Hemostasis & Coagulation Flashcards
Which step in the Hemostasis process would be affected most by a von Willebrand disease
the 3rd step consisting of the contraction of the platelet plug
What substance would you expect to see missing/defected if their was a problem dissolving clots?
the transfer from plasminogen to plasmin
whats the first of 4 steps in the hemostasis process from an injury.
vascular constriction limiting blood flow to affected area
describe the process that platelets derive from…
pluripotent stem cells-megakaryoblasts-promegakaryocytes-megakaryoctyes-breaking into fragments of platelets
why would you recommend a pt stop taking aspirin about 1 week before surgery?
since platelets life span ranges 7-10 days you would want all the effects of aspirin (antiplts) to wear off so they could heal up/clot after cutting/suturing them.
where do your platelets normally reside?
1/3 in spleen and 2/3 circulating
How would you expect the platelets to be affected by a pt with cirrhosis and why?
Circulating platelet counts may be lowered due to hypersleenomegaly and its resulting eating up of the plts.
This mutation has a defect in which the clotting factor is not inactivated by activated Protein C (APC) hence putting the pt at increased risk for clotting
Leiden Factor V
What would you treat a pt presenting with unusual amounts of post-op bleeding with normal PT & PTT’s
Desmopressin (stimulates release of vWF from endothelium)
this is the most common inherited bleeding disorder; often found due to surgery follow up with unexplainable levels of bruising
von Willebrand disease
why would you add citrate to a “blue top” test tube while checking someone’s blood for PT (prothrombin time)
citrate will chelate the Ca++ present; giving the sample time to arrive at lab before clotting since Ca++ will cause it to clot. Once ready, they add Ca++, TF’s & thromboplastin back and measure time
why is the INR paired with PT if it is already controlled with citrate to block calcium
Labs use variety of sources of thromboplastin so this helps to normalize the measurement.
what is the D-Dimer test used for?
to measure FDP (fibrin degradation products) which result from plasmin dissolving clots; useful to detect DVTs or process’ like DIC
this drug is counterindicated for pregnant women because it is known to have tetragenic effects
Warfarin
How could you reverse the effects of heparin
adm. protamine
describe the MOA Heparin works to be an anticoagulant
increases effectiveness of antithrombin III (an endogenous substance) which inhibits Xa
in a normal healthy endothelium layered vessel, how would you expect the plts
inactive
what are factors contributing to the endothelium’s healthy inactive plt environment
NO, prostacyclines (PG I2) and endogenous heparin substances
this drug can cause skin necrosis
warfarin
this drug can cause blue toe syndrome
warfarin
how can you reverse a pt that is bleeding who takes warfarin
vitamin K
If you wanted to choose the strongest class of antiplatelets which pathway would you choose to interfere with?
inhibiting GPIIB/IIIA
Which factor is deficient with Hemophilia A
F. VIII
Which factor is def. in Hemophilia B
F IX
which factor is def. in hemophilia C
X1
which population is most often affected by Hemophilia C
Ashkanazie & iraqi Jewish
what is the cause of Hemophilia disorders
X-linked recessive
which gender is most likely affected by Hemophila A
Males, females will be asx carriers
how would you treat hemophilia A/B
Cryoprecipitate; Factors VIII or IX replacement
what would you expect to see across the routine labs ordered for Hemophilac patient?
Normal plt count & bleeding time, Prolonged aPTT (b/c Factor 8 is only seen in the intrinsic pathway hence no affect on PT which deals wit extrinsic pathway)
What is the term consumptive coagulation describe
Disseminated intravascular coagulation (DIC)- refers to the using up of coag. factors & plts which leads to systemic bleeding
this pt presents with bruising, hemorrhaging, and hemoarthrosis (bleeding into the joint) typically males
Hemophiliac
What would classify a neutropenic fever
1 oral temp. >101 (38.3) OR 2 temps > 100.4 (38.0) separated by 1 hour
ANC refers to
absolute neutrophil count
How would you categorize someone with a ANC < 500
severe neutropenic fever
whats the most common cause of DIC
bacterial sepsis
what are some other causes of DIC in addition to bacterial sepsis
obstetric complications & malignant d/o
which labs would u order to narrow your suspicion of DIC
routine : aPTT, PTT, plt count, **FDP most sensitive
How would u treat DIC
4 main: 1) treat underlying cause, 2) replace coag factors & plts 3) control coag state -heparin 4) support pt -ventilator, dialysis, or transfusion
why would you normally not see Vitamin K deficiency due to dietary shortages alone?
