Duchenne Muscular Dystrophy (Pseudohypertrophic Muscular Dystrophy)

X-linked recessive; 1:3500 live male births; few known cases in females.

Often undiagnosed until age 3–5 y; periop complications can occur before diagnosis.

Deterioration through puberty to death usually before age 25 y.

Periop risks may be present in female carriers.

Respiratory failure, prolonged mechanical ventilation

Cardiac failure (CHF or arrhythmias)

Hyperkalemia and rhabdomyolysis

Poor cardiac contractility, dilated cardiomyopathy, cardiac arrhythmias, pulm Htn from sleep apnea, MVP

Poor respiratory function, restrictive lung disease from scoliosis, chronic pneumonia

Aspiration risk from gastroparesis and dysphagia

Possible hyperkalemic arrest with succinylcholine and volatile agents

Associated with malignant hyperthermia-like syndrome unresponsive to dantrolene

Most boys die from pneumonia, but heart failure is usually present by adolescence.

Gradual onset of muscle wasting, replaced by fat/fibrosis, causing pseudohypertrophy.

Hyperkalemic response to depolarizing NMBs may develop years before the onset of DMD symptoms; the prediagnosis infant may present with only mild gross motor delay.

Increased sensitivity to nondepolarizing NM blockers.

Use of Ca ²⁺ -channel blocker (e.g., verapamil) may prolong or even cause NMB.

Resting tachycardia common; cardiac involvement in 70% of cases, cardiac debilitation usually late.