Hematologic and Blood Disorders Emergencies

Introduction

Hematology is the study of blood and its components, including red blood cells (RBCs), white blood cells (WBCs), platelets, and proteins involved in clotting and bleeding processes. It also includes the hematopoietic system, which consists of the organs and tissues responsible for producing blood cells.

Hematologic emergencies involve disorders affecting the blood, excluding severe blood loss from trauma. True hematologic emergencies are relatively uncommon in EMS and are often related to chronic medical conditions. A hematologic disorder refers to any disease or abnormality involving the blood or blood-forming tissues.

Although EMS treatment options are usually limited in the field, understanding these disorders helps providers deliver better assessments, supportive care, and patient advocacy.

Anatomy and Physiology Review

Blood

Blood is a connective tissue suspended in plasma and made up of cells and cellular fragments. It accounts for approximately 5–6 liters, or about 8% of total body weight, in the average adult.

Major Functions of Blood

Plasma

Plasma is the liquid portion of blood and consists mostly of water along with:

Plasma makes up about half of total blood volume, while the remaining portion consists of formed elements such as RBCs, WBCs, and platelets.

Blood-Forming Organs

Liver

The liver helps produce clotting factors, filters waste from the blood, breaks down old RBCs into bile, and stores blood within its vascular system.

Spleen

The spleen filters old RBCs, assists with WBC production, and stores about one-third of the body’s platelet supply.

Bone Marrow

Bone marrow is a major site of blood cell production, especially RBC formation. Active marrow is commonly found in long bones, the pelvis, skull, and vertebrae.

Red Blood Cells (RBCs)

RBCs, also called erythrocytes, originate from stem cells. Their production is stimulated by erythropoietin, a hormone released by the kidneys.

RBC Lifecycle

RBC Function

Their main role is oxygen transport through hemoglobin, the iron-containing protein that gives blood its red color.

Gas exchange occurs through the Bohr effect, where oxygen is released and carbon dioxide is absorbed depending on concentration gradients.

White Blood Cells (WBCs)

WBCs are essential components of the immune system. They develop from stem cells and specialize into different cell types designed to defend the body against infection and foreign substances.

Immunity

The immune system protects the body from pathogens and harmful substances.

Types of Immunity

Cellular Immunity

Also called cell-mediated immunity, this process uses cells such as T-cells and macrophages to directly attack pathogens.

Humoral Immunity

This form relies on antibodies (immunoglobulins) that recognize specific antigens and help the immune system “remember” threats.

Autoimmune Disorders

Autoimmune diseases occur when the immune system mistakenly attacks the body’s own tissues.

Examples include:

Blood Types

RBCs are classified according to surface antigens using the ABO system:

The Rh factor is another antigen marker:

Matching blood types correctly is critical during transfusions to avoid immune reactions.

Hemostasis

Hemostasis is the body’s natural process for stopping bleeding.

Stages of Hemostasis

1. Vascular Spasm

Damaged blood vessels constrict to reduce blood flow.

2. Platelet Plug Formation

Platelets adhere to the injury site and form a temporary seal.

3. Coagulation

Clotting factors activate fibrin formation, strengthening the clot and forming a thrombus.

Assessment Findings

Assessment of hematologic emergencies follows standard patient evaluation principles, but several findings are especially important.

Common Signs and Symptoms

Neurological

Skin

Gastrointestinal

Musculoskeletal

Cardiorespiratory

Genitourinary

General Management

Airway, Breathing, Circulation

Management priorities remain focused on:

External bleeding should be treated with direct pressure and bandaging. Internal bleeding may require fluid support according to local protocols.

Medications

EMS interventions are often supportive and may include:

Comfort measures and accurate patient assessment are also essential.

Sickle Cell Disease

Sickle cell disease is the most common inherited blood disorder in the United States and occurs more frequently among individuals of African descent.

The disorder causes RBCs to become sickle-shaped instead of round, reducing oxygen-carrying ability and causing chronic anemia.

Sickle cells also have a shorter lifespan than normal RBCs.

Sickle Cell Emergencies

Vaso-Occlusive Crisis

Blocked blood flow causes severe pain, ischemia, and possible organ damage.

Acute Chest Syndrome

Presents similarly to pneumonia with:

Acute Splenic Sequestration Syndrome

Common in children. Sickled cells become trapped in the spleen, causing swelling, anemia, and hypovolemia.

Signs include:

Sickle Cell Management

Treatment focuses on symptom relief and stabilization.

EMS Care Includes

Other Hematologic Disorders

Anemia

Anemia is a reduction in RBCs or hemoglobin, decreasing oxygen delivery.

Common Causes

Leukopenia

Leukopenia is a decreased WBC count, reducing the body’s ability to fight infection.

Common causes include:

Thrombocytopenia

Low platelet levels impair clotting and increase bleeding risk.

Leukemia

Leukemia is a cancer affecting blood-forming tissues and WBC production.

Symptoms

Patients are often immunocompromised and vulnerable to infection.

Lymphoma

Lymphoma is cancer of the lymphatic system.

Symptoms

EMS care is generally supportive.

Polycythemia

Polycythemia causes excessive RBC production, thickening the blood and increasing clot risk.

Possible complications include:

Disseminated Intravascular Coagulation (DIC)

DIC is a severe condition involving widespread abnormal clotting followed by bleeding.

Common causes include:

Mortality is high due to bleeding and poor perfusion.

Hemophilia

Hemophilia is a hereditary clotting disorder causing impaired coagulation.

Types

Patients are at high risk for internal and external bleeding.

Multiple Myeloma

Multiple myeloma is a cancer affecting plasma cells in bone marrow.

Complications may include:

EMS care remains primarily supportive.

Blood Transfusion Complications

Blood transfusions may produce several reactions.

Hemolytic Reactions

Occurs when incompatible blood types trigger destruction of RBCs.

Febrile Reactions

Common and usually mild fever-related reactions.

Allergic Reactions

May progress to anaphylaxis due to preservatives or donor proteins.

Transfusion-Related Lung Injury

Can cause pulmonary edema from capillary permeability changes.

Circulatory Overload

Occurs when blood products are infused faster than the patient can tolerate.

Bacterial Infection

Poor blood handling can introduce infection and potentially cause sepsis.

Key Points