Non-invasive ventilation in Neuromuscular disease

1
Non-invasive ventilation in Neuromuscular disease

• Anita K Simonds
• Royal Brompton Hospital
• GoS Course June 8 2006

2
Eurovent study prevalence of home ventilalation
by age Lloyd Owen et al ERJ 2005251035-31

YEARS
8.9
3
Demographics Paediatric Resp Support (France)
CF
BPD
KS
NMD 33
n263
Fauroux Lofaso ERJ 2001
4
Initiation of NIV in NMD children
Simonds et al 2000 ERJ
N40
5
Impact of treatment trends in Duchenne MD
Jeppesen J Neuromusc Dis 200313804-12
6
Survival in Duchenne MD
Eagle et al Neuromuscular Disorders 2002
7
Quality of life in Duchenne MD
8
Quality of life in Duchenne MD
9
Effect of NIV on sleep quality
Mellies U et al ERJ 200322631-4
10
Evolution of sleep disordered breathing
Khan Y et al 1994
11
When to initiate NIV in NMD

• Background NIV can be lifesaving in hypercapnic
  patients. Mean survival 9.7 months in hypercapnic
  DMD patients if ventilatory support not provided
  (Vianello et al, 1997). Survival extended in
  other cohorts (Bach, Eagle, Simonds). Clinical
  course in other NMD not so predictable
• However preventative NIV in asymptomatic
  normocapnic DMD patients is not beneficial
  (Raphael et al, 1995)
• Hypothesis Initiation of NIV at time of
  nocturnal hypoventilation before development of
  daytime hypercapnia will prevent ventilatory
  decompensation and improve qol

12
Prophylactic NIV in Duchenne MD
Control
NIV
Raphael et al Lancet 1994
13
Randomised controlled trial of NIV in nocturnal
hypoventilation in congenital neuromusculo-skeleta
l disease trial design
Ward S et al Thorax 2005601019-24
14
Method

• Gp 1 2
• Median age 18 yr Noct TcCO2 9.15 kPa
• Diurnal PaCO2 5.9 kPa PaO2 10.5 kPa
• DMD, CMD, SMA II, Beals syndr
• A priori safety criteria for Gp 1
• Daytime PaCO2 gt 6.5 kPa
• Worsening symptoms of nocturnal hypoventilation
• Recurrent RTIs (gt3/yr)
• Failure to thrive
• Acute ventilatory decompensation

15
Results
Group 1 Control Randomised to follow-up n12
Group 2 Randomised to NIV n14
Group 3 Elective NIV n19
3 drop outs
2 F/U elsewhere
2 drop outs
Completed 24 mths NIV n16
Completed 24 mths n12
Completed 24 mths n10
Fulfilled criteria for NIV and -failed F/U n9
Continued NIV n9
Elected not to receive NIV n3
Completed 24 months without NIV n1
Required emergency NIV n2
16
Nocturnal SaO2 and TcCO2 in control and NIV groups

Significant reduction in time TcCO2 gt 6.5 kPa and
increase in mean SaO2 in NIV group
17
Results (2)
i.e. 9/10 patients met criteria to receive NIV by
end of study (70 within 1 year)
18
Results Health status
SF 36 General health
Group 3 Group 2 Group 1


BL- Baseline score End - End of trial
score MD mean difference
BL End Md BL End MD BL End MD
P lt 0.05

Group 1 Controls no NIV Group 2 Randomised to
NIV Group 3 Elective NIV
Inference Neuromuscular patients with nocturnal
hypoventilation are likely to progress to daytime
hypercapnia within 12-24 months
19
Predictors of SDB in congenital NMD (Ragette et
al Thorax 2002)

• Predictor Sensitivity Specificity
  AUC
• VC
• lt60 SDB onset 91 89
  97
• lt40 ContinHV 94 79
  98
• lt25 dVF 92 93
  96
• PiMax mmHg
• lt34 SDB onset 82 89
  85
• lt30 ContinHV 95 65
  80
• lt26 dVF 92 55
  81

20
Ventilator mode AC/VT and PS unload the
respiratory muscles
PTPdi (cm H2O.s.min-1)
10 patients mean age 13 years mean FEV1 25
NB Role of trigger crucial
Fauroux et al. Crit Care Med 2001292097
21
Inspiratory versus expiratory muscle strength
(SMA/DMD)
Normal Insp/Exp strength ratio lt1.0
M.Chatwin et al 2004 Supported by Jennifer
Trust for SMA
22
Cough Flows vs. Age
y 30.87x 9.11
r 0.78, plt0.001
Airen M et al. Am J Respir Crit Care Med
169A896 2004
23
Methods to Augment Cough
24
Breath stacking
25
Patients
Controls

750

400
A
C
300
500
PCF L/min
200
250
100
0
0
UAC
PAC
NIV
E
MI-E
UAC
PAC
NIV
E
MI-E
Paediatric groups A C Cough in-exsufflator
D
B
500
1000


400
750
300
500
200
250
100
0
0
UAC
PAC
NIV
E
MI-E
UAC
PAC
NIV
E
MI-E
Adult groups C D
Chatwin et al ERJ 200321502
26
Most uncomfortable
Most comfortable
Chatwin et al ERJ 200321502
27
Transition issues

• May be increasing physical dependency at a time
  of transition
• Planned, gradual transfer to adult services
• No sudden changes in management plan
• Transfer plan from paediatricians identifying
  most important current problems
• Practical issues solved quickly eg. ventilator
  service arrangements, technician phone nos. etc
• Patient and family CHOICE.
• See individual for part of consultation without
  parents
• Transition co-ordinator
• Adolescent clinics

28
Anticipatory Care Plan

• Identify high risk cases
• 6-12 mthly resp assessment symptoms, signs,
  respiratory measurement PFTs, cough PF, sleep
  studies
• Discussion of options for respiratory support and
  timing.
• Negotiated care plan with ceilings and minimums
• Guidance and education for chronic care
• Cough and secretion mgmt
• Hypoventilation identification
• Immunizations, low threshold for antibiotics
• Nutrition and hydration
• Rapid access to specialty medical care
  providers
• Perioperative management plan