Category: Pediatrics

Dosing Errors With IV Acetaminophen

As a follow-up to the recent posting regarding IV acetaminophen, this recent article in Pediatrics highlights a few case reports regarding overdose.

According to the authors, the most frequent error in administration when the order is written in milligrams, but the medication order is administered in milliliters – a 10-fold overdose.  All of the patients in this series received n-acetylcysteine infusion, and none appeared to suffer significant liver injury specifically attributed to the overdose.

Another lovely demonstration of the potential for iatrogenic injury in healthcare.  Even the most apparently benign orders can have unanticipated harmful consequences, and a demonstration how intravenous administration is at higher risk.

“Intravenous Acetaminophen in the United States: Iatrogenic Dosing Errors”
http://pediatrics.aappublications.org/content/early/2012/01/18/peds.2011-2345.abstract

Happy Holidays!

Holiday break – intermittent and ineloquent blogging will be the norm.  I count 209 blog posts for the year – more than enough to keep anyone busy reading the archives.

But, if you’re done with those, Life In The Fast Lane has a lovely Christmas-themed blog post with great articles including:

“What was wrong with Tiny Tim?”
http://www.ncbi.nlm.nih.gov/pubmed/1340779

“Children’s Nomenclatural Adventurism and Medical Evaluation study”
http://www.ncbi.nlm.nih.gov/pubmed/20415998

“No poinsettia this Christmas”
http://www.ncbi.nlm.nih.gov/pubmed/16866065

Ranitidine Kills Neonates

Specifically, 24 to 32-week premature neonates, but it’s still an interesting demonstration of the unanticipated dangers of reducing the body’s nonimmune defense mechanisms.

This is a non-randomized, controlled, prospective, observational study from Italy that simply looked at how many premature neonates in their NICU received ranitidine treatment for acid suppression.  The secondary endpoints of the study were any observed associations between ranitidine use/non-use and NEC, mortality, sepsis, length of hospitalization, etc.  This is still non-randomized observational data, so the associations may be affected by other unknown confounders – but mortality in the non-ranitidine group was 1.6% and the mortality in the ranitidine group was 9.8%.  This difference is probably all attributable to infection, considering 25.3% of the ranitidine group developed sepsis compared to 8.7% in the non-ranitidine group.

An impressive difference, even in a non-randomized cohort.  Not a lot of obviously significant differences between groups.  We’ve seen similar, smaller increases in infection in ICU adults receiving acid-suppression medication – I wonder if these effects extend to young infants on ranitidine as well?

“Ranitidine is Associated With Infections, Necrotizing Enterocolitis, and Fatal Outcome in Newborns”
http://www.ncbi.nlm.nih.gov/pubmed/22157140

Under/Overtesting in Fever Without a Source

A curious study that observes, from the NHAMCS dataset, the testing performed by Emergency Physicians on children who have fever without a source between the ages of 3 and 36 months.

The general point of the authors, while acknowledging the limitations of this sort of data-dredging, is that testing strategies by Emergency Physicians appear to be generally non-conforming with the American Academy of Pediatrics recommendations for testing in otherwise well-appearing children.  They are hesitant to critique the patients who received laboratory testing – because they have no data on how well-appearing the child may have been or other comorbidities that might indicate testing – but they do take issue with the fact that only 43% of females under age 2 with a fever received a urinalysis and culture.  The 2008 Pediatrics guidelines – not endorsed by ACEP – would recommend that all of them receive UA and culture.  Considering the prevalence of UTI in febrile females under 2 years of age ranges from 8-17%, their criticism is probably valid.
Other trivia: 20% of children with no testing performed received antibiotics.  This could be due to missing ICD-9 data about another clinical diagnosis – but more likely due to simply treating fever unnecessarily.  
And, finally, children from zip codes with higher median incomes were more likely to receive CBC and UA.  More UAs, probably good.  More CBCs, probably bad.
Just an interesting summation of observational data.

Why Aren’t You Using Nitrous Yet?

Another massive study reviewing adverse events encountered during procedural sedation – this time with nitrous oxide given in concentrations up to 70%.  It is odd that resistance is encountered regarding high concentrations of nitrous oxide – considering 30% O2 is still greater than the fraction of inspired oxygen on room air – but this, and other studies like it, should help allay any concerns.

Out of their 7,802 nitrous administrations, they recorded 9 “potentially serious” adverse events – eight desaturations and one potential aspiration event requiring oropharyngeal suctioning.  More importantly, a reasonable percentage of these administrations were in children with comorbid diseases or potentially serious illness that needed sedation for significant procedures – LP, CT scans, NG/G-tube placement, and “other” that included EMGs and botulinium toxin injections.  Their rates of serious events are similar to other published series where either zero or <1% potentially serious events occurred – except for the study that reported 30% adverse events, but included “euphoria” and “dreaming” as adverse events.

This is not, however, an ED-only study, and one of the limitations is that they don’t specifically record whether they are able to successfully complete the intended procedure with this method – however, one would imagine, if it didn’t work the first 7,000 times, they wouldn’t have kept doing it…

“Safety of High-Concentration Nitrous Oxide by Nasal Mask for Pediatric Procedural Sedation”
http://www.ncbi.nlm.nih.gov/pubmed/22134227

Skipping the LP in Infants 30-90 Days – Eh.

This is another one of those “practice-changing” types of articles, where the authors try to debunk some specific aggressive diagnostic or therapeutic modality that is over-utilized in a low-prevalence, high-risk population.  This article, which you may have already seen, is regarding the need for a lumbar puncture in infants between 30 and 90 days.

