PREPARATION OF THE PATIENT.
For all but short anæsthesias conducted chiefly by nitrous oxide, the
intestinal tract of the patient must receive careful preparation. In
doing this, one must avoid excessive starvation and purgation, both of
which tend to increase shock.
We will suppose that the operation is timed for 10 a.m. on Tuesday
morning. On Monday morning the patient receives an aperient which
may be varied a little to suit his taste and habits. If he has no
preference, there is nothing better than an ounce of castor oil. During
the rest of Monday, he has a light diet: fish and milk pudding in the
middle of the day, a little soup at night. The aperient should operate
before 9 p.m. When that is over, the patient retires to bed. During the
day he may be allowed to move about his room a little, but should not
undertake any exertion.
If there be excessive nervousness, or a natural tendency to insomnia,
sulphonal gr. 15 or veronal gr. 8 may be given early in the evening, to
ensure a night’s rest.
About 6 a.m. on Tuesday morning, a large soap and water enema is given,
and when this has operated, a cup of tea or a little soup or Bovril may
be taken. Thereafter nothing should be given by mouth.
The early forenoon is the time of choice for any operation, but if
an afternoon time be of necessity chosen, the patient should not be
starved throughout the forenoon. A repetition of the early morning meal
may be allowed about 11 a.m.
In cases such as gastro-enterostomy, where the alimentary tract will be
opened, the preparation must be a little more stringent. It is usual
to allow no solids at all the day before. A saline enema may be given
an hour or two before operation, when the soap and water has been
evacuated.
Preliminary Hypodermic Medication.
This great improvement in anæsthesia was practised many years ago by
a few surgeons, but it was only when open ether assumed its present
position of pre-eminence that it was widely adopted.
The present routine is to give morphia gr. ⅙, atropine gr. ¹⁄₁₂₀ to
adult patients three quarters of an hour before operation. It has the
following _advantages_:--
(1) The nervous fears of the patient give place to a feeling of
bien-être.
(2) The secretions of saliva and of mucous from the respiratory
mucous membranes are limited.
(3) A little less inhalational anæsthetic is required.
(4) The after vomiting is lessened, and probably the liability
to inflammatory respiratory complications also reduced.
The _disadvantages_ can be met by proper care and dosage. They are as
follows:--
(1) Morphia _plus_ chloroform depresses the respiratory centre
at an early stage of anæsthesia. Respiration becomes infrequent
and shallow, and cyanosis appears before the patient is really
sufficiently anæsthetised for the purposes of the surgeon.
(2) The larger the dose of morphia, the more troublesome is this
premature failure of respiration.
_The moral_ is obvious: give the small doses above recommended and
induced with mixtures weak in chloroform, or better still with ether
only (see page 86).
Some years ago, before these facts were appreciated, there was a
fashion for giving very large doses of preliminary narcotics. The
combinations most favoured were as follows:--
SCOPOLAMINE-MORPHINE.
Scopolamine is a form of hyoscyamine and is itself a powerful narcotic.
Two or sometimes three doses of the mixed drugs were given at intervals
of an hour, the last half an hour before operation. Scopolamine gr.
¹⁄₂₀₀, morphia gr. ⅛ was the usual formula: some surgeons added a dose
of atropine or strychnine with the idea of stimulating the respiratory
centre.
The patients went to the operating or anæsthetising room so drowsy
that they were unaware of their surroundings, and afterwards had no
recollection of the actual beginning of the inhalation. So humane a
method naturally attracted a good deal of attention, but the serious
depression of the respiratory centre which seems inevitable in the
method has gradually caused it to disappear from the practice of
most surgeons and anæsthetists. At the present day, it is only to
be recommended in midwifery practice; to the drowsy semi-conscious
condition produced, the name of _Twilight Sleep_ has been given.
OMNOPON AND OMNOPON-SCOPOLAMINE.
Omnopon is composed of a mixture of several of the alkaloids derived
from opium; the makers claim that it produces less after malaise than
morphia alone. It may be given before anæsthesia in doses of ⅙–⅓ gr.,
either alone or combine with a small dose of scopolamine. It gives
quite good results if not pushed to excess.
HEROIN HYDROCHLORIDE
This comparatively modern sedative is used by some surgeons in
preference to morphia. A dose of ¹⁄₁₂ gr. is quite sufficient, three
quarters of an hour before operation. Atropine should always be
combined with it.
* * * * *
To young children, morphia should not be given, but atropine may be
given freely. A child of twelve months tolerates a dose of ¹⁄₂₀₀ gr.
quite well: one of six years, will take ¹⁄₁₅₀ gr.
In ages ranging from 12 years upwards, greatly reduced doses of morphia
may be given. No child under 15 years requires more than ¹⁄₁₂ gr. of
morphia at most.