INCIDENCE, PRESENTING FEATURES RISK-FACTORS AND SIGNIFICANCE OF LATE-ONSET SEPTICEMIA IN VERY-LOW-BIRTH-WEIGHT INFANTS

Background. Septicemia is a major antecedent of morbidity and mortalit y in very low birth weight (501- to 1500-g) infants. Our purpose was t o determine prospectively the incidence, clinical presentation, labora tory features, risk factors, morbidity and mortality associated with l ate onset septicemia in infants 501 to 1500 g. Methods. Clinical data were prospectively collected for 2416 infants enrolled in a multicente r trial to determine the efficacy of intravenous immunoglobulin in pre venting nosocomial infections. Septicemia was confirmed by positive bl ood culture in 395 symptomatic infants. Multivariate analyses of facto rs associated with septicemia were performed. Results. Sixteen percent of VLBW infants developed septicemia at a median age of 17 days. Fact ors associated with septicemia by logistic regression included male ge nder, lower gestational age and birth weight and decreased baseline se rum IgG concentrations. Increasing apnea (55%), feeding intolerance, a bdominal distension or guaiac-positive stools (43%), increased respira tory support (29%), lethargy and hypotonia (23%) were the dominant pre senting features of septicemia. An abnormal white blood cell count (46 %), unexplained metabolic acidosis (11%) and hyperglycemia (10%) were the most common laboratory indicators. Septicemic infants, compared wi th nonsepticemic infants, had significantly increased mortality (21% v s. 9%), longer hospital stay (98 us. 58 days) and more serious morbidi ty, including severe intraventricular hemorrhage, bronchopulmonary dys plasia and increased ventilator days (P < 0.001). Conclusions. Late on set septicemia is common in very low birth weight infants, and the rat e is inversely proportional to gestational age and birth weight. Septi cemia is more common in males and those with low initial serum IgG val ues. A set of clinical signs (apnea, bradycardia, etc.) and laboratory values (leukocytosis, immature white blood cells and neutropenia) inc rease the probability of late onset sepsis, but they have poor positiv e predictive value.