1,329 calculators and references across 60 specialties, with formula confidence shown up front.
Shock Index (HR/SBP Ratio): Explanation and Clinical Context The Shock Index (SI) is a simple, bedside physiological ratio calculated by dividing the heart rate (HR) by the systolic blood pressure (SBP). It serves as a rapid and sensitive indicator of hemodynamic compromise and circulatory shock. A normal Shock Index typically ranges from 0.5 to 0.7. Values above 0.9 are considered abnormal and have been strongly cor
Stroke Volume Index (SVi): Explanation and Clinical Context Stroke Volume Index is a hemodynamic parameter that describes the amount of blood ejected by the left ventricle during each cardiac contraction, adjusted to body surface area. This index refines the interpretation of stroke volume by incorporating patient size, making it a more accurate indicator of forward flow in individuals with significantly different bo
Stroke Volume Index (SVi) for RV Failure Prediction: Explanation and Clinical Context Stroke Volume Index (SVi) is a hemodynamic parameter that represents the stroke volume normalized to body surface area. It is calculated as cardiac output divided by heart rate and then indexed to BSA, providing a load-adjusted measure of cardiac performance. In the context of right ventricular (RV) failure prediction, SVi has been
STRONG-HF Risk Framework — explanation and clinical context This calculator implements a transparent prototype points system that aggregates commonly reported prognostic features relevant to patients hospitalized for acute heart failure (age, hemodynamics at discharge, NT-proBNP, renal function, potassium, LVEF, recent HF hospitalization, and intensity of guideline-directed medical therapy achieved at discharge). It
Swedish PAH Registry Risk Model: Explanation and Clinical Context The Swedish PAH Registry Risk Model is a validated prognostic tool for patients with pulmonary arterial hypertension (PAH), developed from the Swedish Pulmonary Arterial Hypertension Registry (SPAHR). It integrates six key clinical and hemodynamic variables: WHO Functional Class (FC), 6-Minute Walk Distance (6MWD), NT-proBNP, Right Atrial Pressure (RAP
Systolic Pressure Recovery Index (Post-Pulmonary Embolism Healing): Explanation and Clinical Context The Systolic Pressure Recovery Index (SPRI) is a hemodynamic ratio used to evaluate right ventricular and pulmonary arterial recovery after acute pulmonary embolism (PE). It quantifies the degree of pressure normalization across the pulmonary circulation, specifically reflecting how systolic and diastolic pressures re