Use of nebulised N-acetylcysteine as a life-saving mucolytic in intensive care: A case report

We present a case of critical airway obstruction secondary to a solid tracheal mucus plug in a patient with pneumonia. Following failed conventional mucolysis therapy, nebulised N-acetylcysteine acted as a life-saving mucolytic, and prevented imminent cardiorespiratory arrest. Use of oral N-acetylcysteine as a mucolytic has been long established within respiratory medicine in managing chronic airway disease, but is rarely utilised in critically ill or mechanically ventilated patients due to the lack of comparative studies in literature. A 28-year-old female presented to the emergency department with shortness of breath and a productive cough. She was six weeks post-partum with no past medical history. Initial management for a community acquired pneumonia with type 1 respiratory failure included intensive care admission, antibiotics, fluid therapy and bronchodilators. The patient acutely deteriorated 48 h after admission becoming unresponsive and severely hypoxaemic. Intubation did not achieve ventilation, and subsequent direct bronchoscopy revealed a thick, solid, obstructing tracheal mucus plug, superior to the carina. It was resistant to aspiration despite the use of saline flushes, chest physiotherapy and bronchodilators and the bronchoscope could not pass it. N-acetylcysteine, administered via the bronchoscopic port, caused sufficient mucolysis to enable removal of the thick mucus cast, enabling ventilation and gas exchange. Such resistant mucus plugging is a rare cause of failed ventilation, with limited therapeutic options. Here, the unlicensed and rarely reported use of nebulised N-acetylcysteine was a life-saving mucolytic, allowing removal of the obstructing plug and re-establishing ventilation.