Category Archives: Uncategorized

Review of Button Batteries

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A recent open access article reviews button batteries and reiterates algorithm from poison control (noted in previous blog post: Button Battery Algorithm Link | gutsandgrowth).  This article has some excellent figures detailing the extent of the problem and has relevant pictures of radiographs and mucosal damage.

Here’s the reference:

International Journal of Pediatric Otorhinolaryngology 77 (2013) 1392–1399

Here’s the link:

http://authors.elsevier.com/offprints/PEDOT6686/7551db6b14c8aabfa827016d69367c08 …

Precise Identification of C difficile Transmission

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A recent study uncovers some useful information about C difficile by using whole-genome sequencing on 1250 separate C difficile cases (NEJM 2013; 369: 1195-205).

Between 2007-2011, the authors used genetic sequencing to determine the similarity of C difficile cases.  They were able to successfully sequence 1223 (98%) of the identified cases.  Of these isolates, 71% were from inpatients, 25% from outpatients, and 4% from patients at other hospitals. To determine similarity, they compared single-nucleotide variants (SNVs) between the isolates.  If isolates were related, it was anticipated that there would be 0 to 2 SNVs between transmitted isolates (95% prediction if less than 124 days apart).

This study was from the Oxford University Hospitals which provide all acute care and 90% of hospital services in Oxfordshire, United Kingdom (~600,000 population).

Results:

  • Only 35% of cases were genetically related to at least one previous case.
  • Of the 333 (35%) with ≤2 SNVs (consistent with transmission), and 126 (38%) had close hospital contact with another patient, 120 (36%) had no hospital or community contact with another patient.
  • 13% of cases were genetically related (≤2 SNVs) but without any evidence of plausible contact.
  • 45% of C difficile cases were genetically distinct (>10 SNVs from any previous case) from all previous cases.  This indicates that the source of the infection was not from another symptomatic case; most likely these cases were acquired from asymptomatic persons or an environmental reservoir.
  • There were reductions in the rate of C difficile infection during the 4-year study.  The authors relate this to changes in antibiotic prescribing behavior, specifically the restriction of fluoroquinolones and cephalosporins.

Aspects of the setting may limit some of the conclusions.  For example, the study was conducted in a nonoutbreak setting and the hospitals had established measures to limit transmission from symptomatic patients.  These included the following:

  • isolation of patients with suspected C difficile
  • daily hypochlorite disinfection
  • monitoring of compliance

These measures will decrease nosocomial transmission.  However, at the same time, some of the genetically distinct cases could still have been acquired in the hospital setting from asymptomatic hospital sources. While the authors concede a number of limitations, this study is quite helpful in understanding the role of hospitals in controlling C difficile infection.

Take-home message: the fact that only 35% of cases were related to other symptomatic cases indicates that hospital control measures by themselves will not be effective.  The most important aspect in reducing C difficile infection will be optimizing antibiotic usage.

Related news media: On the same day of that I read this study, there was an article in the Atlanta Journal Constitution (“PLEASE wash your hands … Please.”) which describes a first-hand account of C difficile infection which contributed to a slow recovery from intestinal surgery.  The article contained some questionable assertions including that C difficile was “impossible to eradicate” and that her immune system trapped C difficile in peritoneal abscesses which required drainage (these abscesses were more likely related to the initial operation). However, the article is a stark reminder that many hospital staff do not follow basic hand washing recommendations.  The article is really bad PR for the named hospital.

Related blog posts:

Mitochondrial Liver Disease

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A recent review provides advice for the evaluation of the child with suspected mitochondrial liver disease (JPGN 2013; 57: 269-79).

Clinical presentations:

  • Acute in a child with no history of hepatic dysfunction
  • Chronic liver and CNS dysfunction
  • Onset of liver disease in patient with known CNS disorder

Suggested Tiered Diagnostic Evaluation: Table 1 provides extensive suggestions.

