1,329 calculators and references across 60 specialties, with each tool type shown up front.
Penn Classification (Aortic Dissection Outcome): Explanation and Clinical Context The Penn Classification is a prognostic tool for patients with Type A aortic dissection, focusing on the presence of organ malperfusion and circulatory collapse. It stratifies patients into four categories: - Penn Aa: No evidence of ischemia; patient hemodynamically stable. - Penn Ab: Localized organ ischemia; hemodynamically stable. -
PERC Rule (Pulmonary Embolism Rule-out Criteria): Explanation and Clinical Context The PERC Rule is a clinical decision tool used to identify patients with a very low probability of pulmonary embolism (PE), in whom further diagnostic testing can be safely avoided. It includes 8 criteria: age > 50 years, heart rate > 100 bpm, oxygen saturation < 95%, prior history of PE or DVT, recent surgery or trauma, hemoptysis, es
Pericardial Effusion Tamponade Index (PETI): Explanation and Clinical Context The Pericardial Effusion Tamponade Index (PETI) is a quantitative echocardiographic score designed to assess the hemodynamic significance of pericardial effusion and predict the risk of cardiac tamponade. It combines the durations of right atrial and right ventricular collapse observed during echocardiography with the maximum width of the p
Pericardial Radiation Risk Model: Explanation and Clinical Context The Pericardial Radiation Risk Model estimates the risk of pericardial complications based on the patient's age at the time of radiation exposure and the dose received by the pericardium. This model is crucial for assessing long-term cardiovascular risks in patients who have undergone mediastinal radiation therapy. Understanding these risks aids clini
Pericardiectomy Surgical Risk Model: Explanation and Clinical Context Pericardiectomy is a surgical procedure performed to remove the pericardium, often indicated for conditions such as constrictive pericarditis. The risk associated with this surgery can be influenced by various factors including patient age, underlying etiology, functional status, and the necessity for cardiopulmonary bypass. The model developed by
LAD FAI (HU) (optional) Tube voltage (kVp) 120 100 Other/Unknown High-Risk Plaque (HRP) present on CCTA? No / Not reported Yes (≥1 HRP feature) Coronary Artery Calcium Score (Agatston) (optional) Pericoronary Fat Attenuation Index (FAI): Comprehensive Explanation and Clinical Context Pericoronary (or perivascular) Fat Attenuation Index (FAI) is a CT-derived biomarker representing vascular inflammation by quantifying
Perioperative NT-proBNP Risk Triage Model: Comprehensive Explanation and Clinical Context N-terminal pro–B-type natriuretic peptide (NT-proBNP) is a cardiac biomarker that reflects myocardial wall stress and neurohormonal activation. In large perioperative cohorts, preoperative NT-proBNP provides substantial prognostic information for vascular death and myocardial injury after noncardiac surgery (MINS) within 30 days
Clinical Context This tool supports bedside discussion of dual antiplatelet therapy after acute coronary syndrome by explicitly contrasting ischemic protection with bleeding hazard in the first year after the event. Guideline recommendations describe dual antiplatelet therapy with aspirin plus an oral P2Y12 inhibitor for at least twelve months as the default in patients without high bleeding risk while also emphasizi
Primary exposure setting -- choose -- No known exposure Environmental/household use Occupational – typical handling Occupational – high exposure (mixing/spraying without controls, historical high levels) Exposure duration (years) Predominant pesticide class (optional) -- not specified -- No specific class Organophosphate (OP) Pyrethroid Carbamate Multiple classes / mixtures Type 2 diabetes -- choose -- No Yes Pestici
Clinical reference for Pet CT Perfusion Heterogeneity Index Phi Calculator, with practical context for use alongside current guidance and professional judgment.
Clinical reference for Pet Fdg Uptake Ratio Myocarditis Activity Calculator, with practical context for use alongside current guidance and professional judgment.
