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Functional assessment before lung resection
Before lung resection FEV1 and DLCO are measured and the predicted postoperative value (ppo) is calculated; if both are above 60% the risk is low, if one is between 30% and 60% a simple exercise test is done, and if one is below 30% or the simple test is poor — cardiopulmonary exercise testing, in which VO2max above 20 mL/kg/min indicates low risk and below 10 high risk.
Why it matters in the exam
This is one of the calculation topics in the exam: FEV1, DLCO and the planned resection are given, and the student must calculate and decide. The predicted value after lobectomy: the current value times (1 minus the number of segments to be removed divided by 19). There are 19 segments: 10 in the right lung (3 in the upper lobe, 2 in the middle and 5 in the lower) and 9 in the left (5 in the upper lobe including the lingula and 4 in the lower). Before pneumonectomy a quantitative perfusion scan is used: the current value times (1 minus the perfusion fraction of the lung to be removed). For example, an FEV1 of 70% before right lower lobectomy (5 segments) gives a ppoFEV1 of about 52%.
Following the ACCP 2013 algorithm one starts with cardiac risk assessment (ThRCRI index), then: ppoFEV1 and ppoDLCO both above 60% — low risk, surgery can proceed. One of them between 30% and 60% — a "simple" exercise test: stair climbing to a height of more than 22 metres or a shuttle walk of more than 400 metres indicates low risk. One of them below 30%, or a poor simple test — cardiopulmonary exercise testing: VO2max above 20 mL/kg/min — low risk; 10–20 — moderate risk; below 10 mL/kg/min — high risk, and a limited resection or non-surgical treatment such as SBRT should be considered. Remember that DLCO is measured even when FEV1 is normal, because it independently predicts complications.
In addition, smoking cessation and pulmonary rehabilitation before surgery reduce pulmonary complications.
Key points
- FEV1 and DLCO for every candidate.
- ppo = current value times (1 minus segments removed divided by 19).
- Above 60% — low risk.
- Stairs above 22 metres or shuttle walk above 400 metres.
- VO2max above 20 good, below 10 high risk.
Summary table
| Measure | Low risk | High risk |
|---|---|---|
| ppoFEV1 and ppoDLCO | Both above 60% | One below 30% — proceed to exercise testing |
| Stair climbing | More than 22 metres | Less than 22 metres — cardiopulmonary exercise testing |
| Shuttle walk | More than 400 metres | Less than 400 metres — cardiopulmonary exercise testing |
| VO2max | Above 20 mL/kg/min | Below 10 mL/kg/min |
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Sources
- ACCP Guidelines: Physiologic evaluation of the patient with lung cancer being considered for resectional surgery, 2013 — Functional algorithm
- ERS/ESTS clinical guidelines on fitness for radical therapy in lung cancer patients, 2009 — Recommendations
- BTS Guidelines on the radical management of patients with lung cancer, 2010 — Fitness for surgery
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.