MDCN Assessment cheat sheet

Shock index = heart rate ÷ systolic blood pressure; a value ≥0.9 in adults signals occult hypoperfusion and warrants aggressive resuscitation review.

Anion gap = Na⁺ − (Cl⁻ + HCO₃⁻); normal 8–12 mmol/L. Add 2.5 mmol/L to the gap for every 1 g/dL fall in albumin below 4 g/dL.

Corrected sodium = measured Na⁺ + 1.6 × (glucose − 100)/100 for hyperglycaemia; measured osmolality minus calculated (2Na + glucose + urea) >10 suggests an unmeasured osmole.

Wells score for DVT: +1 each for cancer, immobilisation, bedridden status, localised tenderness, entire-leg swelling, calf swelling >3 cm, pitting oedema, collateral veins; −2 if alternative diagnosis likely.

CHA₂DS₂-VASc adds 1 point each for heart failure, hypertension, diabetes, vascular disease, age 65–74, female sex; 2 points each for age ≥75 and prior stroke/TIA.

CURB-65 for community pneumonia: confusion, urea >7 mmol/L, respiratory rate ≥30, low blood pressure (SBP <90 or DBP ≤60), age ≥65 - one point each.

Acute kidney injury is staged by KDIGO: stage 1 creatinine rise ≥26.5 µmol/L in 48 h or 1.5–1.9× baseline; stage 2 is 2.0–2.9×; stage 3 is ≥3× or creatinine ≥354 µmol/L or dialysis.

For suspected acute coronary syndrome, high-sensitivity troponin is interpreted by serial change (rise/fall pattern) rather than a single absolute value alone.

Permanent tooth eruption sequence (mandibular first): 6-1-2-3-4-5-7-8 years approximately; mandibular teeth generally erupt slightly before their maxillary counterparts.

Universal numbering: 1–16 maxillary right to left then mandibular left to right; FDI uses two digits (quadrant 1–4 plus tooth 1–8).

Primary dentition: 20 teeth, eruption begins ~6 months with mandibular central incisors; mixed dentition spans roughly 6–12 years.

Periodontal staging (2017 classification): stage I–IV by interdental clinical attachment loss (1–2, 3–4, ≥5 mm) and tooth loss; grading A–C by progression rate and bone loss/age ratio.

Caries risk assessment includes visible plaque, dietary sugar frequency, fluoride exposure, salivary flow, and past caries experience; fluoride varnish is applied ≥2×/year for high-risk patients.

Local anaesthetic maximum doses: lidocaine 4.4 mg/kg (with adrenaline), articaine 7 mg/kg, mepivacaine 6.6 mg/kg; 1 cartridge of 2% lidocaine with 1:100,000 contains 36 mg lidocaine and 18 µg adrenaline.

Pulp diagnosis terms: normal, reversible pulpitis, symptomatic/asymptomatic irreversible pulpitis, necrotic pulp, previously treated; periapical diagnosis: normal, symptomatic/asymptomatic apical periodontitis, acute/chronic apical abscess, condensing osteitis.

Antibiotic prophylaxis before invasive dental work is indicated for prosthetic heart valve, prior infective endocarditis, certain congenital heart disease, and cardiac transplant with valvulopathy - not for routine joint prostheses.