First exchange neutrophilia: an index of peritonitis during chronic intermittent peritoneal dialysis.

During intermittent peritoneal dialysis (IPD) early diagnosis of peritonitis may be difficult, because of paucity in clinical signs and delays in bacteriologic studies. We examined prospectively leucocyte counts and their differential composition in initial ascites and dialysis effluent of patients on IPD and correlated these findings to the presence of subsequently bacteriologically proven clinical peritonitis. Total leucocyte counts from either ascites or first exchange effluent did not differentiate infected from noninfected patients. In contrast, first exchange effluent neutrophilia (greater than 43%) proved to be an early indicator of infection, being 100% sensitive and 94% specific for peritonitis. We conclude that in such patients peritoneal effluent neutrophilia should be considered an indication of possible infection.