Pulmonary Artery Pulsatility Index (PAPI) Calculator
Use this tool to calculate PAPI from right-heart catheter values.
What is the PAPI score?
PAPI stands for Pulmonary Artery Pulsatility Index. It is a hemodynamic metric used in critical care and cardiology to assess right ventricular performance, especially in the setting of cardiogenic shock, advanced heart failure, or mechanical circulatory support evaluation.
The value combines pulmonary artery pulse pressure with right atrial filling pressure. In practical terms, it helps answer a common bedside question: how well is the right ventricle handling load right now?
PAPI formula and variables
The equation is simple:
PAPI = (PASP − PADP) / RAP
- PASP: Pulmonary artery systolic pressure
- PADP: Pulmonary artery diastolic pressure
- RAP (or CVP): Right atrial pressure
All values should be measured in the same units (typically mmHg). The numerator (PASP − PADP) is pulmonary artery pulse pressure, and dividing by RAP normalizes that pulsatility to right-sided filling pressure.
How to use this PAPI calculator
Step-by-step
- Enter PASP, PADP, and RAP from your catheterization or monitoring data.
- Click Calculate PAPI.
- Review the calculated value and interpretation band.
This calculator is designed for quick educational use and bedside estimation workflows. Always cross-check with full clinical context, trending values, and the overall shock profile.
Typical interpretation ranges
| PAPI Range | General Meaning | Clinical Signal |
|---|---|---|
| < 0.9 | Low pulsatility reserve | Higher concern for right ventricular failure |
| 0.9 – 1.5 | Borderline reduced reserve | Needs close hemodynamic trend monitoring |
| 1.5 – 2.5 | Moderate/preserved function | Often better short-term RV profile |
| > 2.5 | Relatively strong pulsatility | Generally reassuring, context still matters |
Interpretation thresholds vary by population, setting, and institution. Use local protocols and specialist input for treatment decisions.
Worked example
Suppose a patient has PASP 48 mmHg, PADP 26 mmHg, and RAP 11 mmHg.
Pulmonary pulse pressure = 48 − 26 = 22 mmHg
PAPI = 22 / 11 = 2.0
A PAPI of 2.0 typically suggests preserved right ventricular pulsatility relative to filling pressure, though management decisions still depend on lactate, perfusion signs, left-sided metrics, and response to therapy.
When PAPI is most useful
High-yield use cases
- Cardiogenic shock phenotyping
- Assessing risk of right ventricular failure
- Right-heart monitoring during escalation/de-escalation of support
- Trending response to inotropes, diuresis, or afterload strategies
Why trends beat single values
A single PAPI snapshot is helpful, but serial measurements are often more informative. A rising PAPI over time can signal improved RV performance, while a falling trend may warn of decompensation.
Limitations and cautions
- PAPI depends on accurate invasive pressure measurements.
- Waveform artifacts, transducer leveling errors, or arrhythmias can distort values.
- It should not be interpreted in isolation from broader hemodynamics and clinical exam.
- Extremely low RAP can mathematically exaggerate PAPI.
In other words, PAPI is a strong supporting metric, not a stand-alone diagnosis.
Final thoughts
If you need a quick and clean way to calculate pulmonary artery pulsatility index, this PAPI calculator can streamline your workflow. Enter PASP, PADP, and RAP, then use the output as one piece of a comprehensive right-heart assessment strategy.