2024 Volume 28 Issue 1 Pages 11-20
Background: MostGraph is a measurement device developed based on the forced oscillation technique (FOT), and can measure respiratory resistance and reactance. We found that in many cases with a history of aspiration pneumonia, respiratory resistance measured by MostGraph was increased after eating. We investigated the cause of this phenomenon using swallowing videoendoscopy (VE).
Methods: We studied VE with oral intake in 23 patients with a history of aspiration pneumonia and 17 controls. In addition, we measured pre-VE and post-VE whole-breath respiratory system resistance (Rrs) and reactance (Xrs) using MostGraph.
Results: The change in respiratory resistance (cmH2O/L/s) at 5 Hz (DR5) was significantly higher in the patient group than in the control group [median 0.37 (min －0.46, max 1.13) vs. 0.29 (－1.64, 0.39), p＜0.001]. In the patient group, DR5 did not correlate with the mean value of the index of pharyngeal residuals (YPR-SRS) or the mean value of the laryngeal penetration and aspiration scale (PAS), but showed a significant positive correlation with the mean value of salivary PAS (S-PAS) (Spearman’s rank correlation coefficient ρ＝0.453, p＝0.030). In the patient group＋control group, DR5 showed a significant positive correlation with mean values of dysphagia indices: YPR-SRS (ρ＝0.527, p＜0.001), PAS (ρ＝0.502, p＜0.001) and S-PAS (ρ＝0.550, p＜0.001).
Conclusion: Postprandial elevation of respiratory resistance using MostGraph may be useful in the assessment of dysphagia, especially laryngeal penetration and aspiration of saliva during eating.
