Management of Muscle Extensibility and Joint Contractures
The management of joint contractures requires input from neuromuscular specialists, physical therapists, rehabilitation physicians, and orthopedic surgeons. Programs to prevent contractures are usually monitored and implemented by a physical therapist and tailored to individual needs, stage of the disease, response to therapy, and tolerance. Local care needs to be augmented by guidance from a specialist every 4 months.
Physical Therapy Interventions
Stretching and Positioning
Effective stretching of the musculotendinous unit requires a combination of interventions, including active stretching, active-assisted stretching, passive stretching, and prolonged elongation using positioning, splinting, orthoses, and standing devices. As standing and walking become more difficult, standing programs are recommended.
Active, active-assisted, and/or passive stretching to prevent or minimise contractures should be done a minimum of 4 to 6 days per week for any specific joint or muscle group. Stretching should be done at home and/or school, as well as in the clinic.
During both the ambulatory and non-ambulatory phases, regular stretching at the ankle, knee, and hip is necessary. During the non-ambulatory phase, regular stretching of the upper extremities, including the long finger flexors and wrist, elbow, and shoulder joints, also becomes necessary. Additional areas that require stretching can be identified by individual examination.
Assistive Devices for Musculoskeletal Management
Resting ankle–foot orthoses (AFOs) used at night can help to prevent or minimise progressive equinus contractures and are appropriate throughout life. AFOs should be custom-moulded and fabricated for comfort and optimum foot and ankle alignment. Knee–ankle–foot orthoses (KAFOs; e.g., long leg braces or callipers) for prevention of contracture and deformity can be of value in the late ambulatory and early non-ambulatory stages to allow standing and limited ambulation for therapeutic purposes, but might not be well tolerated at night. Use of AFOs during the daytime can be appropriate for full-time wheelchair users. Resting hand splints for patients with tight long finger flexors are appropriate.
A passive standing device for patients with either no or mild hip, knee, or ankle contractures is necessary for late ambulatory and early non-ambulatory stages. Many advocate continued use of passive standing devices or a power standing wheelchair into the late non-ambulatory stage if contractures are not too severe to restrict positioning and if devices are tolerable.
Surgical Intervention for Lower-limb Contractures
No unequivocal situations exist in which lower-limb contracture surgery is invariably indicated.
Various surgical options exist, none of which could be recommended above any other. Options for surgery will depend on individual circumstances, but there can be a role for surgery in the ambulatory and non-ambulatory phases.
Early Ambulatory Phase
Procedures for early contractures including heel-cord (tendo-Achillis) lengthenings for equinus contractures, hamstring tendon lengthenings for knee-flexion contractures, anterior hip-muscle releases for hip-flexion contractures, and even excision of the iliotibial band for hip-abduction contractures have been performed in patients as young as 4 to 7 years.
Middle Ambulatory Phase
Muscle strength and range of motion around individual joints should be considered before deciding on surgery.
Approaches to lower-extremity surgery to maintain walking include bilateral multi-level (hip–knee–ankle or knee–ankle) procedures, bilateral single-level (ankle) procedures, and, rarely, unilateral single-level (ankle) procedures for asymmetric involvement. The surgeries involve tendon lengthening, tendon transfer, tenotomy (cutting the tendon), along with release of fibrotic joint contractures (ankle) or removal of tight fibrous bands (iliotibial band at lateral thigh from hip to knee).
Equinus foot deformity (toe-walking) and varus foot deformities (severe inversion) can be corrected by heel-cord lengthening and tibialis posterior tendon transfer through the interosseous membrane onto the dorsolateral aspect of the foot to change plantar flexion–inversion activity of the tibialis posterior to dorsiflexion–eversion. Hamstring lengthening behind the knee is generally needed if there is a knee-flexion contracture of more than 15°.
After tendon lengthening and tendon transfer, postoperative bracing might be needed, which should be discussed preoperatively. Following tenotomy, bracing is always needed. When surgery is performed to maintain walking, the patient must be mobilised using a walker or crutches on the first or second postoperative day to prevent further disuse atrophy of lower-extremity muscles. Post-surgery walking must continue throughout limb immobilisation and post-cast rehabilitation. An experienced team with close coordination between the orthopaedic surgeon, physical therapist, and orthotist is required.
