food or water, MMP class IV on airway examination and observer limitation of not able to differentiate between similar looking palatal obturator with the oral mucosa in room light; all probably contributed to the cause of missed finding in the present case. However, we did not encounter any complication during the anaesthetic procedure.

Pre-anaesthesia evaluation is considered as basic element of anaesthesia care and includes a multi-disciplinary approach including patient's medical record, history taking, physical examination and findings from medical tests and evaluations. At the same time, anaesthesiologist should consult other health-care professionals to obtain information relevant to perioperative care to avoid any catastrophe. Assessment performed during pre-anaesthetic evaluation may be used to formulate plans for intraoperative care, post-operative recovery, perioperative pain management and patient education.[6]