PET-CT Uptake Grading Score: Explanation and Clinical Context The PET-CT Uptake Grading Score is used to quantify the metabolic activity of lesions relative to reference tissues (liver and blood pool) in FDG PET-CT imaging. Grade 0 indicates no significant uptake, Grade 1 indicates low uptake (above blood pool but below liver), Grade 2 indicates moderate uptake (equal to or above liver but less than twice liver SUVme
PETCO₂ at AT Index: Explanation and Clinical Context The PETCO₂ at Anaerobic Threshold (AT) Index measures the partial pressure of end-tidal CO₂ at the anaerobic threshold during cardiopulmonary exercise testing (CPET). This index reflects ventilatory efficiency and the balance between CO₂ production and elimination. Lower PETCO₂ at AT (<30 mmHg) indicates inefficient ventilation, often observed in patients with hear
PETIE Index: Explanation and Clinical Context The PETIE Index is a clinical tool designed to estimate the probability of infective endocarditis (IE) in patients undergoing 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT). This index incorporates the following parameters: - FDG-PET/CT Findings: A positive FDG-PET/CT result is associated with a higher likelihood of IE, contributing 2
PFO Closure Risk (RoPE) Score: Explanation and Clinical Context The RoPE (Risk of Paradoxical Embolism) score is a validated 10-point tool designed for patients with cryptogenic ischemic stroke in whom a patent foramen ovale (PFO) is detected. It estimates how likely the index stroke is causally related to the PFO (rather than incidental) and contextualizes the expected 2-year recurrence risk under medical management
Pheochromocytoma Perioperative Cardiac Risk Index (P-PCRI): Explanation and Clinical Context This tool estimates the perioperative risk of significant intraoperative hemodynamic instability during adrenalectomy for pheochromocytoma by integrating preoperative clinical and CT-based predictors. Variables include age, BMI, tumor laterality, tumor shape, MAP score, necrosis, planned surgical technique, CHD status, and pr
Explanation and Clinical Context The PHQ 2 is a brief validated screening instrument designed to identify patients who may be experiencing depressive symptoms. It consists of two core questions that reflect the cardinal features of major depressive disorder which are decreased interest or anhedonia and persistent sadness. Each item is scored from zero to three based on symptom frequency over the previous two weeks an
PHQ 9 Depression Score Explanation and Clinical Context PHQ 9 is a validated questionnaire used worldwide to screen the presence and severity of depressive symptoms. It evaluates nine core symptoms that reflect the diagnostic criteria of major depressive disorder. Each item is scored from zero to three and the total score ranges from zero to twenty seven. Scores correlate with the severity of depression and guide cli
PHQ-9 Depression Score (for Cardiac Patients): Explanation and Clinical Context The PHQ-9 (Patient Health Questionnaire-9) is a widely used, validated tool to screen and measure the severity of depression, specifically useful in cardiac patients where depression is a known risk factor for worse cardiovascular outcomes. It includes 9 questions reflecting DSM-IV criteria for depression, scored from 0 (Not at all) to 3
International Physical Activity Questionnaire (IPAQ) Short Form: Explanation and Clinical Context The IPAQ Short Form is a validated questionnaire designed to estimate weekly physical activity levels in adults. It captures frequency (days per week) and duration (minutes per day) of walking, moderate, and vigorous activities. The resulting MET-minutes/week provides a standardized measure of total physical activity. Ph
PIONEER-AF-PCI Bleeding Algorithm: Explanation and Clinical Context The PIONEER-AF-PCI trial randomized patients with nonvalvular atrial fibrillation who underwent PCI with stent placement to one of three antithrombotic strategies and measured clinically significant bleeding at 12 months. The trial found lower rates of clinically significant bleeding in two rivaroxaban-based strategies compared with standard therapy
Platelet–Lymphocyte Ratio (PLR): Explanation and Clinical Context The Platelet–Lymphocyte Ratio (PLR) is a systemic inflammatory marker calculated as the ratio of platelet count to lymphocyte count in peripheral blood. Elevated PLR reflects both an increased platelet count, often associated with pro-thrombotic and inflammatory states, and a relative lymphopenia, indicating impaired immune regulation. PLR has been stu
PLAX (Parasternal Long Axis) PLAX (Parasternal Long Axis) LV : Left ventricle, RV : Right ventricle, AV : Aortic valve, LA : Left atrium, LVOT : Left ventricular outflow tract, IVS : Interventricular septum, MV : Mitral valve. PLAX (Zoomed MV) LA : Left atrium, MV : Mitral valve, PLAX : Parasternal long axis. PLAX (Increased Depth) LV : Left ventricle, RV : Right ventricle, Ao : Aorta, LA : Left atrium, PLAX : Parast
PLN p.Arg14del arrhythmic risk model — explanation and clinical context This tool implements the primary phenotypic predictors selected in the multivariable PLN p.Arg14del prediction model published by Verstraelen et al. (European Heart Journal, 2021): left ventricular ejection fraction (LVEF; model parameterized per 1% decrease), 24-hour premature ventricular contraction (PVC) count (log-transformed), number of lead
PM Dependency Index: Explanation and Clinical Context The Pacemaker (PM) Dependency Index (PDI) is a quantitative tool used to estimate the degree of a patient’s reliance on ventricular pacing. It integrates intrinsic heart rate, ventricular pacing percentage, and atrioventricular block severity to provide a composite score. A higher PDI indicates greater pacemaker dependency, which can guide clinicians in device pro
Pneumonia Severity Index PSI Explanation and Clinical Context The PSI is a clinical prediction rule that estimates mortality risk in adults with community acquired pneumonia. It integrates demographic factors comorbid conditions physical findings and laboratory and radiographic data. The total score categorizes patients into five risk groups that correspond to increasing severity and mortality. It assists clinicians
Clinical reference for Polygenic Lifestyle Interaction Index Calculator, with practical context for use alongside current guidance and professional judgment.
