1,329 calculators and references across 60 specialties, with formula confidence shown up front.
Familial Dilated Cardiomyopathy (DCM): Explanation and Clinical Context Familial DCM is a hereditary form of dilated cardiomyopathy characterized by left ventricular dilation and systolic dysfunction. It is typically inherited in an autosomal dominant pattern, with variable expressivity and incomplete penetrance. The condition can lead to heart failure, arrhythmias, and sudden cardiac death. Early identification and
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FAST Score: Explanation and Clinical Context The FAST Score (Focused Assessment of Right Heart Strain in Pulmonary Embolism) is a simple risk stratification tool to assess the probability of adverse outcomes in patients with acute pulmonary embolism (PE) exhibiting right ventricular (RV) strain. It assigns 1 point for each of the following: heart rate > 100 bpm, hypotension (systolic blood pressure < 100 mmHg), and e
Use this tool to estimate readiness for early or operating-room extubation after adult cardiac surgery. It combines evidence-informed bedside criteria (hemodynamics, gas exchange, bleeding, neurological status) with perioperative predictors reported in the literature to categorize eligibility as Eligible now, Borderline—optimize, or Not eligible now. Fast-Track Extubation (Cardiac Surgery): Explanation and Clinical C
Major Criteria Fat Embolism Diagnostic Criteria Explanation and Clinical Context Fat embolism syndrome is a clinical condition that arises when fat globules enter the systemic circulation and trigger respiratory neurological and systemic inflammatory manifestations. The Gurd criteria which classify findings into major and minor categories remain widely used for bedside evaluation. Major criteria include petechiae res
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Ferritin–Transferrin Saturation Ratio (Iron Deficiency in Heart Failure): Explanation and Clinical Context The Ferritin–Transferrin Saturation (TSAT) ratio is a widely used laboratory tool to assess iron status in patients with heart failure. Ferritin reflects iron storage, whereas TSAT reflects circulating iron availability. Iron deficiency is highly prevalent in heart failure and is associated with impaired functio
Ferritin–Transferrin Saturation Ratio (Iron Deficiency in Heart Failure): Explanation and Clinical Context The Ferritin–Transferrin Saturation (TSAT) ratio is a widely used laboratory tool to assess iron status in patients with heart failure. Ferritin reflects iron storage, whereas TSAT reflects circulating iron availability. Iron deficiency is highly prevalent in heart failure and is associated with impaired functio
Fetal middle cerebral artery Doppler as an anemia predictor Measurement of fetal middle cerebral artery peak systolic velocity is a non invasive method to assess the risk of fetal anemia. The measured PSV is expressed as a multiple of the median for the same gestational age. A multiple of the median at or above 1.5 has been widely used as a threshold to indicate increased probability of moderate to severe fetal anemi
FEV1 FVC Ratio Analyzer Explanation and Clinical Context The FEV1 FVC ratio is the proportion of forced expiratory volume in the first second to the forced vital capacity expressed as a percentage. A lower ratio reflects a disproportionate reduction in airflow relative to volume which suggests airflow obstruction. In routine clinical practice a fixed threshold of 70 percent after bronchodilator is commonly used to in
FIB-4 in Cardiac Cirrhosis: Explanation and Clinical Context FIB-4 is a non-invasive scoring system originally validated for assessing liver fibrosis in patients with chronic liver disease and has been adapted for cardiac cirrhosis to estimate fibrosis severity. It uses age, AST (aspartate aminotransferase), ALT (alanine aminotransferase), and platelet count as variables. Lower scores (<1.45) indicate low risk of adv
FIB-4 Score (for NAFLD-related CV risk): Explanation and Clinical Context The FIB-4 score is a non-invasive scoring system used to estimate liver fibrosis, particularly in patients with NAFLD. It is calculated using age, AST, ALT, and platelet count. It helps identify patients at low, intermediate, or high risk of advanced liver fibrosis, which has implications for cardiovascular risk stratification, as advanced fibr
FIB 4 index Explanation and Clinical Context The FIB 4 index is a noninvasive score that estimates the probability of advanced liver fibrosis using routinely available values including patient age AST ALT and platelet count. It is calculated as age in years multiplied by AST in U per L divided by platelet count in 10 to the power of 9 per L times the square root of ALT in U per L. Commonly used cutoffs are less than
