iary haemorrhage
is really a recurrence of primary bleeding. As the name indicates, it
occurs during the period of reaction--that is, within the first twelve
hours after an operation or injury. It may be due to the increase in the
blood-pressure that accompanies reaction displacing clots which have
formed in the vessels, or causing vessels to bleed which did not bleed
during the operation; to the slipping of a ligature; or to the giving
way of a grossly damaged portion of the vessel wall. In the scrotum, the
relaxation of the dartos during the first few hours after operation
occasionally leads to reactionary haemorrhage.

As a rule, reactionary haemorrhage takes place from small vessels as a
result of the displacement of occluding clots, and in many cases the
haemorrhage stops when the bandages and soaked dressings are removed. If
not, it is usually sufficient to remove the clots and apply firm
pressure, and in the case of a limb to elevate it. Should the haemorrhage
recur, the wound must be reopened, and ligatures applied to the bleeding
vessels. Douching the wound with hot sterilised water (about 110 F.),
and plugging it tightly with gauze, are often successful in arresting
capillary oozing. When the bleeding is more copious, it is usually due
to a ligature having slipped from a large vessel such as the external
jugular vein after operations in the neck, and the wound must be opened
up and the vessel again secured. The internal administration of heroin
or morphin, by keeping the patient quiet, may prove useful in preventing
the recurrence of haemorrhage.

#Secondary Haemorrhage.#--The term secondary haemorrhage refers to
bleeding that is delayed in its onset and is due to pyogenic infection
of the tissues around an artery. The septic process causes softening and
erosion of the wall of the artery so that it gives way under the
pressure of the contained blood. The leakage may occur in drops, or as a
rush of blood, according to the extent of the erosion, the size of the
artery concerned, and the relations of the erosion to the surrounding
tissues. When met with as a complication of a wound there is an
interval--usually a week to ten days--between the receipt of the wound
and the first haemorrhage, this time being required for the extension of
the septic process to the wall of the artery and the consequent erosion
of its coats. When secondary haemorrhage occurs apart from a wound, there
is a similar septic process attack