  • 1st tier: CMP, INR, AFP, CPK, Phos, CBC/d, ammonia, Lactate/pyruvate (preferably 1 hour after feeding), serum ketone bodies, serum acylcarnitine profile, carnitine profile, urine organic acids, serum amino acids, urine acylglycines and 2-ethylmalonic acid quantification, plasma thymidine (especially if intestinal dysmotility), quantitative serum methylmalonic acid, CSF analysis (lactate and pyruvate, amino acids, protein)
  • 2nd tier: genotyping for more common genes (eg. panel with POLG1, DGUOK, MPV17), other genetic tests based on tier 1 testing (see table for details)
  • 3rd tier: liver biopsy, skin biopsy, and muscle biopsy (see table for details)
  • 4th tier: additional genetic tests based on 1st three tiers

Table 2 describes potential evaluations in other organs.  For example, for brain, MRI, EEG and CSF.

Table 3 lists ~27 mutation/syndromes and clinical features.

The last three words from the conclusion of the publication are not supported by the review.  The authors state that this systematic approach “can aid in making a timely, accurate, and cost-effective diagnosis.”  While the authors do not provide estimates of the expense of these tests, they are probably very expensive, though less costly than a failed liver transplantation.

Bottomline: “Available technology to aid in diagnosis has improved substantially.  Nonetheless, diagnosis of suspected mitochondrial disease in children is complicated.”

Related blog post:

Proven treatments for mitochondrial disorders | gutsandgrowth

NASPGHAN Preview

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I had a few free minutes so I decided to take a look at a bunch of upcoming lectures from the 2013 NASPGHAN upcoming meeting.  With electronic media, it is easy to take a quick glance.  Here’s the master link to all of the following talks:

Annual Meeting page.

Some of the power point lectures that I’ve seen so far:

  • Is my PPI dangerous for me? Eric Hassall MBChB, University of British Columbia One point in his slides that I had not seen much about was a hypothesis that PPI use may predispose to the development of eosinophilic esophagitis by allowing food proteins to be more intact ( attributed to Merwat, Spechler. Am J Gastro ’09).  He explains that “acid reflux” is a clever marketing term and has a slide with Madmen actors.  If there is “acid,” one must need acid suppression.
  • My child doesn’t go to school Lynne Walker MD, Vanderbilt University.  Lynne shows an interesting fax from a parent that asks if the problem is physical, how will she help? And, if it is psychological, how can this be remedied?  She outlines a lot of pain theory and indicates that parents need to become health coaches, avoid catastrophizing (?spelling), and encourages mental health evaluation.  Use the parents words ‘I’m going to refer xxx for relaxation and stress management.’
  • My child’s H. pylori will not go away – (the resistant bug) Benjamin Gold MD, Children’s Center for Digestive Healthcare. Ben manages to stuff so much information into his talk.  His talk is like one of those clown cars where more and more people keep coming out.  He has slides with worldwide resistance maps, slides with treatment regimens and algorithms, and the reasons for treatment failure. Perhaps I can convince him to give a live preview.
  • Administrative/executive functioning Richard Colletti MD, Fletcher Allen Healthcare. Offers personal and pragmatic advice for career advancement.  His slides indicate that he started his GI fellowship at age 40.  One of his quotes, “80% of success is showing up” (Woody Allen) is definitely true.  It’s pretty much akin to what I learned about success in medical school.  You need the three As: availability, affability, and ability.  My mentor said the first was what people needed most.
  • The changing face of intestinal transplantation
    Simon Horslen MD, Seattle Children’s Hospital.  Lecture notes that number of intestinal transplants have decreased dramatically, particularly in children. In 2012, only about 100 intestinal transplants were performed whereas it had peaked at nearly 200.  Much of the credit is due to intestinal rehabilitation work and adjustments in parenteral nutrition (eg. lipid minimization, line care).  Two most common reasons for intestinal transplantation at this time are gastroschisis and volvulus.
  •  Gluten sensitivity: Fact or fiction Alessio Fasano MD, MassGeneral Hospital for Children. This blog has covered a lot of the same material, but Alessio’s slides are pretty impressive.  Also, I was not aware that Lady Gaga consumes a gluten-free diet
  • Controversies in parenteral nutrition Christopher Duggan MD, Boston Children’s Hospital.  This lecture provides a timely update on nutrient deficiencies due to component shortages and discusses lipid minimization compared with fish oil-based lipid emulsions.
  • Vitamin D and immunity James Heubi MD, Cincinnati Children’s Hospital and Medical Center.  In the beginning of the slides, Jim provides a very user-friendly definition of an expert and a suitable picture.  He indicates that in 2011 there were 3746 vitamin D publications but inexplicably only chooses to review a tiny fraction.

