Term
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Definition
| disseminated intravascular coagulation - a response to injury/insult of a blood vessel/tissue cell that results in the loss of its integrity. in DIC, coagulation occurs in all parts of the body, nearly simultaneously rather than just the site of insult. |
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Term
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Definition
| tissue/blood cells contain phospholipids which are released upon rupture, which act to coagulate and stop bleeding. in widespread injury, *many of these cells are affected, leading to utilization of large amounts of clotting factors. this leads to *consumption coagulopathy (factors are consumed), which calls the lytic process into action, degrading large amounts of fibrin and creating large amounts of fibrin degradation products (FDPs) which *contribute to bleeding by inhibition of fibrin crosslinking = platelet dysfunction. |
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Term
| what is the normal coagulation cascade (the part relevant to DIC)? |
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Definition
| thromboplastic material/phospholipids activate prothrombin->thrombin which activates fibrinogen->fibrin which activates plasminogen activator which activates plasminogen->plasmin which activates fibrinolysis and produces FDPs |
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Term
| what are clinical signs of DIC? |
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Definition
| 1) bleeding out of proportion to that expected. 2) bleeding from an unusual site (w/o trauma): IV site, gums, buccal mucosa/lips, eyes, ears, incision, and/or uterus. 3) hypotension (but normal/hypertension if volume replaced). 4) tachycardia. 5) urine output decreased. |
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Term
| when is DIC seen in obstetrics? |
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Definition
| vaginal delivery, C-section, severe preeclampsia/eclampsia, acute fatty liver of pregnancy, spontaneous abortion w/D+C or D+E, induced abortion, amniotic fluid embolism, abruptio placenta, and septic shock. (listed in order of frequency) |
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Term
| what characterizes DIC due to vaginal delivery? |
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Definition
| the placenta is a very invasive organ and sucks blood from the uterine wall, usually on a superficial level. placenta accreta is when the placenta invades just deeper than the endometrium, placenta increta is when the placenta invades 50% into the myometrium, and placenta percreta is when the placenta invades through the walls of the uterus and onto the bowels. when these invasions do not/cannot be separated at birth, the bleeding will not stop b/c the normal method of bleeding cessation is uterine muscles shrinking and closing off the blood supply. if the placenta stays stuck to the wall, the large diameter blood vessels will thus continue to bleed and if the placenta is not passed w/in 30 min of delivery, any of the placental adhesion pathologies may have to be treated via hysterectomy. |
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Term
| what characterizes DIC due to C-section? |
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Definition
| manual separation of the placenta can result in a massive release of phospholipids -> DIC |
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Term
| what characterizes DIC due to severe preeclampsia/eclampsia? |
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Definition
| preeclampsia: high blood pressure, proteinuria, abnormal LFTs. eclampsia: high blood pressure, proteinuria, seizure, abnormal LFTs. HELLP syndrome = severe form of eclampsia (Hemolysis, ELevated LFTs, Low Platelets). any of these may lead to DIC and need to be corrected. |
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Term
| what characterizes acute fatty liver of pregnancy due to severe preeclampsia/eclampsia? |
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Definition
| this occurs in late 3rd trimester and features hematemesis, severe abdominal pain, headache, jaundice, hypoglycemia (differentiates this from HELLP - due to reduced liver glycogen processing), metabolic acidosis, oliguria/anuria, somnolence, comatosity, stillborn infant, and maternal death if untreated. requires liver bx to dx. this is rare. |
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Term
| what characterizes DIC due to spontaneous abortion w/D+C or D+E? |
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Definition
| this may occur as a side effect of D+C or D+E (due to phospholipid release) |
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Term
| what characterizes DIC due to induced abortion w/D+C? |
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Definition
| D+C or manipulation of the uterine wall may lead to DIC (due to phospholipid release) |
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Term
| what characterizes DIC due to amniotic fluid embolism? |
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Definition
| amniotic protein, which is rich in proteins gets into the bloodstream and causes an anaphylactic-like reaction which leads to DIC. (rare) |
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Term
| what characterizes DIC due to abruptio placenta? tx? |
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Definition
| abruptio placenta (detachment of the placenta) causes bleeding 80% of the time. if this occurs before 20 wks, 82% will go to term, but if this occurs after 20 wks, only 27% will due to DIC/other complications. tx: IV fluids/blood. blood only irritates the uterus 17% of the time. |
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Term
| what characterizes DIC due to septic shock? organisms? |
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Definition
| septic shock in OB is due to: septic abortion, acute pyelonephritis, severe chorioamnionitis (infection of amniotic tissue/chorion which surrounds the placenta - due to infection from vagina: ruptured membranes, repeated sex w/STI+ individual, anal intercourse directly followed by vaginal), and endometritis/TSS. organisms responsible for septic shock: e. coli, klebsiella pneumoniae, proteus, pseudomonas, and enterobacter |
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Term
| what are dx tests for DIC? |
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Definition
| *US (visualize abruption, placenta previa, vasa previa, etc), *hemoglobin/hematocrit, and *coagulation profile |
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Term
| what characterizes use of the coagulation profile in dxing DIC? |
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Definition
| fibrinogen should be 450 mg/dl. platelet count should be done. check FDPs (if high, fibrinogens are probably down and DIC is likely). do PT/PTT. and clot tube trick: take a clot tube (red top, no anti-coags), tape it to the wall and if it doesn't clot in 6 min/clots+lyses w/in 30 min - likely coagulation defect, eg fibrinogen < 159 mg/dl. *repeat this and hemoglobin/hematocrit every 2 hours.* |
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Term
| what are the lab findings common to DIC? |
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Definition
| coag factors V, VIII, XIII depleted, fibrinogen < 200 mg/dl, abnormal PT/PTT, and platelets < 100,000, and FDPs *increased |
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Term
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Definition
| 1) depleted factors must be replaced faster than consumed (to permit orderly repair of injured tissues). 2) fetal monitor (toco to measure uterine contractions and FHTs). 3) blood and fluids. |
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Term
| what is DIC tx if fetal compromise (bad heart rate)? |
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Definition
| C-section - only if fibrinogen > 100 mg/dl and platelets > 100,000, if not - observe and allow to labor deliver (expediently). |
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Term
| how should blood and fluids be administered in DIC? |
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Definition
| normal saline (0.9% NaCl) for volume expansion, *w/2-3 cc per 1 cc of estimated blood loss. packed RBCs to restore O2 carrying capacity (Rh/ABO compatible - if severe emergency, use O -). packed platelets, 4-6 units over 10 min (Rh/ABO compatible - if severe emergency, use O -). fresh frozen plasma (ABO compatible, contains all coagulation factors except platelets). cryoprecipitate can also be ordered (contains factors VIII, XII, vWf, and fibrinogen). retest every 2 hours and continue tx until stable. |
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Term
| if the mother has DIC does the baby? |
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Definition
| not necessarily (no direct link of blood supply) |
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