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CASE FILES Internal Medicine
By Eugene C. Toy John T. Patlan Jr.
McGraw-Hill Copyright © 2013 The McGraw-Hill Companies, Inc.
All right reserved.
Chapter One SECTION I
How to Approach Clinical Problems
Part 1 Approach to the Patient
Part 2 Approach to Clinical Problem Solving
Part 3 Approach to Reading
Part 1. Approach to the Patient
The transition from the textbook or journal article to the clinical situation is one of the most challenging tasks in medicine. Retention of information is difficult; organization of the facts and recall of a myriad of data in precise application to the patient is crucial. The purpose of this text is to facilitate in this process. The first step is gathering information, also known as establishing the database. This includes taking the history (asking questions), performing the physical examination, and obtaining selective laboratory and/or imaging tests. Of these, the historical examination is the most important and useful. Sensitivity and respect should always be exercised during the interview of patients.
1. Basic information: Age, gender, and ethnicity must be recorded because some conditions are more common at certain ages; for instance, pain on defecation and rectal bleeding in a 20-year-old may indicate inflammatory bowel disease, whereas the same symptoms in a 60-year-old would more likely suggest colon cancer.
2. Chief complaint: What is it that brought the patient into the hospital or clinic? Is it a scheduled appointment, or an unexpected symptom? The patient's own words should be used if possible, such as, "I feel like a ton of bricks are on my chest." The chief complaint, or real reason for seeking medical attention, may not be the first subject the patient talks about (in fact, it may be the last thing), particularly if the subject is embarrassing, such as a sexually transmitted disease, or highly emotional, such as depression. It is often useful to clarify exactly what the patient's concern is, for example, they may fear their headaches represent an underlying brain tumor.
3. History of present illness: This is the most crucial part of the entire database. The questions one asks are guided by the differential diagnosis one begins to consider the moment the patient identifies the chief complaint, as well as the clinician's knowledge of typical disease patterns and their natural history. The duration and character of the primary complaint, associated symptoms, and exacerbating/relieving factors should be recorded. Sometimes, the history will be convoluted and lengthy, with multiple diagnostic or therapeutic interventions at different locations. For patients with chronic illnesses, obtaining prior medical records is invaluable. For example, when extensive evaluation of a complicated medical problem has been done elsewhere, it is usually better to first obtain those results than to repeat a "million-dollar workup." When reviewing prior records, it is often useful to review the primary data (eg, biopsy reports, echocardiograms, serologic evaluations) rather than to rely upon a diagnostic label applied by someone else, which then gets replicated in medical records and by repetition, acquires the aura of truth, when it may not be fully supported by data. Some patients will be poor historians because of dementia, confusion, or language barriers; recognition of these situations and querying of family members is useful. When little or no history is available to guide a focused investigation, more extensive objective studies are often necessary to exclude potentially serious diagnoses.
4. Past history:
a. Illness: Any illnesses such as hypertension, hepatitis, diabetes mellitus, cancer, heart disease, pulmonary disease, and thyroid disease should be elicited. If an existing or prior diagnosis is not obvious, it is useful to ask exactly how it was diagnosed; that is, what investigations were performed. Duration, severity, and therapies should be included.
b. Hospitalization: Any hospitalizations and emergency room (ER) visits should be listed with the reason(s) for admission, the intervention, and the location of the hospital.
c. Blood transfusion: Transfusions with any blood products should be listed, including any adverse reactions.
d. Surgeries: The year and type of surgery should be elucidated and any complications documented. The type of incision and any untoward effects of the anesthesia or the surgery should be noted.
5. Allergies: Reactions to medications should be recorded, including severity and temporal relationship to the medication. An adverse effect (such as nausea) should be differentiated from a true allergic reaction.
6. Medications: Current and previous medications should be listed, including dosage, route, frequency, and duration of use. Prescription, over-the-counter, and herbal medications are all relevant. Patients often forget their complete medication list; thus, asking each patient to bring in all their medications—both prescribed and nonprescribed—allows for a complete inventory.
7. Family history: Many conditions are inherited, or are predisposed in family members. The age and health of siblings, parents, grandparents, and others can provide diagnostic clues. For instance, an individual with first-degree family members with early onset coronary heart disease is at risk for cardiovascular disease.
8. Social history: This is one of the most important parts of the history in that the patient's functional status at home, social and economic circumstances, and goals and aspirations for the future are often the critical determinant in what the best way to manage a patient's medical problem is. Living arrangements, economic situations, and religious affiliations may provide important clues for puzzling diagnostic cases, or suggest the acceptability of various diagnostic or therapeutic options. Marital status and habits such as alcohol, tobacco, or illicit drug use may be relevant as risk factors for disease.
