Is Propofol Safe in Pediatric Patients with Food Allergy and Eosinophilic Esophagitis?

According to a recent study (P Mehta et al. JPGN 2017; 64: 546-49), propofol was safe in pediatric patients with eosinophilic esophagitis (EoE) and food allergy.

This finding was based on a retrospective study of 1365 upper endoscopies (2013-2014).  Though, propofol was used less frequently, “there was no difference in complication rates relative to propofol use.”

Specifically, egg or soy allergy patients had 38 procedures; 114 children had EoE (without known egg or soy allergy) and 27 and EoE and egg or soy allergy.

This study is important because propofol is used frequently in patients with egg and soy allergies despite a contraindication warning on the package insert. Nevertheless, this study does not provide a definitive answer due to the very low rates of allergic reactions to propofol (~1:10,000 to 1:20,000).  In addition, the diagnosis of food allergy in this study relied on review of the medical record.

My take: This study is limited in scope but did not identify any significant safety concerns with propofol in patients who had EoE and/or egg/soy allergies.

Palace of Versailles

CMV in IBD: Tissue Matters

A recent study (P Tandon et al. Inflamm Bowel Dis 2017; 23: 551-60) was a systemic review regarding the accuracy of blood-based testing for predicting colonic CMV reactivation in patients with inflammatory bowel disease.  The review identified 9 studies.  The overall sensitivity of blood-based testing (either pp65 antigenemia or blood PCR) for CMV was 50.8% and the specificity was 99.9%. Blood PCR was better at 60% sensitivity.

My take: Blood-based tests are not sensitive enough to exclude colonic CMV reactivation. The authors recommend the use of immunohistochemistry or tissue PCR for detecting CMV reactivation in inflammatory bowel disease.

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Palace Gate, Versailles

Two for the PPI Team

Medicine safety is not nearly as straight-forward as most people would expect.  Virtually all medicines have the potential for adverse reactions.  In addition, there are often conflicting reports on how frequent adverse reactions occur; furthermore, negative studies demonstrating safety may be published less frequently due to publication bias.

This problem is compounded by the frequent misunderstanding of statistics.  Frequently, risks of medications are expressed as an odds ratio.  So, if an adverse reaction occurs twice as often with the medication than without the medication, the odds ratio would 2.0.  Yet, if the adverse reaction is rare (eg. one in a million), then the absolute increase in risk remains minuscule.

Proton pump inhibitors have received a lot of press, often about rare increases in adverse reactions. But, there are many potential benefits to these medications and numerous studies demonstrating fairly good safety profiles.  A few more studies (thanks to Ben Gold for these references) on their safety have recently been published:

  • 1. “Long-term Proton Pump Inhibitor Use is Not Associated with Changes in Bone Strength and Structure” LE Targownik et al. Am J Gastroenterol 2017; 112: 95: 101.
  • 2. “Proton Pump Inhibitors Do Not Increase Risk for Clostridium difficile Infection in the Intensive Care Unit.” DM Faleck et al. Am J Gastroenterol 2016; 111: 1641-8.

In the first study, the authors examined 52 PPI-users (>5 yrs) and 52 non-PPI users with mean age of 65 years.  They underwent quantitative CT , DXA, and markers of bone metabolism. “There were no differences detected..between the two groups.”  The conclude that PPIs were not associated with changes that increase a risk of fracture and “provide further evidence that the association between PPI use and fracture is not causal.”

In the second study, the authors analyzed data from 14 ICUs 2010-2013 and identified 18,134 patients (mean age 66-67 yrs) who met inclusion criteria.  271 (1.5%) developed Clostridium difficile infection (CDI) in the ICU.  The main risk factor for CDI was antibiotics with adjusted Hazard Ratio (aHR) of 2.79.  “There was no significant increase in risk for CDI associated with PPIs in those who did not receive antibiotics (aHR 1.56; 95% CI, 0.72-3.35).”  “PPIs were actually associated with a decreased risk for CDI in those who received antibiotics (aHR 0.64; 95% CI 0.48-0.83).”  The authors also noted that even those who received the highest doses of PPIs, “there was no risk for health-care facility-onset CDI.”

My take: PPIs can be life-saving medications and can alleviate a lot of suffering.  These studies pushback on some of the concerns about PPI risk.

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Correlation between Microbiome and Irritable Bowel Syndrome

I vaguely remember jokes that I heard as a teenager about computers that could analyze stool or urine and then come to remarkable conclusions about the person’s health or extramarital problems.  Fast-forward a few decades and these jokes are not so far off.

A recent study (J Tap, M Derrien, et al. Gastroenterol 2017; 152: 111-23) describes an intestinal microbiome ‘signature’ associated with severity of irritable bowel syndrome (IBS).  Thanks to Ben Gold for highlighting this article.  (He placed this one on my desk: “Jay -FYI -It is all about the poop!”)

