Lecture 13 - Hemorrhage and hemostasis

Introduction

Presenter: Harpa Marius, M.D., Ph.D.Topic: Hemorrhage and Hemostasis

Hemorrhage - Classification by Vessel Damage

Arterial Bleeding

Characteristics:

• Bright red blood (except for the pulmonary artery)

• Rhythmic pulsation, corresponding with cardiac contractions

• Rapid blood loss that can lead to significant physiological changes

• Less likely to clot due to the high-pressure environment

• Requires prompt external means (such as compression or tourniquets) to control bleeding

Venous Bleeding

Characteristics:

• Dark red color (except for the pulmonary artery)

• Continuous steady flow of blood

• Can potentially result in large volume loss

• Clotting can occur but may require additional time or interventions to achieve

Capillary Bleeding

Characteristics:

• Occurs within parenchymal organs or the skin

• Characterized by a typical venous appearance; blood oozes out slowly

• May appear massive but usually is easily controlled; often stops spontaneously or with compression

Mixed Bleeding

• Involves damage to both arteries and veins, complicating management and treatment strategies.

Hemorrhage - Classification by Occurrence Location

External Bleeding

• Blood externalizes outside the body through an open wound, often requiring immediate medical attention to manage blood volume and prevent shock.

Internal Bleeding

• Blood collects in a cavity that does not communicate with the exterior, potentially causing pressure on surrounding tissues and organs.

Externalized Internal Bleeding

• Blood flows into a cavity which communicates with the exterior, often seen in traumatic injuries or certain surgical complications.

Interstitial Bleeding

• Blood gathers in tissues, forming a hematoma, which can cause swelling, pain, and potential dysfunction of nearby structures.

Hemorrhage - Classification by Blood Loss

Blood Loss Categories:

• Small: 250-500 ml | ~10% of total blood volume

• Medium: 500-1000 ml | ~10-20% of total blood volume

• Big: 1000-2000 ml | ~20-30% of total blood volume

• Deadly: >2000 ml | ~30-50% of total blood volume; often lethal if not treated immediately.

Hemorrhage - Classification by Cause

Hemorrhagic Causes

• Traumatic:

  • Injury-induced bleeding, which may require surgical intervention.

• Pathologic:

  • Bleeding arising from pathologically altered vessels can often indicate underlying diseases such as cancer, atherosclerosis, or coagulopathies.

Onset and Duration

• Acute:

  • Significant blood loss occurring within a short time, necessitating urgent care to stabilize the patient.

• Chronic:

  • Involves small, repeated hemorrhages that can lead to anemia over time.

Moment of Hemorrhage

• Primary:

  • Blood loss occurring during surgical procedures or immediate trauma.

• Reactionary:

  • Bleeding occurring due to hypertension or dislodging of clots shortly after injury.

• Secondary:

  • Resulting from erosion of the vessel by infection or other complications arising after the initial injury or surgery.

Clinical Features of Hemorrhage

• Symptoms may include:

  • Weakness, dizziness, and tachycardia

  • Hypotension and tachypnea

  • Skin pallor and low temperature of extremities

Severe Hemorrhage and Syncope

• Definition:

  • Sudden loss of consciousness potentially caused by large blood volume loss or vagal reflex collapse.

• Symptoms include:

  • Circulatory collapse and hypotension

  • Weak, imperceptible pulse accompanied by profuse cold sweats

Diagnosing Hemorrhage

External Hemorrhage

• Blood appearance helps establish diagnosis (arterial, venous, mixed).

Internal Hemorrhage

• Local signs depend on the cavity involved, such as:

  • Hemoperitoneum: Pain, bloating, paralytic ileus

  • Hemothorax: Pain, dyspnea, abolished breath sounds

  • Hemopericardium: Signs of cardiac tamponade, enlargement of cardiac dullness

  • Hemarthrosis: Swelling of joints, bone reliefs, pain, functional impotence

Externalized Internal Hemorrhage Types

• Hematemesis:

  • Digestive bleeding presented through vomiting; fresh blood indicates active hemorrhaging and requires rapid medical intervention.

