here - SBS Documents

Dr I Hadjikoumi, Dr S Jheeta, Dr M McGowan
Dept of Developmental Paediatrics,
St George’s Hospital, London
11 th World Down Syndrome Congress,
Cape Town,
15-17 Aug 2012.

Background Q&A
1. What is it?
2. How common is it?
3. What are the symptoms of obstructive sleep apnoea
(OSA)?
4. Why is it important in Down Syndrome (DS)?
5. Can it be treated?
6. How can we screen and investigate?

What is it?
• Upper airway at the back of the throat becoming
blocked repeatedly during sleep
• When this happens, breathing stops for a short time
• These interruptions in breathing (apnoeas) may
occur hundreds of times during the night causing
sleep disruption and poor quality sleep.

What does it look like?
During sleep:
• characteristic abnormal pauses in breathing
OR
• instances of abnormally low breathing

Symptoms of OSA
• Mouth breathing
• Snoring
• Nocturnal pauses in breathing
• Gasping
• Restless sleep
• Frequent waking
• Extended neck posture on sleeping
• Difficulties in waking in morning
• Daytime sleepiness
• Behavioural difficulties
• Bedwetting
• Poorly controlled epilepsy
• Failure to thrive

How common is it?
• General paediatric population
• 0.7 – 2%
• Down syndrome
• 30-60%
• 97% of those who snore in recent study from Sydney,
Australia

Why is it common in DS?
• Anatomical abnormalities
• Narrow nasopharynx
• Shortened palate
• Midfacial hypoplasia
• Small jaw
• Large tongue
• Generalised hypotonia
• Immature immune system

Co-existing conditions
• Tendency to obesity
• Chronic lung disease
• Gastro-oesophageal reflux
• Congenital heart disease

Consequences of untreated OSA
• Pulmonary hypertension
• Cardiac strain secondary to lung problems
(cor pulmonale)
• Behavioural problems
• Poor academic performance
• Failure to thrive

Screening and Investigation
• Clinical history
• Oximetry- measurement of
blood oxygen levels
• Capnography- measurement
of blood CO2 levels
• Polysomnography- O2,
CO2, eye movements,
airflow, brain activity, chest
movement and video

St George’s Hospital Study Stages
• Stage 1. 2007: Initial study prevalence and
symptoms
• Stage 2. 2010: Repeat study of symptoms and
inclusion of oximetry +/- polysomnography
2009: RCPCH guideline
• Stage 3. 2011: New proforma, all offered oximetry,
capnography +/- polysomnography

Stage 1
• SGH 2007-2009
• To determine prevalence and symptom frequency in
outpatient setting

Retrospective analysis
• 44 patients
• Clinic case notes or telephone questionnaire
• Targeted pulse oximetry for those with 3 or more
symptoms

Questionnaire
• Snoring
• Mouth breathing
• Nocturnal pauses in breathing
• Restless sleep
• Frequent waking
• Extended neck posturing in sleep
• Gasping
• Waking difficulties in the morning
• Daytime somnolence
• Poorly controlled epilepsy
• Failure to thrive
• Enuresis

Results
• 16% - diagnosed OSA by ENT
• Of those without documented symptoms in notes (21/24)
had symptoms identified in telephone questionnaire
• 20% - 3 or more symptoms
• 34% - 1 or more symptoms

Pulse oximetry studies
• 10 studies done
- 8/10 from the 3+symptom group
• All normal
-3/10 had frequent desaturations between 95-97%
Learning points:
• Improve documentation of symptoms
• Oximetry easy to perform, identifies high risk patients
(more than 3 desaturations

Stage 2- repeat questionnaire
• 8 patients with 3 or >3 symptoms contacted with same
questionnaire 12 months later
• 3/8 reported still had >3 symptoms
• These 3 patients referred for polysomnography at
Great Ormond Street Hospital
• All 3 polysomnography reports normal
Learning points:
1. Only 3/8 symptoms persisted after 12 months
2. Questionnaire validity
3. No evidence of OSA in any of patients (0/10)

RCPCH Guideline on Sleep Related
Breathing Disorders 2009
• Clinical history is a sensitive screen but low specificity
• Pulse oximetry is a useful screen but “if positive is highly
predictive, but a negative result does not exclude OSA”
1. All children with DS should be offered screening using as
least pulse oximetry
2. Screen once in infancy and then annually until age
5yrs
3. Children with abnormalities in screening or strong
suspicion of false negatives should then have
polysomnography (oximetry, airflow, effort capnography
and video if possible)

2011: Implementation at SGH
• Following publication of RCPCH guideline, a new
proforma for screening of OSA was implemented
• Clinic checklist modified

