[Evaluation of the diagnostic utility scale of NOSEP-1 and NOSEP-1 modified in suspected nosocomial sepsis in preterm infants].

INTRODUCTION: Nosocomial sepsis in premature neonates entertains a high rate of mortality. Diagnosis and timely treatment increase the therapeutic response. The nosocomial sepsis neonate prediction (NOSEP-1) scale has been utilized to evaluate neonatal sepsis; this scale required modifications to improve its sensitivity and specificity (NOSEP-1 modified).

OBJECTIVE: To determine the diagnostic usefulness of the NOSEP-1 and NOSEP-1 modified scales when nosocomial sepsis is suspected in premature neonates.

MATERIAL AND METHODS: Evaluation of the diagnostic test in premature neonates with data suggestive of sepsis. The gold standard was the hemoculture and the following diagnostic tests: nosocomial sepsis neonate prediction (NOSEP-1), with the following five items, including C-reactive protein (CRP); neutrophils; platelets; evaluation of the 24-h parenteral nutrition test, and fever, while NOSEP-1 modified substitutes fever with thermal stability and days on parenteral nutrition are reduced from 14 to 3 days. Precision, sensitivity, specificity, and positive and negative predictive values were calculated. The Fagan nomogram determined diagnostic usefulness. We employed the SSPS ver. 20 statistical software Packaged and statistical significance of p < 0.05.

RESULTS: We studied 77 premature neonates, with application of the gold standard and the diagnostic test. There were 36 (47%) positive hemocultures. NOSEP-1, > 9 in sepsis 24 (67%), without sepsis 15 (36%) (p = 0.012). NOSEP-1 modified, > 9 in sepsis 35 (97%), without sepsis 35 (88%) (p = 0.113). NOSEP-1: sensitivity, 66%; specificity, 63%; positive pressure volume (PPV), 61%; negative pressure volume (NPV), 68%; positive pressure rate (RPP), 1.82, and negative pressure rate (RPN), 1.14. NOSEP-1 modified scale: sensitivity 97%; specificity 14%; positive pressure value (PPV), 50%; negative pressure value (NPV), 85%; positive probability ratio (PPR), 0.53, and negative probability ratio (NPR), 0.19. Diagnostic usefulness: NOSEP-1, 64%, and NOSEP-1 Modified, 53%.

CONCLUSIONS: The NOSEP-1 and the modified NOSEP-1 scales have limited usefulness for diagnosing nosocomial sepsis in premature neonates.