hemost Flashcards

Question

which clotting factors are Vit K dependant?

Answer 1

1. platelet contraction 2. platelets: secretion of * **PDGF (platelet derived growth factor)** \> * helps repair connective tissue with plaques * proliferate smooth muscle * **VEGF (vascular endothelial growth factor)** * regenerate epithelial lining

Answer 2

= 5. step of coagulation cascade protein on surface of endothelial cells: **tissue plasminogen activator** binds to **plasminogen** that is present in the blood converts **plasminogen to plasmin** **PLASMIN eats FIBRIN** and thereore releases **D-DIMER and fibrinogen** into circulation

Answer 3

If there was formation of blood clots and fibrinolysis

Answer 4

turns plasminogen into plasmin which will eat clot

Answer 5

**enhances Antithrombin 3** activity | (AT3 _inactivates_ **2,9,10**)

Answer 6

inhibits Thromboxin A2 that is normally released by platelets when they bind together to attract more platelets

Answer 7

Vitamin K oxide reductase inhibitor -\> inhibits interaction of Vitamin K with factor 2, 7, 9, 10, protein C

Answer 8

inhibits ONLY factor 10 activation

Answer 9

* **AT -** if low: risk for increased clotting, caused by GI or renal losses, consumption with hypercoagulability * **platelet count** (decreased prod, increased destruction, incr consumption) * **D-Dimers:** if high\> increased fibrinolysis, implies hypercoagulative state * Achtung ist auch hoch in physiologischen Situationen zB Chirurgie Fibrinogen not useful bc often high bc of inflammaation

Answer 10

**E-aminocaproic acid** 20-40mg/kg in 1L NaCl IV OR **3,5mg/kg/min for 15 mins, then 0,25 CRI** inhibits plasminogen activator activity and stimulates release of a-antiplasmin that inhibits plasmin directly

Answer 11

* **LMWH:** 50IU/kg s.c. - inhibtis 10a * **Unfractionated Heparin**: enhances AT with all its consequences, 40-60IU IV/SC * **Aspirin:** prevents Txa production in platelets, 10-100mg/kg PO or 20mg/kg per rectum

Answer 12

abnormalities in min 3/5 tests: * PT * aPTT * AT * fibrinogen * D-Dimer

Answer 13

different studies horses with colic: 25-58% of them have prologed PT good prognostic indicator strangulating obstructions are associted with prol PT time

Answer 14

* increased use: * increased clotting f.e. sepsis, hemorrhage * increased destruction * immunmediated (IgG against thromb /megakaryocytes) * infections * decreased production: * neoplasia of bone marrow * idiopathic pancytopenia (PBZ)

Answer 15

Hämophilia A (no factor 8) only males (females are porters) x-chromosomal rezessiv

Answer 16

* NO, PGI2 * heparin sulfate + antithrombin III * thrombomodulin + thrombin (2) + Protein C

Answer 17

TB: 100ml/kg WB: 78ml/kg Drafts: 61ml/kg \> 6-10% of BW

Answer 18

15% of total blood without a problem might tolerate up to 25-30%

Answer 19

donkeys and mules carry this antigen on their RBCs \>\>\> predisposes mule foals for NI similar antigen on their platelets predisposing foals for alloimmune thrombocytopenia \>\>\> donkey blood should not be given to horses horse to donkey is ok

Answer 20

containing Anti Aa and anti Qa antibodies

Answer 21

Blood transfusion mL = kg × 80 mL/kg × ((desired PCV − actual PCV) /donor PCV) ~ **20% of the donor’s blood volume** (8 L in a 500- kg horse) every 30 days (give replacement if more than 15%)

Answer 22

blood bags containing 3.2% sodium citrate at a blood-to-anticoagulant ratio of 9:1. If blood is to be stored, citrate-phosphate-dextrose with adenine (CPDA) should be used and blood kept at 4 degrees

Answer 23

autologous transfer: 3 monate allogeneic transfer: mean halflife of 30d mild to mod crossmatch reaction: mild: 11d half life mod: 5 days half life

Answer 24

**The most antigenic group appears to be Aa**, with all Aa-negative horses developing antibodies if transfused with Aa-positive RBCs; _those persisted for over a year._ _Antibodies against other RBC antigens develop infrequently,_ _don't seem to appear before 1 week post transfusion_ can be detected **1** to 154 weeks after transfusion, and might disappear again after 4 weeks

Answer 25

begin slowly at **0.1 mL/kg for the first 15 minutes** checking vital parameters every 5 minutes. If no adverse reactions are observed, 20 mL/kg/hr, checking vital parameters every 10 to 15 minutes

Answer 26

16% of horses 87.5% in crossmatchincompatible transfusions * hemolysis instantly-24hours after trans * fever * type 1 hypersens reactions * if severe, possible treatments: * antihistamines (hydroxyzine 0.5–1.0 mg/kg PO q12h), * dexamethasone 0.1 mg/kg intravenously [IV]) * epinephrine (0.01–0.02 mL/kg of a 1:1000 solution IV; 5–10 mL for a 500-kg horse)

Answer 27

blood-to-anticoagulant ratio of **15:1** (0.07 mL/mL of blood) instead of 9:1 blood in contact with serosal surfaces for longer than 1 hour becomes defibrinated and platelets and coag factors decrease

Answer 28

can be used for short term if no blood available in horses (11–16 mL/kg) a foal (22 mL/kg) half life: 1,3-12 hours

Answer 29

less than 30,000 to 50,000/μL is likely to be associated with clinical signs such as petechiae or epistaxis. below 10,000/μL, active hemorrhage such as prolonged bleeding after venipuncture or hematoma formation frequently occurs clinical signs often stabilize if you go back up to 15-30

