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 2005;25:1035-31 % YEARS 8.9%

3. Demographics: Paediatric Resp Support (France) CF BPD KS NMD 33% n=263 Fauroux & Lofaso ERJ 2001

4. Initiation of NIV in NMD children Simonds et al 2000 ERJ N=40

5. Impact of treatment trends in Duchenne MD Jeppesen J Neuromusc Dis 2003;13:804-12

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 2003;22:631-4

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-skeletal disease: trial design Ward S et al Thorax 2005;60:1019-24

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 > 6.5 kPa Worsening symptoms of nocturnal hypoventilation Recurrent RTIs (>3/yr) Failure to thrive Acute ventilatory decompensation

15. Results Group 1 Control Randomised to follow-up n=12 Group 2 Randomised to NIV n=14 Group 3 Elective NIV n=19 3 drop outs 2 F/U elsewhere 2 drop outs Completed 24 mths NIV n=16 Completed 24 mths n=12 Completed 24 mths n=10 Fulfilled criteria for NIV and -failed F/U n=9 Continued NIV n=9 Elected not to receive NIV n=3 Completed 24 months without NIV n=1 Required emergency NIV n=2

16. Nocturnal SaO2 and TcCO2 in control and NIV groups Significant reduction in time TcCO2 > 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 = < 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% <60% SDB onset 91 89 97 <40% ContinHV 94 79 98 <25% dVF 92 93 96 PiMax mmHg <34 SDB onset 82 89 85 <30 ContinHV 95 65 80 <26 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 2001:29:2097

21. Inspiratory versus expiratory muscle strength (SMA/DMD) Normal: Insp/Exp strength ratio <1.0 M.Chatwin et al 2004: Supported by Jennifer Trust for SMA

22. 800 Females Males 700 600 500 Cough Peak Flow (L/min) 400 300 200 100 0 4 6 8 10 12 14 16 18 20 Age (years) Cough Flows vs. Age y = 30.87x – 9.11 r = 0.78, p<0.001 Airen M et al. Am J Respir Crit Care Med 169:A896; 2004

23. Breath Stacking Manual / Mechanical Insufflation Manually Assisted Cough L/sec 6.0 cmH2O 50 5.0 40 4.0 Flow rate Subglottic pressure 30 3.0 2.0 20 1.0 10 0.1 sec 0 0.0 Mechanical Insufflation / Exsufflation 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 Paediatricgroups 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 2003;21:502

26. Most uncomfortable Most comfortable Chatwin et al ERJ 2003;21:502

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