Diagnosis and management of Duchenne muscular dystrophy, part 2: respiratory, cardiac, bone health, and orthopaedic management

Abstract

A coordinated, multidisciplinary approach to care is essential for optimum management of the primary manifestations and secondary complications of Duchenne muscular dystrophy (DMD). Contemporary care has been shaped by the availability of more sensitive diagnostic techniques and the earlier use of therapeutic interventions, which have the potential to improve patients' duration and quality of life. In part 2 of this update of the DMD care considerations, we present the latest recommendations for respiratory, cardiac, bone health and osteoporosis, and orthopaedic and surgical management for boys and men with DMD. Additionally, we provide guidance on cardiac management for female carriers of a disease-causing mutation. The new care considerations acknowledge the effects of long-term glucocorticoid use on the natural history of DMD, and the need for care guidance across the lifespan as patients live longer. The management of DMD looks set to change substantially as new genetic and molecular therapies become available.

Figure 1. Assessments and interventions for respiratory care of patients with Duchenne muscular dystrophy by stage of disease

DMD=Duchenne muscular dystrophy. FVC=forced vital capacity. MEP=maximum expiratory pressure. MIP=maximum inspiratory pressure. PCF=peak cough flow. p_etCO₂=end-tidal partial pressure of CO₂. p_tcCO₂=transcutaneous partial pressure of CO₂. SpO₂=blood oxygen saturation by pulse oximetry. *See text for definitions of sleep study results. †All specified threshold values of PCF, MEP, and MIP apply to older teenage and adult patients. ‡Fatigue, dyspnoea, morning or continuous headaches, frequent nocturnal awakenings or difficult arousal, hypersomnolence, difficulty concentrating, awakenings with dyspnoea and tachycardia, or frequent nightmares. §We strongly endorse the use of non-invasive methods of assisted ventilation instead of tracheostomy to optimise patient quality of life; indications for tracheostomy include patient preference, inability of patient to use non-invasive ventilation successfully, three failed extubation attempts during a critical illness despite optimum use of non-invasive ventilation and mechanically assisted coughing, or failure of non-invasive methods of cough assistance to prevent aspiration of secretions into the lungs due to weak bulbar muscles.

Figure 2

Cardiac monitoring, diagnosis, and treatment algorithm for patients with Duchenne muscular dystrophy

Figure 3. Osteoporosis monitoring, diagnosis, and treatment algorithm for patients with Duchenne muscular dystrophy

BMD=bone mineral density. DMD=Duchenne muscular dystrophy. DXA=dual-energy x-ray absorptiometry. *Signs of clinically significant bone fragility are low-trauma fractures of long bones or vertebra. †Clinical stability refers to absence of non-vertebral fractures, stable healed vertebral fractures, absence of new vertebral fractures in previously normal vertebral bodies, absence of bone and back pain, and BMD Z score appropriate for height Z score or higher than −2 SD.

Figure 4

Considerations for orthopaedic and surgical care of patients with Duchenne muscular dystrophy by stage of disease

Figure 5

General guidance on fracture prevention for patients with Duchenne muscular dystrophy and their families

Figure 6. Surgical considerations for patients with Duchenne muscular dystrophy

DMD=Duchenne muscular dystrophy. FVC=forced vital capacity. *Guidance applies to older teenage and adult patients.