Comparison of Two Antibiotic Regimen (Meropenem Versus Meropenem+Moxifloxacin)in the Treatment of Severe Sepsis and Septic Shock

Inclusion Criteria: * Severe sepsis or septic shock according to ACCP/SCCM criteria * Onset of severe sepsis or septic shock \<24 h * Informed consent * Effective contraception in fertile women Exclusion Criteria: * Age \<18 years * Pregnancy * Breast-feeding women * Pretreatment with meropenem, imipenem, or ertapenem within the last 4 weeks (\>1 daily dosage) * Pretreatment with moxifloxacin,ciprofloxacin, or levofloxacin within the last 4 weeks (\>1 daily dosage) * Pretreatment with a pseudomonas effective cephalosporin (cefepime, ceftazidim, cefpirom) or piperacillin within the last 48 hours (\>1 daily dosage). * Pretreatment with other chinolones within the last 4 weeks (\>1 daily dosage) * Presence of infection where guidelines recommend another antimicrobial therapy than the study medication (i.e. endocarditis) * Evidence or strong clinical suspicion of a microorganism where the study medication is known to be ineffective (i.e. tuberculosis, MRSA- or VRE-infection) * Known allergy against meropenem or moxifloxacin * Tendon disease or injury due to past quinolone therapy * Congenital or acquired prolongation of QT-interval * Concomitant medication which prolongs the QT-interval * Electrolyte imbalance, especially uncorrected hypokalemia * Clinically relevant bradycardia * Clinically relevant cardiac dysfunction with reduced left-ventricular ejection fraction * Symptomatic arrhythmias in the medical history * Significant hepatic impairment (Child-Pugh C) or elevation of liver enzymes \>5x the upper normal range * No commitment to full patient support (i.e. DNR order) * Patient's death is considered imminent due to coexisting disease * Concomitant participation in another study or study participation with in the last 30 days. * Relationship of the patient to study team member (i.e. colleague, relative)