Winter's Formula
- Evaluates Respiratory Compensation
- Used in Metabolic Acidosis
- (HCO3 x 1.5 ) + 8 plus-minus 2 = PCO2
- Bicarbonate (HCO3) x 1.5
- + 8
- ± 2
- = Expected Value for PCO2
TIMI Score (Thrombolysis In Myocardial Infarction)
- Mortality Predictor
- Unstable Angina or NSTEMI
- 2 Week Risk of Death and Ischemic Events
- Age Greater or Equal to 65
- Markers Elevated
- EKG ST Changes (Greater or Equal to 0.5mm)
- Risk Factors for CAD (Coronary Artery Disease)
- Ischemia (2 Anginal Events in 24 Hours)
- Coronary Artery Disease (CAD)
- Aspirin Use in the Last 7 Days
CHA2DS2-VASc for Stroke Risk in Atrial Fibrillation
- CHF (+1)
- Hypertension (+1)
- Age 75 + (+2)
- Diabetes (+1)
- Stroke or TIA or Thromboembolism History (+2)
- Vascular Disease (+1)
- Age 65-75 Years (+1)
- Sex Female (+1)
- 0 = No Anticoagulation
- 1 = Consider Anticoagulation
- 2 = Anticoagulation
Calcium Correction for Hypoalbuminemia
- 0.8 * (Normal Albumin - Patient Albumin) + Calcium
- Multiply * 0.8
- Subtract (Normal Albumin - Patient Albumin)
- Add Calcium
Corrected Na+ for Hyperglycemia
- [(Glucose-100) * 0.016 ] + Na+
- Glucose-100
- Multiply * 0.016
- Add Na+
Physiologic Dead Space (VD)
- Tidal Volume (VT)
- Partial pressure of arterial CO2 (PaCO2)
- Partial pressure of CO2 in expired air (PECO2)
- VD = TV x (PaCO2-PECO2) / PaCO2
A-a Gradient
- Partial pressure of alveolar oxygen (PAO2)
- Partial Pressure of Arterial O2 (PaO2)
- Normal 10 to 15 mmHg
- Hypoxemia with an Abnormal A-a Gradient
- Diffusion problem
- Shunting (Low V/Q)
- Dead space (high V/Q)
Alveolar Gas Equation
- Partial Pressure of Alveolar Oxygen (PAO2)
- Partial Pressure of Oxygen in the Inspired Air (PIO2)
- PIO2 Normally Approximated = 150 mmHg
- Arterial Partial Pressure of CO2 (PaCO2)
- Respiratory Quotient (R)
- R Normally Approximated = 0.8
- PAO2 = PIO2 - (PaCO2/R)