Table 3.

24-hour multi-channel intraluminal impedance and pH measurements

Measurements n = 69	N (%)
Abnormal acid exposure time	43 (62.3)
Upright ≥6.2%	18 (26.0)
Recumbent ≥1.2%	28 (40.6)
Total ≥4.2%	20 (29.0)
Total proximal reflux events: acid	714 (50.7)
Non-acid	695 (49.3)
Patients with abnormal proximal reflux events	26 (37.7)
Acid reflux event ≥28	5 (7.2)
Non-acid reflux event ≥13	22 (31.9)
Total reflux event ≥31	15 (21.7)
Total distal reflux: acid	1187 (43.8)
Non-acid	1524 (56.2)
Patients with abnormal distal reflux events	23 (33.3)
Acid reflux event ≥55	0 (0)
Non-acid reflux event ≥27	23 (33.3)
Total reflux event ≥73	5 (7.2)
DeMeester score: positive	20 (29.0)
Negative	49 (71.0)

Twenty-four hour ambulatory simultaneous impedance and pH monitoring: a multi-center report of normal values from 60 healthy volunteers [10].