APPLICATION OF HEAT, COLD, AND COUNTER-IRRITANTS
INFLAMMATION.--A process called inflammation sometimes occurs in tissues
that have been injured or invaded by bacteria. Although painful, it is
nevertheless one of the reparative processes of the body, and therefore
beneficial. Common examples of inflammation are boils, sore throat, and
the swollen, painful condition resulting from sprains and fractures.
Characteristic symptoms of inflammation are heat, redness, swelling, and
pain.
When a tissue has been invaded by bacteria, nearby blood vessels dilate,
thus bringing an increased supply of blood to the affected part. This
extra supply serves to wash away the offending substance, and at the
same time it brings more white blood corpuscles, one function of which
is to destroy bacteria. From the increased supply of blood the affected
part becomes red and hot, and so much blood may come that the vessels
further on are unable to carry it away fast enough. Some of the fluid
part of the blood is then forced out into the tissues, and the part
becomes swollen. Distension of the tissues and pressure on the nerve
endings cause pain, and the injured part now exhibits the characteristic
symptoms of inflammation.
[Illustration: FIG. 21.--"THE HISTORY OF A BOIL." This figure represents
a cross-section of normal skin. Note the surface layer, or cuticle, and
the "true skin," or cutis. In the cutis one sees that the blood
capillaries are just wide enough for the blood-cells to pass through "in
single file." The skin has just been pricked by a dirty pin. On the
point of this pin were several poisonous germs which were deposited at
_a_. (_From Emerson's "Essentials of Medicine."_)]
[Illustration: FIG. 22.--"THE HISTORY OF A BOIL" (continued). The poison
from these germs diffuses through the cutis. The capillaries dilate. The
leucocytes force their way through the walls of the capillaries and
travel towards these germs. Note the dumb-bell shape of the leucocytes
as they pass through the minute holes in the capillary walls, and their
pseudopods as they travel towards their common destination, attracted by
the poison from the germs. The skin in this region is now swollen, red,
hot, and painful. (_From Emerson's "Essentials of Medicine."_)]
At this point, if the injury begins to heal or the bacterial infection
to yield, the extra blood supply is gradually carried off, the blood
vessels resume their normal size, and the tissues return to their usual
condition. If, however, the infection does not yield so quickly, more
and more white blood corpuscles assemble and pass through the walls of
the tiny blood vessels into the tissues. Here the struggle continues.
Some bacteria and some white blood corpuscles are killed, and substances
are formed which liquify these dead cells and also some cells of the
surrounding tissues. The resulting fluid is called pus or matter, and in
the case of a boil we then say it has come to a head. If the infection
occurs near a cavity or near the surface of the body, the pus may escape
by breaking through at the point of least resistance, and may carry most
of the poisons along with it. If the pus finds no outlet it may be
gradually absorbed by the blood stream, and healing may result without
discharging. On the other hand, the germs may make their way into the
circulation, thus causing the serious condition known as blood
poisoning.
[Illustration: FIG. 23.--"THE HISTORY OF A BOIL" (continued). The
migration of leucocytes has continued until now they form a dense mass
surrounding the germs. The poison of the germs has killed all the
leucocytes and also all the cutis immediately around them, and now
digestive fluids from the dead leucocytes is turning the whole dead mass
into liquid pus. The boil has "come to a head." There is a little lump
on the skin and through its thin covering of cuticle can be seen the
yellow pus. (_From Emerson's "Essentials of Medicine."_)]
Inflammation may be treated by means of hot applications, cold
applications, or counter-irritants. The effect of heat is to dilate the
vessels and hence to increase the flow of blood to the injured part.
This increased blood supply makes the reparative process go on more
vigorously, and also makes it possible for the accumulated fluid to be
more rapidly carried away. Moist heat softens the tissues so that pus,
if formed, can escape more easily.
[Illustration: FIG. 24.--"THE HISTORY OF A BOIL" (concluded). The boil
has finally ruptured. The liquid pus has escaped carrying with it the
germs and most of their poisons; the migration of leucocytes has
stopped; the capillaries are returning to normal size and now new tissue
will grow and fill up this hole. (_From Emerson's "Essentials of
Medicine."_)]
Cold acts in just the opposite way. It decreases the size of the blood
vessels so that less blood comes to cause pain and swelling; at the same
time it diminishes the number of white blood corpuscles and the
nutritive substance brought by the blood. The nature and location of the
infection determine whether heat or cold is to be preferred.
Counter-irritants, of which mustard is an example, have a complicated
action. A counter-irritant affects the blood circulation of the place to
which it is applied, and at the same time it irritates the superficial
nerves, which in turn stimulate other more distant nerves. The latter
nerves control the circulation in tissues not adjoining those to which
the counter-irritant is applied, and thus it is possible for a mustard
paste, for example, if applied at one point to bring about changes in
the blood supply of another part of the body. The mechanism by which
counter-irritation is brought about is an intricate nervous process
called reflex action.
HOT APPLICATIONS
In applying either moist or dry heat the danger of burning or scalding a
patient must be constantly kept in mind. This danger is always great,
but it is especially great when the skin is tender like that of babies,
children, and old people, or when the vitality is low as in cases of
chronic or exhausting illness. Unfortunately accidents in applying heat
are not uncommon; a moment's carelessness may cause serious injury and
prolonged suffering.
DRY HEAT.--Hot water bags are used to apply dry heat. They should be
filled not more than two-thirds full of hot water, but the water must
not be so hot that there is the slightest possibility of scalding the
patient if the bag should leak. Boiling water should never be used.
Before the stopper is screwed on, expel the air by squeezing the bag or
by resting it upon a flat surface until the water reaches the top. After
closing the bag make sure that both bag and stopper are in order, by
noting whether leakage occurs when the bag is inverted and pressed
moderately. Before it is placed near the patient the bag should be dried
and entirely covered with a towel or canton flannel bag.
Strong bottles, jugs, and jars, if they can be securely stoppered, may
be used sometimes instead of hot water bags. The same precautions are
necessary. Bricks, flat irons, or thick flannel bags containing salt or
sand may be heated in the oven and used in the same way. Salt and sand
retain heat for a long time, but are correspondingly slow to heat;
therefore one bag should be heating in the oven while the other is in
use. Their effect on the skin must be no less carefully watched than the
effects of other hot applications.
Hot dry flannel may be used without fear of burning a patient, and it
sometimes yields sufficient warmth to relieve pain, particularly
abdominal pain of babies. After it has been heated on a radiator or in
an oven, it should be applied quickly and covered closely with another
flannel to prevent escape of heat.
Dry heat can be applied conveniently by an electric pad. The part to be
heated may be wrapped in flannel or placed directly above or below the
pad. The pad should be carefully watched to see that the switch is not
accidentally turned, as it is possible for the pad to become hot enough
to burn the patient or to set fire to the bed covers.
MOIST HEAT.--To apply moist heat poultices or fomentations (stupes) are
used.
_Poultices_ may be made of various heat-retaining substances, but
flaxseed meal is generally used. The poultices when ready should be
applied without delay, therefore all preparations should be made in
advance. To prepare a poultice, first provide a piece of gauze or thin
old muslin about two inches wider than you wish the poultice to be when
finished, and about two inches more than twice as long. In a shallow
saucepan boil water, varying in amount according to the size of the
poultice desired; about equal parts of water and meal will be needed.
When the water is boiling briskly add the meal gradually, beating
constantly with a spatula or knife. The poultice is done when the
mixture coheres and is thick enough to drop from the spatula leaving it
clean. Quickly spread a layer of the hot flaxseed from a quarter to half
an inch thick on one-half of the muslin, leaving a margin on three sides
of about an inch (Fig. 25). Fold in the margins of the cloth (Fig. 26)
and then bring the other half of the cloth over the flaxseed so that the
top of the poultice is covered. Tuck the free end of the upper half of
the cloth under the turned in edges of the long sides.
[Illustration: FIG. 25.--Turn the edges of the muslin over the flaxseed
by folding first on the line _AA'_, and then on the lines _BB'_ and
_CC'_.]
[Illustration: FIG. 26.--Fold on the line _EE'_, bringing _FF'_ up over
the flaxseed and tucking it under at _D_ and _D'_.]
Carry the poultice on a hot plate, or rolled in a newspaper or hot
towel. Test it carefully with the back of the hand, apply it to the skin
gradually, cover it with cotton batting, oiled muslin, or several
thicknesses of flannel, and keep it in place with a bandage or towel.
Remove it as soon as it has become cold, and unless the skin is much
reddened apply a fresh poultice. If the skin is much reddened, anoint it
with vaseline or sweet oil, wrap it warmly, and apply the next poultice
as soon as the appearance of the skin is normal.
_Stupes_ or _hot fomentations_ are cloths, preferably of flannel or
flannelette, wrung out of boiling water and applied to the skin. Each
stupe should be three or four times as large as the area to be covered.
Two are needed, so that one may be prepared before removing the other.
To prevent escape of heat and moisture the stupe should be covered after
it has been applied, first with a piece of rubber cloth or oiled silk or
muslin, and next with several thicknesses of flannel, or cotton batting
made into a pad. The whole should be kept in place with a bandage or
towel used as a binder. The doctor will tell how often the stupes are to
be applied, but if the skin becomes irritated they must be stopped until
its appearance is again normal.
[Illustration: FIG. 27.--WRINGING STUPE. (_From "Elementary Nursing
Procedures," California State Board of Health._)]
Great care must be taken in applying fomentations. They do little good
unless very hot, but if applied too hot the patient is likely to be
scalded. They must be wrung as dry as possible; but it is difficult to
wring them without scalding the hands unless stupe wringers are used.
Stupe wringers are heavy pieces of cloth, like roller towels or pieces
of ticking, long enough to extend over opposite sides of the basin in
which the stupe is to be boiled, and wide enough to hold the stupe
easily. The wringer should be placed in the basin with the stupe
arranged upon it. Boiling water should then be added, or the water,
stupe, and wringer may be boiled together in the basin. After the stupe
is ready, the wringer with the stupe upon it should be removed from the
water by grasping the dry ends of the wringer. Then the ends should be
twisted in opposite directions until the stupe inside is as dry as
possible. Wringing is made easier if the wringer has wide hems into
which sticks such as pieces of broom handles are inserted. By twisting
the sticks in opposite directions the stupe may be wrung out easily.
COLD APPLICATIONS
DRY COLD.--Cold, like heat, may be used either dry or moist. Bags of
rubber or of Japanese paper filled with small pieces of ice are used to
apply dry cold. When weight is to be avoided, the bag should not be
completely filled. After the bag has been filled and the air has been
expelled, it should be stoppered securely and wrapped in a towel or
piece of flannel, since it is possible for an uncovered ice bag to
freeze the skin. Ice bags are easily punctured, and care should be taken
not to bring pressure upon them especially when filled with sharp pieces
of ice. An ice bag not in use should be thoroughly dry inside and out;
it should be put away with enough absorbent cotton inside to keep the
surfaces from adhering. Bags of Japanese paper are less costly than
rubber, but less durable. To close them one should roll the top over and
then tie it tightly with string.
MOIST COLD.--Cold compresses for the head are often used for patients
with fever or headache; they sometimes quiet a patient who is restless.
An old handkerchief or piece of soft linen folded with the raw edges
inside may be used as a compress. It should be large enough to cover the
forehead. Two compresses at least should be provided, and a large piece
of ice in a basin. One compress should be wrung so that it will not
drip, and then applied to the head. The other meanwhile should be placed
on the ice to cool. As soon as the first compress becomes warm, the
second should be applied in its place.
_Cold Compresses for the Eyes._--Soft material should be selected for
eye compresses. Each one should be cut only a little larger than the eye
and should fit neatly over it. Several compresses should be placed on a
block of ice while one is applied to the eye, and every few minutes the
compress should be changed. If there is discharge from the eye, each
compress should be used but once; when used, they should be collected in
a paper and afterward burned. Separate compresses should be used if both
eyes are being treated. Definite directions in regard to changing
compresses and the length of time the applications should be continued
are generally given by the physician.
COUNTER-IRRITANTS
To some extent all hot applications are counter-irritants, but mustard
pastes, mustard leaves, and the mustard foot-bath already described are
the counter-irritants most commonly used.
_Mustard Paste._--To make a mustard paste, mix dry mustard with flour,
using for adults one part of mustard and six of flour to make a weak
paste; increase the proportion of mustard up to equal parts of mustard
and flour, according to the strength required. Use a smaller proportion
of mustard for children; one part of mustard with from 6 to 10 parts of
flour is generally enough. Add to the mustard and flour enough tepid
water to make a paste, which must be absolutely free from lumps. Do not
use hot water for this purpose, because it destroys some of the active
properties of the mustard. Spread the paste on thin muslin, apply it to
the skin, and remove it as soon as the skin is reddened so that its
color resembles that of a strong sun-burn. If the skin is especially
sensitive, mix a little sweet oil or vaseline with the paste.
_Mustard leaves_ should be dipped in tepid water and may then be applied
to the skin directly, but if specially sensitive, the skin should be
protected by thin muslin or gauze. The leaf should remain until the skin
is well reddened; a few minutes are generally sufficient.
Care must be taken not to leave either a mustard leaf or a paste in
place long enough to blister the skin. After the application has been
removed; the part should be protected by a soft cloth until redness
disappears. Vaseline or sweet oil should be applied to the skin if it is
greatly irritated.
Other counter-irritants in common use are iodine, turpentine, ammonia,
kerosene, camphorated oil, capsicum vaseline, and various liniments.
Tincture of iodine may be diluted with alcohol for especially sensitive
skins; it sometimes causes blisters, and should not be applied more than
once a day at most. Ammonia and turpentine cause blisters; they should
not be used as counter-irritants except by a doctor's order, and then
only after exact directions have been obtained. Turpentine and kerosene
are inflammable and hence dangerous to use. It should be remembered that
the action of all counter-irritants is physiologically the same, so that
no advantage is obtained from the use of dangerous substances like
kerosene and turpentine.
EXERCISES
1. What are the causes and symptoms of inflammation?
2. Describe the process of inflammation.
3. What is the effect of heat on an inflamed area? of cold?
4. What are the dangers from hot applications, and how may they be
guarded against?
5. How should you fill a hot water bag? How should you cover it?
6. Describe the method of preparing and applying a flaxseed poultice.
7. Tell how to prepare and apply fomentations.
8. How should you apply cold compresses to the head? to the eyes?
9. How should you make a mustard paste for a baby six months old? for a
grown person only slightly ill? for a feeble old person with a sensitive
skin?
FOR FURTHER READING
Essentials of Medicine--Emerson, Chapter I.
The Human Mechanism--Hough and Sedgwick, Chapter IX.