GUIDE TO BLOOD TRANSFUSIONS AND MANAGING BLEEDING RISKS

Understanding and Identifying Bleeding Disorders

Bleeding disorders represent a diverse group of conditions characterized by impaired hemostasis, leading to excessive or prolonged bleeding. Identifying these disorders is critical, particularly in the perioperative period, to mitigate risks. This guide outlines key aspects of assessment, screening, etiology, and related complications like Disseminated Intravascular Coagulation (DIC).

Medical History and Physical Findings that Might Identify the Presence and Etiology of a Bleeding Disorder

Assessment begins with a thorough medical history and physical examination, focusing on signs and symptoms suggestive of abnormal bleeding.

Medical History:

• Bleeding Pattern:
  • Onset: Was bleeding noted since childhood (suggesting inherited disorder like hemophilia, von Willebrand disease) or did it develop later in life (suggesting acquired disorder)?
  • Location & Type:
    • Mucocutaneous bleeding (petechiae, purpura, ecchymoses, epistaxis, gingival bleeding, menorrhagia) often suggests platelet or vessel dysfunction.
    • Deep tissue bleeding (hemarthrosis – joint bleeding, muscle hematomas) is more typical of coagulation factor deficiencies (e.g., hemophilia).
    • Excessive bleeding with minor trauma or procedures (dental extractions, surgery, childbirth).
    • Gastrointestinal or genitourinary bleeding.
  • Severity & Duration: How severe are the bleeding episodes? How long do they last?
  • Frequency & Triggers: How often do episodes occur? Are they spontaneous or triggered by specific events (e.g., trauma, menstruation, medications)?
• Family History: Ask about bleeding disorders in relatives (parents, siblings, grandparents, aunts, uncles). This is crucial for identifying inherited conditions.
• Medication Use: Inquire about current or recent use of:
  • Anticoagulants (warfarin, DOACs like apixaban, rivaroxaban, dabigatran; heparin).
  • Antiplatelet agents (aspirin, clopidogrel, ticagrelor).
  • Nonsteroidal Anti-inflammatory Drugs (NSAIDs).
  • Certain antibiotics, herbal supplements, or over-the-counter medications known to affect coagulation or platelet function.
• Comorbidities: Assess for underlying conditions associated with acquired bleeding disorders:
  • Liver disease (cirrhosis, hepatitis).
  • Kidney disease (uremia).
  • Malignancy.
  • Autoimmune disorders (e.g., Systemic Lupus Erythematosus).
  • Thyroid dysfunction.
• Previous Surgical/Procedural History: Elicit details about bleeding complications during past surgeries, dental work, biopsies, or even venipuncture.

Physical Examination:

• Skin & Mucosa:
  • Presence, size, location, and distribution of petechiae (pinpoint hemorrhages <3mm), purpura (3mm-1cm), or ecchymoses (>1cm – bruising).
  • Evidence of active or recent epistaxis or gingival bleeding.
  • Telangiectasias, especially oral/nasal (suggestive of hereditary hemorrhagic telangiectasia).
• Musculoskeletal:
  • Joint swelling, tenderness, or deformity (potential hemarthrosis).
  • Muscle tenderness or swelling suggestive of hematoma formation, potentially leading to compartment syndrome.
• General Assessment:
  • Signs of underlying systemic disease (e.g., jaundice for liver disease, pallor for anemia).
  • Lymphadenopathy or splenomegaly (potential malignancy or autoimmune process).

