Page 90 - Edited - Webster HEAD AND NECK - part 2-Merge PDF

HN 283
Except in very young children, it is impossible to reach such objects with the fingers (HN 287). The following procedure
should be adopted.

a) Ask the subject to bend forward at the waist, so that he/she can support his/her weight on outstretched arms, with hands
on a table or chair back or something of about this height.
b) Using the flat of your hand, strike the subject firmly between the shoulder blades about once a second for up to five
times. If the object is not dislodged, go to c).
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c) The Heimlich manoeuvre. Ask the subject to stand upright, and stand immediately behind them, so you are touching (no
time for etiquette etc.). Encircle them with your arms and interlock your hands by hooking the fingers of each, or by
making a fist with one and grasping the fist with the other. Your hands (the fist if you adopt the second way of
interlocking them) should be touching the subject’s abdomen in the epigastrium (sub-costal angle). Pull your hands
sharply backwards and upwards (trying to force up the subject’s diaphragm). Repeat up to five times, about one pull each
second. If the object is not coughed up, return to steps a) and b).
d) If the subject shows signs of collapse, send for help: resuscitation may be necessary prior to proper exploration of the
pharynx with instruments.
3 GAGGING.

Hard objects entering, or even food persistently lodged in that part of the mouth and pharynx (the oropharynx) for which the
general sensory supply is the glossopharyngeal nerve elicit a gagging reflex. This reverses the second and third phases of the swallowing
process (and the soft palate still shuts off the nasopharynx) in an attempt to eject the food or whatever. Since the neural structures involved
are those related to swallowing, this implies that the co-ordinating mechanism - the pattern generator - in the medulla reverses the order of
events. The laryngeal inlet (and even the glottis) closes in order to prevent the material entering the airway - one reason why gagging is
such an unpleasant experience. If the stimulus persists, a full-blown vomiting response ensues (see below), which is the basis of inducing
vomiting by poking a finger “to the back of the throat”. Gagging is sometimes experienced by dental patients; more often by those being
examined by an ENT surgeon, who inserts a variety of ironmongery into the oropharynx while pulling the patient’s tongue forwards in an
apparent attempt to uproot it. (You should see what they do after they’ve anaesthetised you.)

4. VOMITING

With small but essential differences, vomiting is essentially a reversal of the swallowing mechanism, again co-ordinated by a
pattern generator in the hindbrain. Reverse peristalsis begins in the stomach (and even duodenum) under control of the enteric autonomic
plexus: the vagus nerves carry the triggering signal to the enteric plexus. Peristaltic waves ascend the oesophagus: when the skeletal muscle
of the upper oesophagus and pharynx is reached, the central pattern generator takes over coordination as for swallowing, but in reverse
order. The ary-epiglottic folds are approximated and the laryngeal inlet is closed, to prevent vomit entering the airways, and the soft palate
raised to exclude vomit from the nose: both these manoeuvres occasionally fail - especially if the patient is unconscious (e.g. dead drunk, in
a diabetic coma, suffering from head injury etc.). The tongue is depressed and the oro-pharyngeal isthmus opened to allow the vomit to
enter the oral cavity (the reverse of the swallowing process). Failure of closure of the laryngeal inlet and glottis is serious . Respiratory
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movements have, of course, been interrupted - but vomit entering the larynx will set off the coughing reflex (SI 86), unless the patient is
deeply unconscious, or the interruption of respiratory movements has been prolonged enough for the respiratory to override the coughing
pattern generator, (as occurs during a prolonged bout of coughing) when vomit is inhaled. This is most likely to happen in an unconscious
individual lying on his/her back: the laryngeal iruet will have closed reflexly, dictating temporary cessation of respiration; at the end of the
episode of vomiting, there will be a pool of vomit passively retained in the pharynx and even oral cavity, as determined by the posture and
effects of gravity; the laryngeal inlet opens reflexly to allow an inspiration and down gurgles the vomit, actively drawn into the airway. This
leads to aspiration pneumonia, which is difficult to deal with because of the acid- and enzyme-induced damage. In order to prevent
aspiration of vomit:

(a) Never leave an unconscious patient who is not intubated or under direct medical care lying on his/her back.
(b) During mouth-to-mouth resuscitation, the patient must, however, be lying on his/her back: watch out for signs of vomiting (not good
for the patient, nor for you ... ).
(c) If vomiting starts you have about 5 secs (determined by the speed of the oesophageal peristaltic wave - HN 282; 287) to take
emergency steps, which are

4 Note: Pronounced “Hime-lick”. H.J. Heimlich is an American thoracic surgeon.
5 Note: Once in the airways, the hydrochloric acid and proteolytic enzyme of gastric secretion have a devastating effect on the lungs. And
all those bits of Big Mac and the like .... disgusting to eat, worse to vomit, and appalling to inhale.
\NewCMedPhysSc\20 HN SwallowVomit.