Hematologic and Immunologic Systems 4%

Question 1

Immunosuppressive effects Malnutrition Noise Anesthetic Agents

Answer 1

Cause physiologic or psychological stress which may result in suppression of the immune system

• Malnutrition: humoral immunity
• Anesthetic agents: affect natural defense mechanisms and the actions of the immune system
• Music: noise causes stress, which has a detrimental effect on the immune system

Question 2

Management of Patient with Disseminated Intravascular Coagulation (DIC)

Answer 2

• Avoidance of injections
• Replacement of fluids, blood, and clotting factors
• Turning frequently and gently
• Manual blood pressure reading (avoid NIBP cuff readings because increased pressure can cause bruising/trauma)

Question 3

Indication for Administration of Blood

Answer 3

• Symptoms of hypoperfusion such as chest pain or dyspnea.
• Blood is necessary to carry oxygen
• Absolute hemoglobin or heamtocrit are no longer indications because of the risk of blood-transmitted diseass.
• Inability to control bleeding is an indication for surgery

Question 4

Which Labs Should Be Monitored With Multiple Blood Transfusions

Answer 4

Potassium - Hyperkalemia

• Stored blood has a high potassium content resulting from aging and hemolysis of RBCs

Calcium -Hypocalcemia

• Citrate used as an anticoagulant in banked blood
• Citrate binds with calcium that reduces the ionized calcium level and causes tetany

Question 5

Which Labs Most Specifically Indicate DIC is Cause for Bleeding

Answer 5

Fibrin Degradation Products (FDPs)

• Elevated FDPs speficially indicative of a fibrinolytic process rather than simply a clotting abnormality

D-dimer

• Form of FDP most specific to DIC

Question 6

Heparin-Induced Thrombocytopenia (HIT)

Answer 6

• Immune-mediated adverse effect of heparin
• Causes thrombosis and thrombocytopenia
• Patient receiving heparin therapy by continuous infusion
• Petechiae
• Not dose-related
• Platelets clump (white clots) which causes ischemia and platelet depletion

Question 7

What is the first sign of platelet dysfunction (quantity or quality)?

Answer 7

Petechiae

Question 8

Most common cause of a fatal transfusion reaction?

Answer 8

Mismatched blood transfusion

• Causes hemolytic reaction

Question 9

Disseminated Intravascular Coagulation (DIC)

Answer 9

• Consumptive coagulopathy (consumption of clotting factors)
• Stimulation of the clotting cascade and formation of microclots cause the consumption of clotting factors and platelets
• Stimulation of the fibrinolytic process causes formation of fibrin degradation products (FDPs) from clots
• FDPs also have an anticoagulant effect
• Always secondary and never hereditary or primary
• Results in deposition of thrombi in microvasculature (microembolism) and consumption of clotting factors (hemorrhage)

Question 10

Disseminated Intravascular Coagulation (DIC) Phases

Answer 10

1. Excessive clotting: uses up clotting factors
2. Bleeding
3. Stimulation of the fibrinolytic system

Question 11

Desired platelet count for surgical procedures

Answer 11

Platelet count 50,000/mm³

Platelet counts <20,000/mm³ are associated with spontaneous bleeding

Question 12

Why do patients receiving multiple units of packed RBCs also need to receive platelets?

Answer 12

• RBC’s do not contain platelets
• Clotting abnormalities in these patients result from hypocalcemia, thrombocytopenia, and depletion of clotting factors
• Fresh frozen plasma also is indicated to replace the clotting factors
• Patients receiving multiple units of banked blood develop ineffective clotting

Question 13

Suspected Transfusion Reaction

Answer 13

1. Stop the transfusion -The more blood that is administered = the more severe the reaction
2. Infuse normal saline at a keep-vein-open rate -Keep the IV catheter open in case emergency drugs must be given
3. Check patient’s vital signs
4. Notify the physician and blood bank
5. Order new type and crossmatch
6. Send appropriate specimens to the laboratory

Question 14

Patients with platelet count 10,000/mm3 are at great risk for what?

Answer 14

Spontaneous intracerebral hemorrhage

• Assess level of consciousness
• Manifested by changes:
  
  • LOC
  • headache
  • pupillary changes
  • focal signs
  • hemiparesis
  • hemiplegia
  • aphasia

Question 15

Lab value changes seen with one unit of packed red blood cells

Answer 15

• Increased hemoglobin by 1 g/dl
• Increased hematocrit by 3%
• Changes within approximately 4 to 6 hours

Question 16

DIagnostic panels suggestive of disseminated intravascular coagulation (DIC)

• platelets
• fibrinogen
• prothrombin time (PT)
• activated partial thromboplastin time (aPTT)
• thrombin time
• fibrin degradation products (FDPs)

Answer 16

• decreased platelets
• decreased fibrinogen
• prolonged prothrombin time (PT)
• prolonged activated partial thromboplastin time (aPTT)
• prolonged thrombin time
• increased fibrin degradation products (FDPs)

Question 17

Electocardiogram Signs of Hyperkalemia

Answer 17

• Tall, peaked T waves
• Widening QRS complex

Question 18

Why give heparin in patients in DIC?

