PNA (Internato Médico) flashcards

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

Cardiac output formula

Cardiac output equals heart rate multiplied by stroke volume. Normal resting output is roughly 4–8 L/min; it rises with demand and falls in shock states.

Anion gap calculation

Anion gap = Na⁺ − (Cl⁻ + HCO₃⁻), normally 8–12 mEq/L. An elevated gap indicates unmeasured anions such as ketones, lactate, or uremic acids.

Corrected sodium in hyperglycemia

Add 1.6 mEq/L to measured sodium for every 100 mg/dL glucose above 100. This estimates true sodium when hyperglycemia dilutes serum sodium.

Sensitivity definition

Sensitivity is true positives divided by all patients with disease. A highly sensitive test rarely misses disease, so it is useful for ruling out.

Specificity definition

Specificity is true negatives divided by all patients without disease. A highly specific test rarely produces false positives, so it is useful for ruling in.

Positive predictive value

PPV is true positives divided by all positive results. Unlike sensitivity, PPV depends on disease prevalence in the tested population.

Number needed to treat

NNT equals 1 divided by absolute risk reduction. It expresses how many patients must be treated to prevent one additional adverse outcome.

Kaplan-Meier estimator

A nonparametric method estimating survival probability over time while accounting for censored observations. Curves are compared with the log-rank test.

Hazard ratio meaning

From a Cox proportional hazards model, a hazard ratio above 1 means higher instantaneous risk of the event in the exposed group versus the reference group.

Phase I trial purpose

Phase I trials primarily assess safety, tolerability, and dosing in a small group, often healthy volunteers or selected patients, not efficacy.

Phase III trial purpose

Phase III trials compare a new intervention with standard care in large populations to establish efficacy and monitor adverse effects before licensing.

Intention-to-treat analysis

Analyses participants according to randomized allocation regardless of adherence. It preserves randomization and gives a conservative estimate of real-world effectiveness.

Four ethical principles

Autonomy, beneficence, non-maleficence, and justice. These principles structure clinical ethical reasoning, especially consent and resource allocation decisions.

Informed consent elements

Valid consent requires patient capacity, adequate information about risks and alternatives, and voluntariness free of coercion.

Notifiable disease concept

Certain infectious diseases must be reported to public health authorities to enable surveillance, outbreak investigation, and control measures.

Lead-time bias

Apparent survival gain from earlier detection alone, without postponing death. It can falsely suggest screening benefit in survival analyses.

ST-elevation MI reperfusion

Primary PCI is preferred if achievable within 120 minutes of first medical contact; otherwise fibrinolysis is given when symptom onset is under 12 hours.

High-sensitivity troponin algorithm

Serial high-sensitivity troponin at 0 and 1–3 hours, interpreted with absolute change, rapidly rules in or out acute myocardial infarction.

Acute heart failure diuresis

Intravenous loop diuretics relieve congestion. Beta-blockers are withheld during decompensation; potassium and renal function are monitored closely.

DKA insulin and potassium rule

Start insulin infusion only when potassium is at least 3.3 mEq/L. Add dextrose when glucose falls below 200–250 mg/dL while continuing insulin.

Sepsis one-hour bundle

Obtain cultures, give broad-spectrum antibiotics, measure lactate, and give 30 mL/kg crystalloid for hypotension or lactate ≥4 within one hour.

Stroke thrombolysis window

Intravenous thrombolysis is licensed up to 4.5 hours from symptom onset after non-contrast CT excludes hemorrhage; thrombectomy extends to 24 hours in selected cases.

CURB-65 score

Scores confusion, urea >7 mmol/L, respiratory rate ≥30, low blood pressure, and age ≥65. Scores of 2 or more generally favor hospital admission.

Glasgow-Blatchford score

Risk score for upper GI bleeding using hemoglobin, urea, blood pressure, heart rate, and presentation. Very low scores identify candidates for outpatient care.

Hyperkalemia membrane stabilization

IV calcium gluconate is given first when ECG changes are present, followed by insulin with dextrose and salbutamol to shift potassium intracellularly.

PE hemodynamic instability

In high-risk pulmonary embolism with shock or hypotension, systemic thrombolysis is indicated; stable patients are stratified by sPESI and right ventricular strain.

Diabetic foot ulcer assessment

Assess perfusion, infection, and neuropathy; probe to bone suggests osteomyelitis. Multidisciplinary care with offloading and debridement improves healing.

Acute pancreatitis diagnosis

Requires two of three: characteristic epigastric pain, lipase or amylase above three times normal, and imaging findings. Early fluid resuscitation is central.

Meningitis empiric therapy

Immediate empiric antibiotics with dexamethasone for suspected bacterial meningitis; do not delay treatment for lumbar puncture when signs are present.

Hypertensive emergency definition

Severe blood pressure elevation with acute target-organ damage such as encephalopathy, pulmonary edema, or aortic dissection. Requires controlled intravenous reduction.

Hypoglycemia treatment rule

Conscious patient: oral glucose. Unconscious: IV glucose or intramuscular glucagon. Recheck glucose and identify the precipitating cause.

Anaphylaxis first-line drug

Intramuscular adrenaline into the anterolateral thigh is first-line. Remove the trigger, give oxygen and fluids, then antihistamines and corticosteroids as adjuncts.