Obstructive Sleep Apnoea

Introduction

Obstructive sleep apnoea syndrome (OSA) is a relatively common and potentially serious medical condition in children causing sleep disruption and abnormal physiology (hypertension, tachycardia, hypoxia, inflammation) with potential daytime consequences (sleepiness, mood or behavioral problems, poor attention, learning difficulties, and /or diminished quality of life). It is characterized by intermittent critical airway obstruction resulting from a variable combination of anatomical, muscular (tone) and airway control abnormalities and is at one end of a spectrum of Sleep Disordered Breathing. Obstructive 'events' may be complete (apnoea) or partial (hypopnea) and may or may not be associated with hypoxia. OSA (2-4% of children) can be difficult to differentiate from more mild sleep disordered breathing such as primary snoring (~15-20% of children) by history alone.

Signs and symptoms

History is a valuable tool for screening for OSA though as it occurs only during sleep, the child and other family members may not be aware of breathing problems. REM sleep periods typically occur in the early hours and are both the riskiest and least observed periods of sleep. Audio/video recordings from caregivers can add greatly to clinical insight.

• Snoring - almost universal but non-specific

• Other abnormal noises - gasps, snorts, choking, pauses

• Restless, sweaty or disturbed sleep

• Mouth / mixed breathing

• Unusual positions / postures - neck extension, sleeping with pillows, 'draping' over furniture

• Waking headaches (may indicate sleep hypercarbia)

• Prolonged sleep (to make up for poor quality) and daytime sleepiness

• ADHD symptoms

• Other conditions / syndromes pose particular risk (Downs, craniofacial, Prader Willi syndrome, neuromuscular weakness, obesity).

Standardized questionnaire

Whilst polysomnography remains the (imperfect) gold-standard test for OSA, most children will have clinical diagnoses of OSA or more correctly, Sleep Disordered Breathing, based solely on history. A standardized questionnaire can assist that process though most questions have low individual specificity. The Starship Paediatric Sleep Questionnaire is largely based on the Chervin Paediatric Sleep Questionnaire 22. (Sleep Medicine, 2000). It is intended as an adjunct for the assessment of children and young people with possible sleep disordered breathing and should not be used to 'rule it out.'Chervin et al found that after scoring responses to questions 1-22 with a 1 for "yes" and a 0 for " no" a mean score of >0.33 had a sensitivity 81% of and a specificity of 87% for obstructive sleep apnoea in children aged 2-18 years as defined by polysomnography (AHI>5).

Where the response was "don't know " or "?", the response received no score but the denominator was decreased accordingly. For example an individual whom has 5 yes responses and 13 no responses scores 5/18 or 0.28.While the score does not 'load' responses, the first seven responses were the highest predictors for sleep disordered breathing.

Questionnaire

Access the questionnaire via this link.

This questionnaire is based on the Chervin Paediatric Sleep Questionnaire

Oximetry

As per the NZ Guidelines for Assessment of Sleep-Disordered Breathing in Childhood, whilst not obligatory, oximetry has some role in the investigation and management of childhood OSA. Oximetry is a relatively accessible, available and can be performed in the community by most District Health Boards in New Zealand.  It can be strongly suggestive (up to 97% positive predictive value) and helps plan surgery (prioritisation & peri-operative risk assessment).  It cannot exclude the diagnosis - half of those being assessed for OSA with "normal" or equivocal oximetry studies still have OSA if tested by polysomnography. See Oximetry Guideline.

Level 1 Polysomnography (PSG)

This is the gold standard diagnostic test for OSA in children.  It involves an overnight stay in a sleep laboratory with multiple 'non-invasive' measures of sleep and respiratory physiology.  It is expensive, labour-intensive and relatively scarce.  Additionally, whilst the gold-standard test, the individual impact of OSA is not always well reflected by PSG defined 'severity'.  In NZ this test is used in select cases under the supervision of a paediatric sleep specialist.

Further guidance for the assessment and management of children with sleep disordered breathing

See NZCYCN guideline on sleep disordered breathing, including suggested pathway (Appendix 3 below)

Treatment

A variety of therapies exist and we recommend seeking appropriate expertise to determine what is appropriate for an individual child and their particular health issues. In some cases a period of watch and wait may be appropriate. In others more than one therapy may be required. The most common therapies include:

• Tonsillectomy

• Adenoidectomy

• Nasal steroids (mild)

• Weight loss

• Mask CPAP”