Can someone explain CRP test?

[lccougar02]

I am a new grad and all my babies get a CRP done when they get labs. What does that show if its too high? too low?

[dawngloves, BSN, RN]

A CRP is an indicator of inflammation. An elevated on can be a marker for infection, but you can get an elevated one from a traumatic delivery too.

They are also used to r/o MI's in adults, FYI.

[Gompers, BSN, RN]

I am a new grad and all my babies get a CRP done when they get labs. What does that show if its too high? too low?

It's amazing how different units do things. I've been in my NICU for 8 years and have never seen this lab drawn, ever. Much less with every lab! Very interesting! Do the docs give a rationale for getting it so often?

[dawngloves, BSN, RN]

We'll get it on admission, 12 hour and 24 hour if it is r/o sepsis. But they are starting this new thing of doing it day 6/7 of abx.I don't know why they are doing that.

[RNin2007]

We do CRP as well, and I wondered what it was used for too. I was told it was used as indication for infection related to recent research indicating this as a correlation.

~J

[prmenrs, RN]

I think you need to look @ the whole picture--maternal/infant risk factor, CBC, CRP, and baby. It doesn't take much to trigger the antibiotics--it's easier to stop them than to get behind the 8 ball on a septic kid.

We had a kid last week, unk GBS, initial CBC way off, 12 hour CBC had 51 bands, and 12 hour CRP of 6.6 (or 66 depending on the lab scale). He wasn't @ all symptomatic, but he sure earned himself 7-10 days, and an LP.

[Mimi2RN, ASN, RN]

I think you need to look @ the whole picture--maternal/infant risk factor, CBC, CRP, and baby. It doesn't take much to trigger the antibiotics--it's easier to stop them than to get behind the 8 ball on a septic kid.

We had a kid last week, unk GBS, initial CBC way off, 12 hour CBC had 51 bands, and 12 hour CRP of 6.6 (or 66 depending on the lab scale). He wasn't @ all symptomatic, but he sure earned himself 7-10 days, and an LP.

We'd have treated a kid like that, too. We don't use the CRP as much as we used to do, though.

The funny thing, one of our docs will sometimes hold off on starting abx therapy when we have a higher band count on night shift, redraw in the am, so that the day shift person in the lab can read the slide, and it'll be lower.

[EricJRN, MSN, RN]

Was at a seminar on NEC this week. One of the neo faculty presenters said that some research is showing the CRP to be of value in the diagnosis of those kids that may have NEC but who have no clear-cut signs.

[RainDreamer, BSN, RN]

We don't send a CRP routinely, not even on admission ..... they'll just get a CBC and blood culture.

They usually order for a CRP when they're suspecting sepsis or when they're doing a NEC workup.

[Love_2_Learn]

We do CRPs at my hospital on baby's who we think are septic whether they are newborns or ones who have been in the unit for a long time and suddenly get sick. I have heard somewhere that even a paper cut can cause a person's CRP level to rise a little...

The book, "Fetal & Neonatal Secrets, Second Edition" by Polin & Spitzer has some very good information about the CRP in the chapter on Infection & Immunity which I will share below:

Question #35. What is the relevance of C-reactive protein (CRP) in the diagnosis of neonatal sepsis?

Answer: Serum CRP is an acute phase reactant, which becomes elevated in the face of inflammation or infection, with a response time of 6-8 hours. The normal value in the neonate is 5.0 mg/dL) has a positive value for sepsis of 10%. (References: Benitz WB, Han MY, Madan A, Ramachandra P: Serial serum C-reactive protein levels in the diagnosis of neonatal infection. Pediatrics 102:E41, 1998. and Gerdes JS: Clinicopathologic approach to the diagnosis of neonatal sepsis. Perinatol 18:361-381, 1991.)

Question #36. Can a normal white blood cell (WBC) count, immature-to-total (I:T) neutrophil ratio, neutrophil count, or CRP measurement be used to rule out sepsis on admission?

Answer: Unfortunately not. Neither these nor any other tests can be used to reliably rule out infection in neonates. The usefulness of the tests improves markedly with serial measurements because there have been many cases of sepsis described in which the WBC count or CRP level became abnornal 12-24 hours after the onset of the disease. Furthermore, these tests can be combined in a sepsis screen in which several parameters are used to improve the diagnostic accuracy.

Question #39. What studies are useful in creating a sepsis screen strategy?

Answer: Although diagnostic tests are frequently ordered to identify infants with probable sepsis, their main benefit is to exclude disease in infants with a low probability of infection. A combination of diagnostic tests improves the predictive values over the use of a single test. In this strategy, serial sepsis screens that have negative results substantially reduce the likelihood that the infant has sepsis. One suggested screen is given in Table 12-7. The screen result is considered positive if 2 or more points are present. It is important to recognize that no sepsis screen is perfect, and one should err on the side of caution with neonatal sepsis.

Table 12-7. Parameters for Sepsis Screen Strategy

Test Point Value

Absolute neutrophil count

Total WBC 40,000/mm3 1 point

I:T neutrophil ratio > or =to 0.2 1 point

I:T neutrophil ratio > or =to 0.4 2 points

CRP+ (> or =to 1.0 mg/dL) 1 point

CRP+ (> or =to 5.0 mg/dL) 2 points

I love this book and highly recommend it to NICU nurses for many reasons.

:typing