In this work, we found that whether in univariate or multivariate analysis, the final results were consistent and stable, that was, UEAT did not increase the 30-day mortality rate, while it increased length of hospital stay. Above data showed that UEAT prolonged the length of stay for about 2.5 days, the antibiotic regimens used in this study almost were combined therapy. This result only concerned patients with CRGNB-infected hospital-acquired pneumonia, and the main bacteria were Acinetobacter baumannii (68%). The same results had been found in previous studies[13-15]. However, in other studies, we found that there were disagreement with our conclusion that UEAT could increase 30-day mortality rate[16-20]. This may be due to the high drug resistance rate of CRGNB which lead to serious illness and high mortality rate for CRGNB-infected pneumonia. This high mortality rate may real the role of REAT. But it does not mean that REAT has no effect on 30-day mortality. It may be that REAT can reduce 30-day mortality and hospitalization time of inpatients with mild and moderate diseases but has no obvious effect on severe patients[21]. Besides, in the study of Michek ST[22], it was found that UEAT did not increase mortality in patients with early-onset infection, but increased mortality in patients with late-onset infection. Therefore, there was no difference between UEAT and REAT in 30-day mortality in this article. In addition, other possible reasons for this result may lie in the differences of research type, age distribution, region, bacterial distribution, research object, sample size, variable control and so on.
In tne analysis of hospital stay, pulmonary disease, hemodynamic support at culture taken day and recent surgery are risk factors for hospital stay, which suggests that inpatients with pulmonary disease, hemodynamic support at culture taken day and recent surgery will stay longer. UEAT could extend hospitalization samely. Therefore, clinicians should pay more attention to REAT to reduce the length of stay of patients. Moveover, the results of catheter insertion analysis show that whether catheter, venous catheter, arterial catheter, ventilator or nasal catheter is not a risk factor for hospital stay. which is also different from other literature[23]. The possible reason for this result is that the patient's serious condition does not reflect the influence of mechanical ventilation.
For the analysis of mortality, dementia, unconsciousness are risk factors for 30-day mortality, Clinicians can assess patients' survival status based on this result and thus provide corresponding survival support. In the analysis of REAT by time, we did not find any difference in mortality rate at different time in the early stage. However, literature reports that the evaluation of 72-hour empirical therapy was significantly correlated with the improvement of treatment rate, duration of antibiotic treatment and shortening of hospitalization time[23,24]. The possible reason is that the number of our cases is too small to reflect the real results.
The advantages of our experiment are as follows: firstly, we analyzed a number of variables that may have impact on 30-day mortality and hospital stay, including patient demographic statistics, basic diseases, test results, infection and so on. Secondly, we controlled other variables and analyzed the influence of duration of hospitalization on 30-day mortality by multivariable regression analysis. Finally, we classified experiential therapy according to time and analyzed the experimental data in many directions , which give direct and convenient results.
The experimental shortcomings including the experimental data are limited to the situation of hospital-acquired bacterial pneumonia in one hospital in recent years, there is no comprehensive evaluation of hospitals in different regions. Moreover, the experiment is limited to the hospital-acquired bacterial pneumonia by CRGNB. The situation of community-acquired pneumonia, bloodstream infection and other infections are not clear. In the selection of variables, only some of variables are selected. As we all know, in clinical death cases, any step and environment of patient's life can affect patient's survival, including economic status, medical environment, nursing situation, patient's psychological status and any other aspects. In the research of REAT according to time classification, our total data are less, which may not reflect the real situation, so further research is needed. And the results only assessed the impact of EAT on 30-day mortality and length of stay. Obviously, the causes of death of patients are not only infection and empirical therapy can explain. In addition, there are literature focusing on the classification of therapeutic drugs of empirical antibiotics, including the effects of antibiotics alone and combinedly, which are not reflected in our experiments. The average age of the cases in the experiment was about 60 years old, which was limited to the comparison of the cases in the higher age group. According to chart 2, Acinetobacter baumannii accounted for a large proportion of cases in the random test analysis, which only represented the results of this study. Furthermore, emergency department patients accounted for 55.2%(171/310) in this study.
In conclusion, for severe pneumonia with hospital-acquired CRGNB infection, UEAT does not increase the 30-day mortality rate, while increase the length of hospitalization. At the same time, the excessive or unreasonable use of antibiotics were related to the increase of bacterial resistance, side effects and treatment costs. Considering this, we recommend clinicians give REAT in the treatment of infection.