Anaesthetic management of difficult airway due to retropharyngeal abscess and cervical spondylosis

NS. Sushmitha*, K. Senthil Kumar, Khaja Mohideen, K. Akila

Department of Anaesthesiology, Kauvery Hospitals, Trichy

*Correspondence:sushmithaasuresh@gmail.com

Abstract

A 61-year-old male, with both Diabetes and Hypertension, on regular treatment, came with complaints of neck pain and fever for 1 week. Neck X-ray and computed tomography scan confirmed a retropharyngeal abscess with associated cervical spondylosis. He was posted for incision and drainage under general anaesthesia. Awake fibreoptic intubation was performed. Here we present the successful management of this challenge at Kauvery hospital, Trichy.

Keywords: Retropharyngeal abscess, Cervical Spondylosis, Fibre optic intubation, difficult airway, difficult intubation.

Background

Retropharyngeal abscess poses a great challenge to anesthesiologists due to difficult airway. Retropharyngeal abscess is defined as collection of pus in the retropharyngeal space which extends from base of the skull superiorly to mediastinum inferiorly [1]. Cervical spondylosis, another predisposing factor for difficult airway, adds up in this case making intubation a greater challenge.

Case Presentation

A 61-years- old male came with complaints of neck pain and on & off fever for 1 week. Patient is a known diabetic and hypertensive on regular treatment. After confirming the diagnosis of Retropharyngeal Abscess, he was posted for incision and drainage.

On General examination,

Restricted neck movements
Neck in flexed position
Mallampati grade-4
Limited mouth opening

The respiratory system had the following features. Trachea was in midline. Air entry was equal. Rest of the examination was unremarkable.

Fig. 1. No neck extension.

Fig. 2. Limited mouth opening.

On clinical Assessment,

BP	PR	RR	SPO2	TEMPERATURE	GCS
120/70mmhg	96/min	23/min	98% on RA	97.5 F	15/15

CT neck confirmed the diagnosis of Retropharyngeal Abscess with Cervical Spondylosis. ENT surgeons planned for incision and drainage under GA.

Fig. 3. CXR.

Fig. 4. Instruments.

During preoperative assessment patient and attendants were thoroughly counseled for awake fibre optic intubation. They were explained about each step-in fibre optic intubation and consent was obtained accordingly.

In Preoperative room, Patient was nebulized with 4% LIGNOCAINE and Inj. GLYCOPYRROLATE 0.2 mg IV was administered before shifting to the Operating room (OR).

In view of the anticipated difficult mask ventilation and intubation, all equipments for difficult airway management were kept ready including that for emergency tracheostomy.

After shifting to OR blood pressure, ECG, and pulse oximetry were connected and intubation trolly was kept ready.

Head low position was given to prevent aspiration of abscess contents.

Patientâ€™s oral cavity was anaesthetised with 10% LIGNOCAINE SPRAY. OXYMETAZOLINE Nasal drops were administered before the procedure.

Inj. Fentanyl 50 mcg IV was given.

Awake Nasal fibreoptic intubation was performed with 8 mm size tube and tube position was confirmed with Bilateral symmetrical chest rise and ETCO2 monitoring. After thorough suctioning, throat pack was done to prevent aspiration of blood, pus and secretions.

Then Inj.PROPOFOL 50 mg IV &Inj.CISATRACURIUM 6 mg IV were given. Oxygen, nitrous oxide and sevoflurane were used for maintenance. Abscess was drained without any complications.

Fig. 5. Awake fibre optic intubation.

After the procedure, patientâ€™s adequate breathing efforts were confirmed.

Neuromuscular blockade was reversed with Inj. NEOSTIGMINE 2.5 mg and Inj. Glycopyrrolate 0.5 mg and extubated.

Postoperatively the patient was conscious, alert, breathing adequately, maintaining saturation in room air and hemodynamically stable.

Discussion

Retropharyngeal space extends craniocaudally and is enclosed by alar and buccopharyngeal fascia [2]. It contains chains of lymph nodes that drain the nasopharynx, adenoids, posterior paranasal sinuses and middle ear.

