Steven R. Daugherty, Ph.D.
Director, Education and Testing
Kaplan Medical
Who is in charge when you take you exam? Do you control you exam, or does the exam control you?
The USMLE* requires you to be able to think on your feet. The exam is not testing your knowledge, as such. Rather, each question is designed to assess your ability to sort out what is important, integrate the relevant concepts and solve the problem presented. You do not master this type of question by memorizing a lot of facts and spitting them out. USMLE questions require you to decide early what is relevant, ignore what is not, and pick the option that offers the most optimal solution. Grabbing for the first answer you see will not get you the score you want. You need to learn to think with what you know and come up with the very best choice.
Mastering this thought process for the USMLE is difficult for two reasons. First, much of medical school education is oriented towards strict memorization. Testing in medical school, whether by oral or written exams, often focuses on the subtle details and minute distinctions which demonstrate an in-depth exposure to the material of interest. When you show that you know these details on an exam, the faculty member feels confident that you have spent adequate time and attention on the content of most concern to them. But, being good at memorization and being good at thinking are two separate things. Even if you can think clearly and efficiently, medical school often rewards you for memory, not thought. And after spending time getting good at the processes of memorization, you may have lost the impulse for and habits of thinking well.
Second, the time pressure of the exam forces even those students who have retained the skill of thinking to abandon this higher intelligence and hope for salvation by reaching for the first option that looks familiar. Time pressure degrades our willingness to spend the moment thinking requires and induces us to value speed over effectiveness. We short-circuit our thinking processes by using what cognitive psychologists call "heuristics." Heuristics are ways of generating an approximate answer without fully considering all of the information presented. The two most common heuristics are Availability, where what comes to mind first is given most credibility, and Representativeness, where things with similar features are deemed as being the same in all respects. Both of these heuristics serve you well in medical school. What is most available mentally is likely to be what you just studied as you crammed for an exam. What you have just learned is what will most likely be on the test ( Availability). When you crammed for your exam, you were required to know a finite set of information. All you had to do on the exam was know a relevant detail that let you discriminate within this finite set of material (Representativeness).
But, the Availability and Representativeness heuristics, so valuable in medical school, interfere with the core thought processes essential to do well on the USMLE. The breadth and depth of the content covered by the exam you will face on the USMLE convert these mental heuristics from valuable short-cuts to disastrous dead-ends.
Most medical school exam are about "grab and go." You see an answer that looks familiar and reminds you somewhat of the issue presented in the question, so you grab for it and go on to the next question. A good USMLE score, by contrast, depends on "think and know." You must think about what is presented, compare this with your knowledge base, and reason though to the best possible answer. Sometimes the answer is something you have already seen and already thought about. These are the easy questions. However, increasingly, students say that USMLE questions present material in unique ways, from a perspective they never really considered before. These questions are harder, but are becoming the backbone of the exam. You must answer these integrative questions by applying your knowledge in new ways to situations that are distinct.
The key issue is this: The knowledge needed for the USMLE is the same as that you learned in medical school. What sets the USMLE apart is its insistence that you learn to combine the different threads of the knowledge you have learned and weave them into a new pattern. Doing well depends not on grabbing all the right treads, but learning the art of weaving. On the USMLE, you will be asked to use your knowledge in ways that you may never have before. Not grab and go, but think and know.
The exam is not a quiz show where you get points for spouting esoteric facts. The USMLE is a screening test to see if you have mastered the perspectives and thought processes essential for medical practice. A physician, a good physician, makes a living by thinking and reasoning. Take the time to relearn and practice this art of reasoning and you will reap the reward of a higher score.
Can You Name It? Mechanism of Action:
- The most accepted explanation of its mechanism of action is that it causes relaxation of vascular smooth muscle, producing dilatation of peripheral arteries and veins, especially dilation of veins.
- The therapeutic effects include: dilatation of veins promotes peripheral pooling of blood in the extremities as well as decreasing venous return to the heart. The net result is a reduction in left ventricular end-diastolic pressure and pulmonary capillary wedge pressure (preload). The arteriolar relaxation decreases the systemic vascular resistance, systolic arterial pressure, and mean arterial pressure (afterload).
Indications:
- This agent is indicated for the prevention of angina pectoris due to coronary artery disease.
Route of Administration:
- Oral Tablets (30 mg, 60 mg and 120 mg)
Selected Adverse Effects:
- General: chest pain, edema, fatigue, fever, flu-like symptoms
- CV: hypotension, angina pectoris aggravated, heart murmur, abnormal heart sounds, myocardial infarction, Q wave abnormality, arrhythmias, extrasystole, palpitation, tachycardia, ventricular tachycardia
- Nervous system: dizziness, headache, paresthesia, vertigo
- GI: abdominal pain, constipation, nausea, vomiting
- Metabolic: hyperuricemia, hypokalemia
- CNS: anxiety, concentration impaired, confusion, decreased libido, depression, impotence, insomnia, nervousness, paroniria, somnolence
Selected Drug-Drug Interactions (Drug + Other medication =):
- Other vasodilators = Increased vasodilation and increased adverse reactions
- Alcohol = Increased vasodilation and increased adverse reactions
- Calcium channel blockers, organic nitrates = profound orthostatic hypotension
Special Considerations:
- Contraindications: hypersensitivity or idiosyncratic reactions to other nitrates or nitrites
- Warnings/Precautions: severe hypotension, use with caution in patients who may be volume depleted, paradoxical bradycardia, increased angina pectoris, aggravation of the angina secondary to hypertrophic cardiomyopathy, development of tolerance with time
Drug of the Month: Isosorbide mononitrate (Imdur ®)
Cardiac conundrum
A 54-year-old woman with a history of valve replacement visits her dentist for a routine cleaning. Two days later, she develops a severe fever, has small hemorrhages on her fingers, and funduscopic evaluation reveals the presence of retinal hemorrhages. She becomes hypotensive and is rushed to the emergency department. Which of the following is the most diagnosis?
(A) Acute bacterial endocarditis
(B) Acute rheumatic fever
(C) Libman-Sacks endocarditis
(D) Nonbacterial thrombotic endocarditis
(E) Subacute bacterial endocarditis
The correct answer to the question above is: A.
- CORRECT: Previously damaged heart valves or prosthetic valves are susceptible to infection. Bacteria seed the valves in this case after dental work. The rapid decline of the patient and the peripheral and retinal hemorrhages reveal the likely diagnosis as acute bacterial endocarditis. In mechanical valves, if there is infection around the valve, it can lead to its possible dislodgement.
- Acute rheumatic fever may lead to fever. If the myocardium is affected, conduction abnormalities may result. Repeated bouts affecting the myocardium lead to its scarring.
- Libman-Sacks endocarditis presents as sterile vegetations on both sides of the heart valves. Fever and peripheral hemorrhage are not seen. These vegetations are seen in systemic lupus erythematosus.
- As the name implies, nonbacterial thrombotic endocarditis is characterized by accumulation of small thrombotic emboli on the heart valves. This condition is associated with chronic diseases such as cancers.
- While a normal heart valve is not usually susceptible to the less virulent organisms that give rise to subacute bacterial endocarditis, those with a prosthesis are. The important distinction is rapidity of the onset of symptoms.