Management Airway clearance

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]

DMD: Peak cough flow < 270 L/min or MEP < 60 cmH2O [ATS consensus 2004]

3 types 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

Chatwin et al 2003

C C

NMD NMD

a,c = unassisted coughb,d = insufflation/exsufflation cough

a=ped NMDb=ped controlc=adult NMDd=adult control

Chatwin et al 2003

UAC = unassisted coughPAC = physiotherapy assisted coughEAC = exsufflation assisted coughIEAC = insufflation-exsufflation assisted cough

Miske, L. J. et al. Chest 2004;125:1406-1412

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

Management Supplemental oxygen

REM-related hypoxia May prolong duration of apnea and hypopnea

[Smith et al 1989]

Mechanical ventilatory support Negative pressure ventilation (NPV)

Plexiglass lung, Cuirass shell, Pulmowrap Collapse of upper airway [Levy et al 1989, Hill et al

1992]

Chest cuirassChest cuirass

Management Positive pressure ventilation

Via tracheotomy NIPPV: nasal mask ventilation

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 NIPPV indication

Daytime hypercapnia (PCO2>50 mmHg) [ATS consensus 2004, European Consortium 1996]

Nocturnal hypoventilation (PCO2>50 mmHg and/or hypoxemia (<92%)

Timing of initiation of NIPPV remains controversial 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]