Ward Calculator

Anion gap (with albumin correction)

The unmeasured-anion window: Na − Cl − HCO3, corrected upward by 2.5 mmol/L for every 10 g/L of albumin below 40.

Winter's formula

Expected PaCO2 during metabolic acidosis: 1.5 × HCO3 + 8, plus or minus 2.

Calculated osmolality & osmolar gap

Calculated serum osmolality (2 × Na + glucose + urea, SI units) and the gap against a measured value.

Corrected calcium

Total calcium adjusted for albumin: measured Ca + 0.02 × (40 − albumin), SI units.

Corrected sodium in hyperglycemia

Sodium adjusted for the dilutional pull of glucose: add roughly 0.3 mmol/L of sodium per mmol/L of glucose above 5.6.

FENa / FEUrea

Fractional excretion of sodium: (urine Na × serum Cr) ÷ (serum Na × urine Cr) × 100. FEUrea substitutes urea for sodium when diuretics are on board.

Creatinine clearance (Cockcroft-Gault)

Estimated creatinine clearance from age, weight, sex, and serum creatinine (SI form).

QTc (Bazett and Fridericia)

Rate-corrected QT interval: Bazett divides by the square root of RR, Fridericia by its cube root.

SAAG

Serum-ascites albumin gradient: serum albumin minus ascitic albumin.

Light's criteria

Exudate versus transudate: any one of pleural/serum protein > 0.5, pleural/serum LDH > 0.6, or pleural LDH above two-thirds of the serum LDH upper limit.

CHA2DS2-VASc

Annual stroke-risk stratification in nonvalvular atrial fibrillation.

CURB-65

Community-acquired pneumonia severity: confusion, urea > 7 mmol/L, respiratory rate ≥ 30, BP < 90 systolic or ≤ 60 diastolic, age ≥ 65.

Wells score (pulmonary embolism)

Pretest probability of PE from seven clinical items.