Airway Abnormalities in Adult Mucopolysaccharidosis and Development of Salford Mucopolysaccharidosis Airway Score

Abstract

(1) Background: Mucopolysaccharidoses (MPS) are a heterogeneous group of lysosomal storage disorders caused by the absence of enzymes required for degradation of glycosaminoglycans (GAGs). GAGs deposition in tissues leads to progressive airway narrowing and/or tortuosity. Increased longevity of patients has posed newer problems, especially the airway. This study aims to characterise various airway abnormalities in adult MPS from a regional centre and proposes a method to quantify the severity of the airway disease. (2) Methods: Retrospective analysis by case notes review, clinical examination, endoscopy, cross-sectional imaging, 3-dimensional reconstruction, and physiological investigations were used to assess the airway abnormalities. Quantitative assessment of the airway severity was performed a validated questionnaire of 15 parameters to derive Salford Mucopolysaccharidosis Airway Score (SMAS). (3) Results: Thirty-one adult MPS patients (21M/ 9F; median 26.7 years; range 19–42 years) were reviewed. There were 9 MPS I, 12 MPS II, 2 MPS III, 5 MPS IV, 2 MPS VI, and 1 MPS VII. Airway abnormalities in each MPS type are described. Patients scoring more than 35 on SMAS had some form of airway intervention. The area under curve of 0.9 was noted at a score of 25, so SMAS more than 25 may predict a difficult airway and potential to have complications. Pearson’s correlation between SMAS and height, weight, BMI were poor (p < 0.05). (4) Conclusions: Airway abnormalities in adult MPS are varied and complex. Assessment of the airway should be holistic and include multiple parameters. An objective multidimensional score such as SMAS may help to predict and manage difficult airways warranting further investigation and validation.

Non-cardiac Manifestations in Adult Patients With Mucopolysaccharidosis

“…d. Tracheal tortuosity was observed in MPS IV, VI, and VII ( 30 ), this may be due to disproportionate growth of the spine and trachea. Surgical correction of the tortuous airways have been described as case reports ( 31 ).…”

“…Based on all these methods a scoring system has been described for difficult airways, Salford Mucopolysacharridosis Airway Score (SMAS) ( 30 ). Appendix 1 provides the SMAS.…”

“…This is because, MPS patients may need some form of surgical intervention under anesthetic, secondly, they may present with an airway problem as an emergency. All adult MPS patients have some form of airway abnormality ( 30 ). Having all the airway findings as a document or in electronic form is very helpful.…”

“…The guedel airway prevents the tongue collapsing in the pharynx and nasopharyngeal airway prevents epiglottis falling over the posterior pharyngeal wall. Airway scoring can be performed using SMAS ( 30 ). The indicators of difficult oral intubation include poor mouth opening, reduced cervical spine mobility, prominent teeth, high mallampati grade, high and anterior larynx shown on nasendoscopy and by calculating hyo-mental distance, hyo-mental angle ( 21 ).…”

Hyo-Mental Angle and Distance: An Important Adjunct in Airway Assessment of Adult Mucopolysaccharidosis

“…Most of these patients will need general anesthetic for surgery at some point in their lifetime due to multi-system involvement. In our experience, we noted that most adult MPS patients have a large and bulky tongue, large lower jaw, and short neck [ 5 ]. A high or anterior larynx poses difficulty in access to the airway.…”