PEBC Evaluating Exam cheat sheet

Cardiac output (CO) = heart rate × stroke volume; normal resting adult value is about 5 L/min.

GFR is the volume of plasma filtered per unit time; normal is approximately 125 mL/min/1.73 m²; creatinine clearance overestimates GFR because creatinine is secreted.

Henderson–Hasselbalch for the bicarbonate system: pH = 6.1 + log([HCO3−] ÷ (0.03 × PaCO2)); PaCO2 is in mmHg.

Anion gap = Na+ − (Cl− + HCO3−); normal 8–12 mmol/L; raised by ketoacidosis, lactic acidosis, renal failure, methanol, ethylene glycol and salicylate.

Insulin binds a receptor tyrosine kinase, promotes GLUT4 translocation in skeletal muscle and adipose tissue, and lowers blood glucose.

Beta-1 receptors increase heart rate and contractility; beta-2 receptors cause bronchial and vascular smooth muscle relaxation; alpha-1 receptors cause vasoconstriction.

IgG crosses the placenta and dominates the secondary response; IgM is the first antibody in a primary response; IgA is secreted in mucosal fluids; IgE mediates type I hypersensitivity.

Gram-positive bacteria have a thick peptidoglycan layer that retains crystal violet; gram-negative bacteria have a thin peptidoglycan layer and an outer membrane containing lipopolysaccharide.

t1/2 = 0.693 × Vd / CL; about 4–5 half-lives are required to reach steady state during constant dosing.

Vd = amount of drug in the body ÷ plasma concentration; a large Vd (>1 L/kg) indicates extensive tissue distribution.

At steady state during a continuous IV infusion, CL = dose rate ÷ Css; maintenance dose rate = CL × target Css.

Oral bioavailability F = (AUC_oral × dose_IV) ÷ (AUC_IV × dose_oral); F = 1 for intravenous administration.

Loading dose = (Vd × target concentration) ÷ F; it fills the apparent volume of distribution but does not sustain concentrations.

Michaelis–Menten: V = Vmax × C ÷ (Km + C); at C << Km elimination is first-order; at C >> Km it is zero-order (e.g., phenytoin, ethanol).

Noyes–Whitney dissolution rate = (D × A ÷ h) × (Cs − C); smaller particle size and higher solubility increase dissolution rate.

Weak acid: pH = pKa + log([A−] ÷ [HA]); weak base: pH = pKa + log([B] ÷ [BH+]); ionization affects absorption and renal reabsorption.

Prodrugs: enalapril → enalaprilat; codeine → morphine (CYP2D6); clopidogrel → active thiol metabolite (CYP2C19).

Warfarin target INR is 2.0–3.0 for atrial fibrillation and VTE, and 2.5–3.5 for a mechanical mitral valve; vitamin K is the antidote.

Metformin is first-line for type 2 diabetes; contraindicated when eGFR <30 mL/min/1.73 m²; hold during acute illness or iodinated contrast procedures.

ACE inhibitors cause cough (bradykinin), hyperkalemia, angioedema and acute kidney injury; they are contraindicated in pregnancy.

Statins can cause myopathy and rarely rhabdomyolysis; check CK if muscle symptoms occur; CYP3A4 inhibitors raise simvastatin and atorvastatin exposure.

Digoxin has a narrow therapeutic index (HF target 0.5–0.9 ng/mL); toxicity causes nausea, confusion, visual changes and arrhythmias; hypokalemia increases toxicity; digoxin Fab is the antidote.

N-acetylcysteine is the antidote for acetaminophen overdose; it replenishes glutathione and is most effective within 8 hours; the Rumack–Matthew nomogram guides treatment.

Naloxone reverses opioid overdose; it is shorter-acting than many opioids, so repeat doses or an infusion may be needed; monitor respirations.

Aminoglycosides require peak and trough monitoring; they cause nephrotoxicity and ototoxicity; extended-interval once-daily dosing is common.

Inhaled corticosteroids are first-line maintenance therapy for persistent asthma; short-acting beta-2 agonists are for acute symptom relief.

Health Belief Model constructs: perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action and self-efficacy.

Transtheoretical model stages: precontemplation, contemplation, preparation, action, maintenance; interventions should match the patient's stage.

ARR = control event rate − treatment event rate; NNT = 1 ÷ ARR.

ICER = (cost of intervention − cost of comparator) ÷ (effect of intervention − effect of comparator).

Cost-minimization compares drugs with equal outcomes; cost-effectiveness uses natural units; cost-utility uses QALYs; cost-benefit expresses outcomes in dollars.

Sensitivity = TP ÷ (TP + FN); specificity = TN ÷ (TN + FP); both are independent of disease prevalence.

Proportion of days covered (PDC) = days of medication supplied ÷ days in the observation period; PDC ≥0.80 is commonly used to define adherence.

Evidence hierarchy: systematic reviews/meta-analyses of RCTs > RCTs > cohort studies > case-control studies > case series > expert opinion.

Relative risk = incidence in exposed ÷ incidence in unexposed; odds ratio approximates relative risk when the outcome is rare.