Step 3 Board-Ready USMLE Junkies: The Must-Have USMLE Step 3 Review Companion

By B. Show and B. MD Dr Show

About the Book
Step 3 Board-Ready USMLE Junkies was written to find a systematic approach for reviewing for the USMLE Step 3 examination. It gives you a quick glance at the subject matter while relating it to other important areas in medicine. There is no other Step 3 review book that uses a stepwise, quick, and high-yield approach in this manner

• Language: English
• Publisher: La La Sincerely
• Release date: Jul 30, 2012
• ISBN: 9780985512415

Book preview

Introduction

This book was written to find a systematic approach to reviewing for Step 3. While there are many choices of review books out there, this review book would give you a quick glance at the subject matter while relating it to other important areas in medicine. It is more like a stepwise approach to any subject matter. There isn’t any other Step 3 review book that uses a stepwise, quick, and high-yield approach in this manner.

It is obvious that before you take the Step 3 examination, you would have either taken Step 1 and 2, or you have knowledge of the examination materials already. Step 1 or Step 2 is not any easier than Step 3. However, Step 3 is probably the most important as a practicing physician because it deals with questions that are relevant to patient management both in-patient and out-patient settings.

While it is recommended you take Step 3 during or after your residency, you may still take it before residency if you’re well prepared for it. Step 3 Board-Ready USMLE Junkies will help you achieve this success. Depending on your familiarity with the Step 3 materials, it is important to also use a comprehensive textbook along with this book, Step 3 Board-Ready USMLE Junkies as a supplement.

The topics found on Step 3 cover all subspecialties. The questions are multiple-choices, usually long, and mostly clinically-oriented. The Step 3 is a 2-day examination. The first day is all multiple-choice questions, and the second day is both multiple-choice questions and clinical-case scenarios, a Computer-based Case Simulations (CCS), where you examine and manage a patient in both emergency and office settings. It is important that you practice the clinical-case scenarios before attempting the Step 3 because they are crucial to the passing of this exam. The practice relies on the familiarity with the use of the CCS software.

Computer-based Case

Simulations (CCS)

Practicing your case simulations is very important in order to pass the Step 3. Make sure you are familiar with the software that comes with your registration package or can be found on USMLE website. The exam is given on Day 2 of the Step examination.

Here are some tips to help with making the computer-based case simulations easier.

WHEN TO ADMIT TO ICU

Mnemonics: DR D.E.M.S = DKA Respiratory failure Delirium Electrolytes imbalance MI (post) Shock.

INITIAL WORKUP TO CONSIDER IN

ER

Mnemonics: V.O.I.C.E.S = Vitals (including cardiac & BP monitoring) Oxygen (& pulse Oximetry and/or ABG) IVF (hold off initially in CHF; & IV access) Chest x-ray ECG (and Echo) Symptoms (treat presenting symptoms).

TIPS DURING EXAMINATION

When you just don’t know the answer:

1.   Choose the most common cause.

2.   Remember answers that seem to be right most of the time such as: corticosteroids/steroids (prednisone), indomethacin, or ACEIs. These answers are usually there because they may be the answers. So if you don’t know, they are ‘safer’ options.

3.   Look out for ‘obvious’ or the ‘simpliest’ answer such as: ‘observe’, self-limiting, follow-up with serial x-rays, NPO/IVFs/Antibiotics combination, dietary history, or medication list. These answers are there and can be easily overlooked; they are what we call the ‘DUH moment!’

4.   Be confident. Sometimes, you may need to work from your answer choices back up to the questions (instead of the questions to the answer choices). You should look at the answer choices to see in what scenario they would have been the answers. So you are using the ‘unlikely’ answer choices that you are sure are NOT possible to arrive at the most likely or the ‘got-to-be’ answer choice.

