Impedance May Help in Borderline Reflux Disease Assessment

A recent retrospective study (A Rengarajan et al. Clin Gastroenterol Hepatol 2020; 18: 589-95), with a cohort of 371 patients (mean age 54 years) shows how impedance testing may help identify patients who are likely to respond to reflux management when pH probe testing is equivocal.  The cohort included adults with persistent reflux symptoms.  Response to antireflux therapy was defined as >50% improvement in esophageal symptoms.

Key points:

  • 107 (28.8%) had pathologic acid exposure time (AET) (pH<4 for >6%)
  • 234 (63.1%) had abnormal mean nocturnal baseline impedance (MNBI) (<2292 ohms). MNBI was calculated using baseline values at 10-minute periods between 1-3 am from the 5 cm channel to correspond to total distal AET.
  • Figure 1, shows the combined use of AET and MNBI.  Only 106/107 patients with AET>6, had an abnormal MNBI.  In the borderline category of AET 4-6%, 62/68 (91.2%) had abnormal MNBI values. In those with AET <4, MNBI was abnormal in 66/196 (33.7%)

Response to Treatment:

  • Among patients with AET >6, 66/89 (74%) responded to medical therapy and 18/23 (78%) responded to surgical therapy; among patients with AET 4-6%, 37/56 (66%) responded to medical therapy and 14/17 (82%) responded to surgical therapy. In those with AET <4, 39/185 (21%) responded to medical therapy and 16/23 (70%) responded to surgical therapy
  • Among patients with a low MNBI, 119/198 (60%) responded to medical therapy and 41/50 (82%) to surgical therapy.  In those with a normal MNBI, 23/132 (17%) responded to medical therapy and 7/13 (54%) responded to surgical treatment
  • In those with AET >6, 84/111 (76%) responded to treatment. For those with AET 4-6%, of those with low MNBI, 49/67 (73%), responded (similar to those with AET >6%).  In those with low MNBI and AET <4, 27/70 (39%) responded to treatment
  • 28/138 (20.2%) with normal AET <4 and with normal MNBI responded to treatment

My take: The big takeaway is that all of our tests for pathologic reflux are highly flawed; impedance may (to a small degree) help stratify patients with equivocal evaluation based on AET.  Normal tests do not exclude response treatment (especially surgery).

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Island Ford, Sandy Springs

 

Deconstructing PPI-Associated Risks with Nearly 8 Billion Data Points and More on COVID-19 GI Symptoms (Video)

Link: 22 minute video —COVID-19 and the GI Tract -What We Know Right Now

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A recent study (C Ma et al. Gastroenterol 2020; 158: 780-82) used cross-sectional data from the National Ambulatory Medical Care Survey (NAMCS) (2006-2015) with a total 7,872,115,883 weighted observations.  They used this data to evaluate medication exposures and outcomes.

Key findings:

  • There was no association between PPI use and dementia, pneumonia, or intestinal infections.  There was a trend towards intestinal infections (AOR 1.48, CI 0.80-2.71) but this did not reach statistical significance. “Sensitivity analysis showed an association between PPI use and C difficile.”
  • There was an association with chronic kidney disease (CKD) (AOR 1.26); however, this was seen with a multitude of drug classes including statins, calcium channel blockers, and beta-blockers.

Discussion:

  • This study notes that a recent large randomized controlled trial found no statistically significant differences between those receiving PPIs and those receiving placebo except for intestinal infections.
  • With regard to CKD, “it is extremely unlikely that all of these medications increase the risk of CKD, and therefore, it is likely that these findings are due to residual confounding.”

My take: With the exception of C difficile/intestinal infections, this study provides further evidence of the safety of PPIs and a lack of association between these medications and purported PPI-related adverse events.  That said, it is still a good idea to limit use for appropriate indications.

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Also, IOIBD recommendations for IBD patients and COVID-19 have been published.

Here is link as well:

IOIBD (International Organization for the Study of Inflammatory Bowel Disease) Recommendations (#76) for IBD Patients with Regard to COVID-19:

Full link: IOIBD Update on COVID19 for Patients with Crohn’s Disease and Ulcerative Colitis (3/26/20)