Evidence-Based Clinical Decision Support

Synapse Clinical Calculators & Lab Hub

Comprehensive medical equations with live numerical inputs, risk stratification algorithms, unit converters, and diagnostic lab monographs arranged by specialty.

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Multi-Calculator Point-of-Care Workbench Simultaneous Split-View

Pin and calculate multiple equations side-by-side simultaneously (e.g. eGFR + MAP + Anion Gap).

Active Equations:

General & Intensive Care

BMI & Body Surface Area (BSA)

Anthropometric & Chemotherapy/Hemodynamic Dosing Index

Equation

Height (cm)

Weight (kg)

Body Mass Index

kg/m²

Body Surface Area (Mosteller)

m²

Standard adult: ~1.73 m²

🧮 Equations: BMI = Weight(kg) / (Height(m))² • BSA = √((Height(cm) × Weight(kg)) / 3600)

Cardiology & ICU

Mean Arterial Pressure (MAP)

Organ Perfusion Pressure & Vasopressor Titration Index

Perfusion

Systolic Blood Pressure (SBP mmHg)

Diastolic Blood Pressure (DBP mmHg)

Calculated MAP: mmHg

🧮 Equation: MAP = (SBP + 2 × DBP) / 3 or MAP = DBP + 1/3(SBP - DBP)

Cardiology

Corrected QT Interval (QTc - Bazett)

Torsades de Pointes & Arrhythmia Risk Assessment

ECG

Measured QT Interval (ms)

Heart Rate (bpm)

Calculated QTc: ms

🧮 Bazett Formula: QTc = QT / √(RR in seconds) = QT / √(60 / HR)

Nephrology & Pharmacology

Creatinine Clearance (Cockcroft-Gault)

Gold Standard for Pharmacokinetic Renal Drug Dosing Adjustments

Dosing

Age (yrs)

Weight (kg)

Serum Cr (mg/dL)

Sex Category

Calculated CrCl: mL/min

Required by FDA for dosing antibiotics (Vancomycin, Aminoglycosides), DOACs, and renally excreted therapeutics.

🧮 Formula: CrCl = ((140 - Age) × Weight(kg)) / (72 × Serum Cr(mg/dL)) [× 0.85 if female]

Cardiology & Lipidology

Friedewald Equation for LDL-C

Calculated Low-Density Lipoprotein Cholesterol

Lipids

Total Cholesterol (mg/dL)

HDL Cholesterol (mg/dL)

Triglycerides (mg/dL)

Calculated LDL-C: mg/dL Lipid Profile

🧮 Formula: LDL-C = Total Cholesterol - HDL-C - (Triglycerides / 5) [In SI mmol/L: divide TG by 2.2]

Nephrology & Acid-Base

Serum Anion Gap & Delta Gap

Metabolic Acidosis & Mixed Acid-Base Disturbances

Acid-Base

Sodium Na⁺ (mEq/L)

Chloride Cl⁻ (mEq/L)

Bicarbonate HCO₃⁻

Albumin (g/dL)

Uncorrected Anion Gap

mEq/L

Albumin-Corrected Gap

mEq/L

Accounts for hypoalbuminemia

🧮 Formulas: Anion Gap = Na⁺ - (Cl⁻ + HCO₃⁻) • Corrected = Gap + 2.5 × (4.0 - Albumin)

Mnemonic for High AG Acidosis: MUDPILES (Methanol, Uremia, DKA, Propylene glycol, INH/Iron, Lactic acidosis, Ethylene glycol, Salicylates) or GOLDMARK.

Nephrology & Acute Kidney Injury

Fractional Excretion of Sodium (FeNa)

Prerenal Azotemia vs Acute Tubular Necrosis (ATN) Differentiation

AKI Workup

Urine Na⁺ (mEq/L)

Serum Na⁺ (mEq/L)

Urine Cr (mg/dL)

Serum Cr (mg/dL)

Calculated FeNa: %

🧮 Equation: FeNa = ((Urine Na × Serum Cr) / (Serum Na × Urine Cr)) × 100

Unit Conversions

Live Lab Chemistry & Endocrine Unit Converter

Instant US Gravimetric ↔ International SI Unit Bidirectional Calculation

Converter

Serum Glucose Conversion factor: 18

mg/dL (US)

mmol/L (SI)

Serum Creatinine Conversion factor: 88.4

mg/dL (US)

µmol/L (SI)

Reference Rules: Glucose: mg/dL ÷ 18 = mmol/L • Creatinine: mg/dL × 88.4 = µmol/L • Bilirubin: mg/dL × 17.1 = µmol/L • Calcium: mg/dL × 0.25 = mmol/L

