A modified submental orotracheal intubation.

In patients with concomitant occurrence of maxillofacial and basilar skull fractures, open reduction and internal fixation is the treatment. It requires intermittent intra operative dental occlusion which precludes oral or nasal intubation. In such cases submental intubation (SMI) is a recognized technique in practice. We describe a modified technique for smooth exteriorization of the endotracheal tube (ETT) during SMI. As the SMI technique is unusual for the performer, emphasis is laid on the applied aspects to minimize probable complications during the procedure. With the modified technique we performed SMI uneventfully on five patients.

INTRODUCTION

In patients coming for surgical correction of maxillofacial injuries, associated basilar skull fracture, precludes oral, and nasal intubation,[1] as it demands intermittent dental occlusion.[2]

In 1986, Altemir[34] described submental intubation (SMI) to overcome tracheostomy complications in maxillofacial injuries patients.[5] Since then SMI technique has undergone modifications, to overcome the pitfalls encountered during the procedure.[6]

This observational study illustrates modified technique of exteriorization of the endotracheal tube (ETT) during SMI, to overcome false tracking. This study also emphasizes on the applied aspects of the steps, performed during SMI, as the technique is rarely performed.

METHODS

From November 2013 to June 2015, five patients with maxillofacial trauma associated with cerebrospinal fluid rhinorrhea posted for open reduction and internal fixation were intubated with the modified technique of SMI. Patients requiring prolonged postoperative ventilation were excluded from the prospective observational study. Types of fractures incurred by the patients are shown in Table 1.

Table 1

Patient details

Missing and loose teeth were documented. Airway and temporomandibular joint mobility could not be assessed due to restricted mouth opening secondary to pain. Informed consent was obtained. SMI was planned and discussed with the surgeon.

Following prerequisites were considered for uneventful submental exteriorization of the endotracheal tube

Working laryngoscope and suction catheter

Difficult intubation cart and standby tracheostomy

Flexometallic ETT with Portex connector seal gently released

Xylocaine 2% with adrenaline (1:200000)

Preferably right submental approach

Two Kelly curved forceps

Cheek retractor

Pilot balloon is exteriorized, followed by ETT

Magill forceps and throat pack

ETT is anchored to the skin following throat pack.

Technique

In the operation theater monitors were connected to the patient and was induced with standard anesthesia technique. Conventional orotracheal intubation was done with appropriate size Mallinckrodt™ reinforced cuffed ETT and was fixed with adhesive tape onto the right angle of the mouth.

The procedure of SMI was adopted as described by Altemir. Following aseptic precautions Xylocaine 2% with adrenaline (1:200000) was infiltrated along the line of incision. It was 2 cm long and was 2 cm below, and parallel to the inferior border of the mandible in the right submental region [Figure 1]. To create a submental tunnel, Kelly curved forceps was introduced into the floor of the mouth by blunt dissection through the mylohyoid muscle. In the oral cavity, the mucous membrane was incised at the junction of lingual-attached gingiva and free mucosa ensuring the same size as that of skin incision, to create well-formed tunnel. Applying the cheek retractor, two closed Kelly curved forceps were introduced simultaneously through the skin incision into the mouth for smooth exteriorization of the ETT [Figure 2].

Figure 1

Right submental intubation, adhesive tape around tube and Portex connector, left handed laryngoscopy, and tube secured to the skin by silk suture

Figure 2

Two curved Kelly forceps in submental tunnel

ETT was exteriorized after ventilating the patient with isoflurane 1% in 100% O2 for 3 min. With one Kelly forceps pilot balloon was pulled out. Ensuring no cuff leak, breathing circuit was disconnected and Portex connector was detached from the ETT. Distal end of the ETT was grasped by the second Kelly forceps which was in situ and was pulled out gently by the surgeon, while proximal end being stabilized by the anesthesiologist [Figure 3]. Reattaching the Portex connector to the ETT, it was stabilized with adhesive tape and connected to the anesthesia breathing circuit [Figure 1]. Positioning the ETT in the paralingual groove, throat was packed. Confirming the ETT placement in the trachea by capnography and bilateral equal air entry, it was firmly secured to the skin using three-zero silk [Figure 1].

Figure 3

Submental exteriorization of pilot balloon and endotracheal tube with two different forceps

At the completion of the surgery ETT followed by pilot balloon were pulled into the oral cavity, releasing the stay sutures and disconnecting the breathing circuit. Connecting the breathing circuit, later throat pack was removed. Reconfirming bilateral equal air entry, ETT was stabilized with adhesive tape. Submental wound was closed in layers and standard extubation steps were carried out after the completion of the procedure. No complications were encountered in any of the study cases.

