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190 Cards in this Set
- Front
- Back
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anesthesia providers adminster what amt of all blood products in the US
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50%
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what are the 3 steps in the hemostasis process
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1-traumatized blood vessel contracts
2-primary hemostasis 3-secondary hemostasis |
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what are the ways in which a traumatized vessel contracts
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*neural reflexes
*direct mucular tissue response *local humoral factors |
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what is primary hemostasis
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platelet plug is formed at the site of blood vessel injury
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platelets attach to exposed collagen via what
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von Willebrands factor (vWF)
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how does von Willebrands factor attach
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one end attaches to the platelet and the other end to a receptor on the collagen
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von Willebrands factor is synthesized and released by what
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endothelial cells
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von Willebrands factor is blood coagulation factor ______
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VIII:vWF
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von Willebrands factor regulates the production and release of what
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factor VIII:C
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von Willebrands factor serves as a carrier in the blood for what
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factor VIII:C
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where is factor VIII:C made
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in the LIVER
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as platelets attach to collagen they do what
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degranulate
-releasing cytoplasmic granules containing ADP, serotonin & thromboxane A2 into the blood |
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what does ADP do in regards to platelets
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attracts more platelets to the area
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what does thromboxane A2 do in regards to platelets
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promotes platelet aggregation, degranulation and vasoconstriction
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what does serotonin do in regards to platelets
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promotes vasoconstriction
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what anchors the platelets to each other
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fibrinogen (factor I)
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during coagulation what promotes more platelet adhesion and therefore more ADP and thromboxane
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ADP and thromboxane A2
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ASA and NSAIDs do what
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inhibit production of thromboxane A2 by blocking the COX pathway
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the most common platelet defect is d/t what
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inhibition of thromboxane A2 production
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ticlopidine (Ticlid) and clopidogrel (Plavix) do what
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inhibit ADP induced fibrinogen aggregation of platelets
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platelet plug is normally formed within how long
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5 min
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is the coagulation cascade involved in the formation of a platelet plug
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NO
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what is the life span of a platelet
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7 to 10 days
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what is normal platelet count
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150,000 to 400,000 cells per ml
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approx 33% of platelets are sequestered where
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in the spleen
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aged platelets are removed by what
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*spleen
*reticuloendothelial system |
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a clot begins to form within how long
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15 to 20 sec
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it takes approx how long for clot retraction to close the vessel
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20 min to 1 hr
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the fundamental reaction in blood clotting is what
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the conversion of fibrinogen to fibrin by the action of thrombin
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what normally predominates in the blood procoagulants or anticoagulants
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ANTICOGULANTS
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the coagulation cascade can be activated in response to what
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*tissue trauma (EXTRINSIC)-triggering the release of tissue factor
*(INTRINSIC) damage to the endothelium or blood |
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what is another name for tissue factor
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factor III or thromboplastin
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what are the 3 essential steps necessary for clotting to take place
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1-prothrombin activator is formed in response to damaged vessel or blood itself
2-prothrombin activator catalyzes the conversion of protorombin to thrombin 3-thrombin converts fibrinogen to fibrin |
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platelets & RBC entrapped in the fibrin network of a clot release what and what does this cause to occur
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factor XIII
-this causes covalent cross-linking of the fibrin threads |
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what is released that causes contraction of the clot
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*actin
*myosin |
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clot retraction does what
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pulls the edges of the blood vessel together
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most of the fluid is expressed from the clot within how long
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20 min to 1 hr
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fluid from a clot is what
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serum
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what is serum devoid of
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*fibrinogen
*most clotting factors |
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what is the difference b/t serum and plasma
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serum LACKS clotting factors
-plasma has them |
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what factors contribute to the prevention of intrinsic initiation of the coagulation process in NORMAL vasculature
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*smoothness of vascular endothelium
*rapid movement of blood *neg charged molecules on the inner surface of the vascular endothelium repels plts and clotting factors *heparan *thrombomodulin *protein C *prostocyclin *heparin |
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what does heparan sulfate do
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activates a circulating protein antithrombin III which inhibits thrombin and factor X
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where is heparan located
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on the luminal surface of vascular endothelial cells
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what does thrombomodulin do
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binds thrombin
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what is protein C
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a plasma protein that is activated by the thrombomodulin-thrombin complex to inactivate factors V and VIII
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what is protein S
