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snoring

snoring

Introduction

  • noise during breathing can be of various types depending upon whether awake or asleep and on where the airway obstruction arises
  • snoring is a form of stertor which occurs during sleep either as a result of vibrations of nasopharyngeal structures with raised pharyngeal collapsibility or from nasal obstruction
  • snoring may be inspiratory, expiratory or biphasic
  • everyone snores occasionally
  • habitual snoring affects over 40% of males and nearly a third of females aged 30-60yrs
  • mild “snoring” can be from nasal obstruction and this noise can occur whilst awake and can be reproduced while awake by deep breathe through the nose when it is obstructed.
  • loud snoring however is usually a result of vibrations of the upper airway structures which cannot be reproduced whilst awake and presumably has a neural component with loss of muscular tone of the upper airways during certain phases of sleep
  • loud, habitual snoring may be severe enough to cause obstructive sleep apnoea (OSA) and excessive daytime sleepiness
  • there is no good evidence to support snoring without obstructive sleep apnoea (OSA) is an independent risk factor for hypertension or cardiovascular disease

Pathophysiology

  • snoring results from airflow-induced flutter of soft tissues of the nasopharynx, particularly the soft palate
  • the fact that people do not snore while awake suggests that sleep-induced muscular relaxation is at least part of the aetiology because muscle tone is the only component of flutter that can change during sleep
  • factors include:
    • upper airway obstruction
    • the mass, stiffness, and attachments of the fluttering element
    • the velocity and direction of airflow
      • local airflow velocity increases when the upper airway narrows (assuming inspiratory volume is maintained)

Aetiology of loud, habitual snoring

  • sleep-induced muscular relaxation of the soft palate muscles may cause1):
    • reduced stiffness of the soft palate
    • increased upper airway obstruction and increased air velocity as a result of pharyngeal dilator muscles not being as active
    • risk of this is greater with:
  • nasal obstruction including rhinitis, enlarged tonsils/adenoids, nasal septal deviation
  • craniofacial abnormalities such as macroglossia, micrognathia or retrognathia, enlarged soft palate, enlarged lateral pharyngeal walls
  • post-menopausal status
  • pregnancy
  • familial risk

Treatment

  • avoid alcohol within several hours of bedtime
  • avoid sedatives
  • sleep with head elevated
  • treat nasal congestion with nasal steroids, pseudoephedrine, etc as indicated
  • if over-weight, then lose weight
  • domperidone (Motilium) 10mg nocte with nasal decongestant appears to be effective 3)
  • consider passive EPAP devices
  • consider mandibular advancement devices
  • consider tongue-retaining devices
  • consider powered CPAP devices if obstructive sleep apnoea (OSA)
  • consider surgery for severe cases
snoring.txt · Last modified: 2019/02/05 23:39 by wh