Explanation and Clinical Context The Fick principle is one of the most fundamental physiological methods used to determine cardiac output. This calculation is based on the relationship between oxygen consumption and the arteriovenous oxygen content difference. The method assumes that the uptake or release of oxygen by the tissues is equal to the product of blood flow and the arteriovenous oxygen difference. In clinic
: Explanation and Clinical Context The FINGER-HF Prognostic Tool is designed to estimate the risk of adverse outcomes (such as mortality or heart-failure hospitalization) in patients with chronic heart failure by integrating demographic, haemodynamic, renal, biomarker and ventricular function parameters. It uses commonly available clinical variables — for example age, systolic blood pressure, heart rate, NT-proBNP, s
Inspired Oxygen Fraction FiO2 PaO2 arterial oxygen pressure mmHg PaCO2 arterial carbon dioxide pressure mmHg Atmospheric Pressure Patm mmHg Water Vapor Pressure PH2O mmHg Respiratory Quotient RQ Explanation and Clinical Context This calculator estimates the inspired oxygen fraction FiO2 together with the alveolar to arterial oxygen gradient which provides an assessment of gas exchange efficiency in the lungs. The alv
FiO2 Estimation Calculator: Clinical explanation and context This calculator implements the original formulas provided in this tool template. The formulas are preserved as they were supplied. Users should be aware that some formulas in this tool do not match conventional physiologic equations for alveolar oxygen calculation or for alveolar arterial oxygen gradient. The following text provides clinical context and ref
: Explanation and Clinical Context This predictive model estimates the risk of peri-procedural and short-term complications in patients undergoing pulmonary vein isolation (PVI) via either cryoballoon or radiofrequency ablation, based on demographic, anatomical and procedural variables. It aims to guide clinicians in pre-procedure risk stratification and informed consent discussions. Definition: A logistic regression
FITT Compliance Index (Rehab Adherence): Explanation and Clinical Context The FITT Compliance Index is a quantitative measure of adherence to prescribed exercise-based cardiac rehabilitation programs. It evaluates four key dimensions of exercise prescription: Frequency (number of sessions per week), Intensity (effort level on a 1-10 scale), Time (duration of each session in minutes), and Type (mode of exercise, e.g.,
FLACC Pain Scale for Infants Assessment FLACC Pain Scale for Infants Explanation and Clinical Context FLACC Pain Scale is a behavioral tool designed to assess pain in infants and young children who cannot verbalize their discomfort. It evaluates five observable domains which include Face Legs Activity Cry and Consolability with each category scored from zero to two resulting in a total score range from zero to ten. H
: Explanation and Clinical Context Influenza vaccination has a significant role in reducing cardiovascular morbidity and mortality, especially among elderly individuals and those with established cardiovascular disease (CVD). Viral infections, particularly influenza, can precipitate acute coronary syndromes, decompensated heart failure, and arrhythmias through mechanisms of systemic inflammation, endothelial dysfunct
Explanation and Clinical Context Fluid maintenance requirement determines the physiological daily fluid needs for patients considering metabolic water losses. Clinicians commonly use the four two one formula where the first ten kilogram of body weight receives four mL per kg per hour the next ten kilogram receives two mL per kg per hour and the remaining weight receives one mL per kg per hour. This formula assists in
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
Fontaine Classification (PAD Severity): Explanation and Clinical Context The Fontaine Classification is a widely used system to assess the severity of peripheral artery disease (PAD) based on clinical presentation of the lower extremities. It stratifies patients into four stages: Stage I (Asymptomatic): Patients have arterial narrowing without symptoms; often detected via ABI or imaging. Stage II (Intermittent Claudi
Fontan Failure Index: Explanation and Clinical Context The Fontan Failure Index aims to integrate hemodynamic burden (e.g. elevated central venous pressure, reduced cardiac index) and hepatic injury (represented by liver stiffness by elastography and thrombocytopenia as marker of portal hypertension) to stratify risk of clinical Fontan failure. A higher score suggests greater circulatory stress and end‑organ (hepatic
Fontan Adult Brompton (FAB) Score: Explanation and Clinical Context The FAB score is a clinical tool developed to predict the risk of mortality or need for heart transplantation in adult patients with Fontan circulation. It incorporates six clinical variables: age at first adult visit, history of atrial tachyarrhythmia, history of heart failure, New York Heart Association (NYHA) functional class, systolic blood press
