PKU testing

[doglover21]

I am alittle confussed after talking to a friend of mine in California. They do their PKU's after 12 hours of age. Many of their patients go home prior to 24 hours and C-sections go home in 2-3 days. In the hospital where I work we cannot do the PKU until at least 24 hours from the time of the first feeding. I am interested to see what other peoples standard is. I thought it was a national standard.

[2curlygirls]

We do them after 24 hours. I'm in CA BTW.

Unless babe needs to be transfused in the first 24 hours. Then it needs to be redrawn.

According to an article I read, catabolism is part of newborn physiology so for many tests 24-48 hours is sufficient. Since some IEM's can become syptomatic very quickly and time is essential in reducing morbidity/mortality, I think waiting longer than 48 hours isn't a great idea.

[GingerSue]

Here's what Olds, Sally says in "Maternal-Newborn & Women's Health Care":

The Guthrie blood test for PKU is required for all newborns before discharge. The Guthrie test uses a drop of blood collected from a heel stick and placed on filter paper. It should be done at least 24 hours after the initiation of feedings containing the usual amounts of breast milk or formula so its metabolites begin to build up in the baby with PKU once milk feedings are intiated.

The PKU testing of high-risk newborns should be deferred for at least 48 hours after hyperalimentation is initiated. It is vital that the parents understand the need for the screening procedure, and a follow-up check is necessary to confirm that the test was done.

Early newborn discharge puts infants at risk for delayed or missed diagnosis of PKU and congenital hypothyroidism because of decreased sensitivity of screening prior to 24 hours of age. Newborns should be retested by 2 weeks of age if the first test was done prior to 24 hours of age.

The accuracy of the test for PKU is directly related to the newborn's age. The likelihood of detecting PKU increases as the infant grows older, and the infant must be at least 24 hours old for a valid test. A second test is required in most states, usually between one week and one month of age. to minimize the chance of a positive child going undetected.

[rnin02]

We wait (when possible) till 24 hours after the first feeding, or longer.

With a 24 hr discharge (doesn't happen alot, but sometimes) we do it immediately before discharge. We usually tend to wait until the night before the baby is probably going home, then usually night shift will do it. Our vag deliveries stay 2 days, c/s stay 3-4 days. So, a baby born on the 9th, vag, will have his done with the night shift assessment on the 10th, most likely. This is in VA.

[studentmidwifekitty]

In the UK the Guthrie test isn't done so early. The midwife normally visits the mother at home to do the guthrie test on day 6. I was taught that we can't do it earlier because it isn't as accurate.

[BirthingBabies]

We do our Pku's at no less than 24 hours... we never have pt's go home prior to 24 hours... they have to stay according to policy at our hospital.

[crissrn27, RN]

We do our Pku's at no less than 24 hours... we never have pt's go home prior to 24 hours... they have to stay according to policy at our hospital.

You have never had a baby go before 24 hours? We have the 24 hour policy too......but often a mom and baby will leave AMA before then, we do it at whatever age in that case, unless mom won't let us.

[tinyscrafts]

I'm no expert on PKU, but I've been told the CA state now uses tandem mass spectometry & aparently the test timing using this method is not as sensitive as it was when they used the previous method (Guthries assay) but it is more accurate and can look for more metabolic errors. Any time after 12 hours old is ok, and it doesn't matter what or how much they have eaten, Any earlier and it must be done again.

http://www.dhs.ca.gov/pcfh/gdb/html/NBS/WhentoCollectSpecimens.htm

Guthrie assay: http://en.wikipedia.org/wiki/Guthrie_test

Tandem mass spectometry:

http://en.wikipedia.org/wiki/Tandem_mass_spectrometry#Tandem_MS

& the economics

http://pediatrics.aappublications.org/cgi/content/full/117/5/S1/S280