| Duchenne's | Becker's | |
| Incidence | 1 in 3,500 X-linked recessive |
1 in 30,000 |
| Dystrophin | Total absence | Partial absence |
| Symptoms | Progressive wasting/weakness of proximal muscles Waddling gait → wheelchair bound by teens |
Milder symptoms and more protracted course |
| Other systems | Restrictive lung disease from marked scoliosis 50% of patients have dilated cardiomyopathy by 15yrs |
Dilated cardiomyopathy and cardiac arrhythmia |
| Mortality | Death by 2nd or 3rd decade due to cardiac / respiratory failure | By 4th or 5th decade from cardiac / respiratory failure |
Muscular Dystrophy
Muscular Dystrophy
Resources
- Anaesthesia recommendations for Duchenne muscular dystrophy (Orphan Anaesthesia, 2019)
- Duchenne Muscular Dystrophy (Anesthesia Considerations)
- Neuromuscular disorders and anaesthesia. Part 1: generic anaesthetic management (BJA Education, 2011)
- Neuromuscular disorders and anaesthesia. Part 2: specific neuromuscular disorders (BJA Education, 2011)
- The muscular dystrophies are a heterogenous group of disorders characterised by progress muscule weakness
- They include:
- Duchenne's muscular dystrophy
- Becker's muscular dystrophy
- Limb girdle muscular dystrophy
- Facioscapulohumeral muscular dystrophy
- Emery Dreifuss muscular dystrophy
Perioperative management of the patient with muscular dystrophy
- Patients may present for a variety of Orthopaedic and Spinal surgeries, such as tendon release/transfer or scoliosis correction
- Standard pre-operative care in neuromuscular disease
- Clean anaesthetic machine and TIVA is recommended
Monitoring and access
- AAGBI
- Invasive arterial monitoring
- Wide-bore access in case of bleeding (see below)
Airway
- May have difficult intubation; 3% in one retrospective data set
- Frequently have macroglossia
- Oropharyngeal dysfunction raises risk of aspiration
Volatile agents
- Implicated in non-MH, anaesthetic-induced rhabdomyolysis
- Avoid and use TIVA + clean anaesthetic machine instead
- If gas induction required, then switch to TIVA and clean machine ASAP
NMBA
- Avoid suxamethonium due to risk of hyperkalaemia
- Caution with non-depolarising agents
- Delayed onset and offset is seen, potentially leading to a prolonged block
- If used, monitor neuromuscular blockade
- Can use appropriate IV technique instead
Bleeding risk
- Increased risk of bleeding from smooth muscle and platelet dysfunction
- Cell salvage and invasive monitoring is recommended
- Hypotensive anaesthesia, but avoid hypovolaemia as poorly compliant ventricles leads to relatively fixed CO state
- High risk for post-operative respiratory insufficiency and cardiac dysfunction
- If remain ventilated post-operatively, wean early to avoid prolonged ventilation and associated weakness
- Early physiotherapy and avoid prolonged immobilisation, which may worsen atrophy