Ch. 17 - Hemolytic and Immune Disorders Info to Know

What is the normal hemoglobin (Hgb) range for males?

14-18 g/dL

What is the normal hemoglobin (Hgb) range for females?

12-16 g/dL

At what hemoglobin level is blood transfusion commonly considered?

Below 7 g/dL, depending on the patient's condition and clinical situation

What is the normal hematocrit (Hct) range for males?

42-52%

What is the normal hematocrit (Hct) range for females?

37-47%

How does hematocrit relate to hemoglobin?

Hematocrit is approximately 3 times the hemoglobin value

What is the normal RBC count for males?

4.7-6.1 million/mm³

What is the normal RBC count for females?

4.2-5.4 million/mm³

What does a low RBC count suggest?

Anemia

What is the normal WBC count?

5,000-10,000/mm³

What does a low WBC count increase the risk of?

Infection

What is the normal platelet count?

150,000-400,000/mm³

At what platelet count is spontaneous bleeding a major concern?

Below 20,000/mm³

What is the normal reticulocyte percentage?

0.5-2%

What does a high reticulocyte count indicate?

The bone marrow is responding by producing more red blood cells, often after blood loss or hemolysis.

What is the normal PT (prothrombin time)?

Approximately 11-12.5 seconds

What does PT evaluate?

Primarily the extrinsic and common coagulation pathways.

What can prolong PT?

Warfarin, liver disease, and clotting factor deficiencies.

What is the normal INR?

Approximately 0.8-1.1 in patients not taking warfarin.

What is the typical INR therapeutic goal for warfarin?

2-3 for many indications; 2.5-3.5 for some mechanical heart valves.

What does INR monitor?

Warfarin therapy.

What is the normal aPTT?

Approximately 30-40 seconds.

What does aPTT evaluate?

Primarily the intrinsic and common coagulation pathways.

What medication is commonly monitored using aPTT?

Unfractionated heparin.

What is a typical therapeutic aPTT goal for heparin?

About 1.5-2.5 times control, depending on the laboratory and protocol; anti-Xa may be used instead.

What is the normal fibrinogen level?

200-400 mg/dL.

What happens to fibrinogen in DIC?

It often decreases because fibrinogen is consumed during widespread clotting.

What blood product replaces fibrinogen?

Cryoprecipitate; fibrinogen concentrate may also be used depending on the situation.

What is a normal D-dimer result?

Negative or low, depending on the assay.

What does an elevated D-dimer indicate?

Increased clot formation and breakdown; it can occur with DVT, PE, and DIC, but is not specific to these conditions.

What lab monitors warfarin?

PT/INR.

What reverses warfarin?

Vitamin K; 4-factor PCC for urgent reversal, with plasma as an alternative if PCC is unavailable.

What is the specific reversal agent for dabigatran?

Idarucizumab (Praxbind).

What should be monitored in a patient taking dabigatran?

Bleeding and renal function.

What reverses apixaban or rivaroxaban?

Andexanet alfa, where available and appropriate, or 4-factor PCC according to protocol.

What should be monitored in a patient taking apixaban or rivaroxaban?

Bleeding and renal function.

Which anticoagulant is reversed by protamine sulfate?

Unfractionated heparin; enoxaparin is only partially reversed.

Which anticoagulant is reversed by vitamin K?

Warfarin.

Which anticoagulant is reversed by idarucizumab?

Dabigatran.

Which anticoagulants may be reversed by andexanet alfa?

Apixaban and rivaroxaban.

What is the priority for life-threatening bleeding on an anticoagulant?

Stop or hold the anticoagulant when appropriate, assess and stabilize the patient, notify the provider, and prepare for specific reversal treatment.

When is fresh frozen plasma (FFP) given?

Multiple clotting factor deficiencies, selected cases of DIC, or massive transfusion.

Must FFP be ABO compatible?

Yes. Plasma must be ABO compatible with the recipient.

What is a major risk of FFP transfusion?

Volume overload.

When is cryoprecipitate given?