Minimum Preoperative Screening Tests Necessary When the Patient is Asymptomatic

For an asymptomatic patient with no personal or family history suggestive of a bleeding disorder, minimum preoperative screening tests typically include:

1. Complete Blood Count (CBC) with Platelet Count: Evaluates platelet quantity and screens for anemia or other hematologic abnormalities.
2. Prothrombin Time (PT) / International Normalized Ratio (INR): Assesses the extrinsic and common pathways of the coagulation cascade. Particularly sensitive to deficiencies of Factors VII, X, V, II (Prothrombin), and Fibrinogen, often affected by warfarin or liver disease.
3. Activated Partial Thromboplastin Time (aPTT): Assesses the intrinsic and common pathways of the coagulation cascade. Sensitive to deficiencies of Factors XII, XI, IX, VIII, X, V, II (Prothrombin), and Fibrinogen, and presence of heparin or lupus anticoagulant.

These standard tests are designed to detect the most common significant coagulation factor deficiencies and severe thrombocytopenia that might lead to excessive surgical bleeding in otherwise low-risk individuals. Further testing (e.g., bleeding time, platelet function assay, specific factor assays, von Willebrand testing) is reserved for patients with a suspicious history or abnormal initial screening tests.

Etiologic Factors Contributing to Bleeding Disorders

Bleeding disorders can be broadly categorized as hereditary or acquired.

Hereditary (Inherited) Bleeding Disorders:

• Coagulation Factor Deficiencies:
  • Hemophilia A (Factor VIII deficiency)
  • Hemophilia B (Factor IX deficiency)
  • Hemophilia C (Factor XI deficiency)
  • Von Willebrand Disease (most common inherited disorder, deficiency or defect of von Willebrand factor)
  • Rare factor deficiencies (e.g., Factors I, II, V, VII, X, XIII)
• Platelet Disorders:
  • Inherited Thrombocytopenias (e.g., immune thrombocytopenia, Bernard-Soulier syndrome – also a function defect)
  • Inherited Platelet Function Defects (e.g., Glanzmann thrombasthenia, storage pool disorders)
• Vascular Disorders:
  • Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu disease)

Acquired Bleeding Disorders:

• Medication-Induced:
  • Anticoagulants (Warfarin, Heparin, DOACs)
  • Antiplatelet Agents (Aspirin, Clopidogrel, etc.)
  • NSAIDs
• Systemic Disease Related:
  • Liver Disease (impaired synthesis of coagulation factors, dysfibrinogenemia, thrombocytopenia)
  • Vitamin K Deficiency (impaired synthesis of Factors II, VII, IX, X, Protein C & S)
  • Renal Failure (platelet dysfunction)
  • Malignancy (paraneoplastic syndromes, involvement of bone marrow, triggering DIC)
  • Severe Sepsis/Infection
  • Hypothyroidism
• Immune-Mediated:
  • Immune Thrombocytopenia (ITP)
  • Acquired von Willebrand Syndrome
  • Acquired Factor Inhibitors (e.g., acquired hemophilia due to autoantibodies against Factor VIII)
• Consumption Coagulopathies:
  • Disseminated Intravascular Coagulation (DIC)
  • Massive Transfusion (dilutional coagulopathy, triggering DIC)

Common Surgical Conditions Leading to Disseminated Intravascular Coagulation (DIC)

Disseminated Intravascular Coagulation (DIC) is a complex, acquired disorder characterized by widespread activation of the coagulation system, leading to microthrombi formation throughout the vasculature, which consumes platelets and coagulation factors faster than they can be produced. This paradoxically results in both thrombosis and bleeding. Several conditions encountered in surgical settings can trigger DIC:

