This publication presents a range of challenges that may occur while managing critical clinical situations in adults with MPS. These challenges can be prepared for and resolved through practical steps and strategies, as outlined in Table 1 and the Supplementary information. Practical experience of managing critical clinical situations is often restricted to a limited number of specialist metabolic centres. Although some situations can be planned for in advance and the necessary expertise sought prior to the situation, for emergencies and time-limited procedures an awareness of MPS-specific requirements is needed to support HCPs in their treatment decisions.
In centres with experience of surgery in adults with MPS, there are opportunities to share this experience through providing advice and guidance, possibly through virtual MDTs, and training HCPs at other metabolic centres. It may even be an option for patients to undergo surgical procedures in these experienced centres, although this may limit the spread of knowledge if only clinicians from experienced centres are involved. Templates for preoperative assessments and post-surgical planning can be shared, and these may also assist less experienced centres in identifying areas in which increased experience is needed. Indeed, even experienced centres should seek to broaden their knowledge, as limited patient numbers mean that even an experienced centre may be managing small numbers of patients.
In adult metabolic centres with limited experience of MPS, the key is to seek out guidance from clinicians and centres that have carried out similar procedures and gain a full understanding of the challenges that are likely to be encountered. For example, difficult intubations because of narrowed airways are major factors in deferring complex surgeries (26). Theroux et al. examined potential abnormalities in patients with MPS IV, focusing on those that were specific to this patient group. Abnormalities of the airways frequently result in difficult intubations in this patient group, not only because of GAG deposits in the airways but also spinal instability that affects the anaesthetist’s ability to manipulate the patient’s position. Intubation difficulties are estimated to occur in 25% of patients with MPS, so the MDT may wish to take additional steps prior to this procedure. This involves easy access to preoperative assessment results and imaging studies to guide the planned procedures, support for team members who are not familiar with the patient, and planned alternatives if initial procedures do not go ahead as expected.
Coordination of MPS care by a metabolic specialist ensures input from all relevant MDT members and that each patient’s requirements are accounted for. This is particularly important for progressive heterogeneous diseases, such as MPS, where the types and severity of symptoms can vary widely between patients. The coordinating clinician should integrate information from across the wider MDT, ensuring that all relevant assessments are conducted, the results used to develop surgical plans and that the surgical team are aware of any potential complications. Patients with MPS are at high risk of surgical complications and knowledge of these is the key to optimising each procedure (4, 5, 20, 21). The metabolic specialist should also be involved in decision-making with regard to the potential benefits and risks of surgery. Thorough knowledge of the patient’s condition and understanding of their past medical history and their social circumstances should be gathered prior to every procedure. While some patients may accept the risk of an additional post-surgical procedure, such as a tracheostomy, and are willing to undergo the procedure, others seem to develop tolerance to their stable and not troublesome symptoms and learn how to live with them. Because of the multi-organ involvement in MPS disorders and the potential for adverse impacts on surgery, where possible, symptoms should be resolved or stabilised before surgery is carried out.
Guidance on surgical procedures in MPS is already available, highlighting the importance of experienced team members and thorough preoperative planning (2–5, 21, 26, 27), and should be incorporated into standard operating procedures when possible. Charrow et al. have developed a series of consensus recommendations to support clinicians involved in any aspect of treating patients with MPS IVA (27). They again stress the need to carry out assessments with input from MPS experts, and to establish an MDT with a broad range of specialists to manage the needs of individual patients and provide a list of recommendations for anaesthetic and surgical preparations.
In terms of managing pregnant patients, many patients will undergo a planned Caesarean section. This may be because of either small maternal pelvis size or the position of the baby, but it is also important to consider the risk of a patient with MPS requiring an emergency general anaesthetic (24). Conversely, some patients might have increased intracranial pressure or hip dysplasia meaning that an epidural would be inappropriate. As with other surgery types in patients with MPS, recovery may be prolonged and a full preoperative assessment by an experienced MDT is needed. Plans should be in place for babies of mothers with MPS to be delivered in high-risk maternity units. Throughout pregnancy, some patients with MPS have been reported to experience pain, migraines, arrhythmia and blood pressure fluctuations (24), and plans should be in place to monitor and manage these.
The available literature exemplifies some of the guidance that is already in place to support the management of patients with MPS. A further important resource for metabolic specialists coordinating an MDT is national and international colleagues who are also responsible for metabolic patients. For rare disease HCPs, colleagues can offer information on different approaches to treatment, and alongside publications and case studies, this can deepen the expertise of the metabolic specialist. Conferences and meetings provide a further wealth of information across the field of MPS, which experts can use to inform up-to-date individualised care plans for each patient.