They perform a retrospective review of nonconsecutive infants between 30 and 90 days of age who presented to the Emergency Department and received the “septic workup” – urinalysis/culture, blood culture, and lumbar puncture/CSF culture.  They analyze a data set of 392 infants, the overwhelming majority of which are completely culture negative.  52 of them are culture positive on their urinalysis, 13 are culture positive in the blood, and 4 are CSF culture positive.  The authors note that only one patient who had a positive urinalysis also had a positive CSF fluid culture – and that infant did not qualify as a low-risk infant by the Rochester criteria – so a well-appearing infant with a positive urinalysis need not undergo LP.

So, essentially, this study tells us only that meningitis is rare and that UTIs are common.  The authors attempt to make the flawed logical argument against LP in their discussion by emphasizing the negative predictive value for meningitis in the setting of an abnormal UA is 98.2%.  However, they erroneously discount the negative likelihood ratio of 0.87 (95% CI, 0.5–1.5).  Therefore, statistically speaking, based on their results, repeating this study 100 times could lead to nearly half the study results showing a positive urinalysis favored concomitant meningitis.

Now, in a clinical sense, the authors are likely correct.  An infant who looks well, meets the Rochester criteria, has an identified source for fever, and will be receiving antibiotics is at low risk for meningitis – by prevalence alone, not by anything this study shows – and is probable to have a good clinical outcome since they’re receiving antibiotics (in the event that same organism is resulting in a well-appearing, subclinical systemic and cerebrospinal bacteremia).  The argument should not be that you can generate a zero-risk population with their combination of +UA and Rochester, but that the risk of bad outcome may be similar to the risk of harms associated with the lumbar puncture, false positives, and follow-on treatment/testing.

“Is a Lumbar Puncture Necessary When Evaluating Febrile Infants (30 to 90 Days of Age) With an Abnormal Urinalysis?”

When Parents Refuse a Septic Workup

This is a brief commentary and discussion regarding the implications of parental refusal of hospitalization and evaluation of a potentially septic neonate.  It is absolutely an issue we all hope to never face, but probably will at some point in our careers.

Two pediatricians offer differing opinions on the extent to which social work and child protective services need be involved, raising such issues as the threshold percentage for likelihood of serious bacterial infection/bacteremia should be for “imminent harm” to the child, and the perceived benefits of therapy.  No specific answers are gleaned from the article, but it is worth reading and thinking through the discussions you would have in a similar situation.

“When Parents Refuse a Septic Workup for a Newborn”
www.ncbi.nlm.nih.gov/pubmed/22025599

Soft Drinks & Youth Aggression

This is not an EM article – but it was too bizarre to pass up.  Apparently, the use of soft drinks and junk food is a validated legal strategy for justifying homicide (e.g., the ‘Twinkie Defense’) – and this study finds an association to support it.

2,725 Boston high-school students surveyed regarding non-diet soft drink use and violence towards peers, dates, children, or firearm use.  Attempting to control for other factors, they eventually find statistically significant associations between youths who drink >5 cans of soft drinks in a week and increased alcohol use, increased tobacco use, as well as all categories of violence.  In fact, with all four categories of violence, the incidence of each increased in a dose-dependent manner with soft drink consumption.

This is, of course, an observed association, not necessarily a causal relationship, although the authors speculate on how sugars and caffeine might incite aggression.  If you are the parent of a high-school student, it isn’t necessarily going to prevent violence to deny them access to non-diet soft drinks – but, if your high-school student is a heavy soft drink consumer, look out!

“The ‘Twinkie Defense’: the relationship between carbonated non-diet soft drinks and violence perpetration among Boston high school students.”
http://injuryprevention.bmj.com/content/early/2011/10/14/injuryprev-2011-040117.abstract

Preventing Mechanical Ventilation in Newborns

This is lovely article regarding the treatment of respiratory distress in newborns.  It is not a new concept to use surfactant in clinically indicated situations to improve ventilation in the newborn in distress – however, the typical treatment involves endotracheal intubation and mechanical ventilation prior to application.  This is a randomized, controlled trial of surfactant administration prior to mechanical ventilation.

This involves 220 preterm infants in Germany who were selected for the trial, essentially, if they were on CPAP requiring more than 30% inspired O2.  In the intervention group, patients received intratracheal surfactant if stable on CPAP and 30% O2.  Outcome measures were the portion of patients mechanically ventilated at any time or at day 2 or 3 after birth.  Minimal differences between groups, although the control group was a few grams lighter at birth.

Overall, 33% of all intervention infants required mechanical intervention vs. 73% of the control group.

Simple takeaway – surfactant isn’t just useful after intubation, but may also prevent mechanical ventilation.

“Avoidance of mechanical ventilation by surfactant treatment of spontaneously breathing preterm infants (AMV): an open-label, randomised, controlled trial”
www.ncbi.nlm.nih.gov/pubmed/21963186

Ultrasound In Undifferentiated Infant Vomiting

Is there anything ultrasound can’t do?  Trauma, vascular access, undifferentiated abdominal pain – and another nice case report for vomiting in children.

These authors are using ultrasound in the projectile-vomiting infant looking at the pylorus, and, after finding a normal pylorus, they scan the rest of the abdomen.  Lo and behold, they identify intussusception.  I am not entirely certain I would be able to well-identify the pylorus, but I can definitely see potentially noting the intussusception.  The authors include several nice images as teaching points.

As the barriers to routine ultrasound use in the ER decrease, hopefully we will all become more facile with using it in many more clinical situations.

“Use of Emergency Ultrasound in the Diagnostic Evaluation of an Infant With Vomiting”
www.ncbi.nlm.nih.gov/pubmed/21975504