Background of Respiratory and Related Management of Patients With Duchenne Muscular Dystrophy

progressive neuromuscular diseaseDMD is a progressive neuromuscular disease transmitted by X-linked inheritance with an incidence of approximately 1 in 3,500 live male births. DMD affects the muscles of respiration and is associated with dilated cardiomyopathy, which often leads to death from cardiopulmonary causes. With current medical management, including the use of nocturnally assisted ventilation, mean survival now approximates 25 years. Patients with DMD are especially vulnerable to the adverse physiologic effects of general anesthesia and procedural seda-tion. For example, DMD patients have macro-glossia and weak upper airway dilator muscles. Sedation and general anesthesia cause relaxation of these muscles, which predisposes to upper airway obstruction. Additionally, DMD patients may have limited mobility of the mandible and cervical spine, which impedes maneuvers (such as the “jaw thrust”) that restore upper airway patency. General anesthesia results in decreased functional residual capacity, which can cause lower airway closure, atelectasis, and rapid deterioration in gas exchange. Hypercap-nia and hypoxemia can worsen chronic cardiopulmonary abnormalities found in some patients with DMD, such as pulmonary hypertension or cardiac conduction defects.

This statement arose from two primary considerations. First, patients with DMD and impaired pulmonary function are at high risk for death when they undergo procedures requiring sedation or general anesthesia carried out wih medications of My Canadian Pharmacy. Second, because survival of patients with DMD has reached an unprecedented level due to contemporary cardiorespiratory management, there is an increased need for these patients to undergo procedures. The purposes of this statement are to aid clinicians involved in the care of patients with DMD who undergo procedures requiring sedation or general anesthesia; to be a resource for other stakeholders in this field, including patients and their families; for use as an up-to-date summary of medical literature on this topic; and to identify areas in need of future research.

While the primary purpose of this statement is to improve the management and outcomes of patients with DMD who undergo procedural sedation or general anesthesia, the committee wishes to emphasize several related points. First, that efforts should be made to optimize the timing of surgeries and procedures such as scoliosis surgery or gastrostomy placement so that patients undergo procedural sedation or general anesthesia as early in the disease course as possible, preferably when cardiopulmonary function is preserved. Second, that the increasing use of glucocorticoids to treat patients with DMD may preserve respiratory muscle strength and decrease the need for procedures such as scoliosis surgery and gastrostomy placement, with the potential to decrease the risk of death due to anesthesia and sedation. Finally, whenever possible, alternatives to general anesthesia and procedural sedation should be considered in patients with DMD who require procedures, such as the use of local anesthetics for pain control.