COMPLEX NEURODISABILTY AND NEUROMUSCULAR DISEASE: Respiratory Management and Investigations

1. COMPLEX NEURODISABILTY AND NEUROMUSCULAR DISEASE:Respiratory Management and Investigations Don Urquhart MD, MRCPCH Consultant in Paediatric Respiratory and Sleep Medicine Royal Hospital for Sick Children Edinburgh SEAT Physiotherapy Study Day Thursday 10th November 2011

2. Complex Neurodisability Scenarios where assessment required Assessment options Management of acute and chronic respiratory deterioration in children with complex neurodisability Neuromuscular Disease Methods of assessment From what age? Management of respiratory failure Child-centred approach OBJECTIVES

3. COMPLEX NEURODISABILITYAssessment • Scenarios where assessment required • Acutely unwell/respiratory deterioration • Prior to major surgery i.e. scoliosis • Sleep-disordered breathing/obstruction

4. COMPLEX NEURODISABILITYAcutely Unwell • RD • 6 year old girl • Chromosomal anomaly • Severe developmental delay • Increased work of breathing • SpO2 87% on room air

5. COMPLEX NEURODISABILITYAcutely Unwell • What investigations would you order? • What treatment options might you consider?

6. COMPLEX NEURODISABILITYAcutely Unwell • What investigations would you order? Chest X-ray Blood gas

7. CHEST X-RAY

8. CHEST X-RAY Dense LLL collapse

9. BLOOD GAS Blood gas: pH 7.22 pCO2 10.3 Bicarbonate 36 BE +13

10. COMPLEX NEURODISABILITYAcutely Unwell • What investigations would you order? • What treatment options might you consider?

11. COMPLEX NEURODISABILITYAcutely Unwell • What treatment options might you consider? Antibiotics Oxygen Physiotherapy Mucolytic agents Ventilatory support

12. COMPLEX NEURODISABILITYAcutely Unwell • Antibiotics Based on previous or known cultures • Oxygen • Physiotherapy • Mucolytic agents • Ventilatory support

13. COMPLEX NEURODISABILITYAcutely Unwell • Antibiotics • Oxygen May need to limit flow in setting of type II failure • Physiotherapy • Mucolytic agents • Ventilatory support

14. COMPLEX NEURODISABILITYAcutely Unwell • Antibiotics • Oxygen • Physiotherapy • Secretion management • Airway clearance • Mucolytic agents • Ventilatory support

15. COMPLEX NEURODISABILITYAcutely Unwell • Antibiotics • Oxygen • Physiotherapy • Mucolytic agents • DNase • Hypertonic saline • N-acetyl cysteine • Ventilatory support

16. COMPLEX NEURODISABILITYAcutely Unwell • Antibiotics • Oxygen • Physiotherapy • Mucolytic agents • Ventilatory support • Prior to physiotherapy to augment airway clearance • Bi-level ventilation to assist ventilation

17. COMPLEX NEURODISABILITYPre-operative scoliosis work-up • Scoliosis in a healthy child • Pre-op work-up would include: • Lung Function Testing • Exercise Capacity • Clinical evaluation

18. COMPLEX NEURODISABILITYPre-operative scoliosis work-up • RJ • Quadriplegic Cerebral Palsy • Epilepsy • Global developmental delay • Progressive neuromuscular scoliosis How do we obtain a functional lung assessment on which to estimate risk of major surgery?

19. COMPLEX NEURODISABILITYPre-operative scoliosis work-up • Sleep Study: • During sleep have falls in both respiratory rate and also tidal volume (i.e. reduced VE) • Relative hypoventilation vs. awake • Respiratory system under stress • Blood Gas:- Indicator of any CO2 retention • Chest X-ray: - Evaluate lung fields for parenchymal change

20. COMPLEX NEURODISABILITYPre-operative scoliosis work-up • Sleep Study: • Average SpO2 96%. • No significant obstructive or central events were witnessed. • Blood Gas: • pH 7.39 • pCO2 5.5 • BE -0.5

21. CHEST X-RAY

22. CHEST X-RAY Thoracolumbar scoliosis Small volume lung fields

23. COMPLEX NEURODISABILITYUpper Airways Obstruction • JB • 6-year old boy • Cerebral palsy • Night-time snoring ++ • Frequent arousals • Fragmented sleep • Poor concentration at school