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is a cofactor of protein C and enhances the effects of protein C
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prostacyclin is synthesized by what
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vascular endothelium
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what does prostacyclin do
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potent inhibitor of plt aggregation and inhibits adhesion of activated plts to the endothelial surface
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where does HEPARIN occur
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intracellularly in tissues containing mast cells
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where are mast cells prominenant
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in tissues near pulmunary capillaries and to a lesser extent the liver
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activated coagulation factors are cleared by what
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*liver
*reticuloendothelial system |
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with clot dissolution what system is activated
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fibrinolytic system
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the fibrinolytic system is activated when
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injured tissues and vascular endothelium release a substance known as tissue plaminogen activator (TPA) along with urokinase
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what do urokinase and tPA do
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act upon plasminogen converting it to plasmin
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what is plasmin
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a proteolytic enzyme that cleaves (digests) fibrin
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prothrombin time (PT) measures what pathways
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EXTRINSIC and final common
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what coagulation test is used to measure effect of warfarin
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PT (prothrombin time)
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what is the normal prothrombin time (PT)
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12-14 sec
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partial thromboplastin time (PTT) measures what pathways
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INTRINSIC and final common
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what coagulation test is used to measure effect of heparin therapy
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partial thromboplastin time (PTT)
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what is the normal partial thromboplastin time (PTT)
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25-35 sec
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partial thromboplastin time (PTT) will detect what deficiencies
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> 25% except factors VII and XIII
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activated coaguation time (ACT) measures what pathways
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INTRINSIC and final common
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what coagulation test is the most common measure of heparin therapy in the OR
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activated coagulation time (ACT)
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what is the normal activated coagulation time (ACT)
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80-150 sec
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platelet count measures what
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QUANTITY only
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what is the normal platelet count
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150,000-400,000/mm3
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spontaneous bleeding rarely occurs with plt counts above what
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50,000
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a plt count of at least what is recommended for elective or invasive procedures in anesthesia
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100,000
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what test measures both the quality and quantity of platelets
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bleeding time
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what is the normal bleeding time
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3-8 min
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thrombin time measures what
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final common pathway only specifically factors I and II
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fibrinogen levels below what will prolong the thrombin time
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90 mg/dl
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the best means of detecting a bleeding problem is what
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a properly taken history
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what is the most common coagulation disorder
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von Willebrands disease
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how is von Willebrands inherited
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as an autosomal dominant trait affecting both sexes
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vWF is necessary for what
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platelet adherence to collagen
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what is type 1 von Willbrands
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inadequate production of normal amts of vWF from the endothelial cells and may have decreased factor VIII:C as well
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what is type 2 von Willebrands
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involves a qualitiative abnormality in vWF itself
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what is type 3 von Willebrands
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total absence of vWF an involves deficiences in factor VIII:C of less than 10% of normal
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characteristically people with von willebrands have what signs
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*history of bruising
*mild bleeding usually from muscosal surfaces |
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what is the traditional tx for von Willebrands
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replacement of VIII:vWF with cryoprecipitate or desmopressin (DDAVP)
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what is the treatment regimen of DDAVP for von Willebrands
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*0.3 mcg/kg 30 min prior to sx
or *prophylactic infusions x2 days for 2-4 days |
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how does DDAVP work in von Willebrands
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it is a nonpressor analogue of vasopressin that causes release of endogenous stores of vWF
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with DDAVP and von willebrands platelet adhesion is increased within what amt of time and lasts how long
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*30 min
*4-6 hrs |
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for von Willebrands what is the preferred replacement source of VIII:vWF
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factor VIII concentrate
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what is hemophilia A
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a sex-linked recessive genetic disorder carried by females and affecting males
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with hemophilia A what is there a deficiency of
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factor VIII:C
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what is normal with hemophilia A
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normal amts of VIII:vWF
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what is the incidence of hemophilia A
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1:10,000 male births
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what is the major cause of death with hemophilia A
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CNS bleeding
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what is the best screening test for hemophilia A
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PTT
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what is the TRADITIONAL tx for hemophilia A
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*cryoprecipitate
*FFP |
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what is the PREFERRED tx for hemophilia A
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factor VIII concentrate
