Diagnosis and management of respiratory involvement in Hunter syndrome

Respiratory problems are frequently encountered by patients with Hunter syndrome and contribute to the premature mortality seen in individuals with the disease. Progressive deposition of glycosaminoglycans in the soft tissue of the throat and trachea is thought to be responsible for the airway dysfunction and obstruction, which characterize the syndrome. Other physical characteristics, including abnormalities in the shape and structure of the ribs, abdominal organ enlargement, short neck and immobile jaw, further contribute to the respiratory problems. New measurement systems specifically tailored to paediatric patients now allow clinicians to follow the progressive deterioration of lung function, which was previously challenging in this population. Sleep apnoea is another common feature of Hunter syndrome, which can lead to a reduction in oxygen saturation of the blood and severely disrupts sleep. In our clinic, continuous positive airway pressure (CPAP), in which inspired air at elevated pressure is delivered through a specially designed mask, has proved to be effective for reducing sleep apnoea in patients with Hunter syndrome. As a consequence of the anatomical and pathological changes in the upper airways of patients with Hunter syndrome, general anaesthesia – especially intubation – is a difficult and potentially high‐risk procedure. Consequently, such procedures should be performed by an anaesthetist – ideally accompanied by a paediatric pneumologist/intensivist – with experience in managing patients with Hunter syndrome. Conclusion: Respiratory abnormalities are a major contributor to the premature mortality seen in Hunter syndrome. Treatment of these respiratory problems requires the careful attention of clinicians skilled in the recognition, diagnosis, management and treatment of Hunter syndrome.