1. What is the PPO Calculation?

The Predicted Postoperative (PPO) calculation estimates lung function after surgical resection. It helps assess surgical risk and predict postoperative respiratory function.

2. How Does the Calculator Work?

The calculator uses the PPO equation:

Where:

• \( Preoperative \) — Preoperative lung function (%)
• \( Segments\ Removed \) — Number of bronchopulmonary segments to be removed
• \( Total\ Segments \) — Total number of bronchopulmonary segments (typically 19)

Explanation: The equation estimates remaining lung function by accounting for the proportion of lung tissue removed during surgery.

3. Importance of PPO Calculation

Details: PPO calculation is crucial for preoperative risk assessment, especially in lung cancer surgery. It helps identify patients at risk for postoperative respiratory complications.

4. Using the Calculator

Tips: Enter preoperative lung function (%), number of segments to be removed, and total number of segments. All values must be valid (preoperative > 0, segments removed ≤ total segments).

5. Frequently Asked Questions (FAQ)

Q1: What is a typical total number of segments?
A: The right lung has 10 segments and the left has 8-9, making a typical total of 18-19 segments.

Q2: What PPO value is considered safe for surgery?
A: Generally, PPO FEV1 >40% is considered acceptable for lobectomy, and >30% for pneumonectomy, but individual assessment is needed.

Q3: Are there other methods to estimate PPO?
A: Yes, including perfusion scintigraphy, CT volumetry, and exercise testing, but the segment counting method is widely used.

Q4: How accurate is this calculation?
A: It provides a reasonable estimate but may not account for regional variations in lung function.

Q5: Should this be the sole criterion for surgical decision-making?
A: No, it should be combined with other clinical factors and tests for comprehensive risk assessment.