Late Ambulatory Phase
Despite promising early results, surgery in the late ambulatory phase has generally been ineffective and served to obscure the benefits gained by more timely and earlier interventions.
Early Non-ambulatory Phase
In the early non-ambulatory phase, some clinics perform extensive lower-extremity surgery and bracing to regain ambulation within 3 to 6 months after walking ability is lost. However, this is generally ineffective and not currently considered appropriate.
Late Non-ambulatory Phase
Severe equinus foot deformities of more than 30° can be corrected with heel-cord lengthening or tenotomy and varus deformities (if present) with tibialis posterior tendon transfer, lengthening, or tenotomy. This is done for specific symptomatic problems, generally to alleviate pain and pressure, to allow the patient to wear shoes, and to correctly place the feet on wheelchair footrests. This approach is not recommended as routine.
Assistive/Adaptive Devices for Function
AFOs are not indicated for use during ambulation because they typically limit compensatory movements needed for efficient ambulation, add weight that can compromise ambulation, and make it difficult to rise from the floor. During the late ambulatory stage, a KAFO with locked knee might prolong ambulation but is not essential.
During the early ambulatory stage, a lightweight manual mobility device is appropriate to allow the child to be pushed on occasions when long-distance mobility demands exceed endurance. In the late ambulatory stage, an ultra lightweight manual wheelchair with solid seat and back, seating to support spinal symmetry and neutral lower extremity alignment, and swing-away footrests is necessary. In the early non-ambulatory stage, a manual wheelchair with custom seating and recline features might serve as a necessary back-up to a powered wheelchair.
As functional community ambulation declines, a powered wheelchair is advocated. Increasingly, rehabilitation providers recommend custom seating and power-positioning components for the initial powered wheelchair, to include a headrest, solid seat and back, lateral trunk supports, power tilt and recline, power-adjustable seat height, and power-elevating leg rests (with swing-away or flip-up footrests to facilitate transfers). Some also recommend power standing chairs. Additional custom seating modifications could include a pressure-relieving cushion, hip guides, and flip-down knee adductors.
As upper-extremity strength declines, referral to a specialist in rehabilitation assistive technology is necessary for evaluation of alternative computer or environmental control access, such as a tongue-touch control system, switch scanning, infrared pointing, or eye-gaze selection.
Other adaptations in the late ambulatory and non-ambulatory stages could include an elevated lap tray, with adaptive straw, hands-free water pouch, and/or turntable (indicated if the hand cannot be brought to the mouth or if biceps strength is grade 2/5), power adjustable bed with pressure relief cushion or mattress, bathing and bathroom equipment, and transfer devices, including a hydraulic patient lift, ceiling lift (hoist), slide sheets, and environmental control options.
Recommendations for Exercise
Submaximum, aerobic exercise/activity is recommended by some clinicians, especially early in the course of the disease when residual strength is higher, whereas others emphasise avoidance of overexertion and overwork weakness. High-resistance strength training and eccentric exercise are inappropriate across the lifespan owing to concerns about contraction-induced muscle-fibre injury. To avoid disuse atrophy and other secondary complications of inactivity, it is necessary that all boys who are ambulatory or in the early non-ambulatory stage participate in regular submaximum (gentle) functional strengthening/activity, including a combination of swimming-pool exercises and recreation-based exercises in the community. Swimming, which might have benefits for aerobic conditioning and respiratory exercise, is highly recommended from the early ambulatory to early non-ambulatory phases and could be continued in the non-ambulatory phase as long as it is medically safe. Additional benefits might be provided by low-resistance strength training and optimisation of upper body function. Significant muscle pain or myoglobinuria in the 24-hour period after a specific activity is a sign of overexertion and contraction-induced injury, and if this occurs the activity should be modified.
Daily glucocorticoid treatment has been shown to reduce the risk of scoliosis; however, risk of vertebral fracture is increased.
