Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
JM is a 55 year old man (5’10”, 255 lbs) recently discharged from the hospital where he underwent a successful left hip arthroplasty but also experienced a pulmonary embolus following surgery. Warfarin was begun during hospitalization and his INR at discharge was 2.1.
Which of the following most correctly describes warfarin therapy for this patient? a. wrong drug; use aspirin instead b. correct drug; continue for at least 3 months c. correct drug; continue indefinitely d. wrong therapy; neither warfarin nor aspirin is necessary |
b. correct drug; continue for at least 3 months
Ans: b. Please see objective #5 and slide #46. ASA would be a correct choice for this patient for prevention of embolic events associated with Atrial Fibrillation (see slide 45). Duration of therapy for prevention of a subsequent PE should not exceed 6 months. Since this patient is at risk for another PE (see slide #8), no therapy is not acceptable. |
|
|
Shortly after discharge from the hospital JM is diagnosed with heparin induced thrombocytopenia. Which of the following is the best therapy for this patient at this time?
a. continue warfarin b. discontinue warfarin; start enoxaparin c. continue warfarin; start enoxaparin d. discontinue warfarin; start fondaparinux |
Ans: d. Please see objective 3 and slides 25 thru 30. Because of the potential pro-thrombotic effects of warfarin in association with inhibition of activation of protein C and S, warfarin should be discontinued until the patient’s platelet count is between 100K-500K. Use of enoxaparin in this patient is now contraindicated since it too can contribute to HIT.
|
|
|
VA is a 63 year old man with hypertension, an ejection fraction of 0.4, and a history of transient ischemic events (attacks). He is diagnosed with atrial fibrillation and you are asked about anticoagulation for this patient. Which of the following is the most likely thromboembolic event if this patient were to receive no anticoagulation?
a. Stroke b. pulmonary embolus c. deep vein thrombosis d. this patient is not at risk for any event that might be prevented by anticoagulation |
a. Stroke
|
|
|
LML is a 50 year old man taking warfarin for prevention of a recurrent upper extremity deep vein thrombosis. For the past three months his INR values have ranged from 1.9 to 3.3 while taking warfarin 5 mg qd. Today his INR is 8.8 and he describes two black, tarry stools over the past three days. Which of the following is the most appropriate response to these new findings?
a. do nothing; these are expected effects b. reduce dose of warfarin to 2 ½ mg po qd c. administer vitamin K; he is excessively anticoagulated d. administrates protamine; he is excessively anticoagulated |
c. administer vitamin K; he is excessively anticoagulated
Ans: c. Please see objective #3. The black tarry stools indicated that this patient is bleeding and probably bleeding a lot. Also, the INR of 8.8 is considerably above the desired therapeutic range for this patient (2.0-3.0). Consequently, both a and b are incorrect as they are clearly inadequate for this patient. Selection d is incorrect since protamine is indicated for heparin reversal not warfarin. |
|
|
LML is a 60 year old male (6 feet 0 inches tall; 250 lbs) brought to the emergency room in excruciating left lower back pain. He is subsequently found to have two renal stones lodged in his left ureter and is scheduled for (major) surgery the next day. His past medical history is notable for hypertension (BP in emergency room was 110/75 mm Hg), heart failure, and all lab values in the emergency room were within normal limits including hemoglobin and hematocrit (16 Gm/dl and 49%, respectively).
Which of the following would be the most appropriate strategy for prevention of venous thromboembolism in this patient prior to surgery? a. Heparin 5000 units subcutaneously bid b. Heparin 5000 units subcutaneously tid c. Warfarin 5 mg po qd d. Enoxaparin (Lovenox™) 90 mg subcutaneously bid |
b. Heparin 5000 units subcutaneously tid
Correct answer is b; please see objective #2. Since this patient has at least three risk factors for subsequent development of a DVT (obesity, advanced age, heart failure) and is to receive major surgery, selection “a” would be insufficient. Onset of action of warfarin is too slow to be of any help in this regard. Additionally, there is no guarantee that this dose of warfarin is correct. Selection “d” is incorrect since this is a treatment dose not a prophylactic dose. |
|
|
In spite of a reasonable prophylactic strategy, LML develops a pulmonary embolus the day following surgery. Which of the following is the most appropriate initial treatment strategy for this patient?