Chapter 1

Cardiology

Chest Pain and Myocardial Infarct

1.   While all emergencies are considered emergency in the ER, chest pain is probably the one that requires immediate evaluation. It is a serious symptom that should be further evaluated. It calls for determining whether or not the chest pain relates to the heart.

2.   It is important to remember that atherosclerotic occlusion of the coronary arteries => primary cause of ischemic heart disease.

3.   When you have a patient with epigastric pain, consider acute coronary syndrome = unstable angina in your diagnosis because it is the most common cause of epigastric pain.

4.   Stable angina => a patient has chest pain or shortness of breath during exertion which is relieved with rest or nitroglycerin.

5.   Unstable angina => a patient has chest pain or shortness of breath during rest which is not relieved with rest or nitroglycerin.

6.   Myocardial Infarction => chest pains that persist for 15-30 minutes and may or may not radiate to the shoulder, arm, or jaw. Look for an ECG which shows flipped or flattened T waves and ST-segment elevation.

7.   Don’t make the mistake--some myocardial infarctions are asymptomatic and silent; therefore, they may present as atypical in some young and even elderly patients!

Lab Tests/Diagnosis:

1.   Chest pain => always CHECK cardiac enzymes + ECG + Chest x-ray.

2.   Cardiac enzymes => creatine kinase (CK-MB) (every 8 hours X 3 times), troponin, lactate dehydrogenase (LDH) (rises after 24 hours-late presentation).

3.   Chest x-ray => may show cardiomegaly or pulmonary congestion.

4.   Echocardiography => if you suspect valvular disease or congestive heart failure.

5.   THINK: C. E. C. E => Cardiac enzymes + ECG + Chest x-ray + Echocardiography.

Treatment:

1.   Oxygen, Nitroglycerin, Aspirin, Plavix (clopidogrel), Heparin, ACEI, Beta blocker, Statin (and morphine for pain if pulmonary edema is present) => THINK: ON APH ABS.

2.   Cardiac catheterization is used to locate occlusions and determine the severity. Occlusion may be treated with angioplasty and stent placement.

3.   Cardiac rehabilitation in the form of supervised exercise is recommended 4-6 weeks post-MI.

4.   Order a cardiac stress test after 24-48 hours in a patient with chest pains (non-acute) in the following conditions: no risk factors, when the result is equivocal or the presence of coronary artery disease is uncertain with normal cardiac enzymes, and normal ECG.

5.   A patient complaining of fear of sudden death during sexual activity post-MI may be due to anxiety. Remember also that anxiety is a more common cause of erectile dysfunction in post-MI patients than beta-blockers.

6.   When a less common cause of erectile dysfunction in post-MI patients is due to beta blocker medications just hold the drug and reevaluate!

Post Myocardial Infarction Complications:

1.   Ventricular fibrillation, ventricular tachycardia, sinus bradycardia, heart block, cardiogenic shock, papillary muscle rupture, ventricular septal defect, Dressler’s syndrome, and fibrinous pericarditis.

2.   If acute pulmonary edema exists 2-5 days after an MI => it may be due to papillary muscle rupture and mitral regurgitation. Obtain a transthoracic echocardiography or a transesophageal.

Stress Test

1.   Stress test => may be used to assess pretest probability in patients with history of chest pains and risk factors for coronary artery disease.

2.   It is also used to assess the functional capacity in patients with known coronary artery diseases.

3.   Remember that in a patient with chest pain and coronary artery disease risk factors, always obtain cardiac enzymes to rule out MI before performing a stress test.

4.   Please do not obtain a stress test in patients with: acute aortic dissection, aortic stenosis, third degree heart block, acute coronary syndrome, and decompensated heart failure!

Types of Stress Test:

1.   Exercise Stress Test:

•    Patient walks on treadmill, and the response to stress is evaluated on ECG.

•    Indicated for patients who can walk or exercise without difficulty.

•    Clinical symptoms to observe are chest pains or shortness of breaths.

•    ECG changes may include ST depressions or other arrhythmias.