• Sepsis or Severe Infection: The most common cause of DIC in hospitalized patients. Bacterial infections are frequent culprits, but viral, fungal, and parasitic infections can also trigger it.
• Severe Trauma: Especially massive tissue injury (crush injuries, head trauma, burns), which releases large amounts of tissue factor into the circulation.
• Massive Hemorrhage and Transfusion: Severe bleeding leading to shock, acidosis, and hypothermia can trigger DIC. Massive transfusion protocols, while life-saving, involve administration of large volumes which can dilute existing factors and platelets and, in the context of active bleeding and shock, contribute to the milieu causing DIC.
• Malignancy: Certain cancers, particularly acute promyelocytic leukemia (AML M3), and solid tumors (especially mucinous adenocarcinomas of the pancreas, lung, ovary, stomach) can directly activate coagulation or trigger DIC as a paraneoplastic syndrome.
• Obstetric Complications: These are significant triggers in perioperative settings related to childbirth (e.g., Cesarean section):
  • Amniotic Fluid Embolism
  • Placental Abruption
  • Retained Products of Conception (especially if infected)
  • Severe Preeclampsia/Eclampsia/HELLP Syndrome
  • Septic Abortion
• Major Surgery: Particularly prolonged procedures, especially involving tissues rich in tissue factor (e.g., prostate, lung resection, significant orthopedic or vascular surgery), or procedures complicated by hypoxemia, acidosis, or hypoperfusion.
• Major Burns: Extensive burns cause significant tissue damage and systemic inflammation.
• Transfusion Reactions: Severe hemolytic transfusion reactions can trigger DIC.
• Aortic Aneurysm: Ruptured or dissecting aortic aneurysms can directly activate coagulation.

Understanding these triggers is crucial for early recognition and management of DIC in the surgical and critical care environments.

Blood Transfusion in Surgical Practice

Blood transfusion is a critical, often life-saving, intervention in surgical practice. While indispensable for managing significant blood loss, severe anemia, and coagulopathies, it carries inherent risks. A thorough understanding of blood groups, proper handling, appropriate indications, and potential hazards is paramount for safe and effective transfusion therapy. This guide outlines these essential elements for healthcare professionals involved in surgical care.

The Importance of Major and Minor Blood Groups

Understanding blood groups is the foundational principle of safe blood transfusion. Incompatibility between donor red blood cells and recipient antibodies is the primary cause of acute hemolytic transfusion reactions, which can be life-threatening.

• Major Blood Groups (ABO and Rh Systems):
  • ABO System: This is the most critical system. Individuals have antigens (A, B) on their red blood cells and naturally occurring antibodies in their plasma against the antigens they lack.
    • Type A: A antigens on RBCs, anti-B antibodies in plasma.
    • Type B: B antigens on RBCs, anti-A antibodies in plasma.
    • Type AB: Both A and B antigens on RBCs, neither anti-A nor anti-B antibodies in plasma. (Universal recipient for red blood cells).
    • Type O: Neither A nor B antigens on RBCs, both anti-A and anti-B antibodies in plasma. (Universal donor for red blood cells, specifically O negative).
  • transfusing ABO-incompatible red blood cells (e.g., giving Type A blood to a Type B person) can cause a rapid and severe immune response, leading to hemolysis (destruction of red blood cells), disseminated intravascular coagulation (DIC), renal failure, and death.
  • Rh System: The Rh system, particularly the D antigen, is the second most important.
    • Rh-Positive: Have the D antigen on their red blood cells.
    • Rh-Negative: Do not have the D antigen. Rh-negative individuals do not naturally have anti-D antibodies but can develop them after exposure to Rh-positive blood (transfusion or pregnancy). Once sensitized, subsequent exposure can cause a hemolytic reaction.
  • Matching ABO and Rh types is the fundamental first step in preventing immediate, severe hemolytic reactions. O-negative blood is considered the “universal donor” for red blood cells in emergencies when typing is not possible, as it lacks both A, B, and D antigens, minimizing the risk of immediate reaction.
• Minor Blood Groups (Kell, Kidd, Duffy, MNS, etc.): While less immunogenic than ABO and Rh D, other blood group antigens can also cause the formation of antibodies upon exposure. Transfusion of red blood cells carrying antigens against which a recipient has pre-existing antibodies (due to previous transfusions or pregnancies) can lead to delayed hemolytic reactions or, less commonly, acute reactions. Antibody screening and crossmatching are performed to detect such antibodies and ensure compatibility, minimizing the risk posed by minor blood groups.