Spinal care should involve an experienced spinal surgeon, and comprises scoliosis monitoring, support of spinal/pelvic symmetry and spinal extension by the wheelchair seating system, and (in patients using glucocorticoids, in particular) monitoring for painful vertebral body fractures.
Monitoring for scoliosis should be by clinical observation through the ambulatory phase, with spinal radiography warranted only if scoliosis is observed. In the non-ambulatory phase, clinical assessment for scoliosis is essential at each visit. Spinal radiography is indicated as a baseline assessment for all patients around the time that wheelchair dependency begins with a sitting anteroposterior full-spine radiograph and lateral projection film. An anteroposterior spinal radiograph is warranted annually for curves of less than 15° to 20° and every 6 months for curves of more than 20°, irrespective of glucocorticoid treatment, up to skeletal maturity.
Spinal fusion is done to straighten the spine, prevent further worsening of deformity, eliminate pain due to vertebral fracture with osteoporosis, and slow the rate of respiratory decline. Anterior spinal fusion is inappropriate in Duchenne muscular dystrophy (DMD). Posterior spinal fusion is warranted only in non-ambulatory patients who have spinal curvature of more than 20°, are not on glucocorticoids, and have yet to reach skeletal maturity. In patients on glucocorticoids, surgery might also be warranted if curve progression continues and is associated with vertebral fractures and pain after optimisation of medical therapy to strengthen the bones, irrespective of skeletal maturation.
When deciding the extent of surgical stabilisation for scoliosis, if there is pelvic obliquity of more than 15°, it is necessary to perform correction and stabilisation with bone fusion from the upper thoracic region to the sacrum. If there is no pelvic obliquity, these recommendations can also be used, but fusion to the fifth lumbar vertebra is also effective. Use of a thoraco–lumbar–sacral orthosis is inappropriate if surgery is to be done, but it can be considered for patients unable to undergo spinal fusion.
Bone health is an important part of the lifelong care of patients with DMD. Two previous consensus statements have been published. Figure 1 of the original guideline document outlines the risk factors, possible assessments, and treatment strategies for patients who have DMD. Awareness of potential problems and means to assess these problems and interventions are important, preferably in conjunction with local specialists in bone health and endocrine assessment.
Taking into account the guidelines for safe anaesthesia in DMD, internal fixation is warranted for severe lower-limb fractures in ambulatory patients to allow prompt rehabilitation and the greatest possible chance of maintaining ambulation. In the non-ambulatory patient, the requirement for internal fixation is less acute. Splinting or casting of a fracture is necessary for the non-ambulatory patient, and is appropriate in an ambulatory patient if it is the fastest and safest way to promote healing and does not compromise ambulation during healing.
The care team must include a physician and therapist with skill in the initiation and management of non-invasive ventilation and associated interfaces, lung-volume recruitment techniques, and manual and mechanically assisted cough. Assessments and interventions will need to be re-evaluated as the condition changes (see Figures 2 and 3 in the original guideline document and the respiratory interventions below). In the ambulatory stage, minimum assessment of pulmonary function (such as measurement of forced vital capacity at least annually) allows familiarity with the equipment and the team can assess the maximum respiratory function achieved. The main need for pulmonary care is in the period after the loss of independent ambulation. The pulmonary section of Figure 2 in Part 1 of the original guideline document links these assessments and interventions to the various stages of disease, and comprises a respiratory action plan that should be enacted with increasing disease severity. Although the expert panel recognises that assisted ventilation via tracheostomy can prolong survival, the schema is intended to advocate strongly for the use of non-invasive modes of assisted ventilation. Particular attention to respiratory status is required around the time of planned surgery (see below).
Immunisation with 23-valent pneumococcal polysaccharide vaccine is indicated for patients aged 2 years and older. Annual immunisation with trivalent inactivated influenza vaccine is indicated for patients 6 months of age and older.
