Chapter 18: Blood and Blood Products

Question 1

PT

Answer 1

Prothrombin Time: Tests extrinsic coagulation pathway

PT; Play Tennis→you play tennis OUTSIDE (EXTRINSIC)

Question 2

PTT

Answer 2

Partial Thromboplastin Time: Tests intrinsic coagulation pathway

PTT; Play TABLE Tennis→you play table tennis inside (INTRINSIC)

Question 3

INR

Answer 3

International Normalized Ratio (reports PT results)

Question 4

Packed red blood cells (PRBCs)

Answer 4

• One unit equals ≈300 mL (±50 mL); no platelets or clotting factors
• can bemixed with NS to infuse faster

Question 5

Platelets

Answer 5

Replace platelets with units of platelets (6 to 10 units from single donor orrandom donors)

Question 6

Fresh frozen plasma (FFP)

Answer 6

Replaces clotting factors; (no RBCs/WBCs/platelets)

Question 7

Cryoprecipitate (cryo)

Answer 7

Replaces fibrinogen, von Willebrand factor (vWF), and some clotting factors

Question 8

Which electrolyte is most likely to fall with the infusion of stored blood? Why?

Answer 8

Ionized calcium; the citrate preservative used for the storage of blood binds serum calcium

Question 9

What changes occur in the storage of PRBCs?

Answer 9

↓Ca+, ↑K+, ↓2,3-DPG, ↑H+ (↓pH), ↓PMNs

Question 10

What is the rough formula for converting Hgb to Hct?

Answer 10

Hgb × 3 = Hct

Question 11

One unit of PRBC increases Hct by how much?

Answer 11

≈3% to 4%

Question 12

What is a type and screen?

Answer 12

Patient’s blood type is determined and the blood is screened for antibodies; a type and cross from that sample can then be ordered if needed later

Question 13

What is a type and cross?

Answer 13

Patient’s BLOOD is sent to the blood bank and cross-matched for specific donor units for possible blood transfusion

Question 14

What is thrombocytopenia?

Answer 14

Low platelet count (<100,000)

Question 15

What can be given to help correct platelet dysfunction from uremia,aspirin, or bypass?

Answer 15

DDAVP (desmopressin)

Question 16

What common medication causes platelets to irreversibly malfunction?

Answer 16

Aspirin (inhibits cyclooxygenase)

Question 17

What is Plavix®?

Answer 17

Clopidogrel—irreversibly inhibits platelet P2Y12 ADP receptor (blocks fibrin crosslinking of platelets)

Question 18

What platelet count is associated with spontaneous bleeding?

Answer 18

<20,000

Question 19

What should the platelet count be before surgery?

Answer 19

>50,000

Question 20

When should “prophylactic” platelet transfusions be given?

Answer 20

With platelets <10,000 (old recommendation was 20,000)

Question 21

How to reverse the effect of Clopidogrel (Plavix®)?

Answer 21

No reversal known. Many treat with platelet transfusion

Question 22

What is microcytic anemia “until proven otherwise” in a man or postmenopausal woman?

Answer 22

Colon cancer

Question 23

Why not infuse PRBCs with Lactated Ringer’s (LR)?

Answer 23

Calcium in LR may result in coagulation within the IV line (use NS)

Question 24

For how long can packed RBCs be stored?

Answer 24

≈6 weeks (42 days)

Question 25

What are the symptoms of a transfusion reaction?

Answer 25

Fever, chills, nausea, hypotension, lumbar pain, chest pain, abnormal bleeding

Question 26

What is the treatment for transfusion hemolysis?

Answer 26

* **Stop transfusion** * provide fluids * perform diuresis (Lasix) to protect kidneys * alkalinize urine (bicarbonate) * give pressors as needed

Question 27

What component of the blood transfusion can cause a fever?

Answer 27

WBCs

Question 28

What is the transfusion “trigger” Hgb?

Answer 28

\<7.0

Question 29

What is the widely considered “optimal” Hgb in a patient with ahistory of heart disease or stroke?

Answer 29

Focus Trial = Liberal (\<10 Hgb) vs restrictive (\<8 Hgb) Trigger = No difference in mortality or morbidity

Question 30

When should aspirin administration be discontinued preoperatively?

Answer 30

**At 1 week because platelets live 7 to 10 days** (must use judgment _if patient is a trisk for stroke or MI; it may be better to continue and use excellent surgicalhemostasis in these patients)_

Question 31

What can move the oxyhemoglobin dissociation curve to the right?

Answer 31

* Acidosis * 2,3-DPG * fever * elevated PCO2 (to the right means greater ability torelease the O2 to the tissues)

Question 32

What is von Willebrand’s disease?

Answer 32

Deficiency of vWF and factor VIII:C

Question 33

What is used to correct von Willebrand’s disease?

Answer 33

DDAVP or cryoprecipitate

Question 34

What is the most common inherited hypercoagulable state?

Answer 34

Factor V Leiden (Think: LEiden = LEader)

Question 35

18-year-old woman in high-speed motorcycle collision with subdural hematoma and flail chest; platelets = 189,000; fibrinogen= 400, ionized calcium = 2.8; PT 23 (INR = 3.4); PTT = 35

Answer 35

FFP (fresh frozen plasma)

Question 36

44-year-old man involved in a fall from scaffolding going to theoperating room for exploratory laparotomy for significant free air on CT scan; platelets = 25,000; PT = 13.1; PTT = 38; fibrinogen =200

Answer 36

Platelets

Question 37

Patient s/p (status post) prostate resection develops diffuseoozing; platelets = 200,000; PT = 13; PTT = 39

Answer 37

Amicar® (epsilon-aminocaproic acid) (an antifibrinolytic)

Question 38

56-year-old woman 1 hour s/p CABG × 4 on bypass with continued mediastinal bleeding; surgeons confirm excellent surgical hemostasis; the patient is warm, platelets 178,000; PT =12.9; PTT = 78

Answer 38

Protamine

Question 39

67-year-old patient with liver failure and s/p fall in the operatingroom for an exploratory laparotomy; the patient developsprogressive oozing; the PT and PTT are normalized; platelets =300,000; fibrinogen = 49.7

Answer 39

Cryoprecipitate—provides fibrinogen

Question 40

Patient with liver failure and poor nutrition with elevated PT that isrefractory to multiple transfusions of FFP

Answer 40

Vitamin K, prothrombin complex concentrate (PCC)

Question 41

8-year-old boy with hemophilia A with spontaneous bruising and nose bleed

Answer 41

Factor VIII

Question 42

7-year-old boy with hemophilia B with large right knee

Answer 42

F9

Question 43

23-year-old woman with von Willebrand’s disease who develops bleeding complications

Answer 43

First try DDAVP; then cryoprecipitate prn