In this study, the authors collected fecal and mucosal samples from adult patients who met Rome III criteria for IBS.  They started with an exploratory set of 149 subjects (110 with IBS, 39 controls).  Subsequently, they used a validation cohort of 46 subjects (29 with IBS, 17 controls).

Key findings:

  • “By using classic approaches, we found no differences in fecal microbiota abundance or composition between patients with IBS vs healthy patients.”  But, “a machine learning procedure, a computational statistical technique, allowed us to reduce the 16S ribosomal RNA data complexity into a microbial signature for severe IBS, consisting of 90 bacterial operational taxonomic units.”
  • This microbial signature showed IBS to be associated negatively with microbial richness, exhaled CH4, presence of methanogens, and enterotypes enriched with Clostridiales or Prevotella species.  Figure 6 provides a graphic summary of the study and the microbial signature.
  • The authors note their findings were not explained by differences in diet or medications.
  • Overall, the microbial signature has a low sensitivity and thus at this point does not have clinical applicability.

My take: There are a number of studies showing that our gut microbiome is associated with numerous conditions, including IBS, inflammatory bowel disease, and metabolic syndrome.  Having our poops analyzed by a computer to tell us what is wrong does not seem all that funny anymore.

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Bridge on Seine River

Image Only: Living with Irritable Bowel Syndrome

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Codeine and Tramadol –Additional Warnings

NY Times: FDA Strengthens Warnings for Painkillers in Children

An excerpt:

The Food and Drug Administration announced on Thursday that any child younger than 12 should not take the opioid codeine, and those 18 and younger should not take tramadol, another painkiller, after certain surgeries. In addition, nursing mothers should avoid both drugs, since they pose dangers to breast-feeding babies, the agency said.

“The problem with both codeine and tramadol is that some people are “ultrarapid metabolizers” whose livers metabolize the drugs way too quickly, causing dangerously high levels of opioids to build up, said Dr. Douglas Throckmorton, the deputy director for regulatory programs at the F.D.A.’s Center for Drug Evaluation and Research.

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Pancreatitis Update (Part 2)

Our group received a very helpful update on pancreatitis from Maisam Abu-El-Haija (GI) and Jaime Nathan (surgery). These notes focus on the surgical perspective.  My notes may include some errors in transcription and errors of omission. Some pictures of the slides are included below as well.

Key points:

  • Several surgical procedures can be considered in chronic pancreatitis.  Prior surgical procedures, though, could reduce islet cells if TPIAT needed later.
  • TPIAT –Cincinnati experience: 17 cases in last 2 years.  Highly selected group. Operation time takes about 10 hours (or more).  GJ tube placed due to anticipated poor gastric emptying for 4-6 weeks. Fevers expected during 1st post-operative week due to systemic inflammatory response. ~15% of children remain on opioids after TPIAT, likely due to long-standing problems prior to TPIAT.
  • Post-TPIAT care: PERT, vitamins, insulin (may wean off).  During 1st year, anticoagulation, hydroxyurea/aspirin (if high platelets), and penicillin prophylaxis.  Prior to TPIAT, patients receive vaccines (due to anticipated splenectomy).

Related blog post:

Pancreatitis Update (part 1)

Our group received a very helpful update on pancreatitis from Maisam Abu-El-Haija (GI) and Jaime Nathan (surgery). My notes may include some errors in transcription and errors of omission. Some pictures of the slides are included below as well.

Key points:

  • About 30% of acute pancreatitis patients have a 2nd bout of pancreatitis. Obesity is a risk factor for recurrence.
  • There has been a recent increase in incidence of acute pancreatitis.
  • Cincinnati has a gene panel to examine the four most common mutations which cause hereditary pancreatitis (PRSS1, SPINK1, CFTR, and CRTC) along with 6 other relevant genes. (28 day turnaround) In addition, there is a pancreatitis insufficiency panel.
  • Discussed screening for pancreatic insufficiency.  Directly measuring pancreatic enzymes are more sensitive for early insufficiency, but may be unnecessary if good growth and normal stool elastase.
  • There are NO proven medical/dietary therapies to prevent recurrent or chronic pancreatitis and eliminate pain symptoms.

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FPIES Guidelines

Recently, international consensus guidelines (A Nowak-Wegrzyn et al. J Allergy Clin Immunol 2017; 139: 1111-26) for the diagnosis and management of food protein-induced enterocolitis (FPIES) have been published.