At the time of this posting, I haven’t had a chance to look through these talks:

 

 

How long does it take the liver to recover from PNALD?

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It takes a long time, even when there is no longer biochemical evidence of parenteral nutrition-associated liver disease (PNALD).  A recent study provides long-term data from a population-based, cross-sectional study on liver histology from pediatric intestinal failure (IF) patients (Hepatology 2013; 58: 729-38).  Patients were followed from 1984-2010.  IF was defined as having either >50% small bowel resection or need for PN >30 days.

The 38 IF participants had a median age of 7.2 years.  16 remained on PN after 74 months (range  2.5-204), 22 had weaned off PN 8.8 years (range 0.3-27) earlier after an average of 35 months of PN exposure.

Key findings:

  • Abnormal liver histology was present in 94% of patients on PN and 77% off PN.
  • Nearly 60% of patients on long-term PN had significant or severe fibrosis (Metavir stage ≥2).
  • Significant liver fibrosis and steatosis persisted after weaning off PN. That is, “liver histology remains abnormal up to 9 years after weaning off PN in the majority of IF patients.”
  • One patient off PN developed esophageal varices.
  • Risk factors for increased fibrosis: extensive small intestinal resection, (P=.002) loss of ileocecal valve (P=.048), and recurrent sepsis (P=.002).

Bottomline: While there have been important clinical advances in the management of IF, the data from this study indicate that many patients who have normal liver biochemistries continue to have abnormal liver histology.  Whether this will have an important clinical impact is not known.

Previous related blog entries:

Pediatric Consensus Statement: Perianal Crohn Disease

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A recent report provides a useful reference for the often difficult care of pediatric perianal Crohn disease (JPGN 2013; 57: 401-412).

The statement reviews the background, etiology, presentation and classification systems. Most helpful are Figures 2 & 3.

Figure 2 provides an algorithm for assessment and treatment of perianal fistula.

  1. History/Physical (including rectal exam for stricture) along with colonoscopy
  2. Next either exam under anesthesia (with or without endoscopic ultrasound) or MRI
  3. Main treatments:
  • consider antibiotics, anti-TNF, and immunomodulators
  • in some cases a noncutting seton or fistulotomy will be needed
  • consider advancement flap in rectovaginal fistulae

Figure 3 provides an algorithm for assessment and treatment of perianal abscess.

  1. History/Physical (including rectal exam for stricture) along with colonoscopy
  2. Next either exam under anesthesia (with or without endoscopic ultrasound) or MRI
  3. Main treatments:
  • Incision and drainage
  • Noncutting seton if perianal fistula
  • Antibiotics
  • Treatment of intestinal disease

After outlining these algorithms, the report details the treatments.  Almost all treatments that are effective or questionable for Crohn’s disease are discussed.  The report reiterates that ‘corticosteroids must be used with caution in treatment of perianal fistula; studies have shown worse fistula outcomes for steroid-treated patients.

With regard to noncutting setons, the authors note that they do not prevent treatment with biologic agents and help prevent abscess formation.  They “usually deteriorate and fall out on their own in about 1 year.”  Medical therapy often allows for seton removal.

