MDCG Medical Exam cheat sheet

Informed consent requires capacity, disclosure of material risks/benefits/alternatives, comprehension, and voluntariness; documentation should record the discussion, not just a signature.

Four basic ethical principles: respect for autonomy, beneficence, nonmaleficence, and justice; apply them together when principles conflict.

Confidentiality exceptions include patient authorization, statutory reporting (e.g., communicable disease, abuse), imminent serious harm to self or others, and court order.

Minors: consent rules vary by jurisdiction; emancipated minors and specific services (e.g., reproductive/mental health) may have statutory exceptions; always verify local law.

Mandatory reporting duties commonly cover suspected child abuse/neglect, elder abuse, and certain injuries (e.g., gunshot wounds) as defined by jurisdiction.

Negligence elements: duty of care, breach of standard, causation (actual and proximate), and damages; standard of care is what a reasonably prudent clinician would do.

Emergency exception to consent permits treatment of an incapacitated patient when delay would risk serious harm and no valid refusal is known.

HIPAA Privacy Rule permits disclosures for treatment, payment, and operations; minimum necessary standard applies to most uses and disclosures.

Advance directives (living will, durable power of attorney for health care) guide care when the patient lacks capacity; verify scope and state-specific forms.

Primary survey (ABCDE): Airway, Breathing, Circulation, Disability, Exposure; treat life threats as found before proceeding to secondary survey.

Vital sign thresholds in adults: hypotension <90/60 mmHg, tachycardia >100 bpm, tachypnea >20/min, fever >38.0°C (100.4°F); interpret in clinical context.

Pain assessment: use validated scales (numeric 0–10, Wong-Baker FACES for children); reassess after intervention and document response.

Medication reconciliation at transitions of care reduces adverse drug events; obtain best possible medication history including OTC, supplements, and adherence.

SBAR handoff (Situation, Background, Assessment, Recommendation) standardizes communication and reduces omission of critical information.

Sepsis screening: suspected infection plus ≥2 SIRS criteria (temperature, heart rate, respiratory rate, WBC) prompts evaluation; qSOFA includes altered mentation, SBP ≤100, RR ≥22.

Fall risk assessment (e.g., Morse Fall Scale) triggers multifactorial prevention: bed low/locked, call light within reach, nonskid footwear, toileting assistance.

Pressure injury prevention: reposition at least every 2 hours, keep skin clean/dry, use pressure-redistribution surfaces, and assess nutrition.

Sensitivity = TP/(TP+FN): probability a test is positive in disease; high sensitivity is useful for ruling out (SnNout).

Specificity = TN/(TN+FP): probability a test is negative without disease; high specificity is useful for ruling in (SpPin).

Positive predictive value = TP/(TP+FP) and negative predictive value = TN/(TN+FN); both depend on disease prevalence.

Likelihood ratio positive (LR+) = sensitivity/(1−specificity); LR negative (LR−) = (1−sensitivity)/specificity; LR >10 or <0.1 substantially changes post-test probability.

Post-test odds = pre-test odds × likelihood ratio; convert probability to odds (odds = p/(1−p)) and back (p = odds/(1+odds)).

Number needed to treat (NNT) = 1/absolute risk reduction; number needed to harm (NNH) = 1/absolute risk increase.

Reference standard bias occurs when the test is evaluated against an imperfect gold standard; spectrum bias arises when study patients differ from the target population.

Test characteristics can shift with disease severity and prevalence; a negative test in a high-prevalence setting does not necessarily exclude disease.

First-order elimination: half-life (t½) = 0.693 × volume of distribution / clearance; steady state is reached in about 4–5 half-lives.

Loading dose = (target concentration × volume of distribution) / bioavailability; maintenance dose = (target concentration × clearance) / bioavailability.

Cytochrome P450 interactions: inhibitors (e.g., azole antifungals, macrolides, grapefruit) raise substrate levels; inducers (e.g., rifampin, carbamazepine, St. John's wort) lower them.

Narrow therapeutic index drugs (e.g., warfarin, digoxin, lithium, phenytoin, aminoglycosides) require therapeutic drug monitoring and careful dose adjustment.

Adverse drug reaction reporting: classify by mechanism (Type A augmented/dose-related; Type B bizarre/idiosyncratic) and report serious events to the national pharmacovigilance system.

Renal dose adjustment is guided by creatinine clearance (Cockcroft-Gault) or eGFR; avoid nephrotoxic combinations and monitor levels for renally cleared drugs.

Antimicrobial stewardship: confirm indication, obtain cultures before antibiotics when feasible, choose narrowest effective agent, and reassess at 48–72 hours.

