Introduction
Patients who undergo laryngectomy for laryngeal carcinoma have a tracheostoma formed. This tracheostoma cannot benefit from the humidifying capabilities of the upper airway. Around a third of these patients find mucous crusting troublesome and they can go on to develop acute airway obstruction.Reference Jay, Ruddy and Cullen1 Mucous plugs causing airway difficulty must be evacuated. Saline nebulisers are used to moisten and soften the mucus to assist manual evacuation.
We describe a novel technique to further soften tracheal mucous plugs in cases with limited response to saline nebulisers.
Case report
A 68-year-old female presented to the emergency department with difficulty breathing, of acute onset. Four months previously she had undergone a total laryngectomy with tracheal stoma formation for a tumour–node–metastasis staging T4aN2M0 post-cricoid laryngeal carcinoma.
On examination, the patient was in respiratory distress, with minimal air transfer through the tracheostoma opening. Bedside endoscopy of the trachea revealed dry mucosa with thick, dry plugs of debris in the proximal airway causing a 60 per cent obstruction. An attempt at removal of these obstructions using Tilley's forceps was hindered by the firm and adhesive nature of the plugs. Saline nebulisers were used in an attempt to soften the mucus; these had a limited effect despite back-to-back use.
An N-acetylcysteine nebuliser was used as a second-line treatment. Repeat endoscopy revealed moist mucous membranes; the mucous plug had become softer and was successfully evacuated. A combination of N-acetylcysteine nebulisers and saline nebulisers were continued overnight. The patient was monitored in the high dependency unit but made a good recovery and was discharged home.
Discussion
Laryngectomy stomas (tracheostomas) are formed following total laryngectomies for laryngeal cancer. The majority of complications associated with laryngectomy stomas are long-term; however, on occasion emergency doctors are required to respond to acute complications.
The most serious complication involves luminal obstruction. Stoma sites are prone to develop crusting. This is not unexpected given the crucial role the upper airways play in helping to warm, filter and humidify inspired air. Patients with laryngectomy stomas are given specific instructions to prevent luminal obstruction. This includes regular examining, cleaning and moisturising of the stoma site. Patients are advised to keep the stoma site covered. Adequate humidity is the key to preventing luminal obstruction. Patient education should begin early and be tailored to each patient, so each individual understands their airway and the importance of maintenance.Reference Lewarski2
There is little literature on acute airway complications in laryngectomy stomas. The majority relates to obstruction as a result of mucous collections in patients using tracheal devices long-term. Jay et al. reported that 35 per cent of patients with laryngectomy stomas found crusting to be troublesome.Reference Jay, Ruddy and Cullen1 Ganly et al. found that approximately 7.1 per cent of patients with laryngectomy stomas suffered from acute airway complications.Reference Ganly, Patel, Matsuo, Singh, Kraus and Boyle3
The current stepwise management for luminal obstruction involves conservative measures such as suction and oxygen to alleviate respiratory distress. The lumen can be inspected and any obstructions should be manually removed. Hard, crusty debris can be softened using saline nebulisers. The cessation of respiratory distress following clearance of the obstruction is diagnostically useful. Failure of an appropriate respiratory improvement should prompt other potential diagnoses such as a pneumothorax or lower respiratory tract infection.
N-acetylcysteine is the acetylated precursor of the amino acid L-cysteine.Reference Samuni, Goldstein, Dean and Berk4 It has been used in clinical practice for several decades, principally as a mucolytic in chronic respiratory illnesses as well as in paracetamol overdose. Studies have shown it to be a powerful antioxidant, with a potential use in cancer and heart disease treatment.5
The mechanism of action of N-acetylcysteine is principally attributed to its ability to reduce extracellular cystine to cysteine and act as a source of sulfhydryl groups intracellularly. By supplying sulfhydryl groups, N-acetylcysteine stimulates glutathione synthesis and thus promotes liver detoxification. Its effectiveness as a mucolytic is related to its sulfhydryl group, which interacts with the mucoprotein disulphide bonds; this causes the mucus to be broken down and become less viscous.5 N-acetylcysteine is also reported to act as an expectorant by stimulating ciliary action and therefore clearing mucus from the airways.Reference Zimet6
N-acetylcysteine is rapidly absorbed into various tissues and quickly deactivated by the liver before being renally excreted. Peak plasma levels are seen at 1 hour; within 12 hours, N-acetylcysteine is undetectable in plasma.Reference Samuni, Goldstein, Dean and Berk4 It is pharmaceutically available for use intravenously, orally or by inhalation. In this case, we successfully used N-acetylcysteine via a nebuliser.
There have been several studies on the role of N-acetylcysteine as a mucolytic in chronic respiratory conditions, such as chronic obstructive pulmonary disease and cystic fibrosis.Reference Nash, Stephenson, Ratjen and Tullis7–9 The effects of its use orally and via a nebuliser have been assessed. Although improved patient outcomes are widely reported in N-acetylcysteine treated groups, no statistically significant differences have been found in terms of lung function, mucociliary clearance curves or sputum viscosity following treatment with N-acetylcysteine as compared with control or placebo groups. More research is required to further investigate the role of nebulised N-acetylcysteine in these conditions.
N-acetylcysteine is generally a safe and well-tolerated drug. The most common side effects are nausea and vomiting. Anaphylactic reactions are rare but have been reported, manifesting as rash, pruritus, angioedema, bronchospasm, tachycardia and hypotension.Reference Zimet6
• The most serious complication of laryngectomy stomas is acute airway obstruction
• Management currently involves the use of oxygen and suction, with saline nebulisers to assist in manual evacuation of any obstruction
• This paper describes a case where N-acetylcysteine nebulisers assisted in softening mucous plugs to aid manual evacuation
In the presented case, the patient was not actively involved in her stoma care and thus has had recurrent mucous plugs. The case highlights the importance of patient awareness and prevention of complications. N-acetylcysteine nebulisers were successfully used to soften the mucous plug, allowing it to be manually evacuated.
