Outcome of 24-hour pH-impedance monitoring of treated achalasia patients with (RS+) and without reflux symptoms (RS−)
| Patients with reflux symptoms (RS+) | Patients without reflux symptoms (RS−) | P value | |
| (n=19) | (n=19) | ||
| 24-hour pH-impedance monitoring | |||
| Acid exposure time (AET: % of time pH <4; mean (95% CI)) | |||
| Total | 13.8 (6.7 to 20.9) | 10.9 (4.4 to 17.3) | 0.53 |
| Upright | 10.9 (4.4 to 17.4) | 6.6 (2.6 to 10.6) | 0.24 |
| Supine | 17.7 (7.9 to 27.5) | 16.4 (4.1 to 28.8) | 0.86 |
| Pathological acid exposure (AET pH <4 in >6%; n (%)) | 14 (74) | 10 (53) | 0.18 |
| Acidification patterns (% of time; mean (95% CI)) | |||
| Acid reflux with normal clearance | 0.2 (0.06 to 0.28) | 0.09 (0.01 to 0.16) | 0.39 |
| Acid reflux with delayed clearance | 6 (0.94 to 11.0) | 3.4 (−0.34 to 7.18) | 0.051 |
| Acid fermentation | 6.6 (2.96 to 10.2) | 1.8 (−0.45 to 4.10) | 0.03 |
| Stasis of ingested acidic food | 2.2 (−0.04 to 4.55) | 7.6 (−0.13 to 15.3) | 0.18 |
| Unclassified | 1.8 (−0.49 to 4.11) | 0.01 (−0.02 to 0.04) | 0.11 |
| No of acidification events (median (IQR)) | |||
| Acid reflux with normal clearance | 1 (0–2) | 0 (0–1) | 0.11 |
| Acid reflux with delayed clearance | 1 (0–3) | 0 (0–1) | 0.07 |
| Acid fermentation | 1 (0–3) | 0 (0–0) | 0.002 |
| Stasis of ingested acidic food | 0 (0–1) | 0 (0–2) | 0.54 |
| Unclassified | 0 (0–1) | 0 (0–0) | 0.008 |
| No of patients per acidification pattern (n (%)) | |||
| Acid reflux with normal clearance | 10 (53) | 5 (26) | 0.1 |
| Acid reflux with delayed clearance | 12 (63) | 6 (32) | 0.051 |
| Acid fermentation | 13 (68) | 4 (21) | 0.004 |
| Stasis of ingested acidic food | 6 (32) | 8 (42) | 0.5 |
| Unclassified | 8 (42) | 2 (11) | 0.03 |
| No of symptoms (median (IQR)) | 4 (3–5) | 0 (0–2) | <0.001 |
| Baseline impedance (Ω; median (IQR)) | |||
| Proximal | 2327 (1853–2836) | 2638 (1659–3108) | 0.93 |
| Distal | 487 (69–696) | 476 (338–741) | 0.84 |
AET, acid exposure time.