Pathophysiology,

Suppurative lymphadenitis
Organised phlegma
Mature abscess

Cervical spondylosis also called Cervical osteoarthritis or vertebral osteophytosis is a term referring to degenerative osteoarthritis of joints between the centre of the spinal vertebrae or neural foramina. As age advances the vertebrae gradually forms bony spurs and their shock absorbing disks slowly shrink [1].

Fig. 6. In CT neck, increased pre-vertebral shadow more than 30 percent of the vertebral width denotes retropharyngeal abscess.

With difficult airways, the anatomy is often deviated from normal, and comorbid conditions may lead to loss of normal airway contour. Hence close attention should be given to airway block with local anaesthetics, appropriate IV anesthetic agents and dosages to achieve sedation and analgesia for nasal intubation [3]. Airway block with minimal sedation enables patients to maintain spontaneous ventilation, to be cooperative, and tolerate passage of a fibre optic bronchoscope to facilitate nasotracheal intubation.

During awake intubation, laryngospasm and coughing in response to intubation can be troublesome. Hence effective topical airway anesthesia is essential for the comfort of the awake patient and subsequent airway instrumentation [3].

Lidocaine is the most commonly used topical anaesthetic and it has a good safety and efficacy profile. It can be administered upto 5-7 mg/kg. Midazolam, short acting benzodiazepine also acts as an anxiolytic, sedative and causes loss of airway reflexes. Fentanyl, short acting opiod can attenuate coughing and hemodynamic changes. This approach of low doses of fentanyl with midazolam and topical anaesthesia helps to perform a safe method of awake nasal fibreoptic intubation.

Awake Fibre optic intubation can be performed with the patient in the seated or supine position. For a nasal approach, a vasoconstrictor can be applied to the preferred nares to prevent bleeding during intubation. After slow dilation of the nares with nasopharyngeal airways, a well-lubricated ETT (usually 7.0 mm or smaller) is placed and gently pushed medially and posteriorly around 6-8 cm with the goal of advancing the tube into the posterior oropharynx. If resistance is encountered, it should not be advanced further. If this problem occurs with both nares, then bronchoscope should be introduced first to assess for altered anatomy and also to direct passage around the turbinates. With a firm jaw thrust by an assistant or alternatively, the tongue can be grasped and pulled forward, the bronchoscope is advanced and directed to the glottic opening for a view of the cords . After visualisation of the cords, the Endotracheal tube is advanced to the level of the mid-trachea, and placement is confirmed and finally secured [3].

Anaesthetic implications of retropharyngeal abscess are, patient is often dehydrated hence results in electrolyte imbalance and metabolic derangements due too poor oral intake. Patient may be septicemic. If the presentation is late there may be other complications like emphysema and mediastinitis [1]. Tracheal intubation is challeging due to distorted anatomy. In early stages, induction of general anaesthesia reduces trismus, however in later stages induction may precipitate a â€œcannot ventilate – cannot intubateâ€ situation. Another concern is rupture of abscess and aspiration of contents during laryngoscopy and intubation, hence should be gentle to prevent this complication [1].

Conclusion

Awake Fibre optic intubation is one of the preferred method in patients with head and neck pathology. Adequate measures like pre operative nebulization and airway anaesthetization should be followed to prevent complications.

References

Rao MS, et al. Anaesthetic management of difficult airway due to retropharyngeal abscess. Indian J Anaesth. 2010;54(3):246-8.
Lin J, et al. Retropharyngeal abscess presenting as acute airway obstruction in a 66-year-old woman: A case report. World J Clin Cases. 2019;7(22):3838-3843.
Tsukamoto M, et al. Awake fiberoptic nasotrachealintubation for patients with difficult airway. J Dent Anesth Pain Med. 2018;18(5):301-304.

Dr. K. Senthil Kumar

Head of the Department – Anaesthesiology and Toxicology

Dr. S. Khaja Mohideen

Anaesthesiologist

Dr. K. Akila

Anesthesiologist

Anaesthetic management of difficult airway due to retropharyngeal abscess and cervical spondylosis