Management of an intraoperatively damaged endotracheal tube in a case of difficult airway using fibre-optic bronchoscope with minimal apnoea period.

Damage to the endotracheal tube (ETT) is common in head and neck surgeries, especially in maxillary osteotomy. Airway management in such a crisis is crucial as there is risk of aspiration of blood into lungs, hypoxia and apnoea. This case illustrates a patient with an anticipated difficult airway who had an intraoperative damage to the ETT and was successfully managed by re-intubation with fiberoptic bronchoscope in a minimal apnoea period of <15 s using a new technique.

INTRODUCTION

Head and neck surgeries are real challenge to the anaesthesiologist in view of the difficult airway, prolonged surgery, blood loss and fluid shifts. Particularly, maxillofacial surgeries such as Le Fort I osteotomy and anterior maxillary osteotomy (AMO) pose additional challenges in terms of difficulty in nasal intubation, shared airway, major blood loss, intraoperative tube damage, dislodgement and accidental extubation.[123] One of the major complications in AMO and Le Fort I osteotomies is intraoperative damage to the endotracheal tube (ETT). Damaged or cut ETT poses various risks such as aspiration of blood, changes in ventilation and airway fire due to the leak of fresh anaesthetic gasses in the nasopharynx. Managing such complications is a tough task for the anaesthesiologist. In our institution, we had come across such an airway emergency due to a damaged ETT and managed it successfully.

CASE REPORT

A 23-year-old male reported to our institution with facial asymmetry and difficult airway. The treatment planned was orthognathic surgery including Le Fort I impaction, bilateral sagittal split osteotomy with advancement, sliding genioplasty and left mandibular lower border augmentation with titanium mesh. The patient had undergone left condylectomy for left temporomandibular joint ankylosis, 8 years back. He had no comorbid illness, and his effort tolerance was good. Vitals signs and systemic examination were normal. He had modified Mallampati Class IV. Pre-operative blood investigations, electrocardiogram and chest X-ray were within normal limits. Hence, a difficulty in intubation was anticipated and planned for fibre-optic intubation.

The patient was scheduled for surgery under general anaesthesia, with adequate pre-operative preparation. Fibre-optic bronchoscope (FOB) guided intubation was done with nasal Ring-Adair-Elwyn (RAE) tube of inner diameter 7 mm after external laryngeal nerve block and transtracheal instillation of lignocaine. Subsequently, anaesthesia was induced and maintained with oxygen, nitrous oxide, sevoflurane, vecuronium and fentanyl. Roller gauze was packed around the RAE tube in the throat to prevent aspiration of oral contents into the trachea.

One and a half hour into the surgery, following maxillary osteotomy, the surgeon noticed air bubbles in the nasopharynx. Cuff leak was initially suspected, hence, pilot balloon was reinflated with air. Few minutes later, the surgeon again noticed air bubbles in the nasopharynx. Then, ETT damage was suspected, and the surgery was withheld. On further evaluation, it was found that the pilot balloon was deflating indicating tear of the ETT cuff [Figure 1]. Hence, it was decided to change the ETT. Maintaining the anaesthesia with 1% sevoflurane in 100% oxygen and preserving the neuromuscular blockade, throat pack was removed after head down tilt. Oral suctioning was continuously done. Through the left nares, a sterile FOB with a new nasal RAE tube of internal diameter 7 mm mounted was passed, with the right nares still having the old ETT. Once the FOB reached the hypopharynx, attempts were made to negotiate the FOB cable through the glottic opening with the old ETT in situ. On visualising the tracheal rings, the old ETT, the cuff of whichwas already deflated was removed from the trachea. Following this, the new ETT mounted onto the FOB was guided into the trachea. Endotracheal intubation was confirmed with capnography and the anaesthesia machine was connected to the new ETT. Total apnoea period was <15 s. During the entire procedure, asepsis was maintained with a careful watch for the aspiration of blood. Vital signs and capnography were within normal limits during the procedure. The old ETT revealed a cut on the superior aspect of the pilot tube, approximately 5 cm distal to the RAE bend. Surgery was completed as planned. The patient was not extubated on the same day, in view of anticipated airway oedema but was extubated on the next day. Further, course of patient's stay was uneventful.

Figure 1

Site of damage to the endotracheal tube

DISCUSSION

The role of the anaesthesiologist in troubleshooting mishaps during anaesthesia is vital. First response to events such as the one faced in this report must be to confirm the anticipated mishap by switching to manual ventilation to feel for the lung compliance, checking the connectivity of the circuit between patient and anaesthesia machine, checking for the leak by increasing the fresh gas flow rate, direct laryngoscopy if possible or doing a fiberoptic bronchoscopy.[456] A careful watch over the vital parameters including the ventilatory changes is mandatory. The choice of the modality for airway management is mainly influenced by the nature of damage to ETT, stage of the surgery, patient's vital sign, patient's airway architecture, dynamics, ventilation and arterial blood gases [Figure 2].

Figure 2

Probable sites of intraoperative endotracheal tube damage

Orotracheal intubation was not possible in this case as inter-maxillary fixation would not be possible. Therefore, nasotracheal intubation was the choice technique. However, when the need for intraoperative replacement of the ETT arose, variety of options such as exchanging the existing ETT with a new one over a tube exchanger were available. However, since the surgical procedure was oromaxillary in nature, authors chose to retain the old ETT while a FOB was passed through the other nostril. Only when the FOB was in the trachea that the old ETT was removed and the new one immediately railroaded which helped to restrict the apnoea time to <15 s and minimised the risk of aspiration also. Furthermore, this technique allowed us to ensure that the patient was continually oxygenated and ventilated through the old ETT.

It is of utmost importance that difficult airway cart is always ready.[1] One study on fibre-optic guided intubation has raised a great concern regarding desaturation.[78] Apnoea is an important factor to be kept in mind during fibre-optic intubation as this technique takes a longer time (30–180 s, mean 64 s) than the conventional laryngoscopic intubation.[789]

CONCLUSION

FOB can be useful for intubation with experienced hands even in emergency situations.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.