During an established infection, in addition to use of manually and mechanically assisted cough, antibiotics are necessary, irrespective of oxygen saturation if positive evidence of an infection is established on culture, and irrespective of culture results if pulse oximetry remains below 95% in room air. Supplemental oxygen therapy should be used with caution because oxygen therapy can apparently improve hypoxaemia while masking the underlying cause, such as atelectasis or hypoventilation. Oxygen therapy might impair central respiratory drive and exacerbate hypercapnia. If a patient has hypoxaemia due to hypoventilation, retained respiratory secretions, and/or atelectasis, then manual and mechanically assisted cough and non-invasive ventilatory support are necessary. Substitution of these methods by oxygen therapy is dangerous.
|Respiratory Interventions Indicated in Patients with Duchenne Muscular Dystrophy
Step 1: Volume recruitment/deep lung inflation technique
Step 2: Manual and mechanically assisted cough techniques
- Volume recruitment/deep lung inflation technique (by self-inflating manual ventilation bag or mechanical insufflation–exsufflation) when FVC <40% predicted
Step 3: Nocturnal ventilation
- Respiratory infection present and baseline peak cough flow <270 L/min*
- Baseline peak cough flow <160 L/min or maximum expiratory pressure <40 cm water
- Baseline FVC <40% predicted or <1.25 L in older teenager/adult
Nocturnal ventilation† is indicated in patients who have any of the following:
- Signs or symptoms of hypoventilation (patients with FVC <30% predicted are at especially high risk)
- A baseline SpO2 <95% and/or blood or end-tidal CO2 >45 mm Hg while awake
- An apnoea–hypopnoea index >10 per hour on polysomnography or four or more episodes of SpO2 <92% or drops in SpO2 of at least 4% per hour of sleep
Optimally, use of lung volume recruitment and assisted cough techniques should always precede initiation of non-invasive ventilation.
Step 4: Daytime ventilation
In patients already using nocturnally assisted ventilation, daytime ventilation‡ is indicated for:
- Self extension of nocturnal ventilation into waking hours
- Abnormal deglutition due to dyspnoea, which is relieved by ventilatory assistance
- Inability to speak a full sentence without breathlessness, and/or
- Symptoms of hypoventilation with baseline SpO2 <95% and/or blood or end-tidal CO2 >45 mm Hg while awake
Continuous non-invasive assisted ventilation (with mechanically assisted cough) can facilitate endotracheal extubation for patients who were intubated during acute illness or during anaesthesia, followed by weaning to nocturnal non-invasive assisted ventilation, if applicable.
Step 5: Tracheostomy
Indications for tracheostomy include:
- Patient and clinician preference§
- Patient cannot successfully use non-invasive ventilation
- Inability of the local medical infrastructure to support non-invasive ventilation
- Three failures to achieve extubation during critical illness despite optimum use of non-invasive ventilation and mechanically assisted cough
- The failure of non-invasive methods of cough assistance to prevent aspiration of secretions into the lung and drops in oxygen saturation below 95% or the patient's baseline, necessitating frequent direct tracheal suctioning via tracheostomy
FVC=forced vital capacity; SpO2= pulse oximetry.
*All specified threshold values of peak cough flow and maximum expiratory pressure apply to older teenage and adult patients.
†Recommended for nocturnal use: non-invasive ventilation with pressure cycled bi-level devices or volume cycled ventilators or combination volume-pressure ventilators. In bi-level or pressure support modes of ventilation, add a back-up rate of breathing. Recommended interfaces include a nasal mask or a nasal pillow. Other interfaces can be used and each has its own potential benefits.
‡Recommended for day use: non-invasive ventilation with portable volume cycled or volume-pressure ventilators; bi-level devices are an alternative. A mouthpiece interface is strongly recommended during day use of portable volume-cycled or volume-pressure ventilators, but other ventilator-interface combinations can be used depending on clinician preference and patient comfort.
§However, the panel advocates the long-term use of non-invasive ventilation up to and including 24 h/day in eligible patients.
The care team should include a cardiac specialist who should be involved with the patient and family after confirmation of the diagnosis, not only to manage cardiomyopathy, but also to initiate a relationship to ensure long-term cardiovascular health.
