Esophageal Bolus Transit in Newborns With Gastroesophageal Reflux Disease
Condition: Gastroesophageal Reflux
MeSH terms: Gastroesophageal Reflux; Esophagitis, Peptic
Study type: Observational

Summary: 
      Esophageal dysmotility due to immaturity could promote impaired bolus transit during
      esophageal swallow events,thus influencing gastroesophageal reflux (GER) clearance.

      Aim of this study was to describe esophageal bolus transit characteristics during swallow and
      to evaluate the relationship between esophageal swallow (ES) and GER in newborns with
      gastroesophageal reflux disease symptoms using multichannel intraluminal impedance.

      The simultaneous analysis of swallow and GER events in newborns undergone MII/pH monitoring
      could provide useful information to better understand the physiopathology of gastroesophageal
      reflux disease (GERD) and could help clinicians to identify newborns with prolonged
      esophageal clearance time, making the recommendations for further tests and the therapeutic
      approach more accurate
    

Detailed description: 
      The aim of this study was to evaluate esophageal swallow (ES) frequency and characteristics
      in term and preterm newborns with GERD symptoms using MII and to investigate the possible
      relationship between ES and GER events.

      MATERIAL AND METHODS

      The MII tracings from the beginning of the second feeding up to 3 hours after the end of the
      meal were visually analyzed by two independent investigators using Bioview Analysis software
      (Sandhill Scientific Inc., Highlands Ranch, Colorado, USA) to identify and characterize ES
      and GER events.

      ES events An ES event was identified as a rapid increase in impedance which precedes a drop
      in impedance to 50% of baseline beginning in the proximal channel and preceding in an
      anterograde direction to the most distal channel, followed by the recovery of baseline values
      at each channel.13 The ES events detected by MII/pH were grouped into mealtime events (the
      first nine consecutive ES events with no artifacts after the beginning of the meal) and
      postprandial period events (all the ES events detected in the 3 hours following the end of
      the meal).

      ES event frequency (ES events/hour) was measured, along with the following ES event
      characteristics:

      bolus presence time (BPT): time between bolus entrance and exit recorded in the distal
      channel, measured in seconds; bolus head advancing time (BHAT): time between the bolus
      entrance recorded in the proximal channel and the bolus entrance recorded in the distal
      channel, measured in seconds; bolus head advancing time corrected (BHATc): BHAT corrected for
      esophageal length, expressed in seconds/cm. BHATc was calculated using the formula BHATc =
      BHAT / esophageal length where esophageal length is the distance between proximal and distal
      impedance channels, measured in cm.

      GER events

      A GER event was defined as a retrograde drop in impedance to 50% of baseline, beginning in
      the most distal channel and proceding to one or more proximal channels, of at least 5
      seconds, followed by an impedance recovery of baseline values.GER event frequency was
      measured (GER events/hour), along with the following event characteristics:

      bolus reflux extent (BRE):the proximal extent reached by the refluxate, shown by the number
      of channels sequentially involved in the impedance drop,measured in number of channels; bolus
      clearance time (BCT):time from onset, at the 50% drop in impedance signal from baseline, to
      the end of the event, at the 50% recovery point from nadir to baseline, recorded in the
      distal impedance channel, measured in second.

      Statistical Analysis The distribution of all the continuous variables was assessed by the
      Shapiro-Wilk test. The differences in MII variables between different groups of infants were
      evaluated with the Mann-Whitney test; the Wilcoxon test was used to compare paired data.
      Group correlations were analyzedwith the Spearman correlation test. Statistical significance
      was set at p<0.05.
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Probability Sample
Study population: 
        newborns consecutively admitted to the Torino University NICU who underwent 24-hour MII/pH
        for suspected GERD
      
Keywords: esophageal swallow; gastroesophageal reflux; esophageal impedance; newborn; preterm