Polygenic Risk Score (PRS) for Coronary Artery Disease (CAD-PRS): Explanation and Clinical Context The CAD-PRS quantifies an individual's genetic predisposition to coronary artery disease by summing the weighted effects of multiple single nucleotide polymorphisms (SNPs) identified from genome-wide association studies (GWAS). Each risk allele contributes a specific weight based on its effect size derived from large-sc
This tool estimates the potential population-level yield and benefit of one-time Lp(a) screening. It uses inputs for population size, expected prevalence above a chosen threshold, baseline 10-year ASCVD risk, the relative risk associated with elevated Lp(a), and assumed therapy uptake and relative risk reduction. Notes: Prevalence of Lp(a) ≥125 nmol/L (≈50 mg/dL) is ~20% in many populations; adjust for your local epi
Porto-Systemic Flow Ratio (PSFR): Explanation and Clinical Context The Porto-Systemic Flow Ratio (PSFR) quantifies the relative blood flow between the portal vein and the hepatic vein, reflecting the balance of portal and systemic circulation in patients with chronic liver disease and portal hypertension. A PSFR near 1 indicates a normal physiologic balance, whereas deviations may reflect shunting, hepatic congestion
Physiological Age Cardiac Signs Respiratory History Systolic Blood Pressure Pulse Rate Glasgow Coma Scale Hemoglobin White Cell Count Serum Urea Serum Sodium Serum Potassium Electrocardiogram Score Operative Severity Number of Procedures Blood Loss Peritoneal Contamination Presence of Malignancy POSSUM and P POSSUM Mortality Score Explanation and Clinical Context POSSUM Physiological and Operative Severity Score for
Post acute coronary syndrome secondary prevention optimisation tool explanation and clinical context This tool is designed to support a structured review of long term therapy in patients who have recently experienced an acute coronary syndrome event. The twenty twenty five acute coronary syndrome guideline emphasises that risk of recurrent events remains elevated for months to years after the index presentation and t
Clinical reference for Post Anesthetic Discharge Scoring System PADS Calculator, with practical context for use alongside current guidance and professional judgment.
Explanation and Clinical Context This score is designed for patients resuscitated from cardiac arrest presenting with ST elevation myocardial infarction who achieve return of spontaneous circulation. Early prognostic insight provides clinical value in guiding revascularization timing and post arrest intensive care strategy including ventilation sedation temperature target management and hemodynamic support. Factors i
Explanation and Clinical Context This tool is designed as a structured aid for clinicians who individualize antiplatelet strategy after percutaneous coronary intervention in the setting of acute coronary syndromes. Current professional guidelines emphasize that duration and intensity of antiplatelet therapy after PCI are determined by a balance between ischemic risk related to the coronary event and stent characteris
Post-acute Myocarditis Persistent Inflammation Score (MRI + Biomarkers): Explanation and Clinical Context This calculator provides a pragmatic, literature-informed composite score to estimate the likelihood of persistent myocardial inflammation after an acute myocarditis episode using follow-up cardiovascular magnetic resonance (CMR) features and blood biomarkers. It weights factors consistently linked with adverse o
Post-Cardiac Rehabilitation Risk Reduction Score: Explanation and Clinical Context The Post-Cardiac Rehabilitation Risk Reduction Score (PCRRRS) is a clinical tool designed to assess the potential risk reduction in patients with cardiovascular disease who participate in cardiac rehabilitation (CR). Studies have shown that CR is associated with a 20% to 30% reduction in mortality in individuals with coronary artery di
Post-COVID Arrhythmia Risk Model (Autonomic + ECG): Explanation and Clinical Context This model integrates autonomic markers (HRV indices) and ECG variables to estimate post-acute arrhythmic risk in individuals recovering from COVID-19. Reduced HRV (low SDNN, RMSSD) reflects sympathetic predominance and vagal withdrawal, patterns observed in post-COVID dysautonomia. QTc prolongation captures impaired repolarization r
