[Aspects of calculated and controlled antibiotic therapy].

Strategies for selection of antimicrobial agents may include estimation of the most appropriate agent (empirical therapy), or planned escalation or de-escalation therapy. Severe and life-threatening infections such as peritonitis have a particularly poor prognosis if the initial therapy fails. Hence, in these cases a de-escalation therapy employing broad spectrum agents with proven high efficacy should be employed, and selection pressure arguments and cost considerations should be immaterial. After 48 to 72 hours, this initial therapy should be reconsidered (de-escalated to less powerful agents), especially in light of the microbiological test results.