Coagulation Disorders

Drugs Anticoagulants Antiplatelets Thrombolytics Hemostatics Parenteral = Heparin Enteral = Warfarin Antiplatelets Clopidogrel (Plavix) Thrombolytics Alteplase (activase) Hemostatics Amicar

Hemostasis Stopping of blood flow Involves large number of enzymes and clotting factors Final product is a fibrin clot that stops blood loss

Figure 27.1 Basic Steps in Hemostasis Platelets gather at wound & attempt to block blood flow Calcium, Vitamin K, fibrinogen help platelets form clot when exposed to air Fibrinogen fibrin, weblike mesh trapping blood cells in “scab”

Coagulation Cascade Injured cells release prothrombin activator Prothrombin activator changes prothrombin to thrombin. Thrombin changes fibrinogen to fibrin Fibrin forms insoluble web over injured area to stop blood flow

Fibrinolysis Clot removal Initiated by release of tissue plasminogen activator (tPA) tPA converts plaminogen to plasmin Plasmin digests fibrin strands – thus, circulation is restored Regulated so unwanted clots are removed and fibrin is left in wounds

Diseases of Hemostasis Thromboembolic disorders (need anticoagulants) Thrombus, embolus DVT Thrombocytopenia Bleeding disorders (Hemophilia)

Coagulation Modifiers Anticoagulants Thrombolytics Hemostatics

Lab Tests that Measure Coagulation Used for diagnosing and treating coagulation disorders Prothrombin time (PT) International normalized ratio (INR) Thrombin time Activated partial thromboplastin (aPTT) Liver function tests Bleeding time Platelet count (CBC)

Role of Nurse ANTICOAGULANTS Most serious side effect to assess is bleeding To assess internal bleeding Monitor CBC, abdominal bulging, guaiac tests on stool Essential for patient safety to assess coagulation studies Monitor intake of vitamin K-rich foods; limit intake of garlic Heparin (Heplock) Indirect thrombin inhibitor; Warfarin (Coumadin) Vitamin K Antagonist

Role of Nurse ANTIPLATELET AGENTS Monitor for bleeding Risk increases if given with anticoagulants Prolonged pressure needed to control bleeding at puncture sites Clopidogrel (Plavix) Antiplatelet drug

Role of Nurse THROMBOLYTICS To dissolve existing clots To treat acute myocardial infarction, deep vein thrombosis To treat cerebrovascular accident, pulmonary embolism, arterial thrombosis To clear IV catheters Alteplase (Activase)

Role of Nurse HEMOSTATICS To promote formation of clots by preventing and treating excessive bleeding from surgical sites Aminocaproic Acid (Amicar)

Hematopoietic Disorders

Drugs Hematopoietic Growth Factors Antianemic Drugs Erythropoietin aka epoeitin alfa (Epogen) Colony stimulatin aka filgrastim (Neuopogen) Antianemic Drugs Cyanocobalamin (Nascobal) Ferrous sulfate

HEMATOPOIESIS Process of blood-cell formation Begins with stem cell in bone marrow Erythrocytes (erythropoiesis) –RBC Leukocytes (leukopoiesis) –WBC Platelets (thrombocytopoiesis)

Hematopoiesis

Anemias Blood has reduced capacity to carry oxygen Erythrocyte loss due to hemorrhage Excessive erythrocyte destruction Impaired erythrocyte production Anemia is a sign, not a distinct disease

Anemias Classification of Anemias Common Signs and Symptoms A description of the erythrocyte’s size and color. Sizes are described as normal (normocytic) small (microcytic large (macrocytic). Color is based on the amount of hemoglobin present and described as normal red (normochromic) or light red (hypochromic). Pallor of skin and mucus membranes Decreased exercise tolerance Fatigue and lethargy, dizziness and fainting Increased respiratory rate and heart rate Heart failure

Vitamin B12 Deficiency = Pernicious or Megaloblastic Absence of intrinsic factor, protein secreted by stomach cells required for Vitamin B12 to be absorbed from intestines. Vitamin B12 & Folic Acid

Iron Deficiency Anemia Iron is an important building block for red blood cells. Without iron, blood cannot carry oxygen effectively.

Role of the Nurse Careful monitoring of client’s condition Providing education as it relates to prescribed drug treatment Assess medical, drug, dietary, and lifestyle history Obtain baseline complete blood count and vital signs

Prototype Drugs Epoetin Alfa (Epogen, Procrit) –anemia Filgastrim (Neupogen) –increase neutrophil production Cyanocobalamin (Vitamin B12) –anemia/vitamin supplement Ferrous Sulfate (Feosol) –anemia/iron supplement