Baseline assessment of cardiac function should be done at diagnosis or by the age of 6 years, especially if this can be done without sedation. Clinical judgment should be used for patients under the age of 6 years who require sedation. The recommendation to initiate echocardiographic screening at the time of diagnosis or by the age of 6 years was judged necessary, even though the incidence of echocardiographic abnormalities is low in children aged less than 8 to 10 years. However, there are cases in which abnormalities do exist, which can affect clinical decision making, including decisions about the initiation of corticosteroids and planning for any anaesthesia. A baseline echocardiogram obtained at this age also allows for screening for anatomical abnormalities (e.g., atrial or ventricular septal defects, patent ductus arteriosus), which might affect long-term cardiovascular function.
Minimum assessment should include, although is not limited to, an electrocardiogram and a non-invasive cardiac imaging study (i.e., echocardiogram). Assessment of cardiac function should occur at least once every 2 years until the age of 10 years. Annual complete cardiac assessments should begin at the age of 10 years or at the onset of cardiac signs and symptoms if they occur earlier. Abnormalities of ventricular function on non-invasive cardiac imaging studies warrant increased surveillance (at least every 6 months) and should prompt initiation of pharmacological therapy, irrespective of the age at which they are detected.
Consideration should be given to the use of angiotensin-converting-enzyme inhibitors as first-line therapy. Beta blockers and diuretics are also appropriate, and published guidelines should be followed for the management of heart failure.
Signs or symptoms of abnormalities of cardiac rhythm should be promptly investigated with Holter or event monitor recording and should be treated. Sinus tachycardia is common in DMD, but is also noted in systolic dysfunction. New-onset sinus tachycardia in the absence of a clear cause should prompt assessment, including that of left-ventricular function.
Individuals on glucocorticoids need additional monitoring from the cardiovascular perspective, particularly for hypertension, which might necessitate adjustment in the glucocorticoid dose. Systemic arterial hypertension should be treated.
Prevention of systemic thromboembolic events by anticoagulation therapy can be considered in severe cardiac dysfunction, but is inappropriate in earlier cardiac dysfunction.
Nutritional, Swallowing, Gastrointestinal, and Speech and Language Management
As the condition progresses, access to a dietitian or nutritionist, a swallowing/speech and language therapist, and a gastroenterologist is needed for the following reasons: (1) to guide the patient to maintain good nutritional status to prevent both undernutrition/malnutrition and being overweight/obese, and to provide a well-balanced, nutrient-complete diet (adding tube feeding, if necessary); (2) to monitor and treat swallowing problems (dysphagia) to prevent aspiration and weight loss, and to assess and treat delayed speech and language problems; and (3) to treat the common problems of constipation and gastro-oesophageal reflux with both medication and non-medication therapies.
Maintaining good nutritional status, defined as weight for age or body-mass index for age from the 10th to 85th percentiles on national percentile charts, is essential. Poor nutrition can potentially have a negative effect on almost every organ system. Anticipatory guidance and prevention of undernutrition/malnutrition and being overweight/obese should be goals from diagnosis throughout life. The monitoring and triggers for referral to an expert dietitian/nutritionist in DMD are described in the box below. Diet should be assessed for energy, protein, fluid, calcium, vitamin D, and other nutrients. The panel recommends that each patient should receive a daily multivitamin supplement with vitamin D and minerals. If this is not general practice, a computer nutrient analysis of the patient's diet can provide evidence for the possible need for specific foods or nutrient supplements. If there is a suspicion of undernutrition/malnutrition and poor intake, serum vitamin concentrations can be obtained and supplements could be recommended. Nutritional recommendations with regard to bone health are shown in Figure 1 of the original guideline document.
Improving Underweight and Overweight Status
Monitor regularly for:
- Linear height in ambulatory patients (measured every 6 months)
- Arm span/segmental length in non-ambulatory patients†
Refer for a nutritional/dietetic assessment:
- At diagnosis
- At initiation of glucocorticoids
- If the patient is underweight (<10th age percentile)‡
- If the patient is at risk of becoming overweight (85th–95th age percentile)‡
- If the patient is overweight (>95th age percentile)‡
- If there has been unintentional weight loss or gain
- If there has been poor weight gain
- If major surgery is planned
- If the patient is chronically constipated
- If dysphagia is present
National guidelines and recommendations for diets for underweight and overweight individuals can be found in Kleinman RE, ed. Pediatric nutrition handbook (6th ed). Elk Grove Village, IL: Academy of Pediatrics Press, 2009, and are often available from charities/associations for cardiac disorders and diabetes.