Cardiology

CHA₂DS₂-VASc Score

Atrial Fibrillation Stroke Risk Stratification

Congestive Heart Failure / LV Dysfunction (LVEF ≤ 40%) +1 pt Hypertension (BP > 140/90 or treated) +1 pt Age ≥ 75 years (Major age factor) +2 pts Diabetes Mellitus (Fasting glucose > 126 mg/dL or meds) +1 pt Stroke / TIA / Thromboembolism history +2 pts Vascular Disease (Prior MI, PAD, or Aortic Plaque) +1 pt Age 65–74 years +1 pt Sex Category (Female) +1 pt

Total Score:

Critical Care & Trauma

Glasgow Coma Scale (GCS)

Level of Consciousness & Airway Protection Threshold

Eye Opening Response (E: 1-4)

Verbal Response (V: 1-5)

Motor Response (M: 1-6)

Total Score: /15

Cardiology

HAS-BLED Score

Major Bleeding Risk on Anticoagulation

Hypertension (Uncontrolled SBP > 160 mmHg) +1 pt Abnormal Renal Disease (Dialysis, transplant, Cr > 2.26 mg/dL) +1 pt Abnormal Liver Function (Cirrhosis, Bilirubin > 2x, AST/ALT > 3x) +1 pt Stroke History +1 pt Prior Major Bleeding / Predisposition (GI bleed, anemia) +1 pt Labile INRs (Time in therapeutic range < 60%) +1 pt Elderly (Age > 65 years) +1 pt Drugs predisposing to bleeding (NSAIDs, Antiplatelets) +1 pt Alcohol excess (≥ 8 drinks/week) +1 pt

Total Score:

Critical Care & Sepsis

quick SOFA (qSOFA) Score

Bedside Sepsis Screen & In-Hospital Mortality Risk

Respiratory Rate ≥ 22 breaths/min (Tachypnea) +1 pt Altered Mental Status (GCS < 15) +1 pt Systolic Blood Pressure ≤ 100 mmHg (Hypotension) +1 pt

qSOFA Score: /3

Pulmonology

CURB-65 Pneumonia Severity Score

Community-Acquired Pneumonia Disposition (Outpatient vs Ward vs ICU)

Confusion (Mental test score ≤ 8 or new disorientation) +1 pt Urea > 7 mmol/L (BUN > 19 mg/dL) +1 pt Respiratory Rate ≥ 30 breaths/min +1 pt Blood Pressure (SBP < 90 or DBP ≤ 60 mmHg) +1 pt 65 years of age or older +1 pt

Score: /5

Pulmonology & Emergency

Pulmonary Embolism Rule-out Criteria (PERC)

Rule Out PE Without D-dimer in Low-Probability Patients

Age ≥ 50 years Heart rate ≥ 100 bpm Pulse ox SaO₂ < 95% on room air Unilateral leg swelling Hemoptysis Recent surgery or trauma (≤ 4 wks) Prior DVT or PE Exogenous estrogen use

PERC Criteria: /8 Positive

Pediatrics & Neonatology

APGAR Score (1 & 5 Minutes)

Immediate Postnatal Newborn Assessment & Resuscitation Guide

Appearance (Skin Color)

Pulse (Heart Rate)

Grimace (Reflex Irritability)

Activity (Muscle Tone)

Respiration (Breathing Effort)

APGAR Score: /10

Pulmonology

Light's Criteria for Pleural Effusion

Exudate vs Transudate Thoracentesis Fluid Analysis

Pleural Fluid Protein / Serum Protein Ratio > 0.5 Positive Pleural Fluid LDH / Serum LDH Ratio > 0.6 Positive Pleural Fluid LDH > 2/3 the Upper Limit of Normal Serum LDH Positive

Classification:

Synapse Clinical Calculators & Lab Hub

Multi-Calculator Point-of-Care Workbench Simultaneous Split-View

BMI & Body Surface Area (BSA)

Mean Arterial Pressure (MAP)

Corrected QT Interval (QTc - Bazett)

Creatinine Clearance (Cockcroft-Gault)

Friedewald Equation for LDL-C

Serum Anion Gap & Delta Gap

Fractional Excretion of Sodium (FeNa)

Live Lab Chemistry & Endocrine Unit Converter

CHA₂DS₂-VASc Score

Glasgow Coma Scale (GCS)

HAS-BLED Score

quick SOFA (qSOFA) Score

CURB-65 Pneumonia Severity Score

Pulmonary Embolism Rule-out Criteria (PERC)

APGAR Score (1 & 5 Minutes)

Light's Criteria for Pleural Effusion

Sudden Cardiac Arrest in Ward 4

ACLS Immediate Initial Action:

Defibrillation Decision:

Next Priority Action:

Patient Resuscitated!

Arrest Protocol Timed Out

Synapse Neural Assistant