CHA₂DS₂-VASc Score (AFib Stroke Risk)

Calculate base excess (BE) using the Siggaard-Andersen formula. BE < −3 metabolic acidosis, > +3 metabolic alkalosis. HCO₃⁻ auto-calculated from pH + PaCO₂ if omitted. Derived from Siggaard-Andersen 1974, Cornell PICU, Medscape, and Langer 2022. Not medical advice.

Complete ABG analysis: pH, primary disorder, compensation (Winter's formula), anion gap ± albumin correction, delta ratio for mixed disorder detection. Derived from Emmett 2016, Kraut 2007, Rastegar 2007, LITFL, MDCalc, and Adrogué 1998. Not medical advice.

Calculate the 2005 Caprini Risk Assessment Model to stratify venous thromboembolism (VTE) risk in surgical patients. ~40 items weighted 1/2/3/5 points: 1 point (age 41-60, minor surgery, BMI >25, swollen legs, varicose veins, pregnancy/postpartum, recurrent miscarriage, OCP/HRT, sepsis <1mo, lung disease/pneumonia <1mo, COPD, acute MI, CHF <1mo, bedridden, medical bed rest, IBD); 2 points (age 61-74, arthroscopic surgery, major open surgery >45min, laparoscopic >45min, malignancy, bed >72h, plaster cast, central line); 3 points (age ≥75, personal/family VTE history, factor V Leiden, prothrombin 20210A, lupus anticoagulant, anticardiolipin, homocysteine, HIT, other thrombophilia); 5 points (stroke <1mo, elective major lower-extremity arthroplasty, hip/pelvis/leg fracture <1mo, acute spinal cord injury <1mo, multiple trauma <1mo). Management tiers: 0 lowest, 1-4 low-moderate (mechanical), 5-6 high (consider LMWH 7-10d), 7-8 high (LMWH 7-10d), ≥9 highest (LMWH 30d). Derived from Caprini 2005. Not medical advice.

Calculate the Charlson Comorbidity Index (CCI), including the age-adjusted variant, to predict 1-year mortality from chronic comorbidities. 19 comorbidities are weighted by mortality risk: 1 point (MI, CHF, PVD, cerebrovascular disease, dementia, chronic pulmonary disease, connective tissue disease, peptic ulcer, mild liver disease, diabetes without complications); 2 points (hemiplegia/paraplegia, moderate-to-severe CKD, diabetes with end-organ damage, any non-metastatic tumor, leukemia, lymphoma); 3 points (moderate-to-severe liver disease); 6 points (metastatic solid tumor, AIDS). Age adjustment adds 1 point per decade ≥50 (50-59 +1 … ≥90 +5). Interpretation: 0 ~8%, 1-2 ~25%, 3-4 ~50%, ≥5 ~80-90% 1-year mortality (derivation cohort). Derived from Charlson 1987 (J Chronic Dis) and the 1994 validation. Not medical advice.