Sepse neonatal em unidade de terapia intensiva : características clínico epidemiológicas, etiologia e fatores de risco

Abstract

OBJECTIVE: Neonatal sepsis is currently the most frequent infection and an important cause of death among the newborns admitted at NICU. In order to evaluate the extension of this problem in a tertiary care University Hospital of Northeastern Brazil, a retrospective cohort survey was carried out on all inborn and admitted infants at the Assis Chateaubriand NICU from October 1997 to April 1998. METHOD: the survey design was a retrospective cohort carried out on all inborn infants admitted at the Neonatal Intensive Care Unit during seven consecutive months; 422 newborns were enrolled in the study and each one was followed up from birth to discharge from NCIU or death at the NICU. To compare the levels of the risk factors, two groups were formed: one by the all subjects who developed the outcome and another by all those who did not to. Each member of the cohort was investigated for 34 potential predictors variables concerning mothers factors, neonates factors and hospital procedures. In case of presence of sepsis, the variables were measured just up to the outcome. Standard National Nosocomial Infection Surveillance (NNIS-CDC) definitions of sepsis were used. Chi Square and Fischer’s exact tests were applied for comparison of frequencies; relative risk (RR) with their respective confidence interval of 95% (CI95%) was calculated. Subsequently, a multivariate analysis was done using logistic regression of most significant factors (OR). The level of statistical significance considered was p=0,05. RESULTS: The cohort sepsis incidence was 40,4 for each hundred of newborn admitted at NICU. The bacterias more prevalent of the confirmed cases were the gram-negative bacilli. Most sepsis episodes appeared in the first six days of life (67%). The time of NICU hospitalization of the sick newborn was 4,3 times longer compared to that non-sick newborn. Five factors were selected as independent predictors for neonatal sepsis: central venous catheter (OR=8,7, CI95%=2,31 to 32,69, p=0,001), birth weight of 1000-1499g (OR=4,8, CI95%=2,39 to 9,97, p=0,000), blood transfusions (OR=3,6, CI95%=1,81 to 7,45, p=0,003), singular gestation (OR=2,3, CI95%=1,04 to 5,44, p=0,04) and birth weight of 1500<2500g (OR=2,3, CI95%=1,34 to 4,04, p=0,002). Global mortality reached 25,59% of the cohort. Mortality associated to sepsis was 41,31% with Relative Risk for death = 2,8. CONCLUSION: neonatal sepsis incidence and mortality rates found are higher than in developed countries rates. Birth weight under 2500g, singular gestation, central venous catheter and blood transfusions proved be independent predictors related to neonatal sepsis. This study may contribute for the future strategies for reduction of neonatal sepsis rates and its sequels in our hospital.