Can esophageal pH monitoring predict delayed gastric emptying?
OBJECTIVE
Delayed gastric emptying (DGE) is frequent in patients with gastroesophageal reflux disease (GERD) and may require additional investigation. The current study assesses whether relative esophageal exposure, postprandial (PP) versus fasting, diagnosed by pH monitoring could predict DGE.


METHODS
Thirty patients with GERD underwent extended esophageal pH monitoring and were assigned as DGE or non-DGE according to scintigraphy. The PP to fasting ratio for reflux index, relative frequency of long episodes in PP, and distribution of the longest episode were used to assess the relative esophageal exposure. The effectiveness of these parameters to predict DGE was estimated; the cutoffs for continuous variables were chosen with receiver operating characteristics (ROC) curves and the probabilities were calculated using a logistic regression model.


RESULTS
The area under the ROC curve of PP to fasting ratio for reflux index was greater than that of relative frequency of long episodes in PP. There was a good equilibrium between sensitivity and specificity at a PP to fasting ratio of 1. A PP to fasting ratio greater than 1, ie, a reflux index in PP greater than in fasting, presented a sensitivity of 93% and a negative predictive value of 91%. The occurrence of the longest episode in PP had a specificity of 94% and a positive predictive value of 89%. A reflux index greater in PP plus a longest episode in PP presented a 94% probability of DGE; a reflux index greater in fasting plus a longest episode in fasting had a 95% probability of non-DGE. These combinations represented 60% of the series.


CONCLUSIONS
PP to fasting ratio for reflux index and distribution of the longest episode seem accurate to identify DGE; thus, additional investigation to assess gastric emptying may be avoided in the majority of patients.
Division of Pediatric Surgery, Faculty of Medicine, Hospital São João, Porto, Portugal.
José
J
Estevão-Costa
Jorge Amil
JA
Dias
Miguel
M
Campos
Eunice
E
Trindade
Armando
A
Teixeira-Pinto
José Luis
JL
Carvalho
D002675:Child, Preschool; D005215:Fasting; D005260:Female; D005746:Gastric Emptying; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity