Adult OSA

Please visit

https://www.sleepclinc.com.au

Please note that the following is a general guideline only. For a full assessment, exclusion of any other underlying cause for your symptoms and an individualised treatment approach, you will need to be seen by a qualified specialist.

Definitions

Apnoea- Cessation of breathing for 10 sec (differs in children-usually 2 breath cycles) or more with or without oxygen de saturation ’

Hypopnoea- 50% reduction in respiration associated with reduction of 4% in saturation for 10 sec or more

Respiratory Event Related Arousal-increasing respiratory effort for 10 seconds or longer leading to an arousal from sleep but one that does not fulfill the criteria for a hypopnoea or apnoea

Apnea Hypopnea Index (AHI)-number of Apnoeas and Hypopnoea per hour

<5-normal

5-15-Mild

15-30-Moderate

>30 Severe

OSA Syndrome

Adults-when there is > 15 AHI or > 5 AHI with daytime symptoms due to upper airway collapse during sleep

Children-when there is repeated cessation or reduction in respiration during sleep due to upper airways obstruction with ongoing respiratory effort. No universally accepted paediatric criteria have been agreed on as of yet. Some would say one apnea event per night would qualify.

Snoring

In Adults it is a social problem, AHI <5, no day time symptoms. Children who has simple snoring/ not proven OSA may still have significant effect on their growth.

Pathophysiology of OSA

OSA Occurs due to airway collapse during sleep

airway patency at any given time is dependent on

1 structure/shape (static characteristics)

2 position

3 dilating forces  (Dynamic characteristics)

4 collapsing forces Dynamic)

When abnormal structure (Static characteristics) is exposed to conditions of dynamic airflow during sleep (muscle tone changes and intraluminal pressure changes) it will lead to upper airway collapse

This also can be explained by balances of forces model

Transmural pressure determine size=difference between dilating forces and collapsing forces

Incidence and Prevalence

OSA: 4% men and 2% women

Bimodal distribution Children and adults 50-70

Taking a History

Presentation
Its important to ask about nocturnal hx and day time hx. Also possible underlying medical condtions which may be caused by OSA (Cardio-Pulmonary) or lead to sleep disturbance (i.e. Thyroid disease).

Night Time symptoms (direct evidence)

        snoring, waking gasping for breath, partner’s story, 

nocturnal enuresis

nocturnal sweating

Daytime Symptoms (Indirect evidence)

Epworth score-0-3, 8 situations, total of 24. > 10 sleepy, .18 v sleepy

Other  -xerostomia

-morning head ache

-decreased libido

-poor concentration

PMH

        Weight gain

        Cardiovascular disease

        Thyroid disease

        Pulmonary disease

        Neurologic disease

        Nasal symptoms

PSH

      Upper airway

      Cleft palate etc

Medications

      Sedatives / stimulants

Social history

       Smoking

          Alcohol use

     Occupation – shift work

           Driving / MVA – legal ramifications

       Effect on partner

Epworth sleepiness score

      >11 significant

Examination

General

      Height / weight BMI 

     Neck circumference - >43cm in men / >37cm in women

        Hypothyroidism, acromegaly

     BP

     Peripheral oedema

Facial skeleton

     Maxillary hypoplasia

     Retronathia

     Syndromes eg Treacher-Collins

Nasal Obstruction (Doesn't cause OSA, but makes it difficult to treat OSA unless corrected)

Throat

Occlusion-under bite/ over bite

Oropharyngeal obstruction:

      Tongue size/ palate position (Freedman 1-4)

       Tonsils (grade 1-4)

Flexible Endoscopy

view of the Nasal airway down to the vocal folds: look at the sites of likely collapse.
If tongue base collapse this needs addressing

Investigations

Polysomnography is the gold standard and repeated after treatment

CT sinus: if symptomatic

Treatment

Non-surgical (first line if BMI> 35)
BMI  < 35 has good surgical outcome

Lifestyle

    Weight loss-If BMI >35 , 10% weight reduction -50% reduction in RDI

    Sleep hygiene-Avoid alcohol / stimulants before bed

    Positional changes/ Treat reflux

Medical 

   Treat allergic rhinitis – decongestants / steroids / immunotherapy

   Mandible advancement devices/ Oral appliances/Tongue retaining devices-Poorly tolerated, can develop TMJ dysfunction

   CPAP-40% non Compliance

Surgical

   Mostly reserved for BMI <35 patients

   Septoplasty All patients need a patient nasal airway 

   Adults with large tonsils and a good, hight palatal position with benefit from  tonsillectomy and UPPP (BMI<40)

UPPP (tonsils are removed, pillars sutured , Uvula resected and sutured)

If poor palate / bulky tongue (Freedman 3-4) will benefit from tongue base   reduction- i.e. by Coblation

Coblation; tongue base reduction

Retrognathia- Geniotubercle advancement

Major Stage II (reserved for failed above methods/ and failed Medical Rx)

    Maxillomandibular advancement

    Tracheostomy

    Bariatric surgery