19.1 Disseminated Intravascular Coagulation and Hemorrhage

CPHON Test Content Outline (TCO) V.D.1–2 tests disseminated intravascular coagulation (DIC) and hemorrhage as oncologic emergencies. This is not the Domain IV nadir lecture, not the hemophilia joint-bleed chapter, and not a demand that you recite every adult International Society on Thrombosis and Haemostasis milligram cutoff as Oncology Nursing Certification Corporation (ONCC) fact. The CPHON product is a nurse who recognizes the acute promyelocytic leukemia (APL) coagulopathy, supports sepsis-associated DIC, reads a consumption panel, and does not put a needle in a muscle or a thermometer in a rectum while the child is bleeding.

A 12-year-old with new bruising and gingival oozing, a toddler in septic shock whose fibrinogen is falling, and a 7-year-old with a platelet count of 8,000/µL who says the head hurts are the same domain at different forks.

APL (PML-RARA): treat the leukemia, support the coagulation

APL is the classic pediatric oncology DIC. The driver is the PML-RARA fusion from t(15;17). Promyelocytes express tissue factor and annexin II, which generate thrombin and accelerate fibrinolysis at the same time. The child consumes clotting factors, fibrinogen, and platelets and bleeds from mucosa, intravenous sites, the gut, the alveolar space, and the brain.

Tretinoin (all-trans retinoic acid, ATRA) differentiates the APL clone. Arsenic trioxide is paired with tretinoin on contemporary cooperative-group pathways. The emergency move is start differentiation therapy as soon as APL is suspected. Do not wait a week for a fluorescence in situ hybridization (FISH) report while the child has an intracranial hemorrhage. Blood products support coagulation; they do not replace treating the APL. Differentiation syndrome—weight gain, hypoxia, fever—is a later cardiopulmonary watch from the cardiovascular-effects chapter. Do not skip tretinoin on hour one because you are afraid of that syndrome.

Walk the 12-year-old. The smear shows promyelocytes with Auer rods. The mouth is oozing. Prothrombin time (PT) and partial thromboplastin time (PTT) are prolonged, fibrinogen is 80 mg/dL, D-dimer is markedly elevated, and platelets are 22,000/µL. The nurse's job is a working intravenous line, a type and crossmatch, cryoprecipitate and platelets as ordered, and getting tretinoin to the bedside—not a debate about whether this might just be immune thrombocytopenia.

Sepsis-associated DIC: treat the cause

Infection, especially gram-negative sepsis during neutropenia, is the other high-yield DIC trigger. Endotoxin and inflammatory cytokines flip endothelium to a procoagulant surface. Microthrombi form, factors and platelets are consumed, and then the child bleeds. Treat the sepsis—cultures that do not delay an antipseudomonal beta-lactam, isotonic fluids, intensive care—while you replace what the cascade ate. Therapeutic heparin is not first-line pediatric bedside DIC care in a bleeding child. Do not import an adult heparin-for-every-DIC script as ONCC fact.

A 3-year-old on acute myeloid leukemia (AML) induction with fever, mottled skin, a fibrinogen that dropped from 280 to 90 mg/dL, and oozing around the port dressing has sepsis-associated DIC until proven otherwise. Products without antibiotics will not flip the switch back. Recheck the coagulation panel after each product set; ongoing consumption means the numbers fall again until the infection is controlled.

The laboratory cluster

DIC is a pattern, not a single number:

• Prolonged PT and PTT because factors are consumed
• Low fibrinogen because it is used up and lysed
• High D-dimer because fibrin is being made and broken
• Dropping platelets
• Schistocytes on smear are variable—more classic for thrombotic microangiopathy. Do not refuse a DIC diagnosis because the smear is quiet.

Isolated thrombocytopenia with a normal PT, PTT, fibrinogen, and D-dimer is not DIC. A high fibrinogen is an acute-phase finding, the opposite of consumption.

Replacement as ordered:

• Cryoprecipitate (or fibrinogen concentrate on some pathways) to restore fibrinogen
• Platelets for thrombocytopenia with bleeding or for a planned invasive procedure
• Fresh frozen plasma (FFP) for factor replacement when PT/PTT are prolonged and the child is bleeding

Give products for bleeding or a procedure, not to normalize every computer field. Recheck the panel after transfusion. Ongoing consumption means the numbers fall again until the cause—APL or sepsis—is treated.

Hemorrhage: three sources that look like blood

Mucocutaneous bleeding (petechiae, purpura, gingival ooze, epistaxis), central nervous system (CNS) bleeding, gastrointestinal bleeding, and alveolar hemorrhage are the sites that kill. Alveolar hemorrhage presents with hypoxia, crackles, and a falling hematocrit, sometimes with frank hemoptysis in an older child.

Name the source, because the product and the precaution change:

• Thrombocytopenia: petechiae, mucosal oozing, a wet mouth. Platelet transfusion as ordered.
• Coagulopathy (DIC or liver failure): oozing from line sites, deep hematomas, prolonged bleeding after a stick. Cryoprecipitate and FFP as ordered; treat the cause.
• Mucositis: local bleeding from chemotherapy-injured mucosa even when the platelet count is not rock-bottom. Local care, platelets if the count is also low, and do not assume every bloody mouth is DIC.

Hold intramuscular (IM) injections. No rectal temperatures or rectal medications. Avoid unnecessary venipuncture and nasogastric trauma. The platelet threshold for lumbar puncture (LP) is protocol-specific and is often higher than the threshold for a peripheral stick or even a central-line placement. Many Children's Oncology Group (COG) pathways want a higher count before a needle enters the spinal canal because a spinal hematoma is a paralysis emergency. Do not treat a single 10,000/µL number as the ONCC LP rule. Follow the treating protocol.

Headache plus thrombocytopenia is an emergency computed tomography (CT) scan for intracranial hemorrhage, not acetaminophen-and-reassess-after-lunch. A 7-year-old with platelets of 8,000/µL who is newly photophobic, vomiting, or just not herself is a same-hour CT, platelet support as ordered, and a neurosurgery call—not a playroom time-out. Teach families that a new severe headache, unequal pupils, or sudden confusion during a platelet nadir is a 911 or oncology-emergency-line event, not a wait-until-clinic story.

That is TCO V.D.1–2: start tretinoin for suspected APL while you replace fibrinogen, platelets, and plasma; treat sepsis as the other DIC switch; read the consumption panel; and treat headache plus a low platelet count as a brain emergency.