Ostomy diversion can be helpful in patients with severe perianal disease; however, “the risk of the ostomy becoming permanent is significant.”

Rectal strictures are typically dilated with multiple sessions with general anesthesia.  The goal is at least 18 mm in younger patients and at least 24 mm in adolescents.

Related blog post:

Previous references:

  • -Clin Gastro & Hep 2010; 8: 13.  Another algorithm.  For simple fistula, Rx w abx & medical (thiopurine or Remicade).  If not better, fistulotomy, &/or Rx as complex fistula.  For complex fistula, seton placement, abx, anti-TNF.  If not better, consider tacrolimus or proctectomy.
  • -JPGN 2010; 50: 99.  Perianal dz in young children may be due to autoimmune neutropenia.
  • -Clin Gastro & Hep 2009; 7: 1037.  MRI study of choice for perianal fistulas.  Algorithm: If superficial fistula, Rx c fistulotomy & Abx If deeper, noncutting seton c Abx, 6-MP +/- infliximab; if not effective, try tacrolimus; if not effective, surgery
  • -Ann Intern Med 2001; 135: 906-918.
  • -IBD 2008; 14: 1236.  Anal skin tag description
  •  -JPGN 2005; 41: 667.  Discusses several cases of highly destructive perianal dz. -Gastro 2003; 125: 1503-1507, 1508-1530.  Technical review.
  • -Gastro 2003; 125: 291.  Bourne test to detect occult bladder fistula.  Following nondiagnostic barium enema, urine can be collected, centrifuged,  and xrayed to determine if there is  a connection.

 

Abdominal distention – a medical mystery?

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A recent ‘think like a doctor’ case in the NY Times involved a patient sent to a pediatric gastroenterologist for abdominal distention.  It’s worth a read (thanks to Ben Enav for sharing this reference).

http://well.blogs.nytimes.com/2013/09/05/think-like-a-doctor-the-gymnasts-big-belly/

With regard to bloating and distention, the ‘smartphrase’ that I use to discuss this issue with parents is based on the “5 Fs” that I learned during fellowship.  I decided to modify the phrase a little bit based on the above case:

” I reviewed the issue of bloating/distention with family. Typically, distention or bloating can be caused by “5 Fs” which include flatus (gas), feces (constipation), fluid, fat, and fetus/masses. Flatus can be caused by swallowing air (aerophagia), malabsorption (celiac, lactose intolerance, parasites), muscular discoordination (abdominal phrenic dyssynergia), and motility problems.”

Are there other etiologies that you discuss with your patients?

Practical Advice on Enteral Nutrition

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In a previous post (NASPGHAN: Enteral Nutrition for Crohn’s Remission | gutsandgrowth), this blog provided a link to NASPGHAN information on enteral nutrition. Having reviewed this information further, I wanted to post some more information about one of the references which offers a terrific professional-quality 32 minute video (from IWK Health Centre in Canada).  This You-tube video on tube feeds provides interviews mostly from kids/family members along with some input by physicians and nutritionists; it is a fabulous resource for families weighing the option of tube feeds.  Around minute 23, a teen walks through the process of NG placement including advice on taping.  Around minute 31, a number of written tips are given like cleaning tubing with vinegar (& then rinsing with water).  According to the website there were only 275 views when I had clicked on this.  If that is accurate, it is a real shame.