Answer 30

platelets remain in suspension when RBCs are allowed to settle by gravity as is commonly done for preparation of fresh equine plasma =\> platelet rich plasma store at 22C (under 15: dysfunction) when agitated might be stored for 5 days but bac??? extrapolation from dogs: 5L (10ml/kg) fresh whole blood for 500kg horse increases platelets by 10 000/ul

Answer 31

U/S in 25% to 42% of cases an etiology cannot be established if bleeding continues or recurs despite medical management or if the origin is surgical: retrospective study: 19% detected origin during sx about 42-57% of surgically managed horses survived

Answer 32

~ 2g/L increase through 1L Plasma 500-kg requires approx 4 to 5 L of plasma to increase TP by 10 g/L. calculation: Volume (L) = ([TP desired increase] × 0.05 × [kg]) ÷ TP Donor

Answer 33

fresh: plasma separated from blood within 8 hours of collection and stored at −18°C for up to 1 year. if longer than 1 year: frozen

Answer 34

Reactions to **commercial plasma** have a reported incidence of 8.7% in foals and 0% in adults, while the incidence with **noncommercial plasma is 10%**

Answer 35

* In foals: rib fractures * adult horses: * trauma, * neoplasm, * iatrogenic injury, * strenous treadmill exercise

Answer 36

new lateral flow immunoassay (SUCCEED Equine Fecal Blood Test) detecting equine hemoglobin at concentrations of 5 to 10 μg/g of feces (is positive 24-48 hours after rectal exam) only really useful to rule out

Answer 37

**64-times higher risk** for phenylephrine-associated bleeding was identified for **horses ≥15 years** old prepare blood transfucion immediately even if only tiny bleeding (more is coming)

Answer 38

pyelonephritis (four of seven horses were Arabians), **idiopathic hematuria**, and renal pseudoaneurysm in an Arabian colt

Answer 39

Penicillin low titers of anti–penicillin antibodies of the immunoglobulin M (IgM) class were present in 77% of horses tested. doxycycline = also a suspect

Answer 40

azathioprine (3.0 mg/kg PO q 24 h) immunsuppressiv, verwendet bei Organtransplantationen

Answer 41

reported in a **Thoroughbred and an Arabian colt.** The pathophysiology is presumed to be similar to neonatal isoerythrolysis, but the disease appears to be comparatively **rare.** single injection of **G-CSF (3.5–6 μg/ kg SC)** resulted in a considerable increase in peripheral neutrophils **granulozyten-Kolonie stimulierender Faktor**

Answer 42

characterized by the **simultaneous presence** of * IMHA, * thrombocytopenia, and/or * leukopenia in the absence of a known underlying cause **rare**, and few cases have been published in horses

Answer 43

equine infectious anemia (EIA) virus (lentivirus) Virus replication occurs in * monocytes, * dendritic cells, * tissue macrophages, and * endothelial cells

Answer 44

Once infected, horses remain lifelong carriers. Transmission occurs naturally via blood-feeding insects, particularly Tabanidae (horse and deer flies) or blood-contaminated instruments or needles.

Answer 45

**Fever and thrombocytopenia** are considered to be the most reliable clinical indicators but are far from pathognomonic for EIA **Depression, weakness, hemorrhage, peripheral edema, and weight loss** are commonly seen in the chronic form but can also accompany the acute stages.

Answer 46

varies widely depending on viral dose, virus strain, and test used (between **21 and 180** days).

Answer 47

outbreak in Ireland: **specific PCR and RT-PCR assays** * _detection of Proviral DNA integrated into the host cell_ * _detection of viral RNA_ by RT-PCR detection in all tissues, _nasal secretions, and genital swabs_, and RNA was also detected in saliva. **BLOOD testing:** **agar gel immunodiffusion assay (AGID; Coggins test)** is still most widely used test and detects antibodies against the _major core protein p26._ **100% of seropositive horses detected by serum PCR** **52% of those detected by RT-PCR**

Answer 48

equine-specific hemoprotozoa: **Babesia caballi** and **Theileria** (previously Babesia) **equi**

Answer 49

Carrier state in untreated horses is _lifelong for T. equi_ whereas _B. caballi can be cleared_ from the horse. As the carrier status **protects against active disease and reinfection**, elimination of the parasite is not desired in endemic areas.

Answer 50

EMA (equi merozoite antigens) 1 and 2 detecting cELISA

Answer 51

supportive _in endemic areas:_ no specific treatment bc carrier status is protective against reinfection _in non-endemic areas:_ **Imidocarb** diproprionate (2.2–4.4 mg/kg IM once or q 72 h for 4 doses) alongside with butylscopolamine to prevent of anticholinergic effects

Answer 52

very unspecific: * equine recurrent uveitis, * abortion, * stillbirth or * premature birth, * neonatal disease, and * renal failure RARELY: anemia and bleeding in foals pulmonary hemorrhage in adults

Answer 53

_B. caballi_ directly invades _erythrocytes_ whereas the first developmental stage of T. equi takes place in _leukocytes._

Answer 54

reported in germany infects erythrocytes of horses, dogs, cats, pigs, cattle clinical significance unknown, might cause weight loss, depression, and mild anemia PCR test Treatment: tetracyclines or fluoroquinolones

Answer 55

Oxidants can damage erythrocytes by _oxidizing the heme iron in hemoglobin from Fe2+ to Fe3+_, forming **methemoglobin** and leading to anemia -\> methemoglobinemia (also other cause fe toxic)

Answer 56

_mild anemia_ (decrease of PCV from mean 36% to 28%) with _increased Heinz body formation._ excessive sweating