Management n Airway clearance n n Ineffective airway

Management n Airway clearance n n Ineffective airway clearance can accelerate the onset of respiratory failure [Bach et al 1997] Peak cough flows < 160 L/min → ineffective airway clearance [Bach and Saporito 1996] n DMD: Peak cough flow < 270 L/min or MEP < 60 cm. H 2 O [ATS n 3 types consensus 2004] n n n Manual techniques – glossopharyngeal breathing, air stacking [Kang and Bach 2000] Mechanical techniques – Insufflator-exsufflators [Bach 1994] Mucus mobilization devices – High frequency chest wall oscillator, intrapulmonary percussive ventilation

Peak cough flow in NMD children C C NMD a, c = unassisted cough b, d = insufflation/exsufflation cough Chatwin et al 2003

Chatwin et al 2003 UAC = unassisted cough PAC = physiotherapy assisted cough EAC = exsufflation assisted cough IEAC = insufflation-exsufflation assisted cough a=ped NMD b=ped control c=adult NMD d=adult control

Patient with SMA using the MI-E via a mouthpiece Miske, L. J. et al. Chest 2004; 125: 1406 -1412

Left, A: chest radiograph of 22 -month-old girl with SMA type I and right upper lobe density Miske, L. J. et al. Chest 2004; 125: 1406 -1412

Management n Supplemental oxygen n n REM-related hypoxia May prolong duration of apnea and hypopnea [Smith et al 1989] n Mechanical ventilatory support n Negative pressure ventilation (NPV) n n Plexiglass lung, Cuirass shell, Pulmowrap Collapse of upper airway [Levy et al 1989, Hill et al 1992]

Chest cuirass

Management n Positive pressure ventilation n n Via tracheotomy NIPPV: nasal mask ventilation n Normalize blood gas and alleviate symptoms of hypercapnia [Heckmatt et al 1990, Hill et al 1992] Stabilize declining lung function and prolong life expectancy [Vianello et al 1994] Preventive nasal ventilation

Management n NIPPV indication n Daytime hypercapnia (PCO 2>50 mm. Hg) [ATS consensus 2004, European Consortium 1996] n n Nocturnal hypoventilation (PCO 2>50 mm. Hg and/or hypoxemia (<92%) Timing of initiation of NIPPV remains controversial n n One multi-center study found no evidence of lung function preservation in NIPPV patients [Raphael et al 1994] Those with nocturnal hypoventilation are likely to develop daytime hypercapnia within 2 years [Ward et al 2005]