Here’s the link:

Crohn’s Survival Guide: The Real Deal on Tube Feeds – YouTube

Other information from the NASPGHAN handout (which offers CME) in the link above:

  • Duration of enteral nutrition to induce remission: 8-12 weeks.  Enteral nutrition can induce remission in about 80% and is similar in effectiveness as corticosteroids.
  • Caloric needs: typically 120% of recommended daily allowance
  • Other foods? usually allowed water or clears like sodas, soup broth, and popsicles.  In some studies, up to 10% of energy intake as various other foods have been allowed; however, this creates a lot of difficulty monitoring.
  • Maintenance strategies: partial enteral nutrition (nighttime feeds only) can reduce recurrence.  More typical approaches included maintenance medication for long-term treatment, or enteral therapy in combination with maintenance medical therapy.  Alternatively, maintenance treatment can be instituted with cycles of 1 month exclusive enteral nutrition every few months.
  • What type of formula for NG tube? most commonly polymeric formulas
  • Refeeding syndrome: in children with severe malnutrition institution of tube feedings should be instituted more slowly over several days with electrolyte monitoring.

Tracking down a serial killer

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Truth be told, I really do like the murder mystery genre.  In medicine, that particular type of drama is usually absent.  Nevertheless, it is fascinating when epidemiologists can track down an agent responsible for multiple deaths and widespread illness.  The latest example: Listeria monocytogenes (NEJM 2013; 369:  944-53).

This recent report isolated Listeria monocytogenes as the agent responsible for 147 outbreak-related cases in 28 states; there were 33 deaths.  The investigators used multistage epidemiological, trace-back, and environmental studies.  Molecular finger printing of the cases identified five distinct patterns which defined the outbreak cases. By comparing the outbreak cases to sporadic cases using the “Listeria initiative,” the authors were able to determine that uncut cantaloupe ingestion was much more common among the outbreak-related cases.  Subsequently, the source of the contaminated cantaloupe were traced back to a Colorado  farm that had switched to a different cleaning method in 2011.

Other data:

  • Only 7 cases (5%) were pregnancy-associated; 1 miscarriage occurred
  • The median age was 77 years in this cohort.
  • Most of the deaths were in the elderly, with only 2 deaths occurring in individuals less than 60
  • 143 patients required hospitalization

While this report discussed 147 outbreak-related cases, there were undoubtedly many more outbreak-related cases which were unidentified due to milder illness.

Bottomline: this report provides a framework for identifying outbreaks of contaminated produce.  It reinforces the need for good agricultural practices to minimize food borne-pathogen infections. It is a good read.

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PPIs in Neonates –Helpful?

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Acid suppression in infants has not been proven to be effective in reducing gastroesophageal reflux (GER) symptoms. In a systemic review, this was thought to be either “because the symptoms are not caused by GER or if due to GER, because the symptoms are caused by volume reflux, rather than acidity.”  This quote is noted in the background information of another study which came to the same conclusion (J Pediatr 2013; 163: 692-8).

The pharmaceutical-supported study enrolled neonates (n=52) at 3 centers with gestational ages between 28-44 weeks.  Half of the participants were randomized to esomeprazole (0.5 mg/kg/day) and half placebo.  GER symptoms that were required for enrollment included any 2 of the following:

  • apnea with or without bradycardia
  • apnea with or without oxygen desaturations
  • irritability/pain
  • vomiting/gagging

Participants underwent extensive testing with video monitoring, esophageal pH & impedance testing, and cardiorespiratory monitoring.  They were followed for 14 days.

Findings:

  • There were no significant differences in any GERD-related signs and symptoms.
  • The esomeprazole group had improvement in acid reflux parameters on testing at 7 days, including number of reflux episodes (35 –>23) and mean percent time with pH<4.0.  The latter change was -10.7% was statistically significant (p= .0017) compared to placebo group which had an increase in time with pH<4.0 (2.2% increase).
  • No new safety signals were identified.

Despite its widespread usage, the authors had difficulty enrolling a larger cohort.  The small sample size was one of the study’s limitations along with the 14-day study period.  This limitation also precludes conclusions regarding the safety of these medications in neonates.

Bottomline: this study adds to the growing body of evidence that proton pump inhibitors (PPIs) are not effective in infants with so-called ‘signs and symptoms of reflux.’  PPIs are effective at reducing acid exposure and could be helpful in proven mucosal disease (eg. esophagitis and gastritis).

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