Clinical Study Of