How to Obtain and Store Blood Components

The safety and efficacy of blood components depend heavily on rigorous collection, processing, and storage procedures.

• Obtaining Blood (Donation):
  • Blood is collected from volunteer donors who meet strict eligibility criteria based on health, lifestyle, and travel history to minimize the risk of transmitting infectious diseases.
  • A unit of whole blood (typically 450-500 ml) is collected into a sterile bag containing an anticoagulant and preservative solution.
• Processing Blood:
  • After collection, whole blood is typically separated into its components through centrifugation. This allows for the targeted use of specific blood products based on patient needs:
    • Red Blood Cells (RBCs)
    • Plasma (can be further processed into Fresh Frozen Plasma – FFP, or cryoprecipitate)
    • Platelets
  • Each component undergoes extensive testing:
    • ABO and Rh typing.
    • Screening for antibodies to minor blood groups.
    • Testing for infectious diseases (e.g., HIV, Hepatitis B, Hepatitis C, HTLV, West Nile Virus, Syphilis, Trypanosoma cruzi – Chagas disease). Nucleic acid testing (NAT) significantly reduces the detection window for several viruses.
    • Leukoreduction (removal of white blood cells) is standard practice in many regions to reduce the risk of febrile non-hemolytic transfusion reactions, HLA alloimmunization, and transmission of cell-associated viruses like CMV.
• Storing Blood Components: Specific storage conditions are crucial to maintain the viability and function of each component:
  • Red Blood Cells: Stored at refrigerated temperatures (1-6°C). The standard shelf life is typically 42 days depending on the anticoagulant/preservative solution.
  • Fresh Frozen Plasma (FFP): Frozen quickly after collection and stored at -18°C or colder. Shelf life is usually 1 year. Once thawed, it must be used within 24 hours if stored at 1-6°C.
  • Platelets: Stored at room temperature (20-24°C) with continuous gentle agitation to prevent aggregation. Shelf life is typically 5-7 days due to the risk of bacterial contamination at this temperature.
  • Cryoprecipitate: Stored frozen at -18°C or colder for up to 1 year. Once thawed, it should be used within 6 hours (or 24 hours if pooled).
• Obtaining Blood for Transfusion: Once a patient needs a transfusion, the blood product is requested from the hospital blood bank. The request must include accurate patient identifiers (full name, date of birth, medical record number), the type and amount of component needed, the reason for transfusion, and the desired urgency. The blood bank performs compatibility testing (type and screen or crossmatch) before issuing the product.

Indications for Blood Transfusion in Surgical Practice

Transfusion decisions in surgical patients should be based on clinical assessment, anticipated blood loss, and laboratory values, rather than solely on numerical triggers.

• Acute Blood Loss: This is the most common indication in surgery, particularly in trauma, major vascular procedures, cardiac surgery, or general surgery with significant organ dissection. Transfusion is typically indicated for:
  • Significant, ongoing hemorrhage leading to hemodynamic instability (hypotension, tachycardia, decreased organ perfusion) despite fluid resuscitation.
  • Rapid blood loss exceeding the patient’s compensatory mechanisms, even if hemodynamically stable initially, especially if anticipating further loss.
  • Laboratory values supporting significant anemia (e.g., Hemoglobin drop). The traditional trigger of 10 g/dL has largely been replaced by a more restrictive approach (e.g., Hb < 7 or 8 g/dL) in stable patients, but this threshold is higher in patients with cardiovascular comorbidities or acute hemorrhage.
• Chronic Anemia: While severe chronic anemia (e.g., Hemoglobin < 7 or 8 g/dL) may warrant transfusion, it’s often preferable to optimize the patient’s hemoglobin pre-operatively if time permits (e.g., with iron or erythropoietin). Transfusion for chronic anemia in the surgical setting is usually reserved for:
  • Symptomatic anemia (fatigue, dyspnea on exertion, chest pain).
  • Patients with poor cardiac function who tolerate anemia poorly.
  • Immediately before major surgery in patients with severe anemia that cannot be corrected otherwise.
• Coagulopathy: Transfusion of plasma components is indicated to correct bleeding or reduce bleeding risk due to impaired coagulation.
  • Fresh Frozen Plasma (FFP): Used to replenish clotting factors in patients with multi-factor deficiencies (e.g., liver disease, DIC, warfarin overdose) who are bleeding or undergoing invasive procedures.
  • Cryoprecipitate: Used for fibrinogen deficiency (< 100-150 mg/dL), Factor VIII deficiency (if recombinant factors unavailable), von Willebrand disease (if DDAVP ineffective), or Factor XIII deficiency.
  • Platelets: Indicated for thrombocytopenia (low platelet count) or platelet dysfunction in bleeding patients or those undergoing surgery/invasive procedures. Thrombocytopenia triggers vary, but common thresholds are < 50,000/µL for major surgery, < 20,000/µL for central line insertion, and potentially higher for neurosurgery or ocular surgery.
• Prophylactic Transfusion: Transfusing components solely based on laboratory values without active bleeding or planned invasive procedures is generally discouraged, except in specific high-risk scenarios (e.g., very low platelets before specific surgeries, or very low fibrinogen).

