Gastroesophageal Reflux Characteristics and Patterns in Patients with Idiopathic Subglottic Stenosis

Table 2

Comparison between abnormal and normal pH impedance studies in idiopathic subglottic stenosis patients.

	Abnormal ()	Normal ()	value
Acid exposure (pH)
Esophageal acid exposure (%)
Total	8.9 ± 6.4	0.9 ± 1.4	<0.0001
Upright	11.3 ± 9.5	1.25 ± 1.6	0.0002
Supine	4.8 ± 8.9	0.1 ± 0.3	0.0334
Number of acid exposures
Total	84.9 ± 99.3	15.3 ± 14.0	0.0007
Upright	58.8 ± 33.3	13.2 ± 13.6	<0.0001
Supine	26.4 ± 77.1	2.0 ± 5.8	0.1859
DeMeester score	32.6 ± 26.0	3.6 ± 3.9	0.0001
Reflux episode activity (impedance)
Total	81.47 ± 48.6	26.4 ± 18.1	0.0001
Upright
Acid	49 ± 36.3	8.2 ± 9.0	0.0001
Nonacid	27.5 ± 59.3	15.0 ± 12.4	0.3775
Supine
Acid	3.9 ± 5.0	0.7 ± 1.8	0.0148
Nonacid	1.1 ± 2.6	2.5 ± 5.7	0.3265
Airway symptoms	57.9%	42.1%	0.1715
BMI	30.4 ± 8.9	31.3 ± 8.9	0.7544
On PPI	47.4%	68.2%	0.1763
MVV
Lowest	48.5 ± 19.7	44.6 ± 20.9	0.5430
Closest to pH study	56.5 ± 20.6	57.0 ± 21.9	0.9435

BMI: body mass index; PPI: proton pump inhibitor; MVV: maximum voluntary ventilation.