Case Control Study for Hospital Infections Caused by Gram-Negative Bacilli in Emergency Intensive Care Unit

Almost all hospitals face the problem of the hospital infections. To find out the risk factors and preventive methods of hospital infections in Emergency Intensive Care Unit (EICU), it has became the important method to understand the incidence and affecting factor of hospital infections and provide the basis for the preventing. Many investigations were conducted at home and abroad, but the domestic method described to study before accurately could not measure the strength of contraction between the factors with the hospital infections. For this purpose, adopted method of retrospective case-control study to be conducted. This study was designed to determine the patient risk factors that would prove useful in designing strategies to limit the spread of gram-negative bacilli. Reduction or elimination of these risk factors should extend the usefulness of antibiotic.


Introduction
Almost all hospitals face the problem of the hospital infections. To find out the risk factors and preventive methods of hospital infections in Emergency Intensive Care Unit (EICU), it has became the important method to understand the incidence and affecting factor of hospital infections and provide the basis for the preventing. Many investigations were conducted at home and abroad, but the domestic method described to study before accurately could not measure the strength of contraction between the factors with the hospital infections. For this purpose, adopted method of retrospective case-control study to be conducted. This study was designed to determine the patient risk factors that would prove useful in designing strategies to limit the spread of gram-negative bacilli. Reduction or elimination of these risk factors should extend the usefulness of antibiotic.

Diagnosis standard
According to hospital infections with the diagnosis standard established by National Ministry of Health, China (Tables 1-3).
Multivariable logistic regression analysis of risk factors for hospital infections: Mechanical ventilation, Corticoid use, length of stay, Coma are the independent risk factors for hospital infections caused by gram-negative bacilli ( Table 4).

Discussion
Recent years have witnessed, Length of stay which the patients had the hospital infections was prolonged, were independently associated with hospital infections [1,2].
The research shows that length of stay of the case was much longer than the control, and length of stay in ICU of the case increase in significantly with literature. The researchers reported that length of stay for a long time is risk factor of the hospital infections infection. Some investigation showed the number of length of stay were prolonged more than one double [1,3]. The lengths of stay are the risk factor for the when the lengths of stay was greater than 31 days. An explanation of those associations might be the fact that the hospital is an ecological niche, where the use of antimicrobial agents tends to create a selective pressure that promotes the emergence of resistant organisms and predisposes to colonization with such organisms [4].
There are many kinds of immunity mechanism in human beings, for example, anatomy barriers, Cough reflect, macrophage and leukocytemediated cellular immunity and humeral immunity [5]. Mechanical ventilation destroys anatomy barriers of body. It gave the chance, let the pathogenic bacteria invade body, and led to get hospital infection associated with fewer serious complications and shorter stays in the intensive care unit. The use of NIV instead of mechanical ventilation is associated with a lower risk of hospital infections, less antibiotic use, shorter length of ICU stay, and lower mortality [7,8].
factors of hospital infections caused by gram-negative bacilli are: Mechanical ventilation, Corticoid use, Length of stay and Coma.