PESI Score Calculator

About this calculator

The Pulmonary Embolism Severity Index (PESI) is a validated clinical prediction rule that estimates 30-day mortality risk in patients diagnosed with acute pulmonary embolism, helping clinicians decide who is safe for outpatient treatment versus who needs hospital admission. The score starts from the patient's age in years and adds points for ten independent risk factors: male sex, cancer, heart failure, chronic lung disease, pulse ≥110/min, systolic blood pressure less than 100 mmHg, respiratory rate ≥30/min, temperature less than 36°C, altered mental status, and oxygen saturation less than 90%.

The total score sorts patients into five risk classes (I through V), with Class I–II considered low-risk (roughly under 2% mortality) and Class IV–V considered high-risk (potentially over 10% mortality). PESI, developed by Aujesky and colleagues and later simplified into the sPESI score, is widely used in emergency medicine following ESC and ACCP pulmonary embolism guidelines — but like any clinical score, it supports rather than replaces physician judgment, and this calculator is not medical advice.