[Etiology of ventilator-associated pneumonia at the Cardiovascular Surgery Clinic of Iaşi].

AIM: We want to assess the etiology of ventilator-associated pneumonia (VAP) and emergence of resistant phenotypes for greater efficiency of the first-line antimicrobial treatment post-cardiac surgery. The study focuses on patients with VAP post-cardiac surgery at the Institute of Cardiovascular Surgery between April 2nd 2002 and August 27th 2008, divided in two groups, before and after June 14th, 2005.

MATERIAL AND

METHODS

The tracheal aspirates were examined quantitatively (microscopy, culture). The isolates with clinical significance (> or = 106 CFU/mL) were identified by standard methods and tested by disk difussion or with the breakpoints method for susceptibility to antibiotics.

RESULTS

Among the 1527 operated patients, 28 of them were diagnosed with VAP through the clinical pulmonary infection score > or = 6. The 9 most common pathogens in VAP etiology were Pseudomonas aeruginosa 23.81%, Acinetobacter baumannii 19.05%, Stenotrophomonas maltophilia 11.91%, Candida albicans 9.53%, while Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Corynebacterium striatum/amycolatum, Pneumocystis jirovecii amounted 4.76% each. Acinetobacter baumannii and S.maltophilia appear starting with June 15th, 2005. From that moment on we isolated with a higher frequency the gram-negative bacilli which produce extended-spectrum beta-lactamases 15.62%, with multidrug resistance (MDR) 46.86%. The MDR phenotype was more frequent at A.baumannii (15.62%), S. maltophilia (15.62%) and P. aeruginosa (12.50%) compared to K .pneumoniae (3.12%) or E. coli (0%). Methicillin-resistant S. aureus was isolated with a 6.25% frequency.

CONCLUSIONS

The most common etiologic agents of ventilator-associated pneumonia post-cardiac surgery are Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia and Candida albicans. The large use of antibiotics selects infectious agents with intrinsic resistance and multiresistant