a. Heparin 5000 units subcutaneously bid b. Heparin 5000 units subcutaneously tid c. Warfarin 5 mg po qd d. Enoxaparin 120 mg subcutaneously bid |
d. Enoxaparin 120 mg subcutaneously bid
Correct answer is d; please see objective #2. Since the benefit/risk consideration now shifts to treatment of this patient, he must receive a “treatment” dose of an anticoagulant. Selections “a” and “b” are incorrect since they are prophylactic doses and selection “c” is incorrect since its onset would be delayed even if this were a correct dose. Furthermore, such monotherapy with warfarin may result in an initial pro-thrombotic event. |
|
|
LML’s physician elects to begin therapy with intravenous unfractionated heparin. He is given a loading dose of 7000 units and a maintenance dose of 1400 units/hour. Six hours after initiation of the maintenance dose, his aPTT is reported as 100 seconds (therapeutic 52 -75 seconds) and his anti-Xa value as 0.60 IU/ml (therapeutic 0.3-0.7 IU/ml). His physician asks you for a recommendation for a dose change. Which of the following is the most appropriate reply?
a. continue the present maintenance dose b. stop the infusion for one hour and reduce maintenance dose afterward c. reduce the maintenance infusion d. change to heparin to 5000 units subcutaneously q 8 hr |
a. continue the present maintenance dose
Correct answer is a; please see objective #2. Although the aPTT and anti-Xa level were obtained at the correct time, their values appear to be mutually contradictory. Not so. The aPTT is considered the less reliable of the two and therefore may be discarded. Since the anti-Xa level is therapeutic, no dose change is needed at this time. Selection “d” is incorrect since this is a prophylactic dose of heparin and this patient has already had a pulmonary embolus. |
|
|
LML subsequently develops heparin-induced thrombocytopenia. Which of the following is the most appropriate initial pharmacotherapeutic intervention to manage this problem?
a. continue heparin; this is a benign problem b. reduce dose of heparin c. discontinue heparin and give enoxaparin instead d. discontinue heparin and begin argatroban e. discontinue heparin |
d. discontinue heparin and begin argatroban
Selection “d” is correct; please see objective #3. Given the serious thrombotic complications associated with HIT, “a”, “b”, and “e” are all incorrect. Selection “c” is incorrect since enoxaparin is still a form of heparin and, in this patient, all heparin products must be discontinued. |
|
|
LML is a 60 year old male (6 ft 0 inches; 190 lbs) brought to the emergency room in excruciating left lower back pain. He is subsequently found to have two renal stones lodged in his left ureter and is scheduled for surgery the next day. His past medical history is notable for hypertension (blood pressure in emergency room was 110/75 mmHg) and all lab values in the emergency room were within normal limits including hemoglobin and hematocrit (16 g/dL and 49%, respectively) although gross hematuria was noted on urinalysis. Several hours after admission repeat labs reveal hemoglobin and hematocrit of 12 g/dL and 36%, respectively, with no apparent change in the hematuria.
31. Which of the following would be the most appropriate strategy for prevention of a venous thromboembolism in this patient prior to surgery? A. Heparin 5000 units subcutaneously bid B. Heparin 5000 units subcutaneously tid C. intermittent pneumatic compression stockings D. Enoxaparin 90 mg subcutaneously bid |
C. intermittent pneumatic compression stockings
Answer C: please see objective #2. Since this patient has lost approximately 25% of his circulating blood (see the abrupt decline in hemoglobin and hematocrit), any anticoagulant, even in prophylactic doses, would be inappropriate at this time. Consequently, selections “a” and “b” both incorrect. Selection “d” is incorrect for the same reason but also because this is a treatment dose not a prophylactic dose. |
|
|
In spite of a reasonable prophylactic strategy, LML develops a pulmonary embolus the following day preceding surgery. Which of the following is the most appropriate initial treatment strategy for this patient?