9. Review of systems: A few questions about each major body system ensure that problems will not be overlooked. The clinician should avoid the mechanical "rapid-fire" questioning technique that discourages patients from answering truthfully because of fear of "annoying the doctor."
The physical examination begins as one is taking the history, by observing the patient and beginning to consider a differential diagnosis. When performing the physical examination, one focuses on body systems suggested by the differential diagnosis, and performs tests or maneuvers with specific questions in mind; for example, does the patient with jaundice have ascites? When the physical examination is performed with potential diagnoses and expected physical findings in mind ("one sees what one looks for"), the utility of the examination in adding to diagnostic yield is greatly increased, as opposed to an unfocused "head-to-toe" physical.
1. General appearance: A great deal of information is gathered by observation, as one notes the patient's body habitus, state of grooming, nutritional status, level of anxiety (or perhaps inappropriate indifference), degree of pain or comfort, mental status, speech patterns, and use of language. This forms your impression of "who this patient is."
2. Vital signs: Vital signs like temperature, blood pressure, heart rate, respiratory rate, height, and weight are often placed here. Blood pressure can sometimes be different in the two arms; initially, it should be measured in both arms. In patients with suspected hypovolemia, pulse and blood pressure should be taken in lying and standing positions to look for orthostatic hypotension. It is quite useful to take the vital signs oneself, rather than relying upon numbers gathered by ancillary personnel using automated equipment, because important decisions regarding patient care are often made using the vital signs as an important determining factor.
3. Head and neck examination: Facial or periorbital edema and pupillary responses should be noted. Funduscopic examination provides a way to visualize the effects of diseases such as diabetes on the microvasculature; papilledema can signify increased intracranial pressure. Estimation of jugular venous pressure is very useful to estimate volume status. The thyroid should be palpated for a goiter or nodule, and carotid arteries auscultated for bruits. Cervical (common) and supraclavicular (pathologic) nodes should be palpated.
4. Breast examination: Inspect for symmetry and for, skin or nipple retraction with the patient's hands on her hips (to accentuate the pectoral muscles) and also with arms raised. With the patient sitting and supine, the breasts should then be palpated systematically to assess for masses. The nipple should be assessed for discharge, and the axillary and supraclavicular regions should be examined for adenopathy.
5. Cardiac examination: The point of maximal impulse (PMI) should be ascertained for size and location, and the heart auscultated at the apex of the heart as well as at the base. Heart sounds, murmurs, and clicks should be characterized. Murmurs should be classified according to intensity, duration, timing in the cardiac cycle, and changes with various maneuvers. Systolic murmurs are very common and often physiologic; diastolic murmurs are uncommon and usually pathologic.
6. Pulmonary examination: The lung fields should be examined systematically and thoroughly. Wheezes, rales, rhonchi, and bronchial breath sounds should be recorded. Percussion of the lung fields may be helpful in identifying the hyper-resonance of tension pneumothorax, or the dullness of consolidated pneumonia or a pleural effusion.
7. Abdominal examination: The abdomen should be inspected for scars, distension, or discoloration (such as the Grey Turner sign of discoloration at the flank areas indicating intraabdominal or retroperitoneal hemorrhage). Auscultation of bowel sounds to identify normal versus high-pitched and hyperactive versus hypoactive. Percussion of the abdomen can be utilized to assess the size of the liver and spleen, and to detect ascites by noting shifting dullness. Careful palpation should begin initially away from the area of pain, involving one hand on top of the other, to assess for masses, tenderness, and peritoneal signs. Tenderness should be recorded on a scale (eg, 1-4 where 4 is the most severe pain). Guarding, and whether it is voluntary or involuntary, should be noted.
8. Back and spine examination: The back should be assessed for symmetry, tenderness, and masses. The flank regions are particularly important to assess for pain on percussion, which might indicate renal disease.
a. Females: The pelvic examination should include an inspection of the external genitalia, and with the speculum, evaluation of the vagina and cervix. A pap smear and/or cervical cultures may be obtained. A bimanual examination to assess the size, shape, and tenderness of the uterus and adnexa is important.
b. Males: An inspection of the penis and testes is performed. Evaluation for masses, tenderness, and lesions is important. Palpation for hernias in the inguinal region with the patient coughing to increase intraabdominal pressure is useful.
10. Rectal examination: A digital rectal examination is generally performed for those individuals with possible colorectal disease, or gastrointestinal bleeding. Masses should be assessed, and stool for occult blood should be tested. In men, the prostate gland can be assessed for enlargement and for nodules.
