Anaesthetic implications of the changing management of patients with mucopolysaccharidosis

The mucopolysaccharidoses are a group of inherited metabolic disorders that are renowned for presenting clinical problems, particularly related to cardiac, airway, and skeletal abnormalities, in children during anaesthesia. The changing clinical management of the mucopolysaccharidoses can be described in three phases. An initial phase of accumulation and dissemination of knowledge about the management of this rare disease with a growing recognition that untreated Hurler syndrome and more severe forms of other phenotypes such as Hunter syndrome and Maroteaux-Lamy syndrome were associated with severe complications under anaesthesia. This was followed by a second phase reflecting the beneficial results of new treatments such as haemopoietic stem cell transplantation and enzyme replacement therapy. Early and successful transplantation has dramatically improved long-term outcome and reduced anaesthetic complications in children with Hurler syndrome. Enzyme replacement therapy is available for many forms of mucopolysaccharidosis. If commenced at an early age improvement in many organ systems may be observed with an improved quality of life. However, these current treatment regimens do not appear to improve neurocognitive dysfunction, or cardiac valvular or skeletal abnormalities. We are now entering a third phase where the partial benefits of these treatment regimens are resulting in an increasing number of older patients with partially corrected abnormalities, including difficult airways, presenting for ongoing treatment to a new and potentially unsuspecting group of clinicians. Major airway abnormalities may be encountered and current adult guidelines may need to be adapted. A multidisciplinary team approach involving paediatric and adult anaesthetists is recommended to optimise future management.