The report starts with a review of epidemiology and diagnosis. Table 1 outlines features:

  • early vs. late: <9 months or >9 months
  • severity: mild-to-moderate =repetitive emesis with or without diarrhea, mild lethargy, severe =repetitive projectile emesis, pallor, lethargy, dehydration, hypotension
  • timing: acute vs chronic.  Acute occurs with intermittent exposures with emesis 1-4 h following exposure. Chronic occurs with repetitive food exposures (eg. formula in young infants)
  • IgE positivity: classical FPIES is IgE negative. Atypical FPIES is IgE positive

Some recommendations:

  • #4. “Consider specific IgE testing of children with FPIES to their trigger food because comorbid IgE-mediated sensitization to triggers, such as CM [cow’s milk], can infer a greater chance of persistent disease.”
  • #8. Conduct food challenges “in patients with suspected FPIES in medically supervised settings in which access to rapid fluid resuscitation is available and prolonged observation can be provided, if necessary.”
  • #14. Do not routinely obtain endoscopic evaluation as part of the evaluation of FPIES.
  • #17. Acute FPIES should be considered a medical emergency. “Approximately 15% of patients can have hypovolemic shock.”
  • #19. Consider ondansetron treatment as an adjunct (if >6 months of age)
  • #21. Do not recommend routine maternal dietary elimination of offending triggers while breast-feeding if the infant is asymptomatic.
  • #23. FPIES can occur to multiple foods.  “The majority of children (65% to 80%) have FPIES to a single food, most commonly CM.”  In one study, 5% to 10% of children reacted to more than 3 foods.
  • #26. Use hypoallergenic formula in infants who can no longer breast-feed and are given a diagnosis of FPIES caused by CM. Most will tolerate extensively hydrolyzed formulas; some may require an amino acid based formula
  • #29. Reviews natural history.  “The age of CM tolerance appears to be around 3 years” but there has been variability in reports. For FPIES due to grains, average age of tolerance is 35 months and other solid foods is 42 months.  The average age for soy is 12 months (later in some studies), for rice 4.7 years and 4.0 years for oats. For CM-FPIES with positive SPT response, a much protracted course has been reported, with older age of tolerance (~13.8 years)

Table III lists a differential diagnosis for FPIES and distinguishing features.  This list includes gastroenteritis, necrotizing enterocolitis, anaphylaxis, food aversions, inborn errors of metabolism, cyclic vomiting/neurologic disorders, gastroesophageal reflux, Hirschsprung’s enterocolitis, eosinophilic gastroenteritis, celiac disease, immune enteropathies/IBD, intestinal obstruction, and primary immune deficiencies.  Not listed on this table, but worth a mention, would be medical child abuse (aka Munchausen syndrome by proxy).

With regard to inborn errors of metabolism, these include urea cycle defects, hereditary fructose intolerance, hyperammonemic syndromes, Beta-oxidation defects, proprionic/methylmalonic academia, mitochondrial defects and others. Typically, features could include developmental delay, neurologic manifestations, organomegaly, and in some reaction to fruits.

Table IV specifies diagnostic criteria with the major criteria for acute FPIES: vomiting 1- to 4-h period after ingestion of the suspect food and absence of classic IgE-mediated allergic skin or respiratory symptoms.  Minor criteria include extreme lethargy, pallor, need for emergency room evaluation/IV fluids, and diarrhea in 24 h (usually 5-10 h).

Table VI details management of FPIES.  With moderate bouts, IV fluids with 20 mL/kg normal saline is recommended.  For severe episodes, “consider administering intravenous methylprednisolone, 1 mg/kg; maximum 60-80 mg/dose” in addition to fluid resuscitation.

Table IX provides empiric guidelines for selecting weaning foods in infants with FPIES.  The recommendations need to be considered based on whether the infant has shown tolerance for a number of foods, which can indicate the acceptability of a more liberal approach.  Age-specific guidance:

4-6 months:

  • Begin with smooth, thin purees and progress to thicker purees
  • Lower-risk foods: vegetables, broccoli, cauliflower, parsnip, turnip, pumpkin
  • Moderate-risk: squash, carrot, white potato, green bean
  • Higher-risk: sweet potato, green peas

6-8 months:

  • Continue to expand vegetables and fruits; in breast-fed, high-iron foods and/or supplemental iron are needed (1 mg/kg/day)
  • Lower-risk: fruits, blueberries, strawberries, plum, watermelon, peach, avocado
  • Moderate-risk: apple, pear, orange
  • Higher-risk: banana

8-12 months:

  • Offer soft-cooked and bite-and-dissolve textures
  • Lower-risk: high iron foods, lamb, fortified quinoa, millet
  • Moderate-risk: beef, fortified grits, corn cereal, wheat, barley
  • Higher-risk: fortified infant rice and oat cereals

12 months:

  • Offer tolerated table foods: chopped meats, soft vegetables, grains
  • Lower-risk: tree nuts
  • Moderate-risk: peanut, other legumes (besides green pea)
  • Higher-risk: milk, soy, poultry, egg, fish

Overall, with regard to food introduction: While children with FPIES have increased reactions to other foods, “current early feeding guidelines do not recommend delay in introducing complementary foods past 6 months of life because of FPIES. A practical ordering for introducing solids at about 6 months of age at home could start with fruits and vegetables.”  For infants with history of severe reactions, “supervised (eg. in-office) introduction can be considered…and prevent unnecessary avoidance.”  As with new foods in the home setting, starting with small amounts is recommended and then gradual build up in serving size.

Related blog post: SEED Journal Club: FPIES

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  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.