In conventional SMI technique, the pilot balloon is pulled out with the Kelly forceps and reintroducing the same forceps, ETT is exteriorized.[124678910] While practicing conventional technique, in one of our cases, Kelly forceps and the ETT were tracked falsely. Possibilities in such situation could be hypoxia, injury to the adjacent structures and or lose of the airway while re-tracking. In our case, procedure time was prolonged.

In another case, we encountered endobronchial migration of the tube, when throat was packed following anchoring the ETT to the skin. It was recognized by an abrupt rise in airway pressure and fall in the oxygen saturation. It was confirmed by auscultation after excluding the other probable causes.[19] To reposition the tube sutures had to be removed, which prolonged the procedure time.

These incidences prompted us to scrutinize the applied aspects of the SMI steps executed.

RESULTS

Adopting a modified technique for exteriorization of the ETT, in all five study patients, SMI was performed satisfactorily. Surgeons found the new technique simpler, and anesthesiologists were comfortable with it. Average time taken was 10–12 min. Postoperative follow-up showed no injury to any of the adjacent structures. Wound healing was good. As a team approach, submental exteriorization of the ETT was uneventful.

DISCUSSION

In major faciomaxillary trauma, retromolar intubation being a choice, is not possible in all adult patients due to inadequate space,[7] where tracheostomy was the choice.[5] In 1986, Francisco Hernandez Altmeir described a submental approach to the orotracheal airway, to replace tracheostomy for short surgical procedures, as it carried a significant morbidity.[4] Now it's a recognized technique for airway control in severe maxillofacial injuries.[11]

SMI is also opted in orthognathic surgery,[11] correction of deformity,[8] and congenital malformations.[6] It's not recommended with laryngotracheal disruption, infection at the proposed site and in patients requiring long-term postoperative ventilation.[2]

Submental approach could be in the midline,[25] or submental triangle,[348911] or submandibular region[10] depending on the surgeon's preference or the site of injury. Possible complications of the procedure could be trauma to the submandibular or sublingual gland or duct, damage to the lingual nerve, wound infection, orocutaneous fistula, and or hypertrophic scar.[8] As the SMI is rarely performed,[29] it needs distinctive experience for the safe conduct.[12] Considering the fact, the discussion is focused on the applied aspects of the steps executed.

In general, Portex connector seal of the flexometallic ETT is gently released, to easily detach and reattach at the time of exteriorization of the tube.[12489] In the same way to have a clear surgical field, infiltration of xylocaine with adrenaline have been documented.[511]

In our study right submental approach was opted for the following reasons:

To provide uninterrupted working space to the surgeon when anesthesiologist was stabilizing the tube at the time of exteriorization

To have better visualization of the ETT during throat pack, with left-handed laryngoscopy.

Anwer et al. and Schütz and Hamed have also emphasized the efficacy of this approach in their write up.[29]

Cheek retractor was applied to have better working space, which is not highlighted in any article.

Green and Moore adopted two-tube technique when they had to work with ETT's in which universal connector was nonremovable;[13] similarly, in our case series, we introduced two Kelly curved forceps simultaneously into the mouth, through the skin via the well-formed submental tunnel to evade false tracking at the time of exteriorization of the tube. This technique has not been documented in the literature over the last 25 years.[67] Das et al. also have described two artery forceps technique, but only for better submental tunneling.[7] In our observational study, modified two forceps technique to exteriorize the tube was found easy, convenient, and less time consuming. Kishoria et al. in their case series have mentioned the use of nasal speculum to facilitate passage of ETT through the submental approach.[6]

In our case series, the pilot balloon was exteriorized without deflation to prevent aspiration. Injury to the pilot balloon at the time of exteriorization was ruled out confirming the integrity of ETT cuff. In few literature reports, ETT cuff has been deflated to prevent injury to the pilot balloon, whereas measures taken to protect the airway are not mentioned.[589]

In our case, detached Portex connector was reconnected to the tube after exteriorization and secured with adhesive tape to prevent perioperative disconnection, even though connector seal was gently released. However, Das et al., in their review article, have reported the use of stay suture between the ETT and the universal connector for additional safety.[7]

ETT was anchored to the skin submentally following throat pack, to reposition the tube in case of endobronchial migration. Green and Moore in their case report have followed the same technique.[3] Anwer et al. have reported accidental right endobronchial migration of ETT while tunneling through the submandibular track.[2]

CONCLUSION

In the last three decades, SMI technique has gone through various modifications to tangibly benefit the efficiency of the performing doctors, ensuring patient safety both intra operatively and postoperatively. This study emphasizes on the modified technique, for smooth exteriorization of ETT through submental route and on the knowledge of applied aspects for enhanced safety.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest