10. Types of Bleeding, Blood Control, and Transfusion

I. Bleeding: Etiology and Classification

Bleeding / hemorrhage: Escape of blood from the vascular system
Main danger → Hypovolemia + tissue hypoxia + coagulopathy → Shock and death
Management principle → Recognize severity, resuscitate, stop bleeding, correct coagulopathy

Etiology

Trauma → Blunt/penetrating injury, fractures, solid organ injury, vascular injury
Surgery → Intraoperative vessel injury, postoperative hemorrhage, anastomotic/staple-line bleeding
Medical conditions → Aortic aneurysm rupture, aortic dissection, tumor bleeding, peptic ulcer, varices, infection/erosion, coagulopathy
Drugs → NSAIDs, aspirin/P2Y12 inhibitors, heparin, warfarin, DOACs, thrombolytics

Classification by Source / Vessel

Type	Typical appearance	Clinical significance
Arterial	Bright red, pulsatile/spurting, high pressure	Rapid blood loss; urgent pressure, tourniquet, surgical or endovascular control
Venous	Dark red, steady/free flow, lower pressure	Can still be massive; pressure, ligation, suturing, packing
Capillary	Slow diffuse oozing from wound surface	Usually controlled with pressure, dressing, topical agents, coagulation correction

External and Internal Bleeding

External bleeding → Visible bleeding from wound, drain, surgical field or body surface
Internal bleeding → Bleeding into tissues, cavities or lumen

Visible internal/luminal signs → Hematemesis, melena, hematochezia, hemoptysis, hematuria, vaginal bleeding
Cavity signs → Hemothorax, hemoperitoneum, retroperitoneal hematoma, intracranial bleeding
Occult signs → Falling BP, tachycardia, pallor, cold extremities, sweating, confusion, oliguria, falling Hb/Hct, rising lactate/base deficit

Classification by Timing

1. Related to Trauma / Wound

Primary hemorrhage → At the time of injury/surgery
Reactionary hemorrhage → Within first 24 h

Causes → Slipped ligature/clip, dislodged clot, rise of BP after resuscitation, inadequate hemostasis

Secondary hemorrhage → Days after injury/surgery

Causes → Infection, tissue necrosis, erosion of vessel, anastomotic leak/abscess, pressure injury from drain/tube

2. Related to Operation Phase

Preoperative → Bleeding caused by original disease/injury before operation
Intraoperative → Bleeding during incision/dissection/resection/coagulation failure
Postoperative → Reactionary or secondary hemorrhage; also coagulopathy/transfusion-related bleeding problems

Classification by Duration

Acute bleeding → Rapid blood loss; shock can occur before Hb falls
Chronic bleeding → Slow loss; anemia, fatigue, iron deficiency, occult blood positive stool

Classification by Amount: Hemorrhagic Shock Classes

Class	Blood loss	Pulse	Respiratory rate	Typical clinical picture
I	< 15% < 750 ml	< 100/min	14-20/min	Minimal symptoms, normal BP, anxiety possible
II	15-30% 750-1500 ml	> 100/min	20-30/min	Tachycardia, anxiety, narrowed pulse pressure, delayed capillary refill
III	30-40% 1500-2000 ml	> 120/min	30-40/min	Hypotension, confusion, oliguria, shock; blood transfusion usually needed
IV	> 40% > 2000 ml	> 140/min	> 35/min	Severe shock, lethargy/unconsciousness, life-threatening; massive transfusion/source control

II. Hemostasis and Blood Control

Hemostasis: Stopping bleeding by vascular constriction, platelet plug formation, coagulation and surgical/medical control
Do not wait for labs in life-threatening bleeding → Start ABCDE, pressure/source control and resuscitation
Definitive control may be surgical, endoscopic or endovascular

Immediate Clinical Approach

Call for help, assess ABCDE
Apply direct pressure / pack wound / tourniquet if limb life-threatening bleeding
Two large-bore IV lines or central/rapid access
Blood tests → CBC, coagulation, fibrinogen, blood group/crossmatch, electrolytes, lactate/base deficit
Start warmed fluids/blood products according to severity
Find source → Physical exam, FAST/US, CT if stable, endoscopy/angiography/OR
Definitive source control

Mechanical Hemostasis

Direct pressure with gauze/hand
Pressure dressing / compression bandage
Wound packing, pelvic packing, nasal packing
Tourniquet → Temporary control of severe limb bleeding; document time
Surgical methods → Hemostatic forceps/clamps, ligation, transfixion suture, clips, staplers, vascular repair, tamponade/packing
Endoscopic mechanical methods → Clips, band ligation, balloon tamponade

Thermal Hemostasis

Electrocautery / diathermy → Monopolar or bipolar coagulation
Argon beam coagulator → Diffuse surface bleeding, liver/spleen surface in selected cases
Ultrasonic/vessel sealing devices → Dissection + coagulation
Cryosurgery/cryotherapy → Selected lesions, not routine emergency bleeding control

Chemical / Topical Hemostasis

Oxidized cellulose, gelatin sponge, collagen matrix → Scaffold for clot formation
Fibrin glue/sealant, thrombin spray, fibrin foam
Topical epinephrine → Vasoconstriction, often endoscopic/local temporary effect
Useful for diffuse capillary oozing or difficult surfaces
Topical agents are adjuncts → They do not replace definitive control of major arterial/venous bleeding

Systemic / Pharmacological Hemostasis

Vitamin K → Warfarin/VKA reversal; effect delayed unless combined with PCC/FFP in emergency
Protamine → Reversal of unfractionated heparin and partial LMWH effect
Desmopressin (DDAVP) → Uremic platelet dysfunction, von Willebrand disease, selected antiplatelet-associated bleeding
Tranexamic acid (TXA) → Antifibrinolytic; give early in major trauma bleeding or high-risk major hemorrhage according to protocol
PCC → Rapid reversal of vitamin K antagonist effect; selected factor replacement
Platelets, FFP, cryoprecipitate/fibrinogen concentrate → Correction of thrombocytopenia/coagulopathy/hypofibrinogenemia

III. Transfusion: Indications and Blood Products

Transfusion: Administration of blood components to replace blood loss, restore oxygen delivery or correct hemostatic defects
Decision depends on Hb, rate of bleeding, symptoms, hemodynamics, comorbidities and planned surgery
In active major bleeding → Transfuse according to physiology and protocol, not only Hb

Indications

Major acute blood loss / hemorrhagic shock
Symptomatic anemia → Dyspnea, chest pain, syncope, tachycardia, poor exercise tolerance
Perioperative anemia with expected blood loss or poor cardiopulmonary reserve
Correction of coagulopathy before/after surgery or during active bleeding
Thrombocytopenia or platelet dysfunction with bleeding/procedure risk

RBC Transfusion Thresholds

Stable hospitalized adult → Restrictive strategy; consider RBC transfusion when Hb < 70 g/L (7 g/dL)
Higher threshold may be used in selected patients → Active ischemic heart disease, major orthopedic/cardiac surgery, ongoing bleeding, poor reserve, symptoms
Aim is not a fixed normal Hb → Aim for adequate oxygen delivery and clinical stability
One unit packed RBC usually raises Hb by about 10 g/L (1 g/dL) in a non-bleeding adult

Blood Products

Product	Main content	Main use
Whole blood	RBCs + plasma + platelets	Selected trauma/massive hemorrhage settings where available
Packed RBCs / PRBC	Red blood cells; about 250-300 ml/unit depending on preparation	Increase oxygen-carrying capacity in anemia/blood loss
Fresh frozen plasma / FFP	Coagulation factors	Coagulopathy with bleeding, massive transfusion, liver failure bleeding, warfarin reversal if PCC unavailable/adjunct
Platelets	Platelet concentrate	Thrombocytopenia or platelet dysfunction with bleeding/procedures; often target > 50,000/microliter for major surgery
Cryoprecipitate	Fibrinogen, factor VIII, factor XIII, vWF, fibronectin	Hypofibrinogenemia, DIC/major bleeding, massive transfusion
Fibrinogen concentrate / PCC	Specific factor concentrates	Targeted correction of fibrinogen deficiency or VKA-related coagulopathy according to protocol

Transfusion According to Hemorrhage Class

Class I → Usually no transfusion; crystalloid/observation unless anemia/comorbidity
Class II → Usually no RBC transfusion initially; consider if ongoing bleeding, anemia or cardiopulmonary disease
Class III → Blood transfusion often/probably necessary
Class IV → Blood transfusion and massive hemorrhage protocol usually necessary

Compatibility and Cross-Matching

ABO and Rh(D) typing before transfusion when possible
Antibody screen + crossmatch prevent hemolytic incompatibility
Emergency life-threatening bleeding → Uncrossmatched group O blood may be used until compatible blood available
Check patient identity carefully → Most preventable fatal error is wrong blood to wrong patient

IV. Massive Transfusion and Complications

Massive Transfusion Protocol (MTP)

Massive transfusion: Common definition = at least 10 units RBC in 24 h, or rapid ongoing need such as at least 4 units in 1 h with continued bleeding
Activate early in severe trauma, ruptured aneurysm, major GI bleeding, obstetric bleeding, major operative hemorrhage
Goal → Prevent lethal triad: hypothermia + acidosis + coagulopathy
Use balanced resuscitation → RBC + plasma + platelets early, commonly 1:1:1 or 1:1:2 depending on protocol
Give TXA early in major trauma bleeding if within indicated time window and no contraindication
Monitor and correct → Calcium, potassium, temperature, pH, fibrinogen, platelets, INR/PT/aPTT, lactate/base deficit
Use blood warmer and active warming
Definitive hemorrhage control remains essential → OR, endoscopy, interventional radiology

Complications of Transfusion

Acute hemolytic reaction → ABO incompatibility; fever, flank pain, hypotension, hemoglobinuria, DIC, renal failure
Febrile non-hemolytic reaction → Fever/chills without hemolysis
Allergic reaction → Urticaria to anaphylaxis
TRALI → Transfusion-related acute lung injury; acute hypoxemia/non-cardiogenic pulmonary edema
TACO → Transfusion-associated circulatory overload; pulmonary edema from volume overload
Infection transmission → Rare with screening, but possible
Electrolyte/metabolic → Hypocalcemia from citrate, hyperkalemia, hypothermia, acidosis/alkalosis
Coagulopathy/dilutional thrombocytopenia → Especially during massive transfusion without balanced products
Iron overload → Chronic repeated transfusions

What to Do if Transfusion Reaction Suspected

Stop transfusion immediately
Keep IV line open with normal saline
Check patient identity, blood bag and documentation
Call doctor/blood bank; send blood bag and patient samples according to protocol
Treat ABCDE → Oxygen, fluids, vasopressors, antihistamine/steroid/adrenaline if indicated
Monitor urine output, renal function, coagulation if hemolysis suspected

Exam focus: Classify bleeding by source, visibility, timing, duration and amount; know hemorrhagic shock classes; list mechanical, thermal, topical and systemic hemostasis; explain RBC/FFP/platelet/cryo use; mention crossmatch, MTP, balanced transfusion, TXA and major transfusion complications.