Modification of submental intubation using oral Ring-Adair-Elwyn tubes in faciomaxillary surgeries: A novel approach.

Sir,

Submental intubation (SMI) has been regularly practiced as a method of securing airway in complex faciomaxillary surgeries where nasal intubation is considered contraindicated. Reinforced tubes have been used routinely for this route as they will not get compressed by the acute change of angle that is produced when they traverse orocutaneous plane at the submental incision site. Ring-Adair-Elwyn (RAE) tubes may also be considered as an option, as kink resistant preformed angle can be utilised for this purpose. The low cost nature of RAE tubes may offer an additional advantage to the reinforced tubes. Here, we describe our experience in using RAE tubes for SMI in patients with severe faciomaxillary injuries.

Three adult male patients underwent SMI with RAE tubes in our institute between December 2011 and August 2012. After induction of anaesthesia, orotracheal intubation was performed with 7.5 sized cuffed oral RAE tube. After confirming the position of the tube, an external incision was made at lower border of mandible at submental region 2 cm lateral to median line on the right side [Figure 1a]. Skin, subcutaneous tissue, platysma, deep cervical fascia and mylohyoid planes were bluntly dissected with Kelly's haemostat to reach the oral mucous membrane. Internal incision was placed over the distal end of the forceps. Tunnel was created by repeated opening of the haemostat for the endotracheal (ET) tube to pass through.

Figure 1

(a) oral Ring-Adair-Elwyn tube in place with submental incision site marked (b) Pilot balloon is brought out first (c) Oral RAE tube brought out next (d) Preformed angle is positioned at incision site

After ventilating the patient with 100% oxygen and isoflurane for 3 minutes, pilot balloon was first grasped and brought out through the tunnel [Figure 1b]. This was followed by the distal end of the ET tube after detaching the International Organization for Standardization connector [Figure 1c]. Tube was further negotiated so that the distal curve of the angle was placed at the external incision [Figure 1d]. Tube position was confirmed both clinically as well as with EtCO2 wave forms. Peroperative X-ray examination confirmed non-kinking and properly placed tube [Figure 2]. Anaesthesia was further maintained in routine manner. At the end of the procedure, tube was pulled back into oral cavity and ventilation continued. External wound was closed with interrupted sutures using 3-0 silk and intra oral wound was allowed to heal secondarily. Recovery and extubation were uneventful in all three patients.

Figure 2

Non kinking Ring-Adair-Elwyn tube both externally and internally

Total duration for submental positioning of the tube ranged from 9 minutes to 12 minutes and no additional difficulties were encountered. No patient experienced any desaturation (SpO2 < 94%) during mobilisation of tube as apnea time ranged between 2 minutes and 2.5 minutes. None of the patients had any haemodynamic alterations, any intra operative events like tube migration or compression. No major post-operative complications like haemorrhage, injury to Wharton's duct, mucocele or any prolongation in hospital stay were encountered in any of these patients. Only one patient experienced mild wound infection intra orally which was self-limiting and managed conservatively.

Conventionally nasotracheal intubation is considered as method of airway maintenance for faciomaxillary surgeries. However, this route may be contraindicated in the presence of pan facial injuries for fear of potential complications.[1] Tracheostomy was the available option for these patients until late 1980s. Submental route was first used by Altemier who described this as a “valuable alternative” to tracheostomy.[2]

Since then this technique has undergone various modifications. But, whatever methods have been used most authors performed SMI with reinforced ET tubes only. This is because reinforced tubes will not get compressed while exiting through orocutaneous plane in submental area though an acute angle is produced at this site. RAE tubes with preformed angle may also be utilised for this purpose since angle of RAE tube is also resistant to kinking. We used one size smaller (7.5) tube to avoid any possible endobronchial placement of the tip as the preformed angle is placed at submental region instead of over lower lip. The procedure did not pose any difference or difficulty from the routine SMI done with reinforced tube. Total duration of the procedure of submental tube placement ranged from 9 min to 12 min, which is well within the comparable range as mentioned by Jundt in a literature review.[3] The major advantages of RAE tubes are the easy availability and less expensive nature. Hence oral RAE tube may be considered as an effective alternative to reinforced tube. Major limitation in our report is number of cases, as more numbers may be needed to realise other unforeseen events that did not happen in these three patients.