This diagnostic method, known as vertigraphy, uses an esophageal balloon attached to the distal end of the catheter with a pressure transducer connected to a physiograph and provides readings for [DELTA]Pplmax.
Vertigraphy was followed by endoscopy, and when secretions were observed, tracheal samples were collected for cytology.
Results of the vertigraphy and endoscopy were subjected to statistical analysis with Minitab[R]17.3.1 software using the Chi-square test, with a P [less than or equal to] 0.05 considered statistically significant, to investigate the correlation among increased [DELTA]Pplmax, tracheal mucus [greater than or equal to] 2, and carina edema, and the correlation between tracheal mucus and age.
Based on vertigraphy alone, 47% (n=34) of the horses examined presented some degree of bronchospasm evidenced by interpleural pressure variations higher than 4cm [H.sub.2]0 (Table 1).
Also, 90% of the animals with neutrophilia ([greater than or equal to] 20%) showed abnormalities in both vertigraphy and endoscopy.