24. COMPLEX NEURODISABILITYUpper Airways Obstruction • Admitted ward 1 • Sleep Study arranged

25. SLEEP STUDY

26. OBSTRUCTIVE SLEEP APNOEA

27. OBSTRUCTIVE SLEEP APNOEA Clusters of SpO2

28. OBSTRUCTIVE SLEEP APNOEA Apnoea Apnoea Hypopnoea Hypopnoea Hypopnoea

29. OBSTRUCTIVE SLEEP APNOEAWhat treatment can we offer? • Treatment • 75-100% improve with T&A’s • AAP Technical Report • Schechter et al. Pediatrics 2002 • Success rates much lower if comorbidities • CPAP therapy • Airway adjuncts Waters et al. Am J Respir Crit Care Med 1995

30. OBSTRUCTIVE SLEEP APNOEAPost-adenotonsillectomy

31. COMPLEX NEURODISABILITYAcute Upper Airways Obstruction • JG • 10-year old boy • Unwell child with pneumonia • Secretions +++ • Clamps shut mouth on suctioning • Episodic (but frequent and profound SpO2) Any ideas?

32. NP AIRWAY

33. NP AIRWAY • Bypass obstruction • Tip sits in oropharynx • Conduit for suction • Facilitates airway clearance • PS: Beware the blocked NPA! • Worse than having no adjunct

34. NEUROMUSCULAR DISEASE • Manifold setting of conditions including: • Muscle diseases e.g. myopathies, muscular dystrophies • Nervous system disorders e.g. Spinal muscular atrophy • Myotonic dystrophy Etc.

35. NEUROMUSCULAR DISEASE • Illustrative condition chosen = DMD • Duchenne Muscular Dystrophy • X-linked disease affecting 1 in 3000 boys • Mutation in dystrophin gene (Xp21) • ‘Dystrophin’ is essential protein for muscle structure • Progressive and relentless muscle weakness • Weakness begins in first decade • Wheelchair-bound by aged 10 years • Respiratory muscle weakness by aged 15-20 years • Poor cough clearance predisposes to infection • Eventual compromise to ventilation during sleep

36. NEUROMUSCULAR DISEASE • Neuromuscular Disease • Methods of assessment • From what age? • Management of respiratory failure • Child-centred approach

37. DUCHENNE MUSCULAR DYSTROPHYMethods of assessment • Lung Function • Respiratory Muscle Pressure • Cough Peak Flow • Sleep Study

38. DUCHENNE MUSCULAR DYSTROPHYMethods of assessment • Lung Function • Respiratory Muscle Pressure • Cough Peak Flow • Sleep Study

39. SPIROMETRY

40. SPIROMETRY FLOW-VOLUME LOOP Allows us to measure lung capacity and airflow

41. SPIROMETRY RESPIRATORY MUSCLE WEAKNESS: Reduces ability to forcibly exhale with reduced airflows and also reduced lung volumes.

42. SPIROMETRYWhy do we do it? Spirometry Measure lung volumes Measure changes in lung volumes over time Can be reliably performed in those aged >5 years SPIROMETRY IS A SURROGATE MEASURE OF RESPIRATORY MUSCLE STRENGTH

43. DUCHENNELung Function • Restrictive lung disease pattern • Decreases in TLC and VC closely linked to level of muscle weakness • Change in VC is important • Track changes in lung function in DMD from aged 10 onwards

44. RESPIRATORY MUSCLES • What are they? • What can we measure? • What do the measurements mean?

45. Sternocleidomastoid A B Scalenes I N S P I R A T I O N E X P I R A T I O N External intercostals C Internal Intercostals F D Parasternal Intercostals External abdominal oblique E Diaphragm G Rectus abdominus H

46. RESPIRATORY MUSCLES • What are they? • What can we measure? • What do the measurements mean?

47. RESPIRATORY MUSCLESWhat can we measure? • Inspiratory muscle pressure monitoring • Sniff Inspiratory Pressure [SnIP] • Mouth Inspiratory Pressure [MIP] aka Pimax • Expiratory muscle pressure monitoring] • Mouth Expiratory Pressure [MEP] aka Pemax • Cough peak flow

48. RESPIRATORY MUSCLESWhat can we measure? ATS/ERS statement on respiratory muscle testing. Am J Respir Crit Care Med 2002; 166: 518-624.

49. RESPIRATORY MUSCLESMIP/MEP methods Maximal pressure measured as average over 1 second around peak pressure MIP MEP

50. RESPIRATORY MUSCLESSnIP methods • Sniff nasal inspiratory pressure (SNIP) measures, from FRC, the nasal pressure in an occluded nostril during a maximal sniff • Values in healthy children similar to healthy adults • SNIP 104+/-26 cmH2O in boys • SNIP 93+/- 23 cmH2O in girls