A. Heparin 5000 units subcutaneously bid B. Heparin 5000 units subcutaneously tid C. intermittent pneumatic compression stockings D. Enoxaparin 90 mg subcutaneously bid |
D. Enoxaparin 90 mg subcutaneously bid
Answer D: Please see objective #2. Since the benefit/risk consideration now shifts to treatment of this patient even though he is bleeding, he must receive a “treatment” dose of an anticoagulant. Selections “a” and “b” are incorrect since they are prophylactic doses and selection “c” is incorrect since it will not prevent occurrence of another clot nor prevent extension of the one already present. |
|
|
LML’s physician elects to begin therapy with intravenous unfractionated heparin. He is given a loading dose of 7000 units and a maintenance dose of 1400 units/hour. Three hours after initiation of the maintenance dose, his aPTT is reported as 100 seconds (therapeutic 52 -75 seconds) and his physician asks you for a recommendation for a dose change. Which of the following is the most appropriate reply?
A. continue the present maintenance dose B. stop the infusion for one hour and reduce maintenance dose afterward C. reduce the maintenance infusion D. change to heparin to 5000 units subcutaneously q8h |
A. continue the present maintenance dose
Answer A: please see objective #2. Since the aPPT was obtained before the recommended 6 hour time point, its interpretation is difficult. Consequently, a change in the maintenance infusion would most appropriately be based on an aPTT obtained six hours after initiation of the heparin. Selection “d” is incorrect since this is a prophylactic dose of heparin and this patient has already had a pulmonary embolus. |
|
|
JD is a 22 year old women receiving enoxaparin (Lovenox) 50 mg bid for management of a recent deep vein thrombosis. After 3 days of therapy her aPTT is
35 seconds and her physician requests a dose recommendation designed to achieve a therapeutic aPTT. Which of the following is the most appropriate reply? a. do not change dose; this is a therapeutic aPTT b. do not change dose; enoxaparin has no effect on aPPT c. increase dose; titrate to an aPTT of 50-70 seconds d. decrease dose; titrate to a aPTT < 25 seconds |
b. do not change dose; enoxaparin has no effect on aPPT
Correct answer is “b” (please see objective #2). Since an activated partial thromboplastin time of 35 seconds is within normal limits, selection “a” is incorrect. Since the lower limits of aPTT is 25 seconds, selection “d” is probably an impossibility. Finally, since this patient is receiving a therapeutic dose of enoxaparin (i.e./ 1 mg/kg bid) and it has no effect on aPTT, selection “c” is incorrect. |
|
|
RS is a 45 year old man with hemodialysis – dependant end – stage renal disease who
develops a superior vena cava deep vein thrombosis associated with a chronically indwelling venous catheter. Initial therapy consisted of unfractionated heparin (6000 units intravenously given at 6AM followed by 1100 units per hour). 27. An aPTT obtained at 8AM is 120 seconds and RS’s physician ask you for a dose change recommendation. Which of the following is the most appropriate reply? a. reduce maintenance infusion; titrate to an aPTT of 50 to 70 seconds. b. discontinue heparin for one hour; re-initiate at a lower infusion rate and titrate to an aPTT of 50-70 seconds. c. make no change; this is a therapeutic aPTT. d. make no change; repeat the aPTT 4 hours later. |
d. make no change; repeat the aPTT 4 hours later.
Correct answer is “d” (please see objective #2). Infusion of unfractionated heparin must be continuous for > 6 hours before it can be appropriately interpreted making selections “a” and “b” incorrect. The aPTT value is clearly supra-therapeutic making selection “c” incorrect. |
|
|
JD’s physician inquires about the goal of therapy for this patient once warfarin
(Coumadin) is started. Which of the following most correctly describes the goal of therapy for this patient? a. aPTT 50 to 70 seconds b. aPTT 1 ½ to 2 ½ times control c. INR 2.0 – 3.0 d. INR 2.5 – 3.5 |
c. INR 2.0 – 3.0
Correct is “c” (please see objectives 2 & 5). Warfarin has only a minimal effect on aPTT rendering selections “a” and “b” incorrect. Selection “d” describes INR goal for mitral value replacement. |
|
|
The indwelling venous catheter is subsequently removed. Which of the following
most correctly describes duration of warfarin therapy for this patient? a. at least 3 months b. at least 6 months c. at least one year d. once the catheter is removed, warfarin therapy becomes unnecessary |
a. at least 3 months
Correct answer is selection “a” (please see objective #2). Since the reason for the DVT in the first place was the catheter, therapy for 6 months or longer becomes unnecessary once the catheter is removed making selection “b” and “c” incorrect. Even though the catheter is removed, a DVT is, nevertheless, present and prophylaxis of another event is required rendering selection “d” incorrect. |
