Retromolar Intubation- In Patients of Panfacial Trauma Involving Cribriform Plate of Ethmoid – A Case Report

Pradeep Ingle, Vandana Trasy, Anand Choudhary, Namrata Toshniwal

Abstract
We are presenting a case report of 26 yr old male, with panfacial trauma having fracture mandible with fracture of zygoma, orbital plate, nasal bone, and cribriform plate. Patient was posted for fracture mandible repair with IMF. Securing airway of this patient meant performing submental intubation or tracheostomy. Retromolar intubation in this patient provided a very good alternative procedure with its advantages of avoiding surgical invasion of the airway, thereby avoiding complications of submental intubation and tracheostomy.

Case History
A young 26-year-old male patient weighing 54 kg, with h/o road traffic accident presented with panfacial injury. He was posted for fracture mandible repair with IMF. There was h/o unconsciousness and amnesia for the event. Also there was h/o reduced mouth opening after the trauma. On examination patient was conscious, oriented and higher functions were normal. Vitals were stable. Systemic examination was normal. On evaluation of the airway it was clearly a difficult intubation. Laboratory investigations were normal. CT brain was normal and CT skull revealed fracture left angle and ramus of mandible, zygoma, orbital plate, nasal bone and cribriform plate. ENT examination revealed reduced nasal patency on anterior and posterior rhinoscopy. Both neurosurgeons and ENT surgeon advised tracheostomy for securing the airway, to avoid nasal intubation.

Anaesthesia Management
The options available for securing the airway were
1) Tracheostomy
2) Submental intubation
3) Retromolar intubation
We chose retromolar intubation for this case. This was done after complete preoperative assessment. We checked the retromolar space pre operatively by inserting a gloved finger between cheek and teeth on both sides. Occlusion of jaws was possible with finger in retromolar space. Since the surgery was on left side, right sided retromolar intubation was planned. Surgeons were informed. The patient was explained about the procedure and the alternatives available (tracheostomy and submental intubation). Consent for retromolar intubation was obtained. A possibility of surgical airway, if required, was also explained to the patient.
Patient was premedicated with intravenous midazolam, glycopyrrolate and pentazocine and preoxygenated. Orotracheal intubation using armoured tube no. 38 Fr was done after induction with propofol and vecuronium. Now our aim was to put the tube in the retromolar space behind upper and lower erupted molars. So endotracheal tube was grasped and pushed back into the retromolar space on right side and brought out at the angle of mouth between teeth and cheek. Tube fixed with dynaplast at the angle of mouth after bilateral chest auscultation. Occlusion of jaws checked and confirmed. Tube patency was checked using suction catheter. Surgeons were asked to confirm position of tube so that IMF was possible. Tube fixed using the wire used for IMF to molar teeth in ‘figure of 8’ manner. Throat packed with roller gauze.
Patient monitored using standard monitors and maintained on oxygen, nitrous oxide with controlled ventilation using Propofol infusion and Vecuronium. Intraoperatively IMF was possible without compromising airway patency. Just before IMF, throat pack was removed after adequate suctioning.
Patient was reversed from the anaesthesia and after adequate recovery, patient was extubated through retromolar space releasing tube fixation wires by sliding the tube through retromolar space. Suctioning was done through retromolar approach.
A cutter was kept with the patient for emergency cutting of IMF in case an emergency access was required for airway in recovery room. Vitals checked and found stable. Pain relief with IM Diclofenac was given. Lip oedema on the side of the tube at the angle of mouth was found which resolved in due course of time.

Discussion
Distortion and destruction of anatomy makes airway management a challenge in panfacial trauma. In our patient the anaesthesia related problems were
1) Securing airway throughout the intra operative period
2) Necessity of IMF for restoring dental occlusion thereby making oral endotracheal intubation unfeasible.
3) Nasotracheal intubation is contra-indicated in base skull fracture due to danger of CSF rhinorrhoea.
In retromolar intubation, our aim is to place the orotracheal tube in the retromolar space i. e. space behind the last upper and lower erupted molar teeth.
For this, the orotracheal tube needs to be adequately flexible and nonkinkable, hence armoured or flexometallic tube is preferred for this purpose. Preoperative assessment of the space is a must. Orotracheal intubation is done initially using standard general anaesthesia technique. The tube is grasped with a gloved finger and is placed into retromolar space. It is then fixed by wire ligature to the molar /premolar tooth along the upper and lower maxilla. Wire ligature is same as that used for IMF. It fixes the retromolar tracheal tube with the tooth in “figure of 8” fashion thereby rendering the intraoperative IMF feasible.
At the end of the procedure, patients can be extubated even with IMF done. The only precaution is that to have wire cutters for emergency situations to establish airway access. Retromolar intubation, a non-invasive technique of securing airway in patients with panfacial trauma avoids both submentotracheal intubation as well as tracheostomy.1. Hence we chose this technique REF The most important advantage of retromolar intubation is it avoids the need of surgical airway in the form of tracheostomy and submento tracheal intubation. Submental intubation avoids the need of short-term tracheostomy and is hence an option.2 A tracheostomy for the purpose of administration of anaesthesia should be the last option. Fibreoptic intubation a safe and attractive technique would not have served a purpose here as the issue was not so much a difficult intubation or compromised airway.
Following table compares the techniques of retromolar intubation with submental intubation and tracheostomy.3

Retromolar Intubation
Advantages
1) Avoid surgical invasion of airway
2) Prevents residual morbidity and discomfort
3) Technically easy and can be done even by inexperienced person
4) Avoids controversial nasal route of intubation
5) Allows dental occlusion intra and post operatively
6) No surgical scar
7) Takes less time
Disadvantages
1) Surgeons are not used to this technique so may be uncomfortable initially
2) Deformation of the tube due to ligature is possible
3) Retromolar space may not be adequate in some persons
4) Difficult suctioning
5) Armoured or flexometallic tube is required.

Submental intubation
Advantages
1) Technically easy
2) Allows dental occlusion intra and post operatively
3) Low complication rate
4) Cosmetically acceptable scar
5) Easy to suction the trachea
Disadvantages
1) Surgeon’s unfamiliarity
2) Armoured or flexometallic tube is required
3) Emergency reintubation is not possible
4) Not feasible for prolonged ventilation and weaning
5) Increased risk of tube movement
6) Plastic connector of flexometallic tube is difficult to disconnect

Tracheostomy
Advantages
1) Avoids controversial nasal route of intubation
2) Allows dental occlusion intra and post operatively
3) Better for long term ventilation
4) Easy to suction the trachea
Disadvantages
1) Gives a permanent scar to the patient
2) Risk of haemorrhage, tracheal damage and infection
3) Most invasive technique
4) Weaning from tracheostomy is prolonged

Conclusion
Retromolar intubation avoids the need of any kind of surgical airway. However it should be done only in those cases nasotracheal intubation is contraindicated and orotracheal intubation is not feasible for surgical procedure.

References
1. Malhotra N. Retromolar intubation -A technical note. IJA 2005; 49 (6) : 467-68.
2. Malhotra N. Submental intubation ; An alternative to tracheostomy. Ejypt J Anaesthesia 2004; 20 : 443-47.
3. Joy E Curran. Anaesthesia for facial trauma. Anaesthesia and Intensive Care 2005; 6 : 7-11.