*In non-ambulatory patients, wheelchair weight should be obtained first, then patient and wheelchair weight, or caregiver weight should be obtained first, then the weight of the patient held by the caregiver.
†If the patient has scoliosis, the arm span should be measured if possible.
‡Overweight/underweight status should be judged on the basis of local body-mass index percentiles (weight for age is a possible alternative if height is unavailable). Body composition is altered in Duchenne muscular dystrophy (DMD) owing to the relatively low lean body mass seen in DMD with a relatively higher fat body mass.
Clinical swallowing examination is indicated if there is unintentional weight loss of 10% or more or a decline in the expected age-related weight gain. Prolonged meal times (>30 min) or meal times accompanied by fatigue, excessive spilling, drooling, pocketing, or any other clinical indicators of dysphagia make referral necessary, as do persistent coughing, choking, gagging, or wet vocal quality during eating or drinking. An episode of aspiration pneumonia, unexplained decline in pulmonary function, or fever of unknown origin might be signs of unsafe swallowing, necessitating assessment. There might be contributory factors for weight loss due to complications in other systems, such as cardiac or respiratory compromise.
A videofluoroscopic study of swallowing (also referred to as a modified barium swallow) is necessary for patients with clinical indicators of possible aspiration and pharyngeal dysmotility. Swallowing interventions and compensatory strategies are appropriate for patients with dysphagia. These should be delivered by a speech and language pathologist, with training and expertise in the treatment of oral-pharyngeal dysphagia, who can assess the likely appropriateness of interventions and deliver an individualised dysphagia treatment plan with the aim of preserving optimum swallowing function.
When it is no longer possible to maintain weight and hydration by oral means, gastric-tube placement should be offered. Discussions between other specialists and the family should involve explanations of the potential risks and benefits of the procedure. A gastrostomy can be placed endoscopically or via open surgery, taking into account anaesthetic and ethical considerations and family and personal preference.
Stool softeners, laxatives, and stimulants are necessary if the patient has acute constipation or faecal impaction, and use of enemas might be needed occasionally. Daily use of laxatives, such as milk of magnesia, lactulose, or polyethylene glycol, is necessary if symptoms persist. In the case of persistent constipation, adequacy of free fluid intake should be determined and addressed. In cases of faecal impaction, manual/digital disimpaction under sedation or general anaesthesia is of uncertain benefit. Enemas; stimulant laxatives, such as dulcolax and senna; and stool softeners can be tried before considering manual disimpaction. Milk and molasses enemas are not recommended for paediatric patients. Supplementation with dietary fibre for chronic or severe constipation might worsen symptoms, particularly if fluid intake is not increased.
Gastro-oesophageal reflux is typically treated with proton-pump inhibitors or H2 receptor antagonists, with prokinetics, sucralfate, and neutralising antacids as adjunctive therapies. Common practice is to prescribe acid blockers in children on corticosteroid therapy or oral bisphosphonates to avoid complications such as gastritis and to prevent reflux oesophagitis. It is necessary to recommend nutritional interventions for a patient who has symptoms suggestive of reflux.
Speech and Language Management
Referral to a speech and language pathologist for assessment and treatment is necessary on suspicion of difficulties with speech acquisition or with continuing deficits in language comprehension or oral expression. Oral motor exercises and articulation therapy are necessary for young boys with DMD with hypotonia and in older patients who have deteriorating oral muscle strength and/or impaired speech intelligibility. For older patients, compensatory strategies, voice exercises, and speech amplifications are appropriate if intelligibility deteriorates due to problems with respiratory support for speech and vocal intensity. Voice output communication aid assessment could be appropriate at all ages if speech output is limited.