11. Extremities: An examination for joint effusions, tenderness, edema, and cyanosis may be helpful. Clubbing of the nails might indicate pulmonary diseases such as lung cancer or chronic cyanotic heart disease.
12. Neurologic examination: Patients who present with neurologic complaints usually require a thorough assessment, including the mental status, cranial nerves, motor strength, sensation, and reflexes.
13. Skin examination: The skin should be carefully examined for evidence of pigmented lesions (melanoma), cyanosis, or rashes that may indicate systemic disease (malar rash of systemic lupus erythematosus).
LABORATORY AND IMAGING ASSESSMENT
a. Complete blood count (CBC): To assess for anemia and thrombocytopenia.
b. Serum chemistry: Chemistry panel is most commonly used to evaluate renal and liver function.
c. Lipid panel: Lipid panel is particularly relevant in cardiovascular diseases.
d. Urinalysis: Urinalysis is often referred to as a "liquid renal biopsy," because the presence of cells, casts, protein, or bacteria provides clues about underlying glomerular or tubular diseases.
e. Infection: Gram stain and culture of urine, sputum, and cerebrospinal fluid, as well as blood cultures, are frequently useful to isolate the cause of infection.
2. Imaging procedures:
a. Chest radiography: Chest radiography is extremely useful in assessing cardiac size and contour, chamber enlargement, pulmonary vasculature and infiltrates, and the presence of pleural effusions.
b. Ultrasonographic examination: Ultrasonographic examination is useful for identifying fluid-solid interfaces, and for characterizing masses as cystic, solid, or complex. It is also very helpful in evaluating the biliary tree, kidney size, and evidence of ureteral obstruction, and can be combined with Dopple flow to identify deep venous thrombosis. Ultrasonography is noninvasive and has no radiation risk, but cannot be used to penetrate through bone or air, and is less useful in obese patients.
c. Computed tomography: Computed tomography (CT) is helpful in possible intracranial bleeding, abdominal and/or pelvic masses, and pulmonary processes, and may help to delineate the lymph nodes and retroperitoneal disorders. CT exposes the patient to radiation and requires the patient to be immobilized during the procedure. Generally, CT requires administration of a radiocontrast dye, which can be nephrotoxic.
d. Magnetic resonance imaging: Magnetic resonance imaging (MRI) identifies soft-tissue planes very well and provides the best imaging of the brain parenchyma. When used with gadolinium contrast (which is not nephrotoxic), MR angiography (MRA) is useful for delineating vascular structures. MRI does not use radiation, but the powerful magnetic field prohibits its use in patients with ferromagnetic metal in their bodies, for example, many prosthetic devices.
e. Cardiac procedures:
i. Echocardiography: Uses ultrasonography to delineate the cardiac size, function, ejection fraction, and presence of valvular dysfunction.
ii. Angiography: Radiopaque dye is injected into various vessels, and radiographs or fluoroscopic images are used to determine the vascular occlusion, cardiac function, or valvular integrity.
iii. Stress treadmill tests: Individuals at risk for coronary heart disease are monitored for blood pressure, heart rate, chest pain, and electrocardiogram (ECG) while increasing oxygen demands on the heart, such as running on a treadmill. Nuclear medicine imaging of the heart can be added to increase the sensitivity and specificity of the test. Individuals who cannot run on the treadmill (such as those with severe arthritis) may be given medications such as adenosine or dobutamine to "stress" the heart.
INTERPRETATION OF TEST RESULTS: USING PRETEST PROBABILITY AND LIKELIHOOD RATIO
Because no test is 100% accurate, it is essential when ordering a test to have some knowledge of the test's characteristics, as well as how to apply the test results to an individual patient's clinical situation. Let us use the example of a patient with chest pain. The first diagnostic concern of most patients and physicians regarding chest pain is angina pectoris, that is, the pain of myocardial ischemia caused by coronary insufficiency. Distinguishing angina pectoris from other causes of chest pain relies upon two important factors: the clinical history, and an understanding of how to use objective testing. In making the diagnosis of angina pectoris, the clinician must establish whether the pain satisfies the three criteria for typical anginal pain: (1) retrosternal in location, (2) precipitated by exertion, and (3) relieved within minutes by rest or nitroglycerin. Then, the clinician considers other factors, such as patient age and other risk factors, to determine a pretest probability for angina pectoris.
Excerpted from CASE FILES Internal Medicine by Eugene C. Toy John T. Patlan Jr. Copyright © 2013 by The McGraw-Hill Companies, Inc.. Excerpted by permission of McGraw-Hill. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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