Fontan Risk Score: Explanation and Clinical Context The Fontan Risk Score is a clinical tool developed to predict early mortality risk for patients undergoing the Fontan procedure, both pre- and post-operatively. It incorporates key variables such as age at Fontan, preoperative oxygen saturation, ventricular dysfunction, atrioventricular valve regurgitation, and history of arrhythmia. Each risk factor is assigned a w
FPHN Prognostic Index: Explanation and Clinical Context The FPHN Prognostic Index is a scoring system developed to assess the risk of mortality in patients with pulmonary arterial hypertension (PAH). It incorporates clinical parameters such as age, cardiac index, 6-minute walk distance, NT-proBNP levels, hemoglobin concentration, and right atrial pressure. A higher score indicates a higher risk of mortality, aiding c
Fractional Excretion of Sodium FeNa Explanation and Clinical Context Fractional excretion of sodium FeNa quantifies the percentage of filtered sodium that is ultimately excreted in urine using simultaneously obtained urine and plasma measurements. The formula is FeNa equals Una times Pcr divided by Pna times Ucr all multiplied by one hundred to yield a percentage. FeNa is commonly used to help distinguish reduced ren
Fractional Excretion of Urea FeUrea Explanation and Clinical Context Fractional Excretion of Urea FeUrea estimates the percentage of filtered urea that is excreted in urine. The calculation uses urine urea concentration serum urea concentration urine creatinine concentration and serum creatinine concentration. The formula is FeUrea equals Uurea times Scr divided by Surea times Ucr multiplied by 100 percent. FeUrea co
Fragmented QRS (fQRS) Index: Explanation and Clinical Context Fragmented QRS (fQRS) refers to additional R waves (R’) or notching in the nadir of the S wave in contiguous ECG leads, representing myocardial conduction delay due to fibrosis or scarring. The fQRS Index is calculated as the number of ECG leads showing fQRS divided by the total number of leads (usually 12-lead ECG), providing a quantitative measure of myo
Frailty–AVR Score: Explanation and Clinical Context The Frailty–AVR Score is a clinical tool developed to assess frailty in patients undergoing aortic valve replacement (AVR), including transcatheter aortic valve implantation (TAVI). It incorporates factors such as age, serum albumin levels, body mass index (BMI), functional status (measured by the Katz Activities of Daily Living scale), and mobility (assessed via th
Framingham BMI Model: Explanation and Clinical Context The Framingham BMI Model estimates the 10-year risk of developing cardiovascular disease (CVD) using readily available clinical parameters including age, sex, systolic blood pressure, total cholesterol, HDL cholesterol, smoking status, and BMI. Unlike lipid-based models, BMI is used as a substitute for direct lipid measurements in some versions. The model calcula
Framingham Lipid Risk Subscore: Explanation and Clinical Context The Framingham Lipid Risk Subscore estimates 10-year risk of coronary heart disease (CHD) using the lipid-based model, combining age, total cholesterol, HDL cholesterol, blood pressure, and smoking. It originates from the Framingham Heart Study and the Adult Treatment Panel III (ATP III) guidelines, which provide both point-based and regression-based ri
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
Fried Frailty Phenotype: Explanation and Clinical Context The Fried Frailty Phenotype, developed by Fried et al. in 2001, is a widely used clinical tool to assess frailty in older adults. It consists of five components: unintentional weight loss, self-reported exhaustion, low physical activity, slowness (walking speed), and weakness (grip strength). Each positive criterion scores 1 point, with a total score ranging f
Full Pulmonary Function Test Interpretation Explanation and Clinical Context Pulmonary function testing provides an integrated view of airway physiology. It assesses airflow mechanics lung volume distribution and gas transfer efficiency. Each component reflects a different dimension of cardiopulmonary function and supports a structured evaluation of respiratory disorders. The FEV1 FVC ratio helps identify obstruction
Transfer Score Gait Score Balance Score Endurance Score Functional Mobility Outcome Scale Explanation and Clinical Context The Functional Mobility Outcome Scale is a structured clinical tool used to evaluate patient mobility through four essential components which are transfer ability gait performance balance stability and endurance capacity. Each component reflects a core domain of physical function and allows clini
Furosemide Response Index (FRI): Explanation and Clinical Context The Furosemide Response Index (FRI) is a clinical tool designed to quantify the early response of patients with acute decompensated heart failure (ADHF) to intravenous loop diuretics. It is calculated as the urine output (mL/hour) divided by the administered loop diuretic dose (mg/day). FRI allows clinicians to identify patients with poor diuretic resp