Page 205 - Critical Care Notes

4223_Tab07_199-215 03/09/14 4:25 PM Page 199

199
Hematological and Oncological Disorders
Disseminated Intravascular Coagulation (DIC)
DIC is a disorder characterized by massive systemic intravascular activation of
the coagulation cascade caused by a variety of clinical conditions, including
sepsis (gram-positive and gram-negative infections), severe trauma or burns,
solid or hematological cancers, organ destruction (i.e., pancreatitis), severe
transfusion reactions, and vascular abnormalities. It can also be caused by
some obstetrical conditions, such as placental abruption, amniotic fluid
embolism, placenta previa, and retained dead fetus syndrome.
Pathophysiology
■ Activation of thrombus → fibrinogen fibrin formation and deposition of
fibrin in the microvasculature → an ↑ in platelet aggregation or adhesions →
formation of fibrin clots to form → diffuse obstruction of the smaller
vessels → progressive organ dysfunction (i.e., renal insufficiency, ARDS,
hypotension, circulatory failure, skin necrosis).
■ Concurrent with these events, platelets, prothrombin, and fibrinogen are
depleted → a deficiency of these factors compromising coagulation and
predisposing to bleeding.
■ The excessive clotting at the microvasculature level activates the fibrinolytic
system → production of fibrin degradation products (FDPs) (i.e., fibrin split
products) → an anticoagulation effect of FDP with fibrinogen and thrombin →
interference with the formation of fibrin clot and decreased platelet function →
bleeding → hemorrhagic bleeding.
Clinical Presentation
■ Bleeding (purpura, petechiae, ecchymosis)
■ GI bleeding (hematemesis, melena, tarry stools)
■ GU/GYN bleeding (hematuria, menorrhagia in women) and oliguria
■ Wound bleeding
■ Bleeding and oozing from puncture sites and around invasive catheters
and lines
■ Hematoma formation
■ Dyspnea
■ Pulmonary hemorrhage and hypoxia
■ Large foci of skin necrosis (resulting from tissue injury and necrosis
associated with compromised circulation)
■ Acrocyanosis (cyanosis of hands and feet)
■ Acute multiorgan dysfunction (characterized by hypotension, tachycardia,
oliguria, dyspnea, confusion, convulsions, coma, abdominal pain, diarrhea,
and other GI symptoms)
HEMA/
ONCO