Table 6 Comparison of current study findings with existing literature on tracheal/bronchial measurements and pulmonary function

Current Study (2024)

IPF patients

Subcricoid AP: 18.33 ± 3.68 mm Carina AP: 20.60 ± 3.95 mm

No significant correlation with FVC/DLCO Positive correlation with GAP index (r = 0.318, p = 0.003)

Tracheal measurements correlate with disease severity but not with pulmonary function

Ratwani et al. (2017)

IPF patients

Subglottic: 21.77 mm Carina: 20.47 mm

No significant correlation with FVC Significant correlation with GAP index

Similar findings to current study; tracheal dimensions correlate with disease severity but not FVC

Silva et al. (2018)

Scleroderma patients

Tracheal area and diameter measured

Negative correlation with FVC (r=-0.57, p = 0.002)

Contrasting findings; shows significant correlation between tracheal measurements and lung function

Nathan et al. (2007)

IPF patients

Main bronchial measurements

FVC/DLCO ratio ≥ 1.5 associated with increased PH risk

Focused on PH risk; found FVC/DLCO ratio significant for disease progression

Olivier et al. (2006)

Mixed population

Left main bronchus measurements

Limited correlation with pulmonary function

Primarily focused on anatomical measurements; minimal functional correlation

Occhipinti et al. (2019)

Systemic sclerosis patients

Quantitative CT analysis

Moderate correlation with FVC/DLCO (r=-0.3 to -0.74)

Found stronger correlations using quantitative analysis methods

Abumossalam et al. (2015)

IPF patients

Tracheal measurements by CT and ultrasound

Variable correlation with pulmonary function

Mixed results regarding correlation with lung function parameters