Evaluation of paranasal sinuses on available computed tomography in head and neck cancer patients: An assessment tool for nasotracheal intubation

Abstract

Sir, Nasotracheal intubation is a commonly employed airway plan during head and neck cancer surgeries.[1] Common anatomical abnormalities in the nose are septal deviations and septal spurs, usually presenting on one side of the septum.[2] There are many ways by which we can detect the patency of the nostrils, for example, fibre-optic nasoendoscopy,[1] rate of airflow through each nostril[3]; the patient may be able to confirm a clearer nostril after vasoconstrictors have been applied to the nasal mucosa.[4] Most common complication encountered during nasotracheal intubation is trauma to nasal mucosa or turbinates, leading to bleeding.[5] One of the commonly encountered anaesthetic complications is false passage and tearing off of the endotracheal tube (ETT) cuff.[6] This report presents two cases where cuff tear of two successive ETTs occurred following nasotracheal intubation. Two male patients, diagnosed with head and neck cancer, were posted for surgery under general anaesthesia with nasotracheal intubation. After counselling the patients for nasotracheal intubation, attaching the standard monitors and placement of IV line, general anaesthesia was instituted as per hospital protocol. A 7.5 mm internal diameter (ID) ETT was lubricated with lidocaine jelly 2% and was inserted smoothly through the right nostril in both cases. After confirmation of ETT placement in the trachea with end-tidal carbon dioxide, it was attached to closed circuit with positive pressure ventilation and oxygen at 1L/min along with isoflurane. However, failure to maintain pilot balloon inflation and a low airway pressure along with reduced expiratory tidal volume were noted on monitors. After ruling out leaks in the circuit, cuff damage of the ETT was suspected. The ETT was removed which showed a small tear in cuff. The second attempt at nasotracheal intubation, with a smaller size ETT 7 mm ID was carried out successfully through the same nostril, which also met with the same result. Both the ETTs were examined, and a cuff tear was noted at the same location [Figure 1a]. We noticed cuff tear of two ETTs at similar spots, in our second patient [Figure 1b]. During the interim period of computed tomography (CT) scan evaluation, the patient was ventilated using bag-mask technique. Figure 1 (a) Arrows showing bubbles from the tore endotracheal tube cuff. (b) Arrows showing the linear tear The morbidity associated with cuff tear includes aspiration of saliva, blood or gastric contents, anaesthetic gas leak from the breathing circuit[6] and ineffective ventilation leading to hypoxia. Magill's forceps were not used in either case. As shown in Figure 1, the tear in the cuff is longitudinal suggesting the damage had been caused by a sharp edge. Retrospective evaluation of the CT images of paranasal sinuses (PNS) revealed angulated bony spur in the posterior septum of the right nasal cavity with a deviated septum in both the patients [Figure 2a and b]. The cuff of the ETT can be damaged due to the presence of a bony spur in the nasal septum, use of Magill's forceps, use of lignocaine spray on ETT or placing the ETT in hot water before use as noted in a series of 725 nasotracheal intubations using polyvinylchloride ETT.[7] An unusual case of cuff malfunction due to the suture material going through the pilot line[6] and accidental damage to ETT by the oscillating saw during head and neck surgery[8] was also reported. In our cases, the cuff damage occurred before the start of the surgery. Figure 2 (a) Arrow showing the nasal bony spur of patient1. (b) Arrow showing the nasal bony spur of patient 2 The CT of PNS is routinely performed preoperatively in head and neck surgery patients by the surgical colleagues. If nasotracheal intubation is planned in such patients, we suggest the anaesthesia team to evaluate the CT of PNS to rule out nasal spur on the side where the nasotracheal intubation is to be performed to prevent the complication of cuff damage. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.