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what is hemophilia B
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a sex-linked recessive genetic disorder d/t a deficiency of factor IX
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what is the incidence of hemophilia B
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1:25,000 male births
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what is the tx for hemophilia B
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factor IX concentrate
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what are the 3 clotting factors that are NOT produced in the liver
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*von Willebrands
*Ca (factor IV) *tissue factor III |
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what is the most common cause of an isolated prolonged PT
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liver disease
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what is DIC
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pathologic condition in which there is unopposed activation of the coagulation cascade with resulting consumption of plts and procoagulants
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what is the treatment of DIC
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directed at correcting the underlying cause
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what lab values are indicative of DIC
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*decreased plt count and fibrinogen levels
*elevation in fibrin split products |
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massive transfusion of stored blood may lead to what
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a coagulation disorder
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the most common reason for coagulopathy in pts receiving blood transfusions is what
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lack of functioning plts
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PT and PTT levels greater than what are indicative of dilutional coagulopathy
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1.8 times normal
PT > 25 sec PTT > 80 sec |
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what is the most common aquired coagulopathy
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anticoagulant therapy
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comadin and simliar agents block what pathways
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EXTRINSIC and final common
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what lab value is prolonged in coumarin therapy
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PT
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what is the specific antagonist for coumarin
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vit K
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vit K takes how long to take effect on a pt that has been taking coumadin and has NORMAL liver function
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3-6 hrs
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heparin blocks what pathways
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INTRINSIC and final common
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heparin forms a complex with what and increases its action by 1000 times
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antithrombin III
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what lab values are prolonged with heparin therapy
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*PTT
*ACT |
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biologic half life of heparin depends on what
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dosage and temperature
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heparin is metabolized where
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in the liver by heparinase and its metabolites are excreted by the kidneys
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heparin is antagonized by what
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protamine sulfate
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how to heparin and protamine sulfate work together
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heparin is a strong acid and protamine a strong base and they combine ionically forming a stable salt
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what is idopathic thrombocytopenic purpura
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it is caused by an antiplatelet immunoglobin that binds to the platelet membrane causing its premature destruction
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what is the hallmark of thrombocytopenia
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appearance of petechiae
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who is most often affect by thrombocytopenia
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young healthy females
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whole blood contains factors that can result in what
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febrile or allergic reaction
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when is transfusion of whole blood recommended
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massive blood loss (>25% of blood volume) in the actively bleeding pt
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the transfusion of PRBC can increase the Hgb by what amt
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1 gm
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the transfusion of PRBC can increase the Hct by what amt
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3%
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to increase oxygen carrying capacity what type of blood product is needed
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red blood cells
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in CHRONIC anemia oxygen delivery is facilitated through what
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increases in 2,3 DPG in the RBC
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with CHRONIC anemia cardiac output usually does NOT change until Hgb falls below what level
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7 gms
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ACUTE anemia is well tolerated in healthy individuals why
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b/c of compensatory increases in cardiac output
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what is a class I hemorrhage
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loss of up to 15% of total blood volume
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what are the s/s of a class I hemorrage
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*mild vasoconstriction
*tachycardia |
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what is a class II hemorrhage
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a loss of 15-30% of blood volume
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what are the s/s of class II hemorrhage
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*tachycardia (1st sign)
*decreased pulse pressure *restlessness (unanesthetized) |
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what is a class III hemorrhage
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loss of 30-40% of blood volume
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what are the s/s of class III hemorrhage
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*marked tachycardia
*tachypnea *systolic hypotension *altered mentation (unanesthetized) |
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what is a class IV hemorrhage
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blood loss of more than 40% of blood volume
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what are the s/s of a class IV hemorrhage
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*marked tachycardia
*hypotension *very narrow pulse pressure *low urine output *markedly depressed mental status |
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CDPA allows blood to be stored for how long
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up to 35 days
(adenine extends storage from 21 to 35 days) |
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Adsol, Nurticel and Optisol allow blood to be stored how long
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42 days
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transfusion of one platelet concentration (unit) will increase platelet count by approx how much
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7,000 to 10,000
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how much platelets are normally given
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1 unit/10kg body weight
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platelets are viable for approx how long
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4-5 days
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what are the factors than can PREVENT an increase in plt count following a plt transfusion
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*fever
*sepsis *hypersplenism *DIC |
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blood usually coagulates when coagulation factors are what
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at least 20-30% of normal
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blood usually coagulates when fibrinogen levels are what
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greater than 75 ml/dl
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dilutional coagulopathy does not occur until when
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transfusion exceeds one blood volume or the PT and PTT exceed 1.5 to 1.8 times normal values
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what are the current guidelines for the use of FFP
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*urgent reversal of warfarin
*correction of known coagulation factor deficiencies **antithrombin III deficiency** *correction of microvascular bleeding |
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FFP contains all the procoagulants and plasma proteins except for what
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platelets
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what is cryoprecipitate
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is the fraction of plasma that precipitates when FFP is thawed
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what does cryoprecipitate contain
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significant levels of factor VIII, fibrinogen, von Willebrands factor and factor XIII
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what is the only blood product containing concentrated amts of fibrinogen
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cryo
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what are the guidelines for the use of cryoprecipitate
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*tx bleeding pts with hypofibrinogenemia
*von Willebrands dz *hemophilia A (when factor VIII not available) |
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what concentrations is albumin available in
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*5%
*25% |
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does albumin contain coagulation factors
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NO
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plasma protein fraction is available as what kind of solution
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5% solution of plasma proteins in saline solution
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what is plasma protein fraction used as
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volume expander
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what is hetastarch
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synthetic starch molecule
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what type of solution is hetastarch available in
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6% solution
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what is hetastarch used as
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a volume expander
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how much hetastarch can be safely given before bleeding problems are encountered
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20ml/kg
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what is dextran
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high molecular wt polysaccarides
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what is the half life of dextrans
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2-4 hrs
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what does dextrans do
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*decrease plt adhesiveness
*depress factor VIII activity |
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what is voluven
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synthetic starch in NS
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what is the initial infusion of voluven
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20-30 ml infused slowly b/c can have an anaphylactiod rxn
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how much voluven can be given
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up to 50 ml/kg
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autologous transfusions are proven useful in what type of pts
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*blunt and penetrating trauma of the chest and abdomen
*ruptured ectopic pregnancies *several intra-abd elective and emergency sx |
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with pre-op blood collection the donors H&H must be at least what
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*Hgb 11 gm
*Hct 33% |
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how much may a person donate with pre-op blood collection
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10.5 ml/kg
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how often may a person donate for pre-op blood donation
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no more than 1 time per week
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what is the time limit for donation before sx
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no donation within 72 hrs of sx
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autologous transfusions are proven useful in what type of pts
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*blunt and penetrating trauma of the chest and abdomen
*ruptured ectopic pregnancies *several intra-abd elective and emergency sx |
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with pre-op blood collection the donors H&H must be at least what
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*Hgb 11 gm
*Hct 33% |
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how much may a person donate with pre-op blood collection
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10.5 ml/kg
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how often may a person donate for pre-op blood donation
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no more than 1 time per week
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what is the time limit for donation before sx
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no donation within 72 hrs of sx
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when is intra-op blood collection/transfusion contraindicated
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when procoagulants are added to the surgical field
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what type of filter is used with intra-op transfusion
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40 U filters
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what are the complications of intra-op blood collection/transfusion
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*air embolism
*hemolysis *+ bacterial cultures |
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how much blood is given with one unit with intra-op collected blood
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225ml
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|
IL-8
|
Secreted by Macs.
Major chemotactic factor for PMNs.- also think C5a and leukotriene B4 Help clear infxns. "Clean up on aisle 8" |
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with post-op collection/transfusion the transfusion must occur within how long of collection
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6 hrs
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what is the most common viral agent transmitted by blood transfusion
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CMV
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non-hemolytic reactions are manifested by what
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*fever
*uticaria *chills (all in the awake pt) |
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hemolytic reactions are d/t what
|
admin of INCOMPATIBLE blood
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what are the symptoms of a hemolytic reaction
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*hypotension
*tachycardia *uncontrolled bleeding *hemoglobinuria |
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what is the hallmark sign of a hemolytic blood transfusion reaction in an anesthetized pt
|
hemoglobinuria
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metabolic complications of blood transfusions are d/t what
|
changes that occur during storage of blood
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regarding metabolic complications what may occur with transfusion of large amts of blood
|
citrate intoxication
|
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signs of citrate intoxication are what
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*hypotension
*narrow pulse pressure *PROLONGED QT INTERVAL |
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what is the hallmark sign of citrate intoxication
|
prolonged QT interval
|
