| Abstract | OBJECTIVE: To develop an easy-to-use bedside scoring system, composed of clinical
variables, hematologic variables, and risk factors of infection, to predict nosocomial sepsis in
neonatal intensive care unit patients. SETTING: A neonatal intensive care unit in a
university hospital, Antwerp, Belgium. PATIENTS: Over 2 yrs, we analyzed two groups of
patients. First, we prospectively studied 104 episodes of presumed nosocomial sepsis in 80
neonates (derivation cohort), and then we retrospectively studied 50 episodes in 39 neonates
(validation cohort). INTERVENTIONS: None. MEASUREMENTS AND MAIN
RESULTS: We developed two versions of a scoring system to predict nosocomial sepsis in
sick neonates. The first scoring system (NOSEP-1 score) was based on 15 clinical, 12
laboratory, and 17 historical variables potentially connected with infection; the second one
(NOSEP-2 score) also included the culture results of central vascular catheters. Based on
the odds ratios of all independent variables, an additive and weighted score was developed
and validated in a cohort of 39 patients screened for nosocomial sepsis in the same center.
The NOSEP-1 score consisted of three laboratory variables (C-reactive protein > or =14
mg/L, thrombocytopenia <150 x 10(9)/L, and neutrophil fraction >50%), one clinical factor
(fever >38.2 degrees C [100.8 degrees F]), and one risk factor (parenteral nutrition for > or
=14 days). The NOSEP-2 score consisted of the same variables plus catheter-hub and
catheter insertion site colonization data. Receiver operating characteristic curve analysis
demonstrated good predictor performance of the NOSEP-1 score (area under the curve
[Az] = 0.82 +/- 0.04 [SEM]) and NOSEP-2 score (Az = 0.84 +/- 0.04, p < .05). We
checked whether a complex computer-generated scoring system (CD-1 and CD-2 scores)
based on the original numerical values of the items used in NOSEP-1 and NOSEP-2 would
improve the prediction of nosocomial sepsis. The analysis showed the accuracy of bedside
NOSEP-1 and NOSEP-2 scores to be comparable with the more cumbersome
computer-generated CD-1 and CD-2 scores (receiver operating characteristic curve, Az:
CD-1 score = 0.81 +/- 0.04, p = .69, and CD-2 score = 0.86 +/- 0.04, p = .96). Finally, in the
validation cohort, we showed that the developed scoring system has a good prediction
potential for nosocomial sepsis (Hosmer-Lemeshow goodness-of-fit test, chi2 [19] = 16.34,
p > .75). CONCLUSIONS: The simple bedside scoring system NOSEP-1 composed of
C-reactive protein, neutrophil fraction, thrombocytopenia, fever, and prolonged parenteral
nutrition exposure provides a valuable tool for early identification of nosocomial sepsis. Its
predictive power can be improved by adding central vascular catheter insertion site and hub
colonization to the score. |