Opioid prescribing safety: screen for risk, check prescription drug monitoring program, co-prescribe naloxone when risk is elevated, and avoid concurrent benzodiazepines when possible.

Incidence = new cases / population at risk over time; prevalence = all existing cases / total population at a point or period.

Relative risk (RR) = incidence in exposed / incidence in unexposed; odds ratio (OR) approximates RR when disease is rare.

Attributable risk (risk difference) = incidence exposed − incidence unexposed; population attributable fraction estimates the proportion of disease due to exposure.

Screening criteria (WHO): important health problem, accepted treatment, recognizable latent/early stage, suitable test, test acceptable to population, agreed policy on whom to treat, cost-effective.

Herd immunity threshold depends on basic reproduction number R0: threshold ≈ 1 − 1/R0; higher R0 requires higher coverage.

Levels of prevention: primordial (risk factor avoidance), primary (prevent disease before onset), secondary (early detection/treatment), tertiary (reduce complications/disability).

Outbreak investigation steps: verify diagnosis, establish case definition, find cases, describe by person/place/time, generate hypotheses, test hypotheses, implement control, communicate.

Study designs: cohort yields incidence and RR; case-control yields OR; cross-sectional yields prevalence; randomized controlled trial best controls confounding.

SOAP note structure: Subjective, Objective, Assessment, Plan; each problem should have an assessment linked to a plan.

Documentation must be accurate, timely, legible, and attributable; late entries should be labeled as such with date/time and reason.

Medical decision-making (MDM) elements in E/M coding: number and complexity of problems, amount/complexity of data reviewed, and risk of complications/morbidity/mortality.

ICD-10-CM coding requires specificity: laterality, episode of care, and combination codes; code the condition to the highest level of documented specificity.

CPT evaluation and management codes are selected by level of service (time or MDM); prolonged services and modifiers (e.g., −25, −59) must meet defined criteria.

Medical necessity links the diagnosis, service, and documentation; payers may deny claims when the documented diagnosis does not support the service.

Release of information requires a valid authorization (patient, date, scope, expiration, right to revoke) except for permitted treatment/payment/operations or legal exceptions.

Audit trail: document amendments without deleting original content; retain records per jurisdiction and organizational policy.

Adult cardiac arrest: high-quality CPR at 100–120 compressions/min, depth 5–6 cm, full recoil, minimize interruptions; defibrillate shockable rhythms as soon as available.

ACLS: epinephrine 1 mg IV/IO every 3–5 minutes for nonshockable rhythms and after initial defibrillation attempts for shockable rhythms; amiodarone/lidocaine for refractory VF/pVT.

Post–cardiac arrest care: target oxygen saturation 92–98%, avoid hypotension (MAP ≥65 mmHg), targeted temperature management, and treat reversible causes (Hs and Ts).

Anaphylaxis: intramuscular epinephrine 0.3–0.5 mg (1:1000) in the mid-outer thigh for adults, repeat every 5–15 minutes as needed; adjuncts do not replace epinephrine.

Sepsis bundle: measure lactate, obtain blood cultures before antibiotics, administer broad-spectrum antibiotics and 30 mL/kg crystalloid for hypotension or lactate ≥4 mmol/L within 3 hours.

Acute stroke: activate stroke pathway, obtain noncontrast CT to exclude hemorrhage, check glucose; thrombolysis window generally up to 4.5 hours from last known well in eligible patients.

Acute coronary syndrome: 12-lead ECG within 10 minutes of arrival; aspirin and reperfusion strategy guided by ST-segment changes and risk.

Status epilepticus: benzodiazepine first-line, then second-line antiseizure medication; monitor airway, glucose, and temperature.

Model for Improvement: three questions (aim, measures, changes) plus Plan-Do-Study-Act (PDSA) cycles for iterative testing.

Donabedian framework: structure, process, and outcome measures; balanced measures include equity and patient experience.

Root cause analysis (RCA) is retrospective for sentinel events; failure mode and effects analysis (FMEA) is prospective and prioritizes by severity × occurrence × detection.

Safety event categories: near miss, no-harm event, harmful event, and sentinel event; reporting systems should be nonpunitive and confidential.

Hand hygiene: WHO Five Moments; alcohol-based hand rub preferred when hands are not visibly soiled; observe duration and technique.

Central line–associated bloodstream infection prevention bundle: hand hygiene, maximal sterile barrier, chlorhexidine skin antisepsis, optimal site selection, and daily review of line necessity.

Surgical safety checklist: sign in (before induction), time out (before incision), sign out (before leaving OR); confirm patient, site, procedure, and allergies.

Statistical process control: distinguish common-cause variation from special-cause variation using control charts; act on special causes and redesign systems for common causes.