Hazards of Blood Transfusion and How to Avoid Them

Despite rigorous safety measures, blood transfusion is not without risks. Recognizing these hazards and implementing preventive strategies is crucial.

• Immunologic Reactions:
  • Acute Hemolytic Transfusion Reaction (AHTR): Caused by ABO incompatibility, leading to rapid hemolysis, fever, chills, back pain, hypotension, and often DIC and renal failure. Avoidance: Strict patient identification verified at the bedside before transfusion, correct sample labeling, proper crossmatching.
  • Febrile Non-Hemolytic Transfusion Reaction (FNHTR): Common, caused by cytokines in the blood product or recipient antibodies against donor leukocytes. Symptoms: fever, chills. Avoidance: Leukoreduction of blood components (standard practice).
  • Allergic Reaction: Recipient antibodies against donor plasma proteins. Can range from mild (urticaria/hives) to severe (anaphylaxis). Avoidance: Antihistamine pre-medication for patients with a history of mild reactions; washed red cells/platelets (rarely needed) for severe recurrent reactions.
  • Transfusion-Associated Lung Injury (TRALI): Non-cardiogenic pulmonary edema occurring within hours of transfusion, often due to donor antibodies (anti-HLA or anti-HNA) reacting with recipient leukocytes in the pulmonary vasculature. Avoidance: Use of plasma/platelets from male donors or never-pregnant female donors (as they are less likely to have these antibodies).
  • Transfusion-Associated Circulatory Overload (TACO): Pulmonary edema due to volume overload from too rapid or excessive transfusion, particularly in patients with compromised cardiac or renal function. Avoidance: Slower infusion rate, use of diuretics, careful patient monitoring, consideration of smaller transfusion volumes.
  • Delayed Hemolytic Transfusion Reaction (DHTR): Occurs typically 3-10 days after transfusion. Caused by an anamnestic (secondary) antibody response to a minor blood group antigen encountered previously. Less severe than AHTR. Avoidance: Comprehensive pre-transfusion testing, including antibody screening and identification. Alerting the blood bank to a history of antibodies.
• Infectious Hazards:
  • Transmission of viruses (HIV, HBV, HCV, HTLV, CMV, West Nile Virus), bacteria (especially in platelets), parasites (Malaria, Chagas), and prions (vCJD theoretical risk). Avoidance: Rigorous donor screening, extensive laboratory testing (including NAT for key viruses), bacterial detection methods for platelets, pathogen reduction technologies (emerging). The risk of viral transmission is now extremely low in developed countries due to these measures. Bacterial contamination, primarily of platelets, is a non-trivial risk.
• Other Non-Immunologic Hazards:
  • Hypothermia: Infusion of cold blood can lower body temperature, especially during rapid massive transfusion. Avoidance: Use of approved blood warming devices.
  • Electrolyte Abnormalities:
    • Hypocalcemia: Citrate (anticoagulant) chelates calcium, significant during rapid massive transfusion. Avoidance: Calcium supplementation as needed.
    • Hyperkalemia: Potassium leaks out of RBCs during storage, especially in older units. Significant during massive transfusion or in patients with renal dysfunction.
  • Iron Overload: Patients requiring chronic transfusions over time accumulate excess iron. Avoidance: Judicious use of transfusion, iron chelation therapy for chronically transfused patients.
  • Transfusion-Associated Immunomodulation (TRIM): Transfusion can temporarily suppress the recipient’s immune system, potentially affecting post-operative infection risk or cancer recurrence (though evidence is mixed). Avoidance: Judicious use of transfusion.