•    Specificity is low for patients with resting ECG changes.

•    Adding nuclear component to perfusion study increases sensitivity.

2.   Adenosine Stress Test/Persantine (Dipyrimadole) Test:

•    Vasodilation test helps to dilate arteries with lesions.

•    Indicated for patients who cannot walk or exercise with difficulty due to peripheral arterial disease, osteoarthritis, or obesity.

•    Also indicated for patients already on beta blocker with left bundle branch block (LBBB) or premature ventricular contractions (PVCs).

3.   Dobutamine Stress Test (Echocardiography):

•    Used to determine the abnormal wall and viability. Ischemic wall is hypokinetic.

•    Indicated for patients with moderate to severe COPD or asthma, third-degree heart block, or where persantine is contraindicated.

Valvular Heart Disease

Aortic Stenosis

•    Chest pain + syncope during exertion + exercise intolerance + shortness of breath with heart failure symptoms.

•    Crescendo-decrescendo systolic murmur.

•    ‘Slow’ carotid upstroke => elderly with AS vs ‘brisk’ carotid upstroke => hypertrophic obstructive cardiomyopathy (HOCM).

•    Avoid nitrates (overdiuresis) and ACEIs (vasodilator) in symptomatic patients. Follow up every 6 months to 1 year for physical assessment and evaluation with serial echocardiograms for severe and symptomatic AS.

Aortic Regurgitation

•    Watch for patients who are asymptomatic or become symptomatic with heart failure.

•    Wide pulse pressure, diastolic decrescendo murmur heard best at left sternal border.

•    Look in the history for => aortic dissection, Marfan’s syndrome, syphilis, aortic root disease, ankylosing spondylitis, and reactive arthritis.

THINK: W.A.R Wide pulse pressure => Aortic Regurgitation.

Mitral Stenosis

•    Watch for patients who present with hemoptysis and heart failure. Other symptoms are dysphagia, hoarseness, and AFib.

•    May be caused by rheumatic fever. Seen in immigrant and pregnant patients (due to increased plasma volume).

•    Diastolic rumble after an opening snap.

Mitral Regurgitation

•    Mitral regurgitation may be asymptomatic initially, and it can later present with symptoms of heart failure (dyspnea on exertion).

•    Holosystolic murmur at apex and radiating to axilla.

•    Risk: atrial fibrillation.

Mitral Valve Prolapse

•    Mitral valve prolapse is usually asymptomatic. It may present with palpitations.

•    MVP is associated with panic attacks or panic disorder.

•    Endocarditis prophylaxis is not required for MVP.

THINK: P in Prolapse => Panic attacks Palpitations.

Infective Endocarditis

1.   Symptoms => acute (infectious): fever, rigors, heart failure, and neurologic problems with systemic emboli; subacute: weeks to months of fever, malaise, weight loss; noninfectious: asymptomatic and heart failure.

2.   Physical exam findings => new murmur, tenderness over the spine and focal neurologic deficits (present with septic emboli); infectious: painful nodules (Osler’s nodes) on fingers and toes, Janeway lesions on skin, and retinal exudates (Roth’s spots).

3.   High risk patients => they usually have history of prosthetic heart valves, previous infective endocarditis, cyanotic congenital heart disease, surgically repaired pulmonary shunts, or are injection drug abusers.

4.   High risk procedures needing prophylaxis in high risk patients => dental procedures such as tooth extraction, scaling and cleaning, gingival manipulation, and respiratory procedure such as rigid (not flexible) bronchoscopy.

5.   Organisms that cause endocarditis are => subacute (most common): streptococcus viridians, enterococci, staph epidermidis, and candida. Acute: Staph Aureus in IVDA.

Lab Tests/Diagnosis:

1.   Noninfectious: Echocardiography => incidental finding.

2.   Infectious: Obtain three sets of blood cultures + transthoracic echocardiogram (TTE). If the latter is negative, perform transesophageal echocardiography (TEE) because it is more sensitive and it shows vegetations.

