Sepsis is one of the main causes of mortality and morbidity in an ICU setting, while the responsible microorganisms most frequently isolated are multidrug-resistant gram-negative bacteria. Aminoglycoseides (AG) seem to be particularly effective in dealing with these microbes, however their potential toxicity, especially nephrotoxicity, often makes them an unsuitable treatment option. This becomes particularly evident in patients with already impaired renal function, a common occurrence in septic patients requiring ICU treatment. AG are bacteriocidal antibiotics the efficiency of which depends on the maximum concentration in patients' serum (Cpeak). Pathophysiological changes in critically ill patients, result in significant distribution of the drug extravascullary resulting in a decreased concentration of the biologically active component. On the other hand, impaired renal clearance results in high serum drug levels (C trough) making the desired once-daily administration not always achieved. The purpose of this study is to test the hypothesis of successful clearance of AG after achieving satisfactory serum levels and therefore their maximum effect minimizing potential toxicity, by using continuous veno-venous haemodiafiltration in patients with sepsis or septic shock and impaired renal function. This way, the aforementioned antibiotics could become a more frequent and potentially earlier choice for physicians in the treatment of sepsis and septic shock patients from multidrug-resistant microbes.