The role of esophageal pH monitoring in symptomatic patients on PPI therapy.

Background: Ambulatory pH monitoring while on therapy is often recommended in gastroesophageal reflux disease (GERD) patients with continued symptoms. However, to date, little data exist to justify this indication.

Aim: To assess the role of pH monitoring in symptomatic patients despite aggressive therapy with typical or extra esophageal GERD.

Methods: Retrospective review of 2,291 ambulatory pH tracings (1999-2003) identified subgroup of studies performed on proton pump inhibitor (PPI) therapy. Patients with prior fundoplication or Barrett's esophagus were excluded. Patients grouped on predominant presenting GERD symptoms: typical (heartburn and regurgitation) or extra esophageal (chest pain, cough, hoarseness, sore throat, shortness of breath, asthma). The distribution of abnormal pH parameters in each group calculated and univariate analyses assessed the probability of abnormal pH in each group. Abnormal cutoff values traditionally used in clinical practice and more stringent cutoff values used to determine distribution of abnormality as a function of cutoff values.

Results: A total of 250 patients (mean age 54.3 yrs, 59% female) underwent pH monitoring on either daily (b.i.d.) or twice daily (q.d.) on PPI therapy: 115 (46%) with extra esophageal and 135 (54%) with typical GERD symptoms. Extra esophageal GERD patients were more likely to undergo pH monitoring on b.i.d. PPIs (OR = 2.7; 95% CI = 1.6-4.4; p < 0.01). 52 (93%) of typical and 74 (99%) of extra esophageal GERD patients on b.i.d. PPIs tested normal. The odds of a normal pH values were 11 times higher for patients on b.i.d. PPIs (OR = 11.4; 95% CI = 4.3-30.1, p < 0.01) than those on q.d. PPIs.

Conclusions: 1) The likelihood of an abnormal esophageal pH for symptomatic GERD patients on b.i.d. PPI is very small. 2) In this group of patients failing b.i.d. PPIs causes other than GERD should be sought.