Effective pain management requires accurate determination of the cause. Interventions to address pain include physical therapy, postural correction, appropriate and individualised orthoses, wheelchair and bed enhancements, and pharmacological approaches (e.g., muscle relaxants and anti-inflammatory medications). Pharmacological interventions must take into account possible interactions with other medications (e.g., steroids and non-steroidal anti-inflammatory drugs) and their side-effects, particularly those that might negatively affect cardiac or respiratory function. Rarely, orthopaedic intervention might be indicated for intractable pain that is amenable to surgery. Back pain, particularly in the context of glucocorticoid treatment, is an indication that a careful search for vertebral fractures is needed; such fractures respond well to bisphosphonate treatment and/or calcitonin.
There are several condition-specific issues that need to be taken into account for the planning of safe surgery. Surgery in a patient who has DMD should be done in a full-service hospital that has experience of patients with DMD. In addition, as with any situation in which patients are on chronic corticosteroid treatment, consideration needs to be given to steroid cover over the period of surgery.
The exclusive use of a total intravenous anaesthetic technique is strongly recommended owing to the risk of malignant hyperthermia–like reactions and rhabdomyolysis with exposure to inhalational anaesthetic agents, such as halothane and isoflurane. Depolarising muscle relaxants, such as suxamethonium chloride, are absolutely contraindicated owing to the risk of fatal reactions.
To minimise blood loss and its effects intraoperatively in major surgeries, such as spinal fusion, it is necessary to use mildly hypotensive anaesthetics, crystalloid bone allograft, and cell-saver technology. Other interventions, such as the use of aminocaproic acid or tranexamic acid to diminish intraoperative bleeding, can be considered. Postoperative anticoagulation with heparin and/or aspirin is inappropriate. Use of compression stockings or sequential compression for prevention of deep-vein thrombosis might be indicated.
An echocardiogram and electrocardiogram should be done before general anaesthesia. They should also be done if the patient is undergoing conscious sedation or regional anaesthesia if the last investigation was more than 1 year previously or if there had been an abnormal echocardiogram in the preceding 7 to 12 months. For local anaesthesia, an echocardiogram should be done if an abnormal result had been obtained previously.
Preoperative training in and postoperative use of manual and assisted cough techniques are necessary for patients whose baseline peak cough flow is below 270 L/min or whose baseline maximum expiratory pressure is below 60 cm water (these threshold levels of peak cough flow and maximum expiratory pressure apply to older teenage and adult patients). Preoperative training in and postoperative use of non-invasive ventilation is strongly recommended for patients with a baseline forced vital capacity of below 50% predicted and necessary with a forced vital capacity of below 30% predicted. Incentive spirometry is not indicated owing to potential lack of efficacy in patients with respiratory-muscle weakness and the availability of preferred alternatives, such as mechanical insufflation–exsufflation. After careful consideration of the risks and benefits, patients with significant respiratory-muscle weakness might be eligible for surgery, albeit with increased risk, if these patients are highly skilled preoperatively in the use of non-invasive ventilation and assisted cough.
Because of the involvement of different systems in DMD, many factors must be taken into account on presentation of a patient to an emergency room. From the outset, the diagnosis, current medication, respiratory status, cardiac status, and associated medical disorders should be made clear to the emergency-room staff. Because many health professionals are not aware of the potential management strategies available for DMD, the current life expectancy and expected good quality of life should also be explained to reduce the risk of therapeutic nihilism in acute care. Chronic glucocorticoid use (if relevant) needs to be made clear, with its concomitant risk of reduced stress response, masking of infection, and possible gastric ulceration. Risk of respiratory failure supervening during an intercurrent infection is high in those with borderline respiratory function. Care in the use of opiates and other sedating medication is essential, as is care in the use of oxygen without ventilation owing to the risk of hypercapnia. If nocturnal ventilation is already being used, then access to the ventilator is essential during any acute event or intervention. For patients who are already using ventilation, the team involved in the respiratory care of the patient should be contacted as soon as possible. Awareness of the risk of arrhythmias and cardiomyopathy is important. Anaesthetic issues, as previously discussed, need to be taken into account at all times if surgery or sedation is needed.