Post-COVID Cardiac Symptom Burden Score (Composite): Explanation and Clinical Context This calculator provides a pragmatic composite symptom burden score focused on cardiovascular manifestations reported after SARS-CoV-2 infection. It aggregates nine domains commonly described in post-acute COVID-19 cohorts: dyspnea (rest and exertion), chest pain/pressure, palpitations, dizziness/presyncope, orthostatic intolerance,
Quantitative CMR Perfusion Inputs (preferred) Enter global myocardial blood flow (MBF) from quantitative CMR perfusion mapping. Post-COVID Microvascular Dysfunction (Stress Perfusion Surrogate): Explanation and Clinical Context This calculator estimates microvascular function using quantitative stress perfusion metrics. The primary output is myocardial perfusion reserve (MPR), computed from global stress and rest myo
Post-COVID Thrombotic Risk Composite (D-dimer + Clinical): Explanation and Clinical Context This calculator applies the IMPROVE-DD model, combining clinical factors with D-dimer elevation (≥2× ULN) to estimate venous thromboembolism (VTE) risk in post-COVID patients. Clinical Significance: High scores identify patients who may benefit from extended prophylaxis with rivaroxaban 10 mg daily for 35 days post-discharge (
: Explanation and Clinical Context Post-infectious autoimmune cardiac disorders represent a spectrum of myocardial and endocardial injury that follows infectious triggers such as viral myocarditis, bacterial infections, or systemic inflammatory responses. The immune system, after pathogen clearance, may continue to recognize cardiac antigens as foreign due to molecular mimicry between microbial epitopes and myocardia
clinical explanation Posterior myocardial infarction represents involvement of the basal inferolateral left ventricular wall usually supplied by the circumflex artery. Standard twelve lead ECG often underdetects this pattern because posterior injury current produces reciprocal ST depression in V1 V3 instead of direct elevation. For this reason posterior leads V7 V9 are recommended when posterior infarction is suspect
Postoperative AKI after Cardiac Surgery (AKICS): Explanation and Clinical Context The AKICS score is a bedside tool derived and prospectively validated to predict acute kidney injury (AKI) after elective cardiac surgery. It integrates preoperative, intraoperative, and early postoperative information available at ICU admission: combined surgery (e.g., CABG plus valve), NYHA class ≥ 2, pre-operative serum creatinine >
Postoperative Atrial Fibrillation (POAF) Risk Score: Explanation and Clinical Context The Postoperative Atrial Fibrillation (POAF) Risk Score, developed by Mariscalco and colleagues, provides a simple, evidence-based model to estimate the likelihood of new-onset atrial fibrillation after cardiac surgery. The score incorporates nine routinely available preoperative clinical variables: age, sex, chronic obstructive pul
Geriatric Depression Scale – 5 item (GDS-5) History of Stroke or Transient Ischemic Attack Select... Yes No Serum Albumin (g/dL) Abnormal is defined as <3.5 or >5.2 g/dL in the original rule. Postoperative Delirium Cardiac Risk Score (Rudolph et al., 2009): Explanation and Clinical Context This pre-operative rule was derived and validated in older adults undergoing cardiac surgery and assigns points for cognitive imp
Postoperative Stroke Risk Model: Explanation and Clinical Context This calculator estimates 30-day postoperative ischemic stroke risk after noncardiac, nonneurologic surgery using preoperative variables. Predictors are derived from NSQIP-based studies and include age, prior stroke/TIA, coronary disease, recent myocardial infarction, renal dysfunction, anemia, dysnatremia, COPD, hypertension, smoking, ASA class, emerg
Postpartum Hemodynamic Stress Index (PHSI): Explanation and Clinical Context The Postpartum Hemodynamic Stress Index (PHSI) is a validated metric to assess cardiovascular stress in the early postpartum period, reflecting the balance between heart rate and mean arterial pressure. It is calculated using the formula: PHSI = (Heart Rate / Mean Arterial Pressure) × 100. Mean Arterial Pressure (MAP) is derived from: MAP =
Postprandial Triglyceride Peak Risk Index: Explanation and Clinical Context Postprandial triglyceride (TG) elevation reflects the body’s ability to metabolize dietary fats after meals. Normally, plasma TG peaks within 3–4 hours postprandially and returns to baseline within 6–8 hours. A delayed TG peak, often observed in individuals with insulin resistance, obesity, or metabolic syndrome, is an early marker of endothe