Answer 18

Heparin neutralizes circulating thrombin to prevent clotting.

• Heparin does not affect the fibrinolytic process (plasmin - the active agent of the fibrinolytic system)

Question 19

Platelet

Answer 19

• Smallest of blood cells
• Made in bone marrow
• 200 billion produced per day
• Platelet count measures platelet quantity
• Bleeding time measures platelet function, how well platelets work

Question 20

Intrinsic Coagulation Pathway

Answer 20

• Stimulated by vascular endothelium injury
• Causes
  
  • Cell trauma (valve, IABP)
  • Sepsis
  • Shock
  • ARDS
  • Hypoxemia, acidemia
  • Cardiopulmonary arrest

Question 21

Extrinsic Coagulation Pathway

Answer 21

• Stimulated by tissue injury
• Releases “tissue thromboplastin”
• Causes:
  
  • Extensive trauma
  • OB emergencies
  • Malignancies
  • Dissecting aortic aneurysm
  • Extensive MI

Question 22

Anticoagulant Reversal

Answer 22

• Heparin = Protamine
• Warfarin (Coumadin) = Vitamin K

Question 23

DIC Lab Values

Answer 23

• Primary
  
  • Decrease Platelets
  • Decrease Fibrinogen
  • Decrease Hematocrit
  • Increase Fibrin split products (FSP) (D/t increase fibrinolysis)
  • Increase PT, PTT, INR, bleeding time
• Secondary
  
  • Increase D-dimer assesses presence of clotting
  • Increase Antithrombin III

Question 24

Normal Fibrin split products (FSP) and Fibrinogen levels

Answer 24

• FSP = < 10 mcg/mL
• Fibrinogen = 200 - 400 mg/dL

Question 25

DIC Treatment

Answer 25

* Identify and eliminate underlying cause * Vitamin K * Blood component therapy * Fresh frozen plasma (FFP) * Cryoprecipitate * Platelets * Heparin (low dose) controversial but may be used for patients with chronic, low-grade DIC who have predominantly thrombotic manifestations * Maintain hemodynamic stability

Question 26

Blood Transfusion Reactions Timing

Answer 26

* Acute Transfusion Reaction: Occurs within 24 hours of administration * Delayed Transfusion Reaction: Occurs after 24 hours of administration

Question 27

General Management of Transfusion Reactions

Answer 27

1. Stop the transfusion 2. Disconnect the blood tubing at the intravenous catheter hub, begin a new normal saline and new tubing to keep the vein open. 3. Assess the patient 4. Monitor the patient's vital signs until stable 5. Perform a clerical check on the blood product and the patient's identification

Question 28

Management of Blood Transfusion Reaction Acute hemolytic reactions (antibody mediated)

Answer 28

* Anticipate hypotension, renal failure, and DIC * Prophylactic measures to reduce the risk of renal failure may include vigorous hydration with crystalloid solutions (3,000 mL/m²/24 hr) and osmotic diuresis with 20% mannitol (100 ml/m²/bolus, followed by 30 mL/m²/hr for 12 hr) * If DIC is documented and bleeding requires treatment, transfusions of frozen plasma, pooled cryoprecipitate, and/or platelet concentrates may be indicated

Question 29

Management of Blood Transfusion Reaction Acute hemolytic reactions (non-antibody mediated)

Answer 29

* Transfusion of serologically compatible, although damanged, RBCs usually does not require rigorous management * Diuresis induced by an infusion of 500 mL of normal saline per hour, or as tolerated by the patient, until the intense red color of urine subsides

Question 30

Management of Blood Transfusion Reactions Febrile, non-hemolytic reactions

Answer 30

Acetaminophen

Question 31

Management of Blood Transfusion Reactions Allergic Reaction

Answer 31

Diphenhydramine (Benadryl) is usually effective for relieving pruritus that is associated with hives or a rash

Question 32

Management of Blood Transfusion Reactions Anaphylactic reactions

Answer 32

* Subcutaneous injection of epinephrine (0.3 - 0.5 mL of a 1:1000 aqueous solution) is standard treatment. * If patient is sufficently hypotensive to raise the question of the efficacy of the subcutaneous route, epinephrine (0.5 mL of a 1:10,000 aqueous solution) may be administered intravenously. * Steroids if epinephrine does not relieve symptoms

Question 33

Management of Blood Transfusion Reactions Transfusion-related acute lung injury (TRALI)

Answer 33

* Oxygen, mechanical ventilation if necessary * Diuretics (only if there is also volume overload or cardiogenic pulmonary edema)

Question 34

Management of Blood Transfusion Reactions Circulatory (volume) overload

Answer 34

* Oxygen * If practical, the unit of blood component being transfused may be lowered * Diuretics

Question 35

Management of Blood Transfusion Reactions Bacterial contamination (sepsis)

Answer 35

* Blood cultures * Antibiotics