Sleep Disordered Breathing in Neuromuscular Disease

Philip Davies

April 2015

BrainBrain stemSpinal cord

Anterior horn cell

Nerve

Neuromuscular junction

Muscle

Multisystem disordersAtaxias Metabolic/ MitochondrialChanelopathies/ storage disorders

SMA

Demylinating/AxonalNeuropathy

Myasthenia's

DystrophyMyopathy

Duchenne’s Muscular Dystrophy

• Progressive weakness of proximal muscles

• Falling / fatigue / motor delay / deterioration

• Muscle contractures / skeletal abnormalities

• Learning difficulties / behavioural problems

Respiratory Problems

• Restrictive lung defect

• Atelectasis

• Poor cough

• Bulbar problems

Sleep

• Loss of higher control• Reduced chemoreceptor feedback• Reduced cortical arousal • Reduced muscle tone

• Sleep cycles

• Fall in tidal volume• Elevation in CO2 and mild fall in O2 worse in REM

Obstruction

• Anatomical Blockage – Soft tissue – Bony obstruction

• Reduced airway tone– Poiseuille’s law

Central Hypoventilation

• Poor control of breathing

• Weakness– Central – Peripheral

• Symptoms Sleep fragmentation

Tiredness / hyperactivityRestlessnessDay time sleepinessMorning headachesAnorexia

• Mellies et al (2003)

PSG, Peak inspiratory pressures, inspiratory vital capacity, detailed questionnaire

35/49 had sleep disordered breathing 24/49 had nocturnal hypercarbia

Sleep disordered breathing associated with vital capacity <60%Nocturnal hypercarbia with vital capacity <40%

Peak inspiratory pressure correlated with above

Questionnaire not associated with sleep disordered breathing or nocturnal hypercarbia.

Philips 1999

Survival correlates with:• Daytime CO2• Vial Capacity• Night time saturations

Monitoring

• Spirometry – >60% FVC – low risk for SBD– <40% FVC high risk Wallgren-Petterson

2004

Longitudinal studies suggest FVC declines 2-39%/year median 8%

Sleep studies

• Oximetry• Oximetry plus capnography• “Respiratory studies”• Polysomnography

• Night time only• “Normal” by day• Cheap• Variable tolerance• Facial shape

Mask / Non-invasive ventilation

• Experienced team

• Good education for the child and family• Psychology support • Backup for when problems arise

• Start low and titrate• Mask fitting – not too tight

Starting NIV

Lots of Choice!

Interface is crucial

Complications

Leakage – sore eyes

Ventilator alarms

Gas distension of stomach

Face shape

Pressure sores – best treated early

Malocclusion

Mid-facial flattening

Pressure Sore

Non-invasive ventilation

• Annane 2007- Cochrane reviewEvidence was not clear cut in terms of symptoms, QOL, hospital admissions,

mortality or cost effectiveness but could reduce hypoventilation.

Evidence based on case studies, non-randomised studies and comparisons with historical data.

• Widely used ? Unethical not to offer this

Eagle et al Neuromusc Dis 2002

Trends in survival in DMD- secular trends

• Vianello 1994

• 10 patients with DMD and daytime hypercarbia

• All were offered NIV but half refused

• After two years all on NIV were alive whilst 4/5 who refused had died of respiratory failure.

Simonds Thorax 1998

Mellies 2003

Mellies 2003

Reduce infections• 3 studies – 59 children

• Year before ventilation– 2-4 admissions– 40-50 days

• Year after ventilation– 1 admission– 10days admitted

• Less PICU

Ward Thorax 2005

When to start ventilation?

• Raphael 1994

70 patients with DMD with no daytime hypercarbia

FVC 20-50%

Prophylactic NIV started randomised basis

10 died in NIV group just 2 in control (p=0.05)

Mouthpiece Ventilation

Tracheostomy / Invasive Ventilation

• Day and night• More effective• Greater risk?• Voice• Care package • Delay discharge• Expensive

Invasive Ventilation

DMD in Denmark

• DMD patients: 80 in 1977 170 in 2006 May double over next 20 years

• A review of 15 patients with DMD in Denmark found that 8 died of long standing cardiac disease, 2 had sudden deaths presumed cardiac. 2 died of complications with chest infections, 2 died following abdominal surgery and 1 had a peptic ulcer haemorrhage.

Quality of life: A step too far ?

NIV vs Invasive ventilation

• “The ordinary adult DMD patient states his quality of life as excellent; he is worried neither about his disease nor about the future. His assessment of income, hours of personal assistance, housing, years spent in school and ability to participate in desired activities are positive. Despite heavy immobilization, he is still capable of functioning in a variety of activities that are associated with normal life.”

Rahbek 2005

Palliative Care

• Changing role

• Process over a period of time

• Different conditions, different role

Summary

• Sleep disordered breathing common• Detection by screening• Ventilation in neuromuscular conditions

– Can prolong life– Improve physiology– Improve quality of life– Reduce infections (and help survive them)– Improve symptoms