الملخص
The value of 24 - hour multichannel intraluminal impedance - pH (24 h MII - pH) monitoring is still unknown in most patients with gastroesophageal reflux disease (GERD), and the value of mean nocturnal baseline impedance (MNBI) in the diagnosis of GERD remains controversial. Aims: To analyze the characteristics of esophageal MNBI in GERD patients, and to investigate the diagnostic value of MNBI for GERD. Methods: The clinical data of 111 patients suspected of GERD and monitored for 24 h MII-pH from May 2019 to December 2021 at the Second Affiliated Hospital of Baotou Medical College were retrospectively analyzed. According to DeMeester standard, patients were divided into non - GERD group and GERD group. Reflux parameters and MNBI of each channel between the two groups were compared. The correlation between distal and proximal esophageal MNBI and reflux parameters were analyzed. ROC curve was used to evaluate the sensitivity and specificity of MNBI for GERD. Results: Compared with non-GERD patients, the acid exposure time (AET), DeMeester score, total reflux times, acid reflux times and non-acid reflux times in GERD group were increased, the differences were statistically significant (P<0.01). MNBI at 3 cm, 5 cm and 7 cm above the dentate line and distal MNBI in the GERD group were decreased, the differences were statistically significant (P<0.01). Spearman correlation analysis showed that distal MNBI was negatively correlated with AET, DeMeester score, acid reflux times and weak acid reflux times (P<0.05). There were significant negative correlations between proximal MNBI and AET, DeMeester score and weak acid reflux times (P<0.05). ROC curve analysis showed that AUC of distal MNBI for the diagnosis of GERD was 0.72 (95% CI: 0.66-0.81, P<0.01), when the cut-off value was 1 191.42 Ω, the sensitivity and specificity of distal MNBI for diagnosis of GERD were 82.9% and 53.9%, respectively. Conclusions: Distal esophageal MNBI has good diagnostic significance for GERD patients, and can be used as a new impedance index for the auxiliary diagnosis of GERD.