CC Nov 2016 Elevated INR

echoecho's version from 2016-11-27 15:15


Question Answer
The ability of oral vitamin K antagonist such as warfarin (Coumadin) to reduce systemic thromboembolic events by inhibiting the biosynthesis of factors ____, _____, ______, and _____ has led to widespread use in the United States?II, VII, IX, X
Define INR?it is the most common test for frequent monitoring of the degree of anticoagulation
Studies have shown, however, that even in specialized centers, patients only spend ____% of their time within the desired therapeutic range?60%
The risk of bleeding approximately doubles for each point increase in the INR above ____? 3.0
*** List several options when the INR is supra-therapeutic? What are the reasons that the basis of the decision to choose a particular strategy?1) observation, dose adjustment, administration of vitamin K, administration of a coagulation reversal product 2) depends on the level of INR elevation and the presence or absence of bleeding
What should be done for patients who are not bleeding but has a supra-therapeutic INR?withhold warfarin and monitor the INR until it falls into the desired range
Patients with very high INR (even symptomatic) are not appropriate candidates for what approach?"watch and wait" approach
List the treatment options for elevated INR values (< 4.5 but above goal and NO significant bleeding)?decrease Warfarin or hold dosages; monitor closely
List the treatment options for elevated INR values (> 4.5 but <10 and NO significant bleeding)?hold next 1-2 doses; lower dose by 10-20% and increase monitoring
List the treatment options for elevated INR values (> 10.0 and no significant bleeding)?1) hold until INR therapeutic; resume at dose lower by 10-30%. 2) 2.5 - 5 mg vitamin K orally (may repeat if necessary)
List the treatment options for elevated INR values (serious bleeding and elevated INR, regardless of the magnitude of the elevation)?1) hold until INR therapeutic; resume at dose lower by 10-20% 2) 5-10 mg vitamin K IV (q12 for persistent elevated INR) 3) use 4-factor PCC (dosing depends on INR and patient weight)
What medication is the first line pharmacological option for patients with an elevated INR > 10.0 and no significant bleeding if those with serious bleeding regardless of the level of INR elevation because warfarin antagonizes the vitamin K-dependent factors?vitamin K
Compare IV and oral vitamin K?1) IV vitamin K works more quickly than oral administration but results are similar after 24 hours of use 2) IV formulation usually begins working within the 2 hours and achieves full effect in 24 hours if hepatic function is normal
The risk of ______ is lower with newer IV formulations compared with historically available options?anaphylaxis
Why is subcutaneous administration of vitamin K not recommended?due to its unpredictable effects on the INR
Oral vitamin K is easy to administer and may be used in the outpatient setting, it does not produce what 2 conditions?1) warfarin resistance. 2) anaphylactic reactions
*** List the circumstances when 4-factor prothrombin complex concentrate (PCC) should be administered?when significant bleeding is present and this is defined as life-threatening hemorrhage (intracranial) requiring hospitalization or bleeding leading to a decrease in hgb >2.0 g/dL, requiring transfusion of > 2 units packed red blood cells or resulting in surgical/ procedural intervention
What are the alternatives for 4-factor prothrombin complex concentrate?1) fresh frozen plasma. 2) recombinant factor VII
Compare fresh frozen plasma to 4-factor prothrombin complex concentrate and recombinant factor VIIa?1) FFP has a disadvantage of potential allergic reactions and transmission of infection, longer preparation time and higher volume 2) 4-factor PCC and recombinant factor VIIa are more concentrated, with less infection transmission risk
Why is factor VIIa least preferred by some authors?it does not provide the other vitamin K-dependent factors that are affected by warfarin
The above 3 products are more rapid in onset than vitamin &, although the effect is temporary (up to 24 hours), so when are these products considered?For short-term bridge until vitamin K is effective
After addressing the elevated INR, what is the next step?a careful determination as to why the level of anticoagulation is increased
Warfarin interacts with a variety of drugs and patients should be asked about what?1)dosage changes, as well as any new medications like herbal and alternative products 2) patient family members should be asked about dietary changes and compliance with warfarin administration 3) consider changes in liver function because progressive liver disease will decrease coagulation factor synthesis
*** SUMMARY = What is the guideline for patients with an elevated INR who are not bleeding?withhold warfarin and monitor the INR until it falls into the desired range
*** SUMMARY = What medication is recommended for patients with INR > 10.0, even if no bleeding is present?vitamin K
*** SUMMARY = For patients with significant bleeding (regardless of INR), what should be done?withhold Warfarin and coagulation reversal product (preferably 4-factor prothrombin complex concentration) administered in addition to vitamin K