• Hematochezia:

  • Rectal externalization of fresh blood or clots, typically occurring alongside stools, indicating lower gastrointestinal bleeding.

• Melena:

  • Passing dark, tarry feces; associated with upper gastrointestinal bleeding, often necessitating endoscopic intervention.

• Rectorrhagia:

  • Fresh blood discharged downstream from the angle of Treitz; this can vary in diagnosis based on the specific context of presentation.

• Hemoptysis:

  • Coughing up blood from the lungs/respiratory tract; light red blood is an indicator of active respiratory tract bleeding.

• Hematuria:

  • Urinary tract hemorrhage that can present either microscopically or macroscopically, requiring urological assessment.

• Metrorrhagia:

  • Any hemorrhage occurring outside the menstrual cycle, which may require gynecological evaluation.

Interstitial Hemorrhage

Hematoma

• Appearance of bruises and localized swelling can compress structures, leading to dysfunction and pain.

Prevention of Hematoma

• Understanding varying depths and vascularity in subcutaneous tissues aids in preventing excessive blood accumulation, using compression with bandages to express fluid into a drain.

Drainage to Prevent Hematoma

Techniques:

• Tube drains can be employed to collect fluids into receptacles, forming a closed system that reduces infection risks.

Investigations

Blood Tests

• Complete blood count: assessing hemoglobin and platelet levels is crucial.

• Prothrombin time: evaluating the intrinsic pathway alongside vitamin K-dependent clotting factors.

• INR normal value: 0.8-1.2; elevation indicates anticoagulated patients.

• Activated partial thromboplastin time (aPTT): assesses the intrinsic pathway effectiveness.

• Activated clotting time: measures clotting time post-heparin administration, crucial for monitoring anticoagulation therapy.

Imaging Tests

• Chest X-ray: Useful for assessing conditions like hemothorax.

• Ultrasound: Conducts evaluation for hematic effusion and organ damage not identified on X-ray.

• CT scan: Provides detailed imaging of potential hematic effusion and any organ damage.

• Additional endoscopic examinations such as upper GI endoscopy and colonoscopy can identify internal bleeding causes.

Postoperative Hemorrhage

Types

• Primary: Occurs during surgery, requiring immediate intervention to control bleeding.

• Reactionary: Occurs at the end of surgery as blood pressure normalizes.

• Secondary: Can occur days after surgery due to complications like infection or vessel erosion.

Major Postoperative Bleeding Signs

• Evidence of bleeding may appear as heavily bloodstained fluid from drains, cold, wet peripheries, symptoms of hypovolemia, and abdominal distension following surgical procedures.

Reactionary Postoperative Hemorrhage

• Reintervention may be necessary for complications such as cardiac tamponade, which requires careful evaluation.

Secondary Postoperative Hemorrhage

• Example: a patient with wound dehiscence and significant blood loss occurring a week after an operative procedure.

Blood Loss Classification and Symptoms

Postoperative Hemorrhage Management

• Focused on controlling the source of bleeding, correcting any coagulopathy, and evaluating the necessity for transfusion.

• Reoperation may be essential depending on the situation.

• Goal: Maintain tissue perfusion and oxygenation, restore blood volume, and ensure cessation of bleeding.

Blood Components in Hemorrhage Management

Pretransfusion Testing Steps

1. Determine donor’s ABO and RhD type.

2. Screen for significant antibodies in the patient’s serum.

3. Cross-match donor units with patient’s serum to ensure compatibility.

Specific Blood Products

• Red blood cells: Require ABO identical crossmatch; primarily used in active hemorrhagic shock to restore red cell mass.

• Fresh frozen plasma (FFP): No crossmatch necessary; includes all coagulation factors, particularly when INR is >1.5.