Potassium Requirement: Comprehensive Explanation and Clinical Context The estimation of potassium requirement is an important component of clinical decision making for patients with hypokalemia. Potassium is the predominant intracellular cation and plays a key role in membrane potential regulation, cardiac electrophysiology, skeletal muscle contraction, and acid base homeostasis. Serum potassium does not reflect tota
Preparticipation Physical Evaluation (PPE) Cardiac Screening: Explanation and Clinical Context this calculator uses the American Heart Association (AHA) 14-element cardiovascular screening checklist used during the PPE to identify athletes at risk for congenital or genetic heart disease associated with sudden cardiac arrest or death. It aggregates the 10 history items and 4 focused examination items, providing
Explanation and Clinical Context This calculator estimates the positive predictive value and negative predictive value of a diagnostic test by integrating sensitivity specificity and pretest probability. These metrics help clinicians understand how likely a patient either truly has or truly does not have a disease after receiving a positive or negative test result. Positive Predictive Value PPV expresses the probabil
Pre-eclampsia Cardiovascular Risk Index (PE-CRI): Explanation and Clinical Context The PE-CRI is a predictive model designed to estimate the long-term cardiovascular risk in women with a history of pre-eclampsia. It incorporates factors such as age, body mass index (BMI), blood pressure, and previous pre-eclampsia history to calculate a risk score. This tool aids clinicians in identifying individuals at higher risk f
Pre-op Hemodynamic Optimization Index (PHOI): Rationale, Use, and Evidence The PHOI provided here is a pragmatic composite to help clinicians summarize the patient’s immediate pre-operative hemodynamic state and identify modifiable targets before anesthesia induction. It is not a published or validated score; to our knowledge there is no original “Pre-op Hemodynamic Optimization Index” in the literature. The componen
: Explanation and Clinical Context The International Criteria provide a systematic approach to differentiate physiological, training-related ECG changes from patterns suggestive of cardiac pathology in athletes aged roughly 12–35 years. Borderline findings (left/right axis deviation, left/right atrial enlargement, and complete right bundle branch block) are common variants; a single borderline finding in isolation do
PRECISE DAPT Score Clinical Explanation and Context The PRECISE DAPT Score is a validated clinical tool designed to estimate bleeding risk in patients undergoing dual antiplatelet therapy following percutaneous coronary intervention. The score includes age, hemoglobin, white blood cell count, creatinine clearance, and history of prior bleeding, which together reflect hematologic status, renal function, and vulnerabil
Predict Score: Explanation and Clinical Context The Predict Score is a clinical tool designed to estimate the risk of in-hospital mortality in patients with infective endocarditis. Developed through a retrospective analysis of 530 patients, this score incorporates various clinical and laboratory parameters to stratify patients into low, intermediate, or high-risk categories.
PREDICT-HF Risk Score: Explanation and Clinical Context The PREDICT-HF model (PARADIGM Risk of Events and Death in Contemporary Treatment of Heart Failure) was derived in patients enrolled in the PARADIGM‑HF trial (n ≈ 8,011) with chronic heart failure with reduced ejection fraction, and was subsequently validated in the ATMOSPHERE trial population and in the Swedish Heart Failure Registry (SwedeHF). Key baseline pre
Explanation and Clinical Context This calculator estimates the expected delivery time using the Last Menstrual Period date as reference. Gestation is assumed as forty weeks or two hundred eighty days from LMP which is widely used in clinical obstetrics. This approach supports counselling and follow up planning for fetal growth monitoring and maternal evaluation. Normal pregnancy duration may vary in clinical reality
Pregnancy Risk Algorithm: Explanation and Clinical Context The Pregnancy Risk Algorithm is a clinical tool designed to assess the risk of adverse pregnancy outcomes based on maternal characteristics and medical history. By evaluating factors such as maternal age, body mass index (BMI), presence of chronic hypertension, history of preeclampsia, and family history of preeclampsia, healthcare providers can stratify pati