Microbial Landscape of the Neuroresuscitation and Neuroanesthesiology Department of the Ekaterinburg Clinic of Nervous Diseases and Neurosurgery

D.V. Belsky, A.A. Belkin

Clinic of Nervous diseases and Neurosurgery, Uralsky State Medical University, Municipal Clinical Hospital N 40, Ekaterinburg, Russia

 

More than 1400 patients are treated annually in the 24-bedded Department of Neuroresuscitation and Neuroanesthesiology of the Interregional Center of Microneurosurgery. They are represented by cases with postoperative syndrome (73%) and severe cerebral insufficiency of different etiology (27%), brought from non-specialized resuscitation departments of Ekaterinburg and Sverdlovskaya region. Artificial respiration is used in 120-140 cases and lasts more than 3 days. This category of patients is prone to pyo-septic complications, which are especially typical of the respiratory tract and include tracheobronchitis and ventilator-associated pneumonia. These complications increase a risk of unfavorable outcomes. There is a rather great number of reports, devoted to search for optimum ways of prophylaxis and treatment [1, 2]. However, each department has its own peculiarities of a microbial landscape, demanding an individual approach to realization of general principles.

The goal of the present study was determination of prevalent microscopic flora in patients with "open" airway, treated in the specialized 24-bedded department.

Materials and Methods. The analysis of 214 tracheobronchial cultures of 40 patients with confirmed ventilator-associated pneumonia, treated in 2001-2003, was carried out. Artificial respiration, used in all of them, was replaced by spontaneous breathing through a trachea cannula.

Vacuum aspiration of material from trachea was performed with sterile instruments. The cultures were placed into nutrient media. A number of cultures for each patient was no less than 4.

All the patients received cephalosporins of the third generation on admission to the above department. Then individual antibacterial therapy was carried out. It was based on determination of sensitivity of a specific microorganism to antibiotics. A wide spectrum of antibiotics was used: cephalosporins of the III-IV generation, carbopenems, ftorhinolons, aminoglycosides, protected penicillins. There was no cyclic rotation of the drugs.

A Microscopic Landscape of the Neuroresuscitation Department in 2001-2003

Gram-negative microoganisms

Gram-positive microorganisms

Pseudomonas aeruginosa

Enterococcus faecalis

Acinetobacter baumanii

Staphylococcus saprofiticus

Klebsiella pneumoniae

Corynebacterium spp.

Proteus mirabilis

Staphylococcus epidermitis

Citrobacter freundii

 

Escherichia coli

 

Klebsiella oxytoca

 

Serratia marcescens

 

Pseudomonas fluorescens

 

Results. A microbial landscape was characterized by a great variety (Table 1). The growth was as follows: Pseudomonas aeruginosa -127 cultures (59%), Klebsiella pneumoniae - 53 cultures (25%), Acinetobacter baumanii - 14 cultures (7%), other microorganisms - 20 cultures (9%). Fungi of a Candida type were detected in 36% of cases within 5-14 days after the beginning of antibiotic therapy.

Thus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumanii were the main microorganisms in microscopic flora of the department in 2001-2003.

The microflora analysis showed increased resistance of Pseudomonas aeruginosa to cephalosporins of the III generation (cephoperazon and cephtazidim). There was periodic susceptibility to ciprophloxacin and amicacin. One could watch periodic resistance to a carbopenem group. Acinetobacter baumanii, Klebsiella pneumoniae preserved their susceptibility to ciprophoxacin, amicacin and carbopenems.

Considering a microbial landscape of every patient, watched from admission up to the moment of transfer to the neurosurgical department or death, we failed to find out any regularity in it.

Conclusions

  1. Despite a variety of identified microorganisms, conditioned by a rather large number of patients from other departments of resuscitation and anesthesiology, a microbial landscape of our department, specializing in treatment of cerebral insufficiency, was characterized by stable presence of such Gram-negative microorganisms, as Pseudomonas aeruginosa, Acinetobacter baumanii and Klebsiella pneumoniae.
  2. Use of cephalosporins for initial treatment during 3 years led to resistance of main microorganisms. It was the grounds for changing a protocol of antibiotic therapy. Further investigations will reveal an optimum version of rotation, which can differ from that, described in literature, to a considerable extent [1, 2].

References

  1. Woske HJ, Roding T, Schulz I, Lode H. Ventilator-associated pneumonia in a surgical intensive care unit: epidemiology, etiology and comparison of three bronchoscopic methods for microbiological specimen sampling. Crit Care. 2001;5(3):167-73. Epub 2001 Apr 27.
  2. Gruson D, Hilbert G, Vargas F, Valentino R, Bui N, Pereyre S, Bebear C Strategy of antibiotic rotation: long-term effect on incidence and susceptibilities of Gram-negative bacilli responsible for ventilator-associated pneumonia. Crit Care Med. 2003 Jul;31(7):1908-14.