Hematologic Emergencies
Sickle Cell Anemia
Pathophysiology
– Genetic abnormality causes red cells to contain hemoglobin S rather than hemoblobin A – At low oxygen tensions hemoglobin S forms long, rigid rods – RBCs become distorted, sickle-shaped
Sickle Cell Anemia
Pathophysiology
– Sickled RBCs cannot pass through small vessels »Thrombosis »Infarction – Sickled RBCs are fragile »Hemolysis
Sickle Cell Anemia
Incidence
– Gene present in 10% of black population (sickle cell trait) – One in every 400 to 600 blacks has sickle cell anemia
Sickle Cell Anemia
Incidence
– Also occurs in populations from
» Puerto Rico » Turkey » India » Middle East » Southern Europe » North Africa
Sickle Cell Anemia
Incidence
– Sickle cell gene survives by providing resistance to malaria
» Two normal genes = malaria = death » Two sickle-cell genes = sickle cell anemia = death » One normal gene/one sickle-cell gene = survival
– Persons with sickle cell trait survive, pass gene to offspring
Sickle Cell Anemia
Thrombotic crisis (vasoocclusive-infarctive)
– Precipitated by: » Cold exposure » High altitude » Dehydration » Infections – Gnawing pain in bones (tibias, back), joints, muscles, and abdomen
Sickle Cell Anemia
Hemolytic Crisis
– Rupture of sickled cells – Fall in hematocrit with jaundice
Sickle Cell Anemia
Aplastic Crisis
– Suppression of RBC production – Life threatening decrease in hematocrit
Sickle Cell Anemia
Complications
– Acute Respiratory Insufficiency »Thrombus formation »Pneumonia – CNS Involvement »Vascular occlusion »TIA, CVA
Sickle Cell Anemia
Complications
– Arthropathy »Aseptic necrosis »Hemarthosis »Septic arthritis – Priapism
Sickle Cell Anemia
Complications
– Renal infarction »Flank pain »Hematuria – Narcotic drug addiction
Sickle Cell Anemia
Management
– Oxygen – IV fluids – Analgesia
Hemophilia
Cause
– Inherited, sex linked recessive gene – Produces clotting factor deficiencies »Hemophilia A (Factor VIII) »Hemophilia B (Factor IX)
Hemophilia
Signs
– Swollen, painful joints – Local bleeding out of proportion to injury – Subcutaneous bleeding – Bleeding from mucous membranes – Abdominal pain, distension – Hematemesis, melena
Hemophilia
Management
– Standard techniques for hemorrhage/ hypovolemia – Apply ice packs to hemarthoses/ bleeding sites – In hospital, administration of »clotting factor »cryoprecipitate, or »fresh frozen plasma
Disseminated Intravascular Coagulation (DIC)
Pathophysiology
– Damage tissue, blood vessels, blood cells – Clotting mechanism activation – Excess clotting »Diffuse microthrombi »Consumption of clotting factors
DIC
Pathophysiology
– Split fibrin products from clots inhibit clotting – Clotting factor consumption, split fibrin products lead to: »Hemorrhage »Shock
DIC
Causes
– Gram negative sepsis – Abruptio placentae/missed abortions – Burns – Heat Stroke – Shock – Transfusion reaction with hemolysis
DIC
Signs/Symptoms
– Petechiae and ecchymosis – Bleeding from mucus membranes, orifices, venipuncture sites – Blood in urine, stool, vomitus, sputum – Signs/Symptoms of hypovolemia
DIC
All patients with predisposing conditions or who are critically ill should be monitored for signs of prolonged clotting or of bleeding
DIC
Management
– Control bleeding – Treat hypovolemia – Fresh frozen plasma or cryoprecipitate to inhibit bleeding, activate normal clotting – Identify and treat cause
DIC
Management
– Heparin to inhibit additional clotting (controversial) – Antifibrinolytic Agents (Amicar) to inhibit fibrinolysis and formation of split fibrin products (controversial)
Anticoagulant Use with Hemorrhage
Control bleeding/treat hypovolemia with standard techniques Use ice packs to supplement pressure dressings Antidotes
– Coumadin » Vitamin K, fresh frozen plasma – Heparin » Protamine sulfate
Leukemia
Definition
– Neoplastic disorder of blood cell forming tissues – Causes uncontrolled production of white cells
Leukemia
Clinical manifestations
– Decreased RBCs – Bleeding (decreased platelets) – Infection »WBC immaturity »Chemotherapy
Leukemia
Clinical manifestations
– Bone pain – Liver, spleen, lymph node enlargement – Anorexia
Leukemia
Management
– Oxygen – IV – Analgesia – Infection control procedures