New Proforma
3 months 6 months 12 months 2 years
Date: Date: Date: Date:
Exact age: Exact age: Exact age: Exact age:
Growth
Height:
Weight:
Centile
Centile
Vision:
Growth
Height:
Weight:
Centile
Centile
Vision – Clinical
Examination/ Visual
Behaviour
Growth
Height:
Weight:
Centile
Centile
Growth
Height:
Weight:
Centile
Centile
Vision – Full Ophthalmology
Assessment
Neonatal Hearing Screen Full Audiological Assessment Audiology Review
Neonatal TSH Screen
Checked? – Yes/No
Heart
Thyroid Screening
Thyroid Screening
Other Medical Problems: Other Medical Problems: Other Medical Problems: Other Medical Problems:
Areas of Developmental concern Areas of Developmental concern Areas of Developmental concern Areas of Developmental concern
Discuss DLA/Benefits
Formal Notification of SEN to
Education
Symptoms of OSAS Symptoms of OSAS Symptoms of OSAS
Oximetry/ Sleep Studies
Oximetry/ Sleep Studies

Sleep Apnoea Down Syndrome Study
Under 5
History
Telephone
Normal
Questionnaire and
Sleep Study at
Home
With Capnography
(Up to X2)
Low
Suspicion
High
Suspicion
Abnormal
Annual Screen
Joint Respiratory Clinic
ENT Polysomnography Other

Stage 3 – Analysis in Outpatient setting
• Screening

Telephone questionnaire n=10
• 3 patients - no symptoms of OSA
• 7 patients- between 1-9 out of a possible 12
symptoms
• Mean no of symptoms =2
• Commonest symptoms: mouth breathing and
snoring.

All offered Capnography Sleep Study
• 3 x parental declined
• 2x cancelled by parents
n=10
• 5 sleep studies performed
• 5/5 “poor data” and none showed abnormal CO2
levels or desaturations
Learning Points
1. Parents declined, why?
2. Poor quality of results, why?

Equipment used
• TOSCA 500 device
used for home
monitoring
• Cost of machine and
probes approx £4500
• New probes needed per
patient approx £30
applied to earlobe
• Cost of 1x inpatient
admission

Study limitations
• Small numbers
• Nurses/parents not familiar with using the TOSCA
500
• Co-operation difficult in this population
(developmental delay, young age, uncomfortable
probes)

Criteria for a screening programme
• Important health problem
• Well understood natural history of condition
• There should be a detectable early stage
• Early stage treatment more beneficial than late stage
• Test possible in early stage
• The test should be acceptable
• Intervals for repeating the test should be determined
• Adequate health service provision
• The risks, both physical and psychological, should be less
than the benefits
• The costs should be balanced against the benefits
WHO 1968

Does OSA screening in DS fit these
criteria?
• Screening tool technically difficult?
• Uncertainty about treatment
• Natural history of condition not well understood
• Acceptability?

Questions
• Is capnography useful screening tool for OSAS?
• Sensitivity/ specificity of TOSCA 500
• Why were results unobtainable?
• Technique?
• What other tools can be used in screening?
• Devise more reliable scoring system relating to
severity of symptoms
• Cost vs benefit

What is next?
• Accurate scoring of clinical symptoms needed
• Which symptoms have more weight?
• Larger numbers
• Multi centre studies to create best screening tool
• Retrospective study in polysomnography centre
• Study to correlate symptoms, polysomnography
and clinical evolution
• ?Role of sleep nasendoscopy to evaluate
obstruction

Conclusion
- Need for robust data from multi centre studies to
identify best screening tool for OSA
- And if we find a good screening tool, then what
do we do about it?

References
1. Nixon GM, Kermack AS, Davis GM, Manoukian JJ.
Planning Adenotonsillectomy in children with obstructive
Sleep Apnoea: Thee role of overnight pulse oximetry.
Paediatrics. 2004:113: 19-25
2. Caulfield, H. Investigations in paediatric obstructive
sleep apnoea:do we need them? Int Journal of Pediatric
Otorhinolarynogology (2003) 67s1, s107-110.
3. RCPCH Working Party on Sleep Physiology and
Respiratory Control Disorders in Childhood. Sept 2009

Acknowledgements
• Dr R Chavasse- Consultant Paediatric Respiratory Medicine, SGH
• Dr Kilner –Consultant Paediatric Respiratory Medicine, GOSH
• Dr Suzanne Crowley- Consultant Paediatric Respiratory Medicine
• Dr Christos Tzivinikos- ST Paediatrics
• Dr Helen Wolfenden- ST Paediatrics
• Dr Sian Jenkins – ST Paediatrics
• Dr Lauren Filby – ST Paediatrics