Identifying Different Components of Blood and How to Order Each

Healthcare professionals must be familiar with the various blood components and the correct procedure for ordering them from the blood bank.

• Common Components:
  • Packed Red Blood Cells (pRBCs): Red cells with most of the plasma removed. Primary Use: To increase oxygen-carrying capacity in patients with symptomatic anemia or significant blood loss. Ordering: Specify “Packed Red Blood Cells” and the number of units (typically 1-2 units for stable patients, more for acute hemorrhage per protocol or assessment). Specify urgency (Routine, Urgent, Emergency).
  • Fresh Frozen Plasma (FFP): Plasma separated and frozen within hours of collection, preserving labile clotting factors (V and VIII). Primary Use: To correct multiple clotting factor deficiencies in bleeding patients or those undergoing procedures (e.g., liver disease, DIC, warfarin reversal). Ordering: Specify “Fresh Frozen Plasma” and the number of units or volume (typically 10-15 ml/kg). Specify urgency.
  • Platelets: Concentrated platelets. Can be obtained from multiple donors (random donor platelets – RDPs) or from a single donor by apheresis (single donor platelets – SDPs). Primary Use: To control or prevent bleeding in patients with thrombocytopenia or platelet dysfunction. Ordering: Specify “Platelets” and the number of units (e.g., 1 apheresis unit or 6 RDP units). Specify urgency.
  • Cryoprecipitate: A concentrate derived from FFP, rich in fibrinogen, Factor VIII, Factor XIII, von Willebrand Factor, and fibronectin. Primary Use: Primarily for fibrinogen deficiency, also used for certain factor deficiencies or vWD. Ordering: Specify “Cryoprecipitate” and the number of units (typically 10 units for an adult). Specify urgency.
• Ordering Process: Requests are typically made electronically or via a standardized paper requisition form. Essential information includes:
  • Patient’s full name and Medical Record Number (MRN).
  • Patient’s date of birth.
  • Patient’s ABO/Rh blood type (if known, blood bank will confirm).
  • Component type and amount needed.
  • Reason for transfusion (clinical indication).
  • Desired urgency (Routine, Urgent, Emergency).
  • Ordering physician’s name and signature.
  • Ward/Location of the patient.

Urgent/Emergency requests often bypass full crossmatching in favor of issuing ABO/Rh compatible blood (Emergency: O-negative for RBCs, AB plasma; Urgent: type-specific uncrossmatched RBCs). This accepts a small increase in risk for immediate availability.

Conclusion

Blood transfusion in surgical practice is a complex process requiring meticulous attention to detail from indication through administration. A deep understanding of blood group compatibility, proper handling and storage, appropriate clinical triggers, the specific uses of different components, and the comprehensive spectrum of potential hazards and their avoidance strategies is essential for all members of the surgical team. By adhering to established protocols and maintaining vigilance, the significant benefits of transfusion can be maximized while minimizing risks to the patient. Continuous education and adherence to local and national transfusion guidelines are vital for ensuring patient safety.