[Nosocomial infection in newborn infants on mechanical ventilation]

During a two-year period (1988-1989), were studied newborns treated with intermittent mandatory ventilation (IMV). The goal was to know incidence of infections in these patients and characteristics of these process. Of 187, 40 (21.3%) were infected. For these neonates the mean gestational age was 33 +/- 3 weeks and average for birth weight was 1755 +/- 644 g. In 32 the infecting agent was isolated, being the most common coagulase negative Staphylococcus, it was found in 18 (45%), Klebsiella sp in 7 (17%), Escherichia coli in 1 and Candida albicans in 1. In the remaining 8 (20%) with negative cultures, postmortem confirmation was made in 5 and in 3 by clinical, radiologic or hematologic evidence. Of the 17 positive blood cultures and 3 spinal fluid culture, the same bacteria grew as in the bronchial aspirate. Were found, thrombocytopenia in 22 (55%) and leucocytosis in 19 (47%) as the most common blood changes. Pneumonia was the most common form of infection; it was found in 30 (75%); 22 of 40 died (55%). We concluded that 21.3% of neonates under IMV without infections, may get infected later in the hospital. S. epidermidis is the etiologic agent that predominates through the whole year, except during epidemics caused by others agents.