• Platelets: Aim for ABO compatibility; indicated when platelet count drops below 50,000/mm3.

Additional Points

• Crystalloids play a critical role in restoring circulating volume and preventing hypovolemic shock, particularly when blood products are not immediately available.

• Ensure emergency stocks of group O red cells are readily accessible.

• Accessibility to 24/7 cell salvage may be crucial in certain surgical situations.

• During major hemorrhage, it may be prudent to transfuse FFP in a 1:2 ratio with red blood cells to ensure coagulation factors are also replenished.

Acute Transfusion Reactions

Immunological Reactions

• Acute Hemolytic: Caused by ABO-incompatible transfusion; symptoms include chills, fever, chest tightness, hypotension, and shock; this reaction can be fatal.

• Transfusion-Related Acute Lung Injury (TRALI): Occurs due to HLA or neutrophil antibodies present in donor plasma reacting with the recipient's leukocytes.

• Febrile Nonhemolytic: A mild reaction to donor leukocytes, typically self-resolving.

• Allergic Reactions: Range from mild urticaria to severe anaphylaxis; management varies based on severity.

Nonimmunological Reactions

• Involves complications such as bacterial contamination during collection/storage or transfusion-associated circulatory overload, symptoms of acute left ventricular failure.

Delayed Transfusion Reactions

• Immunological Reactions:

  • Delayed Hemolytic: Develops due to non-ABO antibodies; symptoms can include jaundice and hemoglobinuria.

  • Alloimmunization and Posttransfusion Purpura: Can cause severe thrombocytopenia, posing complications.

  • Graft versus-host disease: High mortality risk if T lymphocytes are transfused into immunocompromised recipients.

Nonimmunological Reactions

• Can include transfusion-transmitted infections and iron overload complications, especially with chronic transfusions.

Complications of Massive Transfusion

• Not detailed in the provided notes; further reference to the primary text is required for comprehensive coverage.

Disseminated Intravascular Coagulation (DIC)

• Characterized by microvascular coagulation, severe fibrinolysis, ischemia, and consumption of clotting factors.

• Diagnosis is established through:

  • Thrombocytopenia

  • Elevated prothrombin time (PT)

  • Elevated activated partial thromboplastin time (APTT)

  • Decreased fibrinogen levels

  • Elevated D-dimer levels

• Management focuses on treating underlying causes, including sepsis, trauma, burns, etc.

Hemostasis Techniques

Compression

• Application of pressure or packing into cavernous bleeding areas effectively reduces blood flow.

Ligation

• Tying off the margin of a bleeding vessel using absorbable or non-absorbable materials to stop hemorrhage effectively.

Electrocauterization

• Techniques include:

  • "Touch buzz" for small vessels

  • "Painting" technique for larger epithelial areas

Clipping and Stapling

• Utilization of metal or synthetic clips for smaller vessels, providing a quick means of hemostasis.

Suturing

Types

• Continuous: Tightens with vessel distension, effectively reducing bleeding risk.

• Interrupted: Optimal for small vessels or in pediatric cases; care needed to avoid stitch separation during healing.

Key Points

• Uncontrolled bleeding is associated with poor surgical outcomes; anticipation and prevention strategies should focus on:

  • Correcting anemia and clotting defects, especially in high-risk patients.

  • Managing anticoagulants and ensuring an adequate blood supply during procedures.

Bibliography

1. Garden, O. James, and Rowan W. Parks. Principles and Practice of Surgery. 7th edition. Edinburgh; New York: Elsevier, 2018.

2. Henry, Michael M., and Jeremy N. Thompson. Clinical Surgery. 3rd edition. Edinburgh: Saunders, 2012.

3. Myint, Fiona. Kirk’s Basic Surgical Techniques. 7th edition. Edinburgh; New York: Elsevier, 2018.

4. Hartman, Christopher M., and Louis R. Kavoussi. Handbook of Surgical Technique. Philadelphia: Elsevier, 2018.