Added Zemel 2015 Down syndrome growth calculator

Calculates Z-scores and percentiles based on the Zemel 2015 study for children ages 0 - 36 months and 2 - 20 years in United States with Down syndrome. Includes weight, length, head circumference, weight for length (for 0 - 36 months), and BMI for age (for 2 - 20 years).

On testing, the results seem to match the published work pretty well, but there are definitely small deviations that I am attributing to the use of only 2 significant digits of precision in the reference parameters in the publication supplementary materials. So, please don’t be surprised if the percentiles are 1 - 2% off.

Added Olsen 2015 BMI calculator for preterm infants

Calculates Z-scores and percentiles based on the Olsen 2015 reference curves (gender-specific) for BMI in prematurely born infants. Please let me know if there are any problems or bugs.

2014 AAP RSV prophylaxis policy statement added

On the Fenton 2013 growth calculator page, the decision support was amended to include the 2014 AAP Policy Statement on RSV prophylaxis with palivizumab (reference link at the bottom of the page).

Because some units are continuing to use the 2009 guidelines, I have not removed the older policy recommendations (yet).

Improvements in WHO 0-24m and CDC 2-20y, and bugfix for GA calculator

Implemented new features:

  • WHO 0 - 24 month growth calculator, added predicted increases in weight / head circumference / length to maintain current percentile, for both chronologic and corrected age
  • CDC 2 - 20 year growth calculator, added ability to also display calculations for corrected age, for children who were born premature
  • Gestational age calculator, updated to properly display age when > 1 year old

Thanks to the PediTools users who pointed out the problems and made suggestions for improvement!

Management of hyperbilirubinemia

Added a hyperbilirubinemia management tool, based on the AAP 2004 recommendations.

In addition to specifying the Bhutani nomogram risk zone and displaying the phototherapy initiation thresholds, it also displays the exchange transfusion thresholds, and also shows the point plotted on the three different graphs (risk nomogram, phototherapy thresholds, exchange transfusion thresholds).

To consider doing: add date/time of birth and lab draw, rather than entering hours of age.

Easy to do (actually, already done), but probably not much demand: ability to plot multiple points on the graphs, to better visualize trend and effect of therapy.

Note: when plotted, the points on the graph are sometimes a fraction off. This is because the figures as published are not perfectly horizontally / vertically aligned. The error is probably too small to be clinically significant. The reported numeric thresholds should be more accurate.

Fixed the GA calculator

Thanks to the folks who let me know that the GA calculator got broken. I think I’ve fixed the problem, but please let me know if you notice any problems.

Details: My web provider updated to a newer version of PHP, which broke the function I was using to generate the text of the difference between two dates -- e.g., “2 months and 5 days.” I found a nice built-in function that seems to do the same thing with less effort, so all is well. I think...

Added CDC 2000 measures for triceps and subscapular skin fold measures

Uses the 2000 CDC Reference for triceps and subscapular skinfold-for-age, to report percentiles and Z-scores on children from 1.5 to 20 years of age.

Added WHO 2007 measures for arm circumference and triceps / subscapular skin fold calculations

Added WHO 2007 measures for arm circumference and triceps / subscapular skin fold calculations, as requested by a pediatric dietitian at Rainbow Babies. Please report any inaccuracies, bugs, or concerns.

Added support for the Olsen 2010 intrauterine growth curves

I added support for the Olsen 2010 intrauterine growth curves, derived from data from 391,681 infants in the Pediatrix Medical Group, aged 22 - 42 weeks gestation at birth.

Multiple new features -- Fenton 2013, WHO, and CDC growth charts

Added growth parameter calculators for premature infants using the newly published Fenton 2013 growth chart, as well as the W.H.O. growth standard (for infants from 0 - 24 months old) as well as for the CDC growth charts (for infants from 0 - 36 months old and children from 2 to 20 years old).

The premature infant tool has now been integrated with the gestational age calculator. Some decision support has also been included, including for retinopathy of prematurity screening examination and respiratory syncytial virus (RSV) prophylaxis.

Converted inches / pounds-oz automatically in the growth tool

  • I’m currently at a hospital that reports weights in pounds-oz and lengths in inches, so am trying some tweaks to the Growth Calculator to make things a bit easier. In the main data entry area:
  • for head circumference and length, if you enter a number followed by double quotes (“), it will convert the number from inches to centimeters
  • for weight, if you enter two numbers separated by a dash (-), it will convert from pounds and ounces to grams

Please let me know if there is any unexpected behavior or incorrect calculations.

Improved gestational age calculator

Thanks to user feedback, I made a few changes to the GA calculator tool:
  • starts off with default day of interest to TODAY, rather than separately reporting results for TODAY
  • reports both chronologic age and either corrected age or time until due date, for the date of interest in years / months / days (helpful for infant follow-up clinic)
  • reports when first ROP exam would be due for all initial gestational ages (to include babies born at >31 weeks, but with birth weight <1500 grams)

Changing website hosting

  • I’ve noticed that access to PediTools has been occasionally very slow or non-responsive, particularly in the middle of the day. I’m going to try a different shared web hosting provider, in the hopes that that will help.

New features

Thanks to user feedback, some additional features have been added.
  • growth parameter calculator now has a tool to help calculate corrected gestational age
  • gestational age calculator now also reports chronologic and corrected age in years, months, and days
  • parenteral nutrition calculator now shows pie chart of calorie distribution, and indicates when calorie distribution percentages are out of goal ranges. Reformatted output to better fit on iPhone screens.

Site launch

Launching the PediTools website, using the RapidWeaver web development tool for now. Will have to see how well RapidWeaver pages play with PHP-scripted pages.

This site should be considered Under Construction for now. If you use the medical calculation tools, please keep an eye out for bugs / problems, and use the Contact link to let me know about them.