Management

1
Management

• Airway clearance
• Ineffective airway clearance can accelerate the
  onset of respiratory failure Bach et al 1997
• Peak cough flows lt 160 L/min ? ineffective airway
  clearance Bach and Saporito 1996
• DMD Peak cough flow lt 270 L/min or MEP lt 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

2
Peak cough flow in NMD children
C
C
NMD
NMD
a,c unassisted cough b,d insufflation/exsuffla
tion cough
Chatwin et al 2003
3
Chatwin et al 2003
aped NMD bped control cadult NMD dadult
control
UAC unassisted cough PAC physiotherapy
assisted cough EAC exsufflation assisted
cough IEAC insufflation-exsufflation assisted
cough
4
Patient with SMA using the MI-E via a mouthpiece
Miske, L. J. et al. Chest 20041251406-1412
5
Left, A chest radiograph of 22-month-old girl
with SMA type I and right upper lobe density
Miske, L. J. et al. Chest 20041251406-1412
6
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

7
Chest cuirass
8
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

9
Management

• NIPPV indication
• Daytime hypercapnia (PCO2gt50 mmHg) ATS consensus
  2004, European Consortium 1996
• Nocturnal hypoventilation (PCO2gt50 mmHg and/or
  hypoxemia (lt92)
• 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