NPE flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Positive likelihood ratio

Sensitivity divided by (1 minus specificity). A value above 10 substantially raises posttest probability, making the positive result useful for ruling in disease.

Negative likelihood ratio

(1 minus sensitivity) divided by specificity. A value below 0.1 substantially lowers posttest probability, making a negative result useful for ruling out disease.

Ankle-brachial index

Ratio of ankle to brachial systolic pressure. Normal is 1.0 to 1.4; 0.90 or less suggests peripheral arterial disease, and 1.4 or more suggests noncompressible arteries.

Volume of distribution

Amount of drug in the body divided by plasma concentration. A large value indicates extensive tissue distribution, prolongs elimination, and reduces removal by dialysis.

Loading dose formula

Loading dose equals volume of distribution times target concentration divided by bioavailability. It depends on distribution, not on clearance, and fills the body compartment quickly.

Half-life and steady state

Half-life equals 0.693 times volume of distribution divided by clearance. Roughly four to five half-lives are required to reach steady-state plasma concentrations.

CYP450 inducers

Drugs that increase cytochrome P450 enzyme activity and lower concentrations of substrates. Examples include rifampin, carbamazepine, phenytoin, and St. John's wort.

Warfarin mechanism

Warfarin inhibits vitamin K epoxide reductase, reducing synthesis of clotting factors II, VII, IX, and X. Effect is monitored with INR and reversed with vitamin K.

Metformin boxed warning

Metformin carries a boxed warning for lactic acidosis. It is held before iodinated contrast when renal function is impaired and avoided in severe renal insufficiency.

Colorectal cancer screening ages

Average-risk adults begin screening at age 45 and continue through age 75. Options include colonoscopy every 10 years or annual fecal immunochemical testing.

Lung cancer screening criteria

Annual low-dose CT is recommended for adults aged 50 to 80 with at least a 20 pack-year history who currently smoke or quit within 15 years.

Tdap in pregnancy

Tdap is given during every pregnancy, preferably at 27 to 36 weeks gestation, regardless of prior vaccination history, to protect the newborn from pertussis.

Teach-back method

The clinician asks the patient to restate instructions in their own words. This confirms comprehension more reliably than asking whether the patient understands.

Ottawa ankle rules

Radiography is indicated with malleolar pain plus bone tenderness at the posterior malleolus or navicular, or inability to bear weight four steps.

Centor criteria

Fever, tonsillar exudate, tender anterior cervical nodes, and absence of cough. Scores of 0 to 1 generally do not warrant streptococcal testing.

CURB-65

Pneumonia severity score using confusion, urea above 7 mmol/L, respiratory rate 30 or higher, low blood pressure, and age 65 or older.

Asthma exacerbation severity

Peak flow 40 to 69 percent of personal best indicates a moderate exacerbation. Below 40 percent indicates severe exacerbation requiring urgent treatment.

Gout flare treatment

Acute flares are treated with NSAIDs, colchicine, or glucocorticoids. Urate-lowering therapy is not started or adjusted during an acute flare.

Hypertension stage 2

Stage 2 hypertension is a systolic pressure of 140 mmHg or higher or a diastolic pressure of 90 mmHg or higher. Stage 1 is 130 to 139 over 80 to 89.

Metabolic syndrome criteria

Three of five: elevated waist circumference, triglycerides 150 or higher, low HDL, blood pressure 130/85 or higher, and fasting glucose 100 mg/dL or higher.

Heart failure reduced ejection fraction therapy

Guideline-directed therapy combines an ARNI, ACE inhibitor, or ARB with an evidence-based beta blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor.

COPD spirometric definition

A post-bronchodilator FEV1/FVC ratio below 0.70 confirms persistent airflow limitation. Severity grades use FEV1 percent predicted, from GOLD 1 through GOLD 4.

Osteoporosis T-score

A bone mineral density T-score of negative 2.5 or lower defines osteoporosis. Lower scores indicate greater fracture risk and support pharmacologic treatment.

Informed consent elements

Valid consent requires patient capacity, disclosure of material risks and alternatives, patient comprehension, and voluntariness. Consent is an ongoing process, not merely a signature.

Negligence elements

A malpractice claim requires duty to the patient, breach of the standard of care, causation linking breach to injury, and actual damages. All four must be proven.

Good Samaritan statutes

These laws protect clinicians who give emergency care outside their usual duty from liability absent gross negligence. They do not create a duty to rescue.

Mandatory reporting

Clinicians must report suspected child abuse, elder abuse, and specified communicable diseases to authorities, generally without patient authorization and despite confidentiality.

Medicare Part A coverage

Part A covers inpatient hospital stays, skilled nursing facility care, hospice, and some home health. Part B covers outpatient care and durable medical equipment.

Medicare Part D

Part D provides outpatient prescription drug coverage through private plans. Out-of-pocket insulin is capped at 35 dollars monthly, and an annual out-of-pocket cap applies.

Incidence versus prevalence

Incidence counts new cases divided by the population at risk over a period. Prevalence counts all existing cases divided by the total population at a point in time.

Herd immunity threshold

Estimated as 1 minus 1 divided by R0. Measles, with an R0 of 12 to 18, requires roughly 92 to 95 percent population immunity.

Positive predictive value and prevalence

For fixed sensitivity and specificity, positive predictive value falls as disease prevalence decreases, so the same test performs worse in low-prevalence populations.