[Diffusion of ceftriaxone in healthy and infected peritoneal tissue]

The authors studied the peritoneal diffusion of ceftriaxone in the four quadrants of the abdomen (right and left inguinal and right and left hypochondrium) in 50 adult patients divided into 4 groups: pre-operative IVD administration of ceftriaxone in patients with healthy peritoneum, 1 g (group I), 2 g (group II): pre-operative IVD administration of ceftriaxone in patients presenting peritonitis 1 g (group III), 2 g (group IV). After laparotomy, a fragment of peritoneal membrane was resected from each of the four quadrants, the product was extracted from the peritoneum by a crushing technique and the assayed by HPLC with concomitant blood level assay. The mean assayed concentrations in situ are respectively in groups I to IV: 27.2, 31.2, 31.36 and 43.65 micrograms/g, with a rapid time of appearance (30 minutes) and a homogeneous topographic distribution for all peritoneal sample sites. In cases of peritonitis, the concentrations are higher by a factor of 1.15 and 1.39 for the dosages of 1 and 2 g as compared to healthy peritoneum. Beyond the third hour after injection, peritoneal concentrations remained high at 9.8 micrograms/g in patients having received 1 g of ceftriaxone and very high at 22.6 micrograms/g in patients having received 2 g. These levels are therefore effective whatever the posology in antibioprophylaxis, taking into account the MIC of the product on Gram- bacilli.