Sepsis is a common complication in Neonatal Intensive Care Units (NICU), seen especially in low birth weight (LBW) infants. A recent study showed that fungal or gram-negative sepsis is associated with a greater degree of thrombocytopenia than is seen with gram-positive sepsis. So, this study was undertaken to examine the platelet counts and platelet indices in LBW infants during episodes of sepsis.

We analyzed 36 cases with culture-proven sepsis on chart review in LBW infants admitted to the NICU at Wonkwang University Hospital from January 2001 to June 2006.

Patients were grouped by organism type: gram-positive bacteria (1,521±309 g, 31.3±2.9 wk, 15/36), gram-negative bacteria (1,467±290 g, 30.6±3.6 wk, 17/36), and fungi (1,287±205 g, 30.0±3.9 wk, 4/36). The most common organism was Staphylococcus epidermis and the incidence of thrombocytopenia was 88.9%. When compared with infants with gram-positive sepsis, those with gram-negative sepsis had significantly higher incidences of thrombocytopenia, lower initial platelet count, lower platelet nadir, and greater mean percentage decrease in platelet count from before the onset of sepsis. Those with fungal infections were similar to gram-negative sepsis, but they were not significant because of the small number of patients. And mean platelet volume (MPV) in sepsis was increased more significantly in time of platelet nadir than before the onset of sepsis.

We conclude that decrease in platelet count was significantly greater in gram-negative sepsis than gram-positive sepsis, and also greater than fungal sepsis-which was insignificant because of the small number of patients-in LBW infants. And elevation in MPV will be helpful in the diagnosis and treatment of sepsis in LBW infants.