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]