Outlines in Clinical Medicine on Physicians' Online
A. Screening See outline "Cancer
Screening"
- Definition: application of a test to an asymtomatic group to estimate
probability that members of group will have a disease
- Diseases for which screening is appropriate:
- Have serious consequences
- Are progressive
- Are treatable and early treatment produces better results than late
treatment
- Prevalence of detectable preclinical phase is high in the population
being screened.
- Characteristics of Good Screening Tests
See outline "Diagnostic
Tests"
- Inexpensive
- Comfortable enough to be acceptable to patients
- Convenient to perform
- Reliable (consistent, relatively insensitive to technique of performer)
- Valid (sensitivity - few false negatives, and specificity - few false
positives, are high)
- High positive and negative predictive value, measures which combine test
sensitivity and specificity with prevalence in the population being
considered
- Results of an appropriate screening program
- For acute diseases, reduced morbidity and mortality
- For chronic diseases, reduced severity and/or prolonged remissions
- For infectious disease, screening and early treatment may reduce disease
transmission, reducing disease incidence
- Results of inappropriate screening
- Exposes patient to risks associated with screening test (eg. radiation
exposure from mammography for low risk women under 40 years old)
- Exposes patient to risks associated with diagnostic test following
positive screening test (eg. prostate biopsy following positive digital
rectal exam)
- Exposes patient to anxiety associated with positive screening test (PSA,
mammography)
- Creates unnecessary expense (CA-125 test for patient at low risk for
ovarian cancer.)
B.
Hyperglycemia See outline "Diabetes Mellitus
Type 2"
- General screening for anyone >45 years of age is now recommended
- Fasting serum glucose random test very sensitive (but not specific)
- Abnormal tests may be followed up with glucose tolerance test
- Consider fructosamine and/or hemoglobin A1c (HbA1c) levels added to
glucose level
- Persons at elevated risk for type 2 DM should be screened earlier
- All obese and overweight persons
- Strong family history
- Chronic use of glucocorticoids
- Consider evaluating patients with hypertension (HTN)
- Incidence of type 2 DM higher in African versus Caucasian Americans [22]
- 1.5X higher incidence in men
- 2.4X higher incidence in women
C. Cardiovascular
- Low risk cardiovascular profile associated with ~5-10 year increased
lifespan [19]
- Blood Pressure See outline "Hypertension"
- Usually done 2 or more times per year in patients >40 years
- Younger patients should have at least one blood pressure per 2 years
- Diagnosis of HTN usually requires 3 separate determinations of high
blood pressure
- Use home monitoring to distinguish true from white coat hypertension
- Pulse - all patients
- Electrocardiography (ECG) - patients with significant cardiac risks,
preoperative
- Chest Radiography
- Symptomatic evaluation of chest pain
- Not useful for routine pre-operative evaluations
- Cholesterol levels (see below)
- Carotid Ultrasound See outline "Cerebrovascular
Disease"
- All patients with evidence of coronary artery disease
- Patients with other vasculopathy
- Patients with carotid bruits
- Abdominal Aortic Aneurysms [15,16]
See outline "Aneurysms"
- High suspicion in patients with other cardiovascular disease,
particularly HTN
- More common in men than women
- Physical examination is unreliable [17]
- Ultrasound is screening method choice
- Repeat ultrasound for aneurysms >3-4cm
- Attention to all aspects of therapy for patients with cardiovascular
disease [9]
- Patients should NOT smoke
- Alcohol - 1-2 servings of alcohol per day is associated with improved CV
outcomes
- Weight should be maintained in normal range
- Exercise should be strongly encouraged
D. Cholesterol See outline "Hypercholesterolemia"
- NCEP recommends screening in all patients >25 years of age
- Possibly in younger patients with multiple cardiovascular risk factors
- Normal cholesterol level (<200mg/dl) should be followed q5 years
- Abnormal level should be repeated with complete cholesterol profile
- Very Low Total Cholesterol
- Has been associated with increased risk of cancer, hemorrhagic stroke,
trauma [2]
- Part of the cancer risk is due to confounding variables: smoking, GI
disease, alcohol [3]
- High Cholesterol is associated with atherosclerosis and other diseases
- Primary prevention of adverse events in patients with high cholesterol
using pravastatin costs $20-35,000 per life year saved [12]
E. Stool Occult Blood Analysis
See outline "Cancer
Screening"
- Occult blood tests are mainstay of colorectal cancer screening
- Usually 1 survey per year in all patients >49 years (or >45 years)
old
- At least 3 stool specimens should be surveyed
See outline "Colon
Cancer"
- Biennial occult blood screening reduces death due to colorectal cancer
~20% [6]
- For any history of rectal bleeding, full evaluation of colon is
recommended [8]
- Sigmoidoscopy + double contrast (barium/air) enema OR
- Full Colonoscopy
- Majority (~60%) of patients with positive occult blood have uper GI
lesions [13]
- Many patients with upper GI lesions take aspirin, ethanol, or other
NSAIDs chronically
- Esophagitis, gastric ulcer, gastritis and duodenal ulcer all found
- Flexible sigmoidoscopy in asymptomatic persons over age 50 is recommended
regardless of stool occult blood results
- Finding of even small adenomas (<6mm) should lead to further evaluation
[7]
- Positive Occult Blood and Negative Colonoscopy [18]
- All patients with positive occult blood and negative colonoscopy had
upper endoscopy
- Of the 498 asympatomic patients, 67 (13%) had upper gastrointestinal
(GI) lesions
- Majority of these had peptic ulcer disease (40 patients)
- Another 56 (11%) patients had nonbleeding upper GI lesions which led to
therapy change
- 1% of the patients were diagnosed with cancer (4 gastric, 1 esophageal)
- In the 133 patients with anemia (Hb <12-14gm/dL), 39 had significant
upper GI lesions
- Therefore, upper GI endoscopy should be considered in patients negative
for colonoscopy and positive on fecal occult blood testing
F. Urinalysis and Renal
Function
- Urinalysis - all pregnant women; renal patients; symptomatic patients
- Serum Electrolytes - baseline may be recommended q1-5 yrs
- Renal Dysfunction - screening BUN and Creatinine; urinalysis for
hematuria, proteinuria
- Hematuria - malignancy evaluation is required
G. Endocrinopathies
- Thyroid Dysfunction See outline "Thyroid
Disease"
- Any patient with hypertension or tachycardias
- Any patient with suggestive symptoms
- Screening women over 35 yrs every 5 years with TSH is cost effective [5]
- Whether men should be screened with TSH is less clear [5]
- Screening all women >50 with a TSH test is recommended (1 in 71 will
be positive) [20]
- Persons with TSH <0.4 mU/L have subclinical hyperthyroidism
- These persons are at increased risk for atrial fibrillation,
osteoporosis, and frank hyperthyroidism
- Persons with TSH >5 mU/L (>10% of women >60 years) have
subclinical hypothyroidism
- These persons are at risk for hypercholesterolemia and frank
hypothyroidism
- Hemochromatosis [1,14]
See outline "Hemochromatosis"
- Genetic screening of all patients before age 30-40 is not recommended at
this time [14]
- Current genetic tests have ~85% sensitivity and very high specificity
- Functional screening may be warrented:
- Hemochromatosis is a common and very treatable disease in early stages
- Functional screen consists of ferritin level, iron, and transferrin
saturation
- Transferrin saturation >60% and/or ferritin >500ng/mL are strongly
suggestive
- Such patients should be evaluated liver function testing, possible liver
biopsy
- Women at much reduced risk than men (usually develop disease at later
age)
- Osteoporosis See outline "Osteoporosis"
- Should be considered in all post-menopausal women
- Consider in all patients at increased risk
- Consider in patients with abnormal fractures
- Routine screening with bone densitometry is increasingly recommended
H. Substance Abuse
- Smoking See outline "Smoking"
- Alcohol See outline "Alcoholism"
- Recreational Drug Abuse
- Cocaine See outline "Cocaine
Overdose"
- Opiates See outline "Opioid
Overdose"
- Anabolic Steroids
- Particularly in young athletes
- Androstenedione available over the counter 300mg/d increases serum
testosterone [21]
I. Pulmonary Function
See outline "Pulmonary Function
Tests"
- Pulmonary Function Tests (PFTs)
- Active pulmonary disease
- Smokers with symptoms See outline "Cancer
Screening"
- PFTs for pre-op evaluation only in symptomatic patients
- Chest radiograph - symptomatic screening only, asbestos exposure
J. Depression Screening [11]
See outline "Depression"
- This is a critical (often overlooked) part of primary care medicine
- Two questions can cover depression screening about as well as more complex
screens
- "During the past month, have you often been bothered by feeling down,
depressed, or hopeless ?"
- During thepast month, have you been bothered by little interest or
pleasure in doing things ?"
- This test has a fairly high false positive rate (specificity 57%)
- Positive answers to above questions should prompt further assessment
- Additional information about other aspects of life should be assessed
- This includes sleep, eating, social and sexual activity, hopes, et
cetera
- Depression is a major problem in primary care (~30% of typical practice)
- Screening is considered a standard and essential component of primary
care
- Failure to detect depression may result in unnecessary diagnostics,
treatments, suffering, and even suicide
- Majority of managed care organizations require depression screening in
primary care
- Failure to detect and/or treat depression may have negative medicolegal
ramifications
K.
Miscellaneous Screening
- Domestic Violence
- Glaucoma - tonometry for intraocular pressure
See outline "Glaucoma"
- Breast Implants See outline "Breast
Disease"
- No increased risk of breast cancer
See outline
"Breast
Cancer"
- Increased risk of local reactions
- Small, questionable increased risk of connective tissue diseases [4]
- Systemic lupus incidence was NOT increased in this large study [4]
- Main risk was "any connective tissue disease", not any specific disease
- Melanoma [10]
See outline "Cancer
Screening"
- Monthly to bimonthly self screening
- Help from spouse / significant other
- Yearly or semi-annual screening by dermatologist
- Special attention to screening in high risk groups
See outline
"Melanoma"
- Hemochromatosis See outline "Hemochromatosis"
- Overall incidence is 0.5-1% in Caucasian populations
- Screening with iron levels ± transferrin is generally considered
cost-effective
- Persons with (mild) chronic elevations of transaminases should be
evaluated
References
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