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Predicted postoperative FEV₁ and DLCO

For lobectomy or segmentectomy, it uses the initial functioning segment count (19 minus the obstructed segments). For pneumonectomy, it requires the measured percentage of total perfusion attributable to the lung to be resected. The segmental method does not replace this measurement. Predicted function is calculated within ELUCENIA; the result alone does not approve surgery.

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Method · Limits of application

ERS/ESTS 2009, page 22: initial estimate from functioning segments and pre-pneumonectomy formula using the measured perfusion fraction; thresholds from the ACCP 2013 abstract: both >60%, either between 30–60%, and either <30%; no complete clinical conformance

An estimate for functional assessment of lung resection candidates, with preoperative values expressed as percentages of predicted values. Select the method appropriate to the intervention: segment counting for an initial estimate; for pneumonectomy, enter the measured perfusion of the lung to be resected. Perfusion is not deduced from 19 segments. Enter segments as integer counts; the number to be resected cannot exceed 19 minus the obstructed segments. Perfusion of 0–100% is the implementation's mathematical domain; 0% and 100% do not establish surgical eligibility. Without DLCO, only a partial FEV₁ result and an incomplete assessment are available. Cardiovascular algorithms, exercise tests, the 2014 correction, and the full ACCP article were not checked in this batch. The ERS/ESTS 2009 source was read on this specific page; the ACCP 2013 source was read in abstract form. Clinical review and professional translation were not performed.

Conditions of use

Check the population, units, inclusion and exclusion criteria, and version in the original source. A result alone does not establish a diagnosis, discharge decision or prescription.

Documented parameters

Estimation method
Preoperative FEV₁ (postbronchodilator) · % of predicted
Preoperative DLCO · % of predicted
Functioning segments to be resected
Obstructed (nonfunctioning) segments in the whole lung
Perfusion of the lung to be resected · % of total perfusion

5/5 reference cases checked. Numerical tests are not clinical validation.

Sources and documentation

Documented formula

Transcribed from the source or a recorded revision; this is not a clinical recommendation.

Segmental mode: PPO = preoperative value × (1 − y/z), where y is the number of functioning segments to be resected and z = 19 minus the number of obstructed segments. Segments are integer counts, and y cannot exceed z.

Perfusion mode: PPO = preoperative value × (1 − P/100), where P is the measured percentage of total perfusion attributable to the lung to be resected. This fraction is not inferred from the segment count.

The equation is applied separately to FEV₁ and DLCO. Without DLCO, the result is a partial FEV₁ result and the assessment remains incomplete. Clinical selection of the intervention and assessment strategy requires professional review.

References

Identifier: vef1-dlco-pos-operatorio

Original clinical content: Brazilian Portuguese.

Method version

vef1-dlco-pos-operatorio@native-2026-10-05+f82b8e546c1d

The bibliographic edition identifies the source. By itself, it proves neither full conformity of the formula nor clinical approval.

Synthetic cases checked (5)

Synthetic cases for checking the implementation, with no patient data.

Case 1

reference-001

Inputs

Preoperative FEV₁ (postbronchodilator): 90 % of predicted
Preoperative DLCO: 85 % of predicted
Functioning segments to be resected: 2

{
  "vef1": 90,
  "dlco": 85,
  "seg": 2
}

Expected result

{
  "fev": 80.53,
  "dlco": 76.05
}

Actual result

{
  "fev": 80.52631578947368,
  "dlco": 76.05263157894737
}

Case 2

reference-002

Inputs

Preoperative FEV₁ (postbronchodilator): 80 % of predicted
Preoperative DLCO: 75 % of predicted
Functioning segments to be resected: 5

{
  "vef1": 80,
  "dlco": 75,
  "seg": 5
}

Expected result

{
  "fev": 58.95,
  "dlco": 55.26
}

Actual result

{
  "fev": 58.94736842105263,
  "dlco": 55.26315789473684
}

Case 3

reference-003

Inputs

Preoperative FEV₁ (postbronchodilator): 50 % of predicted
Preoperative DLCO: 55 % of predicted
Functioning segments to be resected: 9

{
  "vef1": 50,
  "dlco": 55,
  "seg": 9
}

Expected result

{
  "fev": 26.32,
  "dlco": 28.95
}

Actual result

{
  "fev": 26.31578947368421,
  "dlco": 28.94736842105263
}

Case 4

reference-004

Inputs

Preoperative FEV₁ (postbronchodilator): 70 % of predicted
Functioning segments to be resected: 5
Obstructed (nonfunctioning) segments in the whole lung: 2

{
  "vef1": 70,
  "seg": 5,
  "obs": 2
}

Expected result

{
  "fev": 49.41
}

Actual result

{
  "fev": 49.411764705882355,
  "dlco": null
}

Case 5

reference-005

Inputs

Preoperative FEV₁ (postbronchodilator): 70 % of predicted
Functioning segments to be resected: 18
Obstructed (nonfunctioning) segments in the whole lung: 2

{
  "vef1": 70,
  "seg": 18,
  "obs": 2
}

Expected result

{
  "error": true
}

Code and reproducibility

This tool’s code on GitHub

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Sources, version and reproduction instructions

README

Local installation

Code license: Apache-2.0

Guidelines and conditions

This repository’s license applies to the code. Third-party instruments, questionnaires, data and models remain subject to their owners’ conditions.

The code tests are technical checks. Clinical approval and professional translation review are recorded separately.

Relationship with cancer research

General context — relationship to be defined

A resource for general clinical contexts. This edition does not assign a specific oncological relationship; selecting it for a study requires a justified question, population and purpose.