Page 19 - Edited - Webster HEAD AND NECK - part 2-Merge PDF

HN 217

SNORING

Snoring is usually regarded with levity and humour. It can, however, be serious.

CAUSES

During sleep, skeletal muscle tone decreases. In the pharynx, this leads to laxity of its walls. The soft
palate similarly relaxes. The overall result is an increased proximity of soft palate and pharyngeal wall. In
some individuals the relaxation is sufficient to bring the soft palate and pharynx close enough to impede air
flow. (Obesity is a predisposing factor, extra-pharyngeal fat pushing in the pharyngeal walls. So is sleeping
on one's back, allowing the soft palate to fall backwards.) The result is that the soft palate vibrates. This is
snoring. The noise, as common observation will reveal, is generated during inspiration, when the pressure
differential tends to collapse the over-relaxed pharynx abnormally, and approximate it to the soft palate.

CONSEQUENCES

(a) Social. The noise may be so loud as to wake not only one’s partner, but to disturb the sleep
of a whole household, regularly night in, night out. Family breakdown has been known to occur - certainly,
snoring partners have been banished to a garden shed.

(b) Physical. During sleep, blood pCO2 always rises slightly. The restricted upper airway of a
snorer limits ventilation and blood pCO2 rises abnormally: by driving the respiratory centres, this increases
the extent of respiratory movements, but the resulting increased pressure differentials tend to make the
pharynx collapse even more (with each inspiration it is "sucked in" ever more deeply). Hence, the increasing
crescendo of snoring until the snorer is wakened, because eventually the pharyngeal collapse is sufficient to
cause apnoea, i.e. to prevent inspiration completely. This is sleep apnoea, which is dangerous: the raised
blood pCO2 also drives the cardiovascular centres, and blood pressure rises steadily, marching upwards with the
crescendo of sound, to reach a maximum as respiratory movements stop. This is why an habitual snorer is more
prone to stroke than other mortals: their blood pressure rises to dangerous levels, especially if the snorer is
already hypertensive. Together with the social reasons, this is why habitual, violent snoring should be taken
seriously.

TREATMENTS
(a) Prevent the snorer from sleeping on his/her back: a tennis ball in a pocket sewn into the back
of the pyjama jacket or nightdress is very effective. If the patient sleeps naked, well ....

(b) Positive pressure ventilation. While sleeping, the sufferer wears a small mask covering
mouth and nose, through which he/she breathes air at slightly higher than atmospheric pressure (a small
bedside ventilator is provided). This keeps the pharynx inflated, and its walls well separated from each other
and from the soft palate. Not very sexy, but neither is snoring.

(c) Surgery. An extreme remedy: the soft palate is trimmed down, so that in a hyper relaxed state it
cannot reach the pharyngeal wall. Advantages: permanent, requires no bedroom apparatus (not even a
tennis ball). Disadvantages: all surgery has risks. With this operation a particular hazard, over and above
the general, is removing too much tissue; nasal reflux of food/drink will occur, and speech will become
hypernasal (HN 216; 276).

K.E.W.

\NewCMedPhysSc\16 HN 217 Snoring.