Septicemia in the Neonatal Intensive Care Unit Over the Past 15 Years

Abstract

We retrospectively reviewed the records of 2093 infants hospitalized in the neonatal intensive care unit (NICU) of Ota General Hospital, Health Insurance Union of Fuji Heavy Industry, for 15 years from 1981 to 1995 to determine characteristics of septicemia. Fifty cases of clinically organisms were detected in blood cultures, were evaluated for patient-gestational age, birth weight, age (days) when septicemia occurred, causative organism, and administration of prophylactic antibiotics. When cases were classified by patient birth weight, the incidence of septicemia in the group weighing at least 1500 g was 1.0% (based on the total number of infants hospitalized in the same period), while those in the groups weighing 1000 g to 1499g and <1000 g were 10.1% and 22%, respectively, indicating that the incidence of septicemia increased markedly as the birth weight was reduced. When cases were grouped by patient age (days) when septicemia occurred, the incidence in the 7-day or older group was 76%, indicating predominantly horizontal transmission of infection in this group, rather than intrauterine infection or vertical transmission, whereas it fell to 24% in the group aged younger than 7 days at onset of septicemia. This tendency was more pronounced in those of lower birth weights. A variety of causative organisms were found, and their distribution was dependent on the administration of prophylactic antibiotics. When antibiotics were given prophylactically, detection of gram-negative rods increased markedly compared with that found in the group not given prophylactic antibiotics. Many causative organisms originated from the intestinal bacterial flora. Neonates who have to be hospitalized in NICU, like extremelylow birth-weight infants, have many factors such as endotracheal intubation, tube feeding, and administration of antibiotics, which inhibit the formation of normal intestinal bacterial flora, thus many of them possess extremely abnormal intestinal bacterial flora. This may contribute to the development of septicemia.