How helpful is a pH-Impedance Study in Identifying Reflux-Induced Symptoms?

In both kids and adults, individuals presenting with complaints of reflux more often have other problems like functional heartburn or reflux hypersensitivity (see posts below).  A recent prospective, cross-sectional study (LB Mahoney et al. JPGN 2020; 70: 31-36) provides data that further shows that abnormal pH-impedance (pH-MII) testing does NOT predict reduced quality of life (QOL) in children with reflux symptoms (n=82).

Key findings:

  • 38% had abnormal pH-MII testing; however, there were no significant differences in QOL scores on any of the tested questionairres between those with normal or abnormal pH-MII studies.
  • Subjects with gross esophagitis on EGD reported significantly worse QOL scores. Microscopic esophagitis was not associate with differences in QOL scores.

The implication of this study is that reflux without esophagitis is NOT a driver of abnormal QOL parameters; instead, functional GI disorders are likely more important.

My take: This study makes it clear that gross endoscopic findings are much more consequential than abnormal pH-MII studies.

Related blog posts:

Another Study Questions the Efficacy of Drip Feeds for Reflux

Several years ago, a small study showed that bolus feeds were as well-tolerated in premature infants as drip feeds: Which is Safer -Drip Feeds of Bolus Feeds for Preterm Infants?

Now, a retrospective study (LB Mahoney, E Liu, R Rosen. JPGN 2019; 69: 678-81) found no difference in the rate of reflux in 18 children who were with gastrostomy-tube dependent.

In this study, 24-hour multichannel intraluminal impedance with pH monitoring (MII-pH) examine reflux events in children receiving exclusive enteral nutrition with a combination of daytime bolus feeds and overnight continuous feeds; each patient served as their own control.  this included 6 with prior fundoplication.

Key finding:

  • There was no difference in rate of reflux events when comparing bolus feedings and drip (aka continuous) feedings.

The limitations in this study include the small sample size and retrospective design.  The authors estimate that to achieve adequate power (80% power) to detect a risk ratio of 1.2 would require 211 patients.

My take: This study and other small studies challenge the assumption that drip feedings are safer. Though, until a larger prospective study is performed, we will not know.

Quebec City

Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

How Bad is Reflux in Children with Esophageal Atresia?

A recent retrospective study (FWT Vergouwe et al. JPGN 2019; 69: 515-22) with 57 children with esophageal atresia (EA) found most children have a normal reflux index.

This study, analyzing data between 2012-2017, reviewed all 24-hour pH-impedance (MII) studies in children at ≤18 months and 8 year olds with EA.  “All children with EA born in our hospital are offered a 24-hour pH-MII study at the age of 0.5 years and 8 years.”  In this institution, PPI treatment is given for at least 6 months after surgery. Of the 57 in the cohort, 20 had completed pH-MII at <18 months of age and 32 at age 8 years.

Key findings:

  • In children ≤18 months of age, median reflux index was 2.6% (abnormal in 2), median number of retrograde boluses was 61 (62% nonacid, 58% mixed)
  • In the older cohort (~8 years of age), median reflux index was 0.3% (abnormal in 4) and median number of retrograde boluses was 21 (64% nonacid, 75% mixed)
  • Overall, 10 of 57 children (17.5%) had GERD with reflux index >7% (n=6) or positive SI/SAP (n=4).  The authors note that much higher rates of GERD have been found in prior studies.  If they included children with fundoplication who were considered as having GERD (prior to fundoplication), then the GERD rate was 32%.

My take: This study showed that reflux in this cohort of children with EA was similar to the general population and likely indicates that a substantial portion of patients with EA do not need indefinite PPI therapy.  In children with more complex EA, PPI therapy is likely to be more beneficial.

Related blog posts:

Recent (November 4th) GI-Related Tweets:

How to Make a Study Look Favorable for Reflux Surgery Compared to Medical Treatment

A recent study (SJ Spechler et al. NEJM 2019; 381: 1513-23) on first glance appears to support surgery as more effective than medical treatment for refractory heartburn.