Vit. K is synthesized in our gut by colonic flora
In what few instances would u suspect Vit K defieciency due to dietary causes….
alcoholics, malnourished, those on parenteral nutrition without a Vit K supplement
What are some main causes of Vit. K deficiency
iatrogenic: either surgical interventions alter GI making it ineffective to absorb or long term abx use wiping out normal colonic flora; chronic liver dz such as primary biliary cirrhosis; otherwise warfarin
what would you suspect in a low plt count in an otherwise normal healthy ind.
pseudothrombocytopenia
vasodilator substances such as NO and PG I2 (prostacyclin) are normally functioning how
inhibit platelets
What tumor marker is associated with hepatpcellular cancer; germ cell cancers.
Alphafetoprotein (AFP)
What cancer is associated with the carcinoembryonic antigen (CEA) tumor marker
bowel & breast; used to cx if colorectal ca has spread & recurrence/tx response of breast.
what cancer is associated with the CA-125 tumor marker
ovarian cancer (used 4 diagnosis, assess response to tx, evaluate 4 recurrence)
what marker is used to check for prostate cancer
prostate specific antigen (PCA)
which tumor marker is associated with breast cancer; used to determine whether tx w/ hormonal therapy (tamoxifen) is appropriate
estrogen receptor
what cancer(s) is associated with the tumor marker HER2/neu
breast & gastric; (assess tx with trastuzumab)
What is the Ann Arbor Staging system used for…
certain cancers don’t follow TNM staging like leukemia, lymphoma, & myeloma
Describe the 4 stages of Ann Arbor staging system
I- one lymph node II-2 or > same side diaphragm III-nodes on both side and IV-spread to organs (spleen/liver)
What is the Gleason score most often associated with
prostate cancer
How would you distinguish Class A and B for Ann Arbor
A is asx vs. B-fever, night sweats
What signs/sx would you expect to find with Superior Vena cava syndrome tht would indicate an oncologic emergency
neck & face swelling, dilated neck viens, edema of face, cyanosis as obstruction results in impaired venous return
Tumor Lysis syndrome (a tx-related emergency) is identified with what findings:
hyperuricemia, hyperkalemia, hyperphosphatemia, & hypocalcemia
pt presents with pain that is colicky in nature (comes & goes) Upon PE you find **High pitched bowel sounds, abd distenstion w/ tympany, ascities, and visible peristatsis….. what is the diagnosis? How would you treat this pt?
Most likely a tumor obstruction in the intestine, this is an Emergency & should intervene surgically.
how would you describe cauda equine syndrome
low back pain, diminished sense of sensation over butt, saddle sign (numbness in perineal area), rectal & bladder dysf. lower ext. weakness
what oncological emergency would you worry about with the symptoms associated with the cauda equine syndrome
malignant spinal cord compression
what is the most common neoplastic syndrome resulting from an overproduction of PTHrP (parathyroid hormonone related protein)
hypercalcemia
this pt presents with hyperparathyroidism, (osteoporosis, kidney stones, excessive urination, abd pain, weakness, N&V, or loss appetite)
hypercalcemia due to a tumor calling for medical emergency
What two things would an aPTT be useful for
heparin & hemophiliacs
what two things would be useful for PT time
warfarin & liver disases
how would you tx a high risk neutropenic fever pt
Admit, start on anti-pseudomonal cephalosporins
how would u tx a low risk pt with suspected neutropenic fever
tx: oral cipro with augmentin or if PCN allergy=cipro with clindamycin… OBSERVE 4 hours b4 dx and f/u 24hrs
what are two caveats to high risk neutropenic fever pts that would indicate the need for adding aminoglycoside
pneumonia or evidene of gram - bacteria (klebsiella)
if a pt with neutropenic fever are suspected to have abd sxs or Cdiff. what medication could be given to help
metronidazole
Vancomycin can be used for neutropenic pts with certain cases:
resistnce to or prior use of cipro/cephalosporin TMP/SMX PCN allergy, hypotenstion. indwelling catheters/lines, mucositis
