A 7 1 -year-old woman presents with I day of headache and left-sided weakness after complaining for several days of dyspnea and confusion. Her history is notable for nonvalvular atrial fibrillation and hypertension; she denies any prior history of thrombosis or bleeding. Her medications include a beta-blocker and warfarin (coumadin). Examination is notable for partial left hemiplegia; ecchymoses are noted over both forearms. The remainder of the examination demonstrates rales over both lung bases, an irregularly irregular heart rhythm, and a heave at the left sternal border. CBC: Hemoglobin/hematocrit – 12 g/dU35% MCV – 89 fL MCH – 30 pg MCHC – 27 g/dl RDW-CV – I 0% WBC count 6,500/gL Platelet count – 225,000/!!L PT = 55.1 seconds (< 14=”” seconds)=”” inr=”7.” 1=””>< 1.3)=”” ptt=”39″ seconds=”” (22-35=””….
Daily Archives: January 25, 2021
A 37-year-old woman presents to the emergency department with a swollen, tender left calf and dyspnea. She noted the development of symptoms 3 days ago, the day following her arrival on a plane trip from Austral ia to the United States. She admits to pleuritic chest pain but denies cough or fever, and has no significant past medical history. Her only medication is an oral contraceptive. She does not smoke cigarettes or use alcohol. Her parents are alive; her father takes a “blood thinner” medication for an unknown reason. Examination reveals a diaphoretic white female with tachypnea; positive examination findings include an inspiratory friction rub on the left side of the chest, a swollen left calf with a circumference 50% greater than on the right, and a positive….
The patient presents with a high-probability clinical picture for venous thrombosis and pulmonary embolism (PE), given the swollen left calf, positive Homans sign (calf pain on simultaneous extension at the knee and flexion at the ankle), and several signs of PE including pleuritic pain, tachypnea, the friction rub, and a low oxygen saturation without fever or evidence of infection. As for the screening laboratory tests, there is no troponin leak indicative of myocardial ischemia, and the D-dimer is significantly elevated, which is compatible with ongoing thrombosis. At the same time, the D-dimer never establishes a diagnosis of venous thrombosis; its principle value is to rule out thrombosis in low-risk patients. Therefore, the patient must undergo an immediate radiologic workup for VTE including chest radiograph, compression ultrasound of the….
The patient demonstrates several risk factors for thrombosis, including oral contraceptive use, a recent long airplane trip (venous stasis), and a presumptive family history of an inherited thrombophilia (father is on anticoagulation therapy). This will require further testing but not as a prerequisite to beginning appropriate therapy. Based on the radiological studies, the patient has a deep vein thrombosis and bilateral pulmonary emboli with significant clot burden in her lungs to lower her arterial 02 saturation. She is therefore a potential candidate for thrombolysis, especially in light of her presenting within 3 days of developing symptoms and the absence of comorbid conditions that would increase her risk of bleeding. Following thrombolysis, she will need to be anticoagulated, beginning with heparin, and then transitioned to warfarin therapy with an….
A 57-year-old woman, scheduled for an elective hysterectomy, is referred for management of her anticoagulation during the perioperative period. She is currently receiving warfarin 3 mg daily for a 5-year history of atrial fibrillation with past evidence of a single embolic event. Other medical problems include hypertension and diabetes, controlled with an angiotensin-converting enzyme (ACE) inhibitor and diet. She also takes a baby aspirin each day. Examination reveals a healthy black female with no complaints. Positive findings on examination include an irregularly irregular heart rhythm and a faint diastolic murmur Vital signs: BP – 1 55/80 mm Hg, pulse – 75 bpm, resp – 1 6/min, T – 3rc. Coagu lation studies: Platelet count = 21 0,000/J.LL PT = 25. 1 seconds (< 14=”” seconds)=”” inr=”2.4″ (0.8-=”” 1=””….
A surgical procedure requires reversal of oral anticoagulation to guarantee adequate hemostasis during and after the operation. This does not generally apply, however, to low dose (8 1 mg/d) aspirin therapy since, unlike high-dose antiplatelet drug therapy, it is not associated with increased perioperative bleeding. The key to management of a patient on long-term warfarin therapy is to minimize the “unanticoagulated” interval and the associated risk for a thromboembolic event. Patients maintained at an INR of 2-3 can usually be managed by discontinuing their oral anticoagulant 4 days prior to their surgery to reach an INR below 1 .5 on the day of surgery. This time interval wi ll al low a return of depressed coagulation factors, in patients with normal liver function, to levels above 30%. If….
For most surgical procedures, anticoagulation can be safely instituted after 1 2-24 hours of demonstrated hemostasis. Some situations may temper that interval, including the nature of the operation, for example neurosurgery where bleeding into a closed space can be disastrous or when there is an ongoing difficulty with bleeding at the operative site. In low-risk patients, warfarin therapy can be restarted with a daily dose of 5 mg until the INR is above 2.0. This patient is at somewhat greater risk due to her complicating illnesses (atrial fibrillation and a heart murmur), and therefore probably should be considered for bridging therapy with unfractionated heparin, starting 1 2-24 hours after surgery and continuing until the INR is in a therapeutic range for 1 -2 days. She can then return….
For each of the following atoms, write down a ground state electronic configuration and indicate which electrons are core and which are valence: (a) Na, (b) F, (c) N, (d) Sc. Draw energy level diagrams (see Fig. 1.15) to represent the ground state electronic configurations of the atoms in problem 1.26.
Write down the ground state electronic configuration of boron, and give a set of quantum numbers that uniquely defines each electron. Write down (with reasoning) the ground state electronic configurations of (a) Li, (b) O, (c) S, (d) Ca, (e) Ti, (f) Al. Draw energy level diagrams to show the ground state electronic configurations of only the valence electrons in an atom of (a) F, (b) Al and (c) Mg.
How do you account for the fact that, although potassium is placed after argon in the periodic table,
it has a lower relative atomic mass? What is the evidence that the aufbau principle is only approximately true? The first list in the table opposite contains symbols or phrases, each of which has a ‘partner’ in the second list. Match the ‘partners’; there is only one match for each pair of symbols or phrases.
Suggest explanations for the following. (a) High values of ionization energies are associated with the noble gases. (b) The enthalpy changes associated with the attachment of the first and second electrons to an O atom are exothermic and endothermic, respectively. (c) In an Li atom in its ground state, the outer electron occupies a 2s….
(a) Draw possible stereoisomers for the trigonal bipyramidal [SiF3Me2]_ anion (Me ¼ CH3). An
X-ray diffraction study of a salt of [SiF3Me2]. shows that two F atoms occupy axial sites. Suggest why this stereoisomer is preferred over the other possible structures that you have drawn.
(b) Account for the fact that members of the series of complexes [PtCl4]2, [PtCl3(PMe3)]–, [PtCl2(PMe3)2] and [PtCl(PMe3)3]þ do not possess the same number of stereoisomers.