Only ~20% of enrolled patients were included in the reported outcomes!

Here’s what happened.  Among a cohort of VA patients (n=360, mean age 48 years) who were reportedly refractory to PPI-treatment:

  • 78 were excluded during prerandomization
  • 42 had relief of their heartburn during a 2-week omeprazole lead-in (20 mg BID)
  • 70 did not complete trial procedures
  • 23 had non-GERD disorders
  • 99 had functional heartburn

This left 78 patients who underwent randomization.  All patients in this highly-selected group had undergone endoscopy with biopsy, impedance-pH testing, and esophageal manometry.  18 of 27 (67%) had treatment success with surgery compared to 7 of 25 patients treated with baclofen/PPI and 3 of 26 with control medical treatment (PPI alone).

Key points:

  • Careful evaluation is needed in any patient with refractory heartburn, especially if contemplating surgery.  Most will either respond to PPI treatment or have a disorder other than reflux; the authors note that 122 patients (out of 360 patients) did NOT have reflux –99 had functional heartburn.
  • Careful instruction in PPI use can be helpful.  Omeprazole and similar agents should be taken 30 minutes before meals.
  • The authors noted that in addition to reflux, that reflux hypersensitivity can “respond to fundoplication…treatment success was 71% among the 14 with reflux hypersensitivity and 62% among the 13 with abnormal acid reflux.”

Limitations: The VA population is not representative of the general population; this trial had a predominance of white males. Also, it is hard to exclude that some of the ‘success’ of the procedure could relate to a powerful placebo response.

My take: This trial reinforces the notion that reflux surgery is helpful in very few highly-selected patients.

Related blog posts:

Are There Any Babies with a Normal GI Tract?

A recent study (S Salvatore et al. J Pediatr 2019; 212: 44-51) examines the role of neonatal antibiotics and prematurity on the development of functional gastrointestinal disorders in the first year of life.

What is most striking, though, in this study is how many of these infants have a GI disorder.

Background: Prospective cohort multicenter study with 934 infants who completed study; n=302 premature, n=320 antibiotic recipients

Key findings:

  • 718 (77%) had at least one functional GI disorder (FGID) based on Rome III criteria, including 47% with colic, 40% with regurgitation, 32% with dyschezia, 27% with constipation, and 4% with functional diarrhea
  • Preterm infants had FGID rate of 86% compared with 73% of full term infants (P=.0001)
  • Use of antibiotics was associated with FGIDs as well, with aRR of 1.16 (P=.001)
  • The prevalence of FGIDs was highest in the first three months of life and then improved markedly by 6 months of age; by 12 months of age, each of the FGIDs was well below 10%.

Limitation: This study relied on parental reports which could overestimate infant’s symptoms.

My take: More than 75% of infants had at least one FGID.

Related blog posts:

#NASPGHAN18 Highlights and Tweets (part 1)

I did not make it to this year’s meeting but did get a chance to catch up on a lot information via the PG 2018 Syllabus and based on information posted online.

Here are a couple of highlights for me:

Slides from postgraduate course on CVS from Dr. Katja Kovacic

The slide from Dr. Lightdale (pg 22 in Syllabus) below suggests it is OK for scope if platelets >20K and OK for biopsies if platelets >50K. It is worth noting that some adult data indicate that even lower biospy thresholds are reasonable for biopsies (Post: Lower Endoscopic Thresholds for Thrombocytopenia). As always, one needs to consider carefully the risks compared with the benefits.

From Postgraduate Course

 

 

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications/diets (along with potential adverse effects) should be confirmed by prescribing physician/nutritionist.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Top Posts 2016

The following posts are the ones that I think are most useful from 2016.

Gastroenterology:

Liver:

General:

Doctoring:

IBD:

Nutrition:

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