CONTEMPORARY RECOMMENDATIONS ON PATIENT BLOOD MANAGEMENT IN JOINT ARTHROPLASTY.

Hip and knee replacement surgery are a common and effective procedure for the relief of pain and loss of function. The number of procedures is increasing and great interest is given how to improve outcome following hip and knee replacement surgery. Last two decades have been characterized by many innovations in hip and knee replacement surgery including minimally invasive technique but also by improvements in anesthetic technique and blood management. The patients undergoing hip and knee replacement surgery are commonly elderly and have cos-existing organ dysfunctions. These procedures are characterized by great perioperative disturbances including cardiovascular complications, high incidence of thromboembolic complications, possible significant perioperative blood loss, possible bone cement effect and high level of postoperative pain. Anesthetic assessment of patients include preoperative preparations, intraoperative and postoperative care. In this article, all problems of perioperative blood management are discussed. The recent data of advantages of blood management for every patient are outlined. Blood management include preoperative preparation, use of autologous blood in perioperative period and administration of drugs for minimizing intraoperative blood loss. The final result of improvements in blood management is reducing in blood loss and need for allogeneic blood and significant reduction in perioperative morbidity.

Polyclonal spread of colistin resistant Klebsiella pneumoniae in Croatian hospitals and outpatient setting.

INTRODUCTION: Recently, a marked increase in the rate of colistin resistant Klebsiella pneumoniae was observed in Croatian hospitals and the outpatient setting. This prompted us to analyze the molecular epidemiology of these isolates and the mechanisms of spread. METHODS: In total 46 colistin-resistant K. pneumoniae isolates from five hospitals and the community were analyzed. The presence of genes encoding broad and extended-spectrum ß-lactamases, plasmid-mediated AmpC ß-lactamases and carbapenemases was determined by PCR. Plasmids were characterized by PCR based replicon typing. Isolates were genotyped by pulsed-field gel electrophoresis. Virulence traits such as hemolysins, hyperviscosity and resistance to serum bactericidal activity were determined by phenotypic methods. RESULTS: High resistance rates were observed for cefuroxime, ceftazidime, cefotaxime, ceftriaxone and ertapenem, ciprofloxacin and gentamicin. The majority of OXA-48 producing isolates were resistant to ertapenem but susceptible to imipenem and meropenem. Nine strains transferred ertapenem resistance to E. coli recipient strain. Thirty-nine strains were phenotypically positive for ESBLs and harbored group 1 of CTX-M ß-lactamases. OXA-48 was detected in 39 isolates, KPC-2 in four and NDM-1 in one isolate. The isolates belonged to six PFGE clusters. All isolates were found to be resistant to serum bactericidal activity and all except four strains positive for KPC, produced ß-hemolysins. String test indicating hypermucosity was positive in only one KPC producing organism. CONCLUSIONS: The study demonstrated the ability of K. pneumoniae to accumulate different resistance and virulence determinants. We reported dissemination of colistin resistant K. pneumoniae in five hospitals, located in different geographic regions of Croatia and in the outpatients setting. mcr genes responsible for transferable colistin resistance were not found, indicating that resistance was probably due to chromosomal mutations.

In vitro synergy and postantibiotic effect of colistin combinations with meropenem and vancomycin against Enterobacteriaceae with multiple carbapenem resistance mechanisms.

AIM: The aim of the study was to determine in vitro synergy and postantibiotic effect of colistin alone and combined with meropenem or vancomycin against Enterobacteriaceae producing multiple carbapenemases; combinations of two metallo-ß-lactamases (MBL) or MBL with OXA-48. Colistin-resistant strain positive for OXA-48 was also included in the study. METHODS: The antibiotic susceptibility was tested by broth microdilution method. Synergy was tested by chequerboard, time-kill and 2-well method. PAE was determined by viable counting. RESULTS: The chequerboard analysis revealed synergy for colistin combination with meropenem in all isolates with FICI values ranging from 0.12 to 0.24. FICI values for combinations with vancomycin were below 0.5 indicating synergy in two out of four isolates. K. pneumoniae 609815 positive for OXA-48 and colistin resistant showed the most pronounced and consistent synergy effect with meropenem in both chequerboard and time-kill method. Synergy effect in time-kill curves, was observed for K pneumoniae 145846 with two MBLs and colistin resistant K. pneumoniae 609815 positive for OXA-48, with both combinations including meropenem and vancomycin. Colistin alone exhibited short postantibiotic effect (PAE) against all tested isolates. Meropenem markedly prolonged the PAE in two isolates in contrast to vancomycin which did not demonstrate significant effect on the duration of PAE. CONCLUSIONS: The synergy effect and the duration of PAE was strain and antibiotic dependent but not related to the resistance gene content.