Randomization will be conducted using generator of random numbers. This sequence will be incorporated in simple digital patient database internet access to which will be password protected. One educated ICU nurse will enter only basic patients´ data and system itself will determine whether to prepare placebo or diluted antibiotic. Since that moment this information will be confidential and software will be accessible only for entering other monitored parameters. Dividing into individual groups will be conducted in interim controls after six months intervals and final division after completion of study. Totally there will be 2 major groups and 6 subgroups and those 3 subgroups according to individual diagnosis each one with 1 control group. If severe complication (allergy reaction) occurs, the principle investigator can uncover the blinding using specific password; system entry will automatically mean exclusion of the patient from study.