3.   ECG (if it shows heart block => indicates abscess).

Treatment:

1.   Antibiotics => nafcillin + gentamicin or vancomycin + gentamicin in IVDA. Gentamicin provides synergism.

2.   Prophylaxis is recommended only in high-risk patients.

3.   Prophylaxis is not recommended in gastrointestinal or gastrourinary procedures.

4.   Prophylaxis treatment is a single dose of oral azithromycin or clindamycin one hour prior to the procedure or 30 minutes prior intravenously.

5.   Injection drug abusers should discontinue injection drug use for preventive measures of further occurrence of infectious endocarditis.

Complications:

•    Septic emboli, acute aortic regurgitation, and aortic valve abscess.

Congestive Heart Failure

1.   Most common cause => atherosclerosis.

2.   Heart failure => categorized into => systolic, diastolic, valvular, and arrhythmia-causing heart failures.

3.   Systolic: Heart is unable to pump well => this may be due to ischemia and long-standing hypertension with S3 gallop, orthopnea, and lower extremity swelling.

4.   Diastolic: Heart is stiff and unable to relax and fill with blood => this may be due to hypertension with left ventricular hypertrophy.

Lab Tests/Diagnosis:

1.   Obtain ECG and cardiac enzymes to rule out myocardial infarct.

2.   Obtain echocardiography to determine ejection fraction and valvular defects.

3.   Obtain chest x-ray to evaluate fluid overload.

4.   Obtain TSH.

Treatment:

1.   ACE inhibitor; if there’s cough as a side effect, => use ARB. If angioedema and cough exist => use hydralazine + isosorbide.

2.   Beta blocker (metoprolol, atenolol, or carvedilol). Use with caution in acute cases.

3.   Loop diuretics (furosemide) in exacerbation.

4.   Spironolactone for stage III/IV.

5.   Hydralazine + Nitrates reduce mortality in African Americans.

6.   Digoxin reduces morbidity (the need for hospitalizations) not mortality.

7.   ACEIs + beta blockers + spironolactone => decrease mortality they are used in long-term treatment of CHF.

8.   Aspirin and statin.

9.   Most common cause of death in CHF => arrhythmia place implantable cardioverter or automatic implantable cardiac defibrillators (AICDs).

10. Indications for AICDs => dilated cardiomyopathy, cardiogenic shock, and persistent CHF with EF < 35%.

11. Cardiac Resynchronization Therapy (CRT) or cardiac transplantation. CRT is used in severe CHF when QRS complex > 130 msec. AICD and CRT combination reduces mortality.

12. Remember to determine the secondary cause of CHF such as MI, hypertension, atrial fibrillation, or missed dialysis, and treat the underlying cause.

Arrhythmias

Atrial Fibrillation

1.   Causes vary from structural, hyperthyroidism, metabolic, CHF to alcohol.

2.   Check TSH when you suspect hyperthyroidism.

3.   For stable patients who are symptomatic control the ventricular rate with medications such as metoprolol, diltiazem, or verapamil. Digoxin and amiodarone may also be used to control rate.

4.   For unstable patients who are symptomatic use emergency cardioversion.

5.   A patient is considered unstable, and need cardioversion, when presented with symptomatic hypotension, congestive heart failure resistant to treatment, hypoxia, and angina.

6.   For acute asymptomatic patients no specific treatment is needed.

7.   Anticoagulate in chronic cases with heparin and warfarin.

8.   Atrial fibrillation existing for 48 hours or more should be evaluated with TEE before cardioversion to rule out thrombus and prevent risk of stroke.

9.   If thrombus is present and AFib is 48 hours or more, anticoagulate first for 3 weeks with warfarin cardiovert then continue warfarin for another 4 weeks.

10. For patients with Atrial fibrillation + CHF control the rate first with metoprolol + digoxin then with furosemide if pulmonary edema exists,