DIFFERING OUTCOMES OF GRAM-POSITIVE AND GRAM-NEGATIVE PERITONITIS

Peritonitis remains the leading cause of patient dropout from continuo us peritoneal dialysis (CPD) therapy. Few studies have compared patien t morbidity, mortality, and outcome for patients undergoing CPD who de velop gram-positive and gram-negative peritonitis. We retrospectively reviewed the charts of patients who developed either gram-positive or gram-negative peritonitis between January 1, 1993, and December 31, 19 95. Three hundred seventy-five patients who developed 415 episodes of gram-positive and gram-negative peritonitis were maintained on CPD the rapy during this time period. There was no difference in age, race, an d sex between patients who developed gram-positive or gram-negative pe ritonitis. More patients with diabetes developed gram-negative periton itis than gram-positive peritonitis (53% v 40%, respectively; P < 0.05 ). Coagulase-negative staphylococcal species accounted for 47% of all gram-positive episodes, whereas Klebsiella organisms, Escherichia coil , and Enterobacter organisms accounted for 63% of all gram-negative ep isodes. Significantly more patients who developed gram-positive perito nitis continued CPD therapy 2 weeks and 6 months after the onset of pe ritonitis than patients who developed gram-negative peritonitis (97% v 73%; P < 0.05 at 2 weeks and 81% v 58% at 6 months; P < 0.05, respect ively). Nine percent of the patients who developed gram-positive perit onitis died within 6 months after the onset of peritonitis, whereas 21 % of the patients who developed gram-negative peritonitis died (P < 0. 05). Patients who developed gram-negative peritonitis were significant ly more likely to require hospitalization than patients who developed gram-positive peritonitis (74% v 24%; P < 0.001). More patients with g ram-negative peritonitis required peritoneal catheter removal than pat ients with gram-positive peritonitis (18% v 4%; P < 0.001), Thirty-two percent of the patients who developed gram-positive peritonitis re-de veloped an episode of peritonitis with the same organism compared with only 9% of the patients who developed gram-negative peritonitis. Furt hermore, peritonitis recurrence with the same organism within 6 months after the initial episode was noted in 60% of the patients with perit onitis caused by Staphylococcus aureus compared with 24% of patients w ith peritonitis caused by other gram-positive organisms (P < 0.05), We conclude that the outcomes of gram-positive and gram-negative periton itis are different. When rates of peritonitis are used to predict outc ome, it appears that gram-positive and gram-negative peritonitis rates need to be examined separately. (C) 1998 by the National Kidney Found ation, Inc.