This monograph summarizes the data of the prospective study on the immunological characteristics of cancer patients with sepsis and septic shock developed after surgery. Patients without signs of infectious complications and symptoms of organ failure, as well as a group of healthy donors, were considered as references. The comparative analysis of blood parameters that characterized humoural and cell immunity (concentrations of cytokines and their receptors, immunoglobulins, lipopolysaccharide and other active biomolecules) has been performed. An estimation of diagnostic and prognostic significances of these parameters has been performed as well. In the final chapters, the properties of the new perspective hypercrosslinked polymeric hemosorbents are presented. The monograph could be interesting for a wide array of specialists in the fields of resuscitation, healthcare therapy, oncology and surgery, as well as for researchers aimed toward the development of new types of biocompatible materials.