What is the interpretation of a Forced Vital Capacity (FVC) of 83%, Forced Expiratory Volume in one second (FEV1) to Forced Vital Capacity (FVC) ratio of 79%, and Forced Expiratory Volume (FEV) of 103%?

From the Guidelines

The pulmonary function test results show normal lung function, with no evidence of obstructive or restrictive lung disease, and no specific intervention is needed based on these results alone. The FVC (Forced Vital Capacity) is 83% of predicted, which is within normal range (typically normal is considered >80%) 1. The FEV1/FVC ratio is 79%, which is also normal (typically normal is >70%) 1. The FEV1 (Forced Expiratory Volume in 1 second) is 103% of predicted, which is completely normal. These values indicate that the patient has normal lung volumes and normal airflow. According to the GOLD 2025 report, the diagnosis of COPD should be considered in individuals with chronic respiratory symptoms and/or exposure to risk factors, and forced spirometry demonstrating airflow obstruction after bronchodilation is required to confirm the diagnosis using a threshold of forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio <0.7 1. However, in this case, the FEV1/FVC ratio is 79%, which is above the threshold, indicating no airflow obstruction. The slightly lower FVC at 83% is still within normal limits but could be monitored on future tests to ensure it doesn't decrease further.

Some key points to consider:

• The FEV1/FVC ratio is used to distinguish between obstructive and restrictive lung diseases 1.
• A ratio <0.7 indicates airflow obstruction, while a ratio >0.7 indicates normal lung function or restrictive lung disease 1.
• The FVC and FEV1 values are used to assess lung volumes and airflow, respectively 1.
• The GOLD 2025 report recommends using pre- and post-bronchodilator spirometry to diagnose COPD, but in this case, the results indicate no airflow obstruction 1.

Overall, the pulmonary function test results indicate normal lung function, and no specific intervention is needed based on these results alone. However, it is essential to consider the patient's clinical history, symptoms, and risk factors when interpreting these results.

From the Research

Interpretation of Spirometry Results

The given spirometry results are:

• FVC (Forced Vital Capacity): 83
• FEV1/FVC (Forced Expiratory Volume in 1 second to Forced Vital Capacity ratio): 79
• FEV1 (Forced Expiratory Volume in 1 second): 103

Analysis of Results

• The FEV1/FVC ratio is 79, which is lower than the normal range (typically above 80) 2. This suggests an obstructive pattern.
• The FVC is 83, which is slightly below the normal range, but not significantly low.
• The FEV1 is 103, which is above the normal range.

Possible Implications

• The low FEV1/FVC ratio may indicate the presence of an obstructive lung disease, such as chronic obstructive pulmonary disease (COPD) or asthma 2.
• However, the high FEV1 value suggests that the obstruction may not be severe.
• The methacholine challenge test may be used to further assess airway hyperresponsiveness and diagnose asthma 3, 4.

Limitations

• The given studies do not provide direct evidence for interpreting the specific spirometry results provided.
• Further testing, such as the methacholine challenge test, may be necessary to confirm a diagnosis of asthma or other obstructive lung diseases 3, 4.