Hematological Part 5

Hematological Disseminated Intravascular Coagulation (DIC) -primary problem: clotting -overstimulation of clotting cascade -use up all of your clotting factors until you bleed -normal clots lyse in 7-10 days, in DIC, clot lyses right away -whenever clot lyses into fibrin split products, they are anticoagulant in themselves and make you bleed even more -DIC affects the clotting cascade -can make a clot via instrinsic or extrinsic pathway → intrinsic = endothelial injury (ARDS, septic shock, hypotension) clotting factors 12, 11, 9, 8 → extrinsic = tissue injury (releases tissue thromboplastin), clotting facor 7 → placenta and brain have highest amount of tissue thromboplastin, so head problems and obstetrical emergencies have high risk for DIC -then factors 5, 10 and calcium → prothrombin → thrombin → fibrinogen → fibrin → clot → FSP (lyses into fibrin split products in about 7-10 days, or right away in DIC and causes bleeding) *DIC = decreased fibrinogen levels (because you are using up all of your clots), increased PT and PTT, increased fibrin split products, increased D-Dimers *Treatment = heparin → stops the clotting cascade (bolus, then drip) -then give fresh frozen plasma (FFP) -then give cryoprecipitate (8, 13, fibrinogen) -you NEED to give heparin first, or else you're just giving more and more clotting factors that are lysing right away and causing more bleeding -get rid of the triggering event/cause Heparin -Heparin inhibits the conversion of prothrombin into thrombin -inactivates circulating thrombin -inhibits the conversion of fibrinogen into fibrin -works all over the place (prevents and breaks down clots), works on both pathways, prevents from making new clots and breaks current clots down Heparin Induced Thrombocytopenia (HIT) -In patient who do not have anti-thrombin III, heparin may have the opposite effect, thus causing the blood to clot -your body needs anti-thrombin III to metabolize heparin, so if the pt does not have anti-thrombin III, their PTT will not budge because they cannot metabolize heparin, it will not affect their clotting cascade -in these pts, heparin has the opposite effect → causes their blood to clot -Argatroban (ACOVA) =a thrombin inhibitor which does not require anti-thrombin III Immune System Lymphocytes B Cells: humoral immunity, immunoglobulins, bacteria -makes IgM, IgA, IgD, IgG, IgE -navy: goes through body tissues looking for bacteria T Cells: tissue (cellular) immunity, helper T-cells, virus, transplant -like the army, track through tissues looking for viruss and newly implanted organs -cyclosporin = T cell supressor, stops you from attacking the newly implanted organ Practice Questions 1) The most common immunoglobulin whose primary effect against bacterial disease is: -IgG (made by B cells) 2) Which of the following statements regarding cellular immunity is TRUE? -it is important in development of autoimmune and graft rejection 3) The immediate adminstration of which of the following is essential in the initial management of anaphylaxis? -Epinephrine 0.5-1 mL of 1:1,000 solution 4) Which of the following blood products contains only factors VIII, fibrinogen, and XIII and is utilized in hemophilia A and DIC? -Cryoprecipitate 5) Disseminated intravascular coagulopathy is: -Widespread inappropriate clotting that triggers bleeding 6) The pathophysiology of DIC includes: - Enhanced production of intravascular thrombin resulting in increased fibrin and platelet aggregation 7) Which of the following laboratory findings is NOT likely to be seen in DIC? -fibrinogen increased (fibrinogen level is low in DIC because you are using all your clotting factors) -would be seen in DIC = PT and PTT prolonged, platelet count decreased, fibrin split products elevatd 8) Which of the following laboratory diagnostic findings is MOST LIKELY to be seen in DIC? -PT and PTT prolonged 9) The intrinsic system of blood clot initiation is: -activated by endothelial injury 10) Release of what substance into the circulation secondary to retained dead fetus, abruptio placenta, and stress may cause DIC? -tissue thromboplastin 11) The beneficial effects of heparin in DIC are thought to be due to its: -neutralizing of free-circulating thrombin