[Antibiotic treatment in acute peritonitis].

The selection depends on several factors and in particular: -the means of transport by which the antibiotic reaches the peritoneum : the aminosides and the betalactamines attain the peritoneum easily while the polymyxins do not; -the causative agent: most often it is a gram negative aerobic or anaerobic bacteria. The entero-bacteria predominate but in the last few years Bacteroides fragilis has been frequently encountered giving rise to numerous studies. The flora is most often polymicrobic. The betalactamines act on gram positive bacteria whether they are aerobic or anaerobic. The aminosides are active against aerobic gram negative bacteria. The same can be said for Colimycine (except for certain Proteus and Providencia). All these antibiotics (other than carbenicillin) are not effective against Bacteroides fragilis which are however very sensitive to lincomycine, to the cyclines and in particular to doxycycline and to the derivatives of imidazole. The laboratory is an important aid in judging therapeutic effectiveness by determining the bacteriacidal strength of the serum and even the serum level of the antibiotic whatever the cause it is imperative: to avoid toxicity and to pay particular attention to the frequent problem of renal insufficiency in these subjects.