Low fibrinogen, including in selected cases of DIC or major bleeding.

Which clotting components are found in cryoprecipitate?

Fibrinogen, factor VIII, factor XIII, and von Willebrand factor (vWF).

Which blood product increases oxygen-carrying capacity?

Packed RBCs.

Which blood product helps treat thrombocytopenia?

Platelets.

Which blood product replaces multiple clotting factors?

Fresh frozen plasma (FFP).

Which blood product is rich in fibrinogen?

Cryoprecipitate.

What is a key safety rule for blood transfusions?

Verify patient and blood product identification, use the required blood tubing and compatible fluid, and monitor closely for transfusion reactions.

What should you do if a transfusion reaction is suspected?

Stop the transfusion, maintain IV access with normal saline using new tubing, assess the patient, and notify the provider and blood bank per protocol.

What does ANC stand for?

Absolute neutrophil count.

What is the formula for ANC?

WBC × (% segs + % bands) ÷ 100.

What are segs?

Mature segmented neutrophils.

What are bands?

Immature neutrophils.

A patient has WBC 2,000/mm³, segs 20%, and bands 5%. What is the ANC?

500/mm³. Calculation: 2,000 × (20 + 5) ÷ 100 = 500.

What ANC indicates neutropenia?

ANC below 1,500/mm³.

What ANC indicates moderate neutropenia?

ANC below 1,000/mm³; commonly classified as moderate at 500-999/mm³.

What ANC indicates severe neutropenia?

ANC below 500/mm³; highest risk of serious infection.

Why is a low ANC dangerous?

Neutrophils fight infection, so a low count increases the risk of serious infection.

What is tumor lysis syndrome (TLS)?

Rapid cancer cell breakdown releases intracellular contents into the blood.

Which cancers increase TLS risk?

High-grade lymphoma, leukemia, and bulky tumors.

When does TLS commonly occur after chemotherapy?

Often within 12-72 hours.

What happens to potassium in TLS?

Increases (hyperkalemia), risking life-threatening dysrhythmias.

What happens to phosphate in TLS?

Increases; phosphate binds calcium.

What happens to calcium in TLS?

Decreases (hypocalcemia), potentially causing tetany and seizures.

What happens to uric acid in TLS?

Increases and can cause acute kidney injury.

How can TLS be prevented or treated?

IV hydration as tolerated; allopurinol prevents new uric acid, and rasburicase lowers existing uric acid.

What should nurses monitor in TLS?

Electrolytes, ECG, creatinine, and urine output.

When might dialysis be needed for TLS?

Severe kidney injury or dangerous, treatment-resistant electrolyte abnormalities.

What causes HIT, and when does it usually occur?

Antibodies attack heparin-PF4 complexes and activate platelets; usually 5-10 days after starting heparin.

What platelet change suggests HIT?

A platelet drop of 50% or more from baseline.

Why does HIT cause clotting instead of bleeding?

Antibodies activate platelets, causing dangerous clots while platelets are consumed.

What tests identify HIT?

PF4/heparin antibody immunoassay; serotonin release assay (SRA) confirms platelet-activating antibodies.

What should you do if HIT is suspected?

Stop all heparin, notify the provider, and anticipate a non-heparin anticoagulant.

What is DIC?

A life-threatening condition where widespread clotting consumes platelets and clotting factors, causing both clots and bleeding.

What happens to platelets and fibrinogen in DIC?

Both decrease because they are consumed forming widespread clots.

What happens to PT/INR and aPTT in DIC?

Both increase (prolong) because clotting factors are depleted.

What happens to D-dimer and fibrin degradation products (FDPs) in DIC?

Both increase due to widespread clot formation and breakdown.

What are schistocytes, and why are they seen in DIC?

Fragmented red blood cells caused by shearing as they pass through fibrin-rich microclots.

What are common causes of DIC?

Sepsis, major trauma, and obstetric emergencies.

What is the priority treatment for DIC?

Treat the underlying cause; provide supportive care and blood products when indicated.