| Objective:Ventilator is the strong instrument when with the patients need respiratory support. When the breathing machine in ICU is widely used, ventilator-associated pneumonia is increasing. Ventilator-associated pneumonia is the infection of lung parenchyma of the patients receiving mechanical ventilation after 48h, the major complication of patients with mechanical ventilation, is one of the most common ICU infections. That will make mechanical ventilation longer, can cause disease with recurrent.VAP is a common nosocomial infection in ICU in the hospital, the main reason that nosocomial infection is increased mortality, hospitalization and treatment costs is higher, so seriously affect the prognosis of patients with mechanical ventilation. VAP pathogens present are mainly in many Gram negative bacilli (generally 80%), Gram Yang cocci accounted for 10%-15%, fungal infection may account for 5%-10%. The former three of the Bacterial infections are Pseudomonas aeruginosa (26.8%), Acinetobacter (18.8%) and Klebsiella (14.1%).Many studies show that the irrational use of antimicrobial easily lead to flora imbalance, changes normal microbial parasites in patients, and makes ventilator patients in critical condition, makes immune function decreased or inhibited, can not effectively eliminate pathogens, so that increases the chance of VAP, changes bacterial resistance. Therefore, the mechanism of the occurrence of VAP and preventive measures for clinical applications can improve the level of mechanical ventilation, improve the successful rate of patients with critically ill and reduce mortality and health care costs, those have important practical significance. This study was designed to study distribution of VAP pathogens and drug resistance, provided reference for the use of antimicrobial drugs for clinical treatment of VAP.Materials and methods1,General Information:From July 2005 to July 2009, in ICU of the First Affiliated Hospital of China Medical University, the patients needed mechanical ventilation 2685 cases, of which there were 697 cases of VAP occurred, the rate was 25.96%. VAP patients:404 cases of male,293 cases of female; average age is 64.24±14.095 years.2,The diagnostic criteria and exclusion criteria of VAP:Mechanical ventilation for more than 48h; X-ray showed new or persistent or progressive shadow; it has three or three more of the following indicators:①body temperature> 38.0℃or<35.5℃;②white blood cells> 10×109/L and (or) a left shift or<3×109;③tracheal aspirate Gram stain each high magnification> 10 white blood cells;④tracheal secretion culture is positive.Case exclusion criteria:①mechanical ventilation≤24h persons;②mechanical ventilation before the diagnosis of pneumonia,;③died within 72h of mechanical ventilation or automatically discharged from hospital;④for oropharynx and trachea, trauma or surgery patients and the use of breathing apparatus before has been used in patients with endotracheal intubation3-. Specimen collection:Patients with mechanical ventilation 48 hours after the use of disposable sterile dental cleaning suction tube or bronchoscope pollution prevention brush, draw the lower respiratory tract secretions, immediately placed in sealed sterile containers for inspection. And every 24-48h collected the specimens were cultured, bacteria identification and susceptibility testing until patients stop using the breathing machine. 4,Bacterial identification and susceptibility testing:According to the U.S. Committee for Clinical Laboratory Standards (NCCLS) guidelines, using agar dilution method, bacterial culture cultured for 2 times, the same strain was identified as the pathogen. All strains use the French bio-Mei Aili company VITEK automatic analyzer for microbial identification of bacteria. Bacterial culture medium is recommended by WHO MH agar. Susceptibility test used KB method and the results are judged according to NCCLS (1999 edition) standard.5,tatistical analysis:Enter the data into the computer, use SPSS16.0 software for statistical analysis, x2 test was used to compare rates, statistical significance level requirement for the a=0.05.Results:1,From 2005 to 2009, the First Affiliated Hospital of China Medical University, the situation of the patients with VAP in ICU:During the five years, in ICU of the First Affiliated Hospital of China Medical University, the number of VAP in mechanical ventilation cases and incidence rate of VAP increased year by year. Pathogen test results showed that about 50%of patients with VAP are a variety of mixed infection of bacteria.2%The changes and distribution of characteristics in VAP pathogens:2.1,The distribution characteristics in VAP pathogensFrom 2005 to 2009,152,184,306,336 and 411 respectively are isolated. Gram-negative bacteria is the first VAP pathogens in the 5 years, constitute more than 70%. Overall, in second place is the gram-positive cocci, the third is a fungus. The ratio of fungi constitutes 16.1%higher than the gram-positive cocci of 12.2%only in the last year, rising to the second VAP pathogens in 2009.2.2,The changes of VAP pathogen speciesPseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Klebsiella pneumoniae, Burkholderia cepacia, Stenotrophomonas maltophilia, and colon coli bacteria are the mainly in VAP pathogens. Staphylococcus aureus is the most important Gram-positive cocci in VAP, the top of the non-gram-negative bacteria. The row of gram-negative bacilli has little changes in 5 years; changes only have only the ranking order between them. Pseudomonas aeruginosa constitutes almost 20%in 5 years, is the most important pathogens in VAP. The proportion in Acinetobacter baumannii has upward trend in 5 years, has jumped to the first (32.8%) in 2009, is the most obvious trend in the VAP pathogens. The proportion of fungi is relatively stable until 2009 (8.5%), suddenly increases to 16.1%in 2009, more than Gram-positive cocci.3,The resistance of VAP pathogen species3.1,Gram-negative bacteria to the era of major changes in rates of antibiotic resistance3.1.1 Pseudomonas aeruginosa has very high resistance to various antibiotics in general from 2005 to 2009, has lower resistance to imipenem and meropenem.3.1.2 Acinetobacter baumannii has higher resistance to antibiotics in five years, and the resistance rate was shown as a rising trend. In contrast, it has lower resistance to cefoperazone/sulbactam.3.1.3 Klebsiella pneumoniae 5 years, the rate of resistance to various antibiotics is lower than Pseudomonas aeruginosa and Acinetobacter baumannii in general, the rate of resistance to meropenem and imipenem is very low.3.1.4 For Burkholderia cepacia, the rate of resistance to most antibiotics is not high, only the rate of resistance to amikacin and imipenem is relatively high.3.1.5 For Stenotrophomonas maltophilia, the rate of resistance to various antibiotic resistance rates is very high in 5 years, but it has a very high sensitivity to levofloxacin and cotrimoxazole.3.1.6 E. coli has highly sensitive to the hydrocarbon vinyl drugs (imipenem and meropenem) in 5 years, while it has shown a very high resistance to most other antibiotics.3.2,The major changes in the era of antibiotic resistance rates on Gram-positive bacteriaSusceptibility test results show that Staphylococcus aureus has very high resistance to many antibiotics, is higher than MRSA. Staphylococcus aureus demonstrated a high degree of sensitivity to teicoplanin and vancomycin. 3.3,The major changes in the era of antibiotic resistance rates on fungiCandida albicans and Candida tropicalis are higher on the appropriate antibiotics, Candida tropicalis is sensitive due to small sample size.Conclusion:From 2005 to 2009, in ICU of the First Affiliated Hospital of China Medical University, the incidence of VAP increased year by year, about 50% of the VAP patients has a variety of bacteria belonging to the mixed infection. Gram-negative bacilli is the first VAP pathogens in the 5 years. Overall, the gram-positive cocci is the second place, the third is a fungus. However, the constituent ratio of fungi is higher in 2009, Gram-positive cocci raised to the second VAP pathogens. Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Klebsiella pneumoniae, Burkholderia cepacia, Stenotrophomonas maltophilia, and colon coli bacteria are mainly VAP pathogens.Susceptibility test results showed that Pseudomonas aeruginosa and Acinetobacter baumannii have higher resistance to various antibiotics in general in five years. The resistance of Klebsiella pneumoniae to various antibiotics is lower than the previous two. Staphylococcus aureus have very high resistance to many antibiotics, but MRSA has higher resistance to antibiotics in general. Staphylococcus aureus demonstrated a high degree of sensitivity to teicoplanin and vancomycin. Fungi are higher on the appropriate antibiotics...
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