C‐Reactive protein as a diagnostic tool of sepsis in very immature babies

Abstract

Three hundred and nine septic screens were performed on 123 consecutively admitted infants of < 30 weeks gestation. As part of the septic screen, serial quantitative measurements of C-reactive protein (CRP) were performed daily until discontinuation of antibiotic therapy. Complete blood counts were performed daily for the first 2 days of each septic episode. The babies had a mean birth weight of 1035.8 g s.d. 273.2 and a mean gestational age of 27 weeks s.d. 1.8. A CRP level of 10 mg/L or above was considered abnormal. Subsequently the receiver operator characteristic curve for CRP was constructed to demonstrate the ideal cut off value. Of the 309 septic screens, there were 51 instances of proven sepsis and 39 instances of deep culture negative sepsis. In the remaining 219, a diagnosis of proven or deep culture negative sepsis could not be made. On the first day of the septic episode CRP showed a sensitivity of 62.7%, specificity of 87.2% and negative predictive value of 92.2% for proven sepsis. There was a significant increase in the sensitivity (90.2%) and negative predictive value (97.7%) of CRP with a specificity of 80.6 when both day 1 and 2 estimations were combined. We conclude that when the CRP is elevated on day 1 and/or day 2, the diagnosis of sepsis is extremely likely and when the CRP is within normal limits on days 1 and 2 of the septic episode, neonatal sepsis can be confidently excluded and antibiotic therapy ceased.

Clinical Microbiology of Bacterial and Fungal Sepsis in Very-Low-Birth-Weight Infants

“…Serial measurements of CRP levels appear to have the best discriminatory value for predicting septicemia among the tests currently available in many hospital laboratories, and the ability to produce CRP does not appear to be affected by gestational age (8,377,426). Several studies have specifically addressed the utility of CRP screening in VLBW neonates, with the sensitivity of a CRP value greater than 1 mg/dl for blood culture-proven sepsis ranging from 48 to 63% when a single test is performed and from 84 to 90% when multiple CRP screens are performed over a 24-to 48-h period following onset of symptoms (77,487). In many studies, CRP has been shown to have higher sensitivity and negative predictive value than leukocyte indices such as the immature/total neutrophil ratio for predicting bacteremia (154).…”

Retinol-Binding Protein, Transthyretin, and C-Reactive Protein in Extremely Low Birth Weight (ELBW) Infants

“…9,11 C-reactive protein (CRP) is an acute phase reactant that increases with infection and inflammation and is used as a screening tool for neonatal sepsis. [12][13][14] There is recent evidence that CRP may have a proinflammatory role in addition to being an inflammatory marker, [15][16][17] and high concentrations of CRP have been shown to correlate with mortality and organ failure in critically ill adults. 18 It is possible that CRP may be useful as a prognostic marker in ELBW infants.…”

How accurate are leukocyte indices and C-reactive protein for diagnosis of neonatal sepsis?

“…The variability in the accuracy of leukocyte and CRP to predict sepsis is still remarkable. However, it is important to note that both tests are quite predictive of neonatal sepsis when measured serially (16)(17)(18)(19). Thus, these tests when repeated provide useful information when treating an infant with suspected sepsis but negative blood cultures.…”

“…In this updated review, few articles published since 1994 that evaluated CRP and leukocyte parameters were identified (16)(17)(18)(19). The variability in the accuracy of leukocyte and CRP to predict sepsis is still remarkable.…”