Evaluation of plethysmography for diagnosis of postintubation tracheal stenosis

Post-intubation tracheal stenosis is a serious disease caused by cuff pressure during tracheal intubation. The reported prevalence of post-intubation tracheal stenosis is 10%-22% in intubated patients. Invasive diagnostic methods based on fiberoptic or rigid bronchoscopy are suggested for initial assessment and treatment. This study aimed to evaluate plethysmography as an alternative diagnostic tool for post-intubation tracheal stenosis. We also assessed the relationship between plethysmography and bronchoscopy findings in patients with post-intubation tracheal stenosis.

The sample included 30 patients who were admitted to our intensive care unit or surgical ward during the course of a year, and diagnosed with post-intubation tracheal stenosis. All patients underwent plethysmography and rigid bronchoscopy. The relationship between the plethysmography and bronchoscopy findings was examined.

Stricture intensity had the strongest correlation with upper airway resistance (p = 0.001). The relationship of length of stricture to forced expiratory volume in 1 s and maximum expiratory flow 50 and 75 was significant in univariate analysis, and to reserve volume and total lung capacity in multivariate analysis.

Significant relationships were found between plethysmography variables and rigid bronchoscopy findings in patients with post-intubation tracheal stenosis, and some formulas were developed to give an alternative estimate of stricture severity, without bronchoscopy.