Describe Haemorrhage — Classification & Management in detail.

The Concept

Haemorrhage is the escape of blood from the circulation. It matters in surgery both as an emergency in its own right and as the commonest cause of hypovolaemic shock. Classifying a haemorrhage — by its source, its timing and the amount lost — is not academic: each classification directly guides how urgently and how you must act.

Classification BY Source

• Arterial — bright red blood spurting in pulsatile jets (high pressure).
• Venous — darker blood welling out in a steady flow.
• Capillary — a generalised ooze from raw surfaces.

Classification BY Timing — a High-yield Idea

The timing of bleeding after an injury or operation points to its cause, which is why this classification is so useful:

• Primary haemorrhage — occurs at the time of injury or surgery.
• Reactionary haemorrhage — occurs within 24 hours, typically as the blood pressure recovers after resuscitation and dislodges a clot, or a ligature slips.
• Secondary haemorrhage — occurs 7–14 days later, when infection erodes a vessel wall. Recognising this mechanism explains its delayed timing and its association with sepsis.

Classes of Haemorrhagic Shock (atls)

The ATLS system grades acute blood loss by physiology, and reading it carefully teaches an important point about compensation:

Management — 'stop the Bleeding, Restore the Volume'

The two priorities run together. Control the bleeding by direct pressure and elevation, a tourniquet for a limb, definitive surgery, or interventional radiology (embolisation). Simultaneously, restore circulating volume through two large-bore cannulae — initially with warmed isotonic crystalloid, then blood for significant loss. In major trauma, modern practice uses damage-control resuscitation: permissive hypotension (accepting a lower blood pressure until surgical control, so as not to 'pop the clot'), a massive transfusion protocol giving red cells, FFP and platelets in a balanced ~1:1:1 ratio, and tranexamic acid early. Throughout, one aims to avoid the 'lethal triad' of hypothermia, acidosis and coagulopathy, which reinforce one another and make bleeding impossible to stop.

Methods of Arresting Haemorrhage

Bleeding is stopped by natural and artificial means. The body's own response is vessel retraction and constriction, then platelet plug and clot formation. Surgically, control is achieved by direct pressure and elevation first, then definitive measures — ligation or clipping of the vessel, diathermy (electrocautery), suture, topical haemostatic agents, a tourniquet for a limb, or angiographic embolisation by interventional radiology. Choosing the method depends on the vessel and the situation.

Concealed (internal) Haemorrhage

Not all serious bleeding is visible. Concealed haemorrhage into the chest, abdomen, pelvis or around a long-bone fracture can rapidly cause shock with no external blood loss — so in a shocked trauma patient one must actively look for hidden bleeding (e.g. With fast ultrasound of the abdomen). This is why the shocked patient with no obvious wound still needs a systematic search for the source.

Assessing Blood Loss

Blood loss is estimated from the physiological response (the ATLS class — heart rate, pulse pressure, mental state and urine output), rather than from the visible blood alone, because young patients compensate so well that a large loss may be masked until sudden collapse.

Reactionary VS Secondary — the Mechanism Matters

It is worth dwelling on why the timing tells you the cause. Reactionary bleeding appears within hours because the event that caused it is mechanical — as the patient warms and the blood pressure is restored by resuscitation, a small vessel that had gone into spasm reopens, a clot is washed away, or a ligature slips. Secondary bleeding appears a week or two later because the cause is biological — infection in the wound gradually erodes the wall of a vessel until it gives way. So the same symptom (bleeding) at different times demands different thinking: re-explore and secure the vessel for reactionary bleeding; control infection and often ligate the vessel more proximally for secondary bleeding.

Blood pressure falls late — tachycardia comes first.

• Haemorrhage = escape of blood from the circulation; classify by source, timing and amount.
• By source: arterial (bright, spurting), venous (dark, steady), capillary (ooze).
• By timing: primary (at injury), reactionary (<24 h, clot dislodges/ligature slips), secondary (7–14 d, infection erodes vessel).
• ATLS classes I–IV by % loss; pulse pressure narrows in Class II before systolic falls in Class III — hypotension is late.
• Stop the bleeding (pressure/tourniquet/surgery/embolisation) + restore volume (crystalloid then blood); trauma → permissive hypotension, 1:1:1 massive transfusion, tranexamic acid, avoid the lethal triad.