Gram-negative bacteria as causative agents of ventilator-associated pneumonia and their respective resistance mechanisms.

Ventilator-associated pneumonia (VAP) is a serious and common complication in patients admitted to intensive care unit (ICU) and contributes to mortality. Multidrug Gram-negative bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae are frequently associated with VAP in ICU. A prospective study was set up in three ICUs of the University Hospital Center Zagreb and one ICU in General Hospital Pula from September 2017 to March 2018. Antibiotic susceptibility was determined by broth microdilution method. Production of extended-spectrum ß-lactamases (ESBLs) was determined by double-disk synergy test and carbapenemases by Hodge and carbapenem inactivation method (CIM). The genes encoding ESBLs, carbapenemases of class A, B and D and qnr genes were determined by PCR. In total 97 Gram-negative bacteria isolates were analyzed. P. aeruginosa demonstrated high resistance rates for imipenem and meropenem with 74% and 68% of resistant strains, respectively. Moderate resistance rates were observed for ceftazidime andpiperacillin/tazobactam, ciprofloxacin and gentamicin (44%). All except three A. baumannii isolates, were resistant to carbapenems and to all other antibiotics apart from colistin and amikacin. Eight A. baumannii isolates were positive for blaOXA-23 and 12 for blaOXA-24 genes. Four K. pneumoniae and two E. cloacae strains were ESBL positive and harboured group 1 of CTX-M ß-lactamases. Three P. mirabilis strains were positive for plasmid-mediated ampC ß-lactamase of CMY family. Two carbapenem-resistant K. pneumoniae harboured OXA-48 and one carbapenem-resistant E. cloacae VIM-1. A high proportion of multidrug-resistant P. aeruginosa, K. pneumoniae and extensively resistant A. baumannii was reported. Acquired resistance mechanisms, mainly production of carbapenemases and ESBLs were dominant in A. baumannii and K. pneumoniae, respectively. Resistance of P. aeruginosa isolates was more likely due to upregulation of efflux pumps or porin loss. A marked diversity of ß-lactamases was identified in Enterobacteriaceae.

Anaphylaxis during pregnancy.

Anaphylaxis occuring during pregnancy has a potential to cause devastating damage to the unborn baby and the mother. However, majority of adverse outcomes of anaphylaxis during pregnancy frequently affect the neonates rather than the mothers. The negative neurologic outcomes of the fetus are mostly due to delayed caesarean delivery or inadequate doses of adrenaline during anaphylaxis. Most of the current knowledge on this clinical scenario is based on case reports and very few review articles. This is a mini review of the causes, diagnosis and management of anaphylaxis occuring during pregnancy.

Possible transfusion-related acute lung injury (TRALI) in cardiac surgery patients.

AIM: To determine the incidence of possible transfusion-related acute lung injury (TRALI) and related risk factors in cardiac surgery patients. METHODS: A single-center prospective cohort study was conducted from January 2009 to March 2010 at the Zagreb University Hospital Center, Croatia. Patient-, transfusion-, and surgery-related data were collected. The study included 262 patients who were observed for respiratory worsening including measurements of arterial oxygen saturation (SaO2), fraction of inspired oxygen (FiO2), and partial pressure of arterial oxygen (PaO2). Possible TRALI was defined according to the Toronto Consensus Conference definition broadened for 24-hour post-transfusion. This cohort was divided in two groups. TRALI group included 32 participants with diagnosis of TRALI and the control group included 220 patients with or without respiratory worsening, but with no signs of ALI. RESULTS: Possible TRALI was observed in 32 (12.2%) patients. Compared with the control group, possible TRALI patients had higher American Association of Anesthesiology scores, higher rate of respiratory comorbidity (43.8% vs 15.5%), and required more red blood cells (median 4, range [2.5-6] vs 2 [1-3]), plasma (5 [0-6] vs 0 [0-2]), and platelet units (0 [0-8] vs 0 [0-0]) (P<0.001 all). Risk factors for possible TRALI were total number of transfused blood units (odds ratio [OR] 1.23; 95% confidence interval [CI] 1.10-1.37) and duration of cardiopulmonary bypass (OR 1.08; 95% CI 1.05-1.11). Post-transfusion PaO2/FiO2 ratio was significantly decreased in possible TRALI patients and significantly increased in transfused controls without acute lung injury. CONCLUSION: We observed a higher rate of possible TRALI cases than in other studies on cardiac surgery patients. Serial monitoring of PaO2/FiO2 ratio and detection of its post-transfusion worsening aids in identification of possible TRALI cases.