Recognition of
types of haemorrhage
Arterial
haemorrhage
Arterial haemorrhage is recognised as bright
red blood, spurting as a jet which rises and falls in time with the pulse. In
protracted bleeding, and when quantities of intravenous fluids other than blood
are given, it can become watery in appearance.
Venous
haemorrhage
Venous haemorrhage is a darker red, a steady
and copious flow. The colour darkens still further from excessive oxygen
desaturation when blood loss is severe, or in respiratory depression or
obstruction. Blood loss is particularly rapid when large veins are opened, e.g.
common femoral or jugular.
Venous
bleeding can be under increased pressure as in asphyxia, or from ruptured
varicose veins. Portal vein pressures (see Chapter 47) are high enough to
cause rapid blood loss, especially in portal hypertension with oesophageal
varices. Pulmonary artery haemorrhage is dark
red (venous blood) at around 30 mmHg (4 kPa), whereas bleeding from the
pulmonary veins is bright red (oxygenated).
Capillary
haemorrhage
Capillary haemorrhage is a bright red, often
rapid, ooze. If continuing for many hours, blood loss can become serious, as in
haemophilia.
Primary
haemorrhage
Primary haemorrhage occurs at the time of
injury or operation.
Reactionary
haemorrhage
Reactionary haemorrhage may follow primary
haemorrhage within 24 hours (usually 4—6 hours) and is mainly due to rolling
(‘slipping’) of a ligature, dislodgement of a clot or cessation of reflex
vasospasm. The precipitating circumstances are: (1) the rise in blood pressure
and the refilling of the venous system on recovery from shock; and (2)
restlessness, coughing and vomiting which raise the venous pressure (e.g.
reactionary venous haemorrhage within a few hours of thyroidectomy).
Venous
haemorrhage, whether primary or reactionary, can tax the skill of even an
experienced surgeon, for it may be exceedingly difficult to bring under control.
Penetrating wounds involving main veins in the thigh or groin are potentially
fatal, as exsanguination may follow the removal of a first aid dressing which
has apparently controlled the bleeding (butcher’s thigh). Such a wound
should never be treated in a perfunctory manner; it requires careful examination
and closure in an operating theatre.
Secondary
haemorrhage
Secondary haemorrhage occurs after 7—14
days, and is due to infection and sloughing of part of the wall of an artery.
Predisposing factors are pressure of a drainage tube, a fragment of bone, a
ligature in an infected area or cancer. It is also a complication of arterial
surgery and amputations. It is heralded by ‘warning’ haemorrhages, which are
bright red stains on the dressing, followed by a sudden severe haemorrhage which
may be fatal. A warning haematemesis may occur in the case of a peptic ulcer,
and is a danger signal which it is imprudent to ignore. In advanced cancer, the
erosion of a main vessel (e.g. carotid or uterine) by a locally ulcerating
growth becomes the way of a swift and merciful termination to the patient’s
suffering. Secondary haemorrhage is prone to occur with anorectal wounds, for
example after haemorrhoidectomy.
External
haemorrhage
External haemorrhage is visible, revealed
haemorrhage.
Internal
haemorrhage
Internal haemorrhage is invisible, concealed
haemorrhage. Internal bleeding may be concealed
as in ruptured spleen
or liver, fractured femur, ruptured ectopic
gestation or in cerebral haemorrhage. Concealed haemorrhage may become revealed
as in haematemesis or melaena from a bleeding peptic ulcer, as in haematuria
from a ruptured kidney, or via the vagina in accidental uterine haemorrhage of
pregnancy.
Measurement of
acute blood loss
Assessment and management of blood loss must
be related to the pre-existing circulating blood volume, which can be derived
from the patient’s weight:
•
infant 80—85 ml/kg;
•
adult 65—75 ml/kg.
Measuring blood
loss
• Blood clot the size of a clenched fist is roughly equal to 500 ml.
• Swelling in closed fractures. Moderate swelling in closed fracture of the
tibia equals 500—1500 ml blood loss. Moderate swelling in a fractured shaft of
femur equals 500—2000 ml blood loss.
• Swab weighing. In the operating theatre, blood loss can be measured by weighing the
swabs after use and subtracting the dry weight. The resulting total obtained (1
g = 1 ml) is added to the volume of blood collected in the suction or drainage
bottles. In extensive wounds and operations, the blood loss is grossly
underestimated, due to evaporation of water from the swabs before weighing each
batch. Prompt transfer of discarded swabs into polythene bags reduces this
source of error. Blood, plasma and water are also lost from the vascular system
because of evaporation from open wounds, into the tissues, sweating and expired
water via the lungs. Indeed, for operations such as radical mastectomy or
partial gastrectomy it may be necessary to multiply the swab weighing total by a
factor of 1.5. For prolonged surgery via larger wounds, as in abdominothoracic
or abdominoperineal operations, the total measured may need to be multiplied
by 2.
This is estimated in g/100 ml
(g/dl), normal values being 12—16 g/100 ml (12—16 g/dl). There is
no immediate change in haemorrhage, but after some hours the level falls by
influx of interstitial fluid info the vascular compartment in order to restore
the blood volume.
Measurement of
central venous pressure
For measurement of central venous pressure (CVP)
see later.
The treatment
of haemorrhage
Minimise further blood loss by pressure and
packing, position and rest, operative procedures (ligation, repair and
excision) and then fluid resuscitation as described below.
Restore
blood volume by blood transfusion, albumin 4.6 percent, SAG-mannitol (SAG-M)
blood, saline, gelatin, dextran and plasma infusions.
The first-aid
treatment of haemorrhage from a wound is a pressure dressing made from
anything handy which is soft and clean. The dressing or pack should be bound on
tightly.
Other
examples of pressure used to control
haemorrhage include digital pressure, for example the use of forefinger and
thumb or a clothespeg for epistaxis. The use of a double balloon in the
oesophagus and the stomach to control the bleeding from oesophageal varices is
another example of pressure being applied.
Packing by means of rolls of wide gauze is an important standby in operative
surgery. If several rolls are used, the ends must be tied together to ensure
complete removal later.
N.B. If on removal of pressure or packing, bleeding appears to have
ceased completely, one should not assume that all is well, especially when
dealing with deep wounds involving large veins. Continued close observation is
required and rapid operative action may be called for.
Position and
rest
Elevation of
limbs (e.g.
in ruptured varicose veins) employs gravity to reduce bleeding. Elevation also
causes helpful vasoconstriction (Lister). A
bed elevator is often used to raise the foot of the bed, and thus increasing
venous return to the heart also augmenting cardiac output. Gravity is also used
in certain operations, as in thyroidectomy when the patient is tilted feet
downwards (reverse Trendelenburg position) or as in stripping of varicose veins
when a head-down tilt is used (Trendelenburg).
Examples of
operative techniques in haemorrhage
Artery forceps (haemostats) and clips are
mechanical means of controlling bleeding by pressure. The clamped vessel can be
ligated or it can be coagulated with diathermy. When an incision is made through
the scalp for craniotomy, the profuse bleeding is not easily arrested by direct
pressure, so the cranial aponeurosis is picked up by a series of forceps which
are everted together, thus exerting pressure. Silver clips (Cushing) may be
applied to cerebral vessels.
Suturing
may be employed. The vessel can be underrun or transfixed by needle and suture,
and then ligated, while if the continuity of a main vessel is to be restored 4/0
silk or polypropylene is used on a 20-mm atraumatic needle.
Pressure by packing, using rolls of wide gauze, has been previously mentioned,
but temporary light pressure with a ‘peanut’ of gauze held by forceps aids
the sealing of an arterial suture line after reconstruction following trauma,
embolectomy or in artery grafting. About 5
minutes is required for the platelets to seal the join.
Patches
of vein or Dacron mesh may be used to repair a vascular defect. A patch of
muscle, lightly hammered, provides thrombokinase to stop a troublesome ooze.
Other
topical applications for oozing include gauze or sponge, which is absorbed by
the body. ‘Oxycel’ or gelatin sponge provides a network upon which fibrin
and platelets can be deposited. This is the modern counterpart of the use of
cobwebs by our forefathers, or sphagnum moss by our neolithic ancestors. Gauze
soaked in adrenalin (1:1000) can be applied. Bone wax (Horsley) is used for
oozing bone.
The
whole or part of a bleeding viscus may have to be excised (e.g. splenectomy or
partial hepatectomy). A ruptured kidney is treated conservatively if possible
(see Chapter 63).
Natural blood
volume and red cell recovery
The recovery of blood volume begins
immediately by the withdrawal of fluid from the tissues into the circulation.
There is haemodilution. Plasma proteins are replaced by the liver. Red cell
recovery takes some 5—6 weeks. The
iron content will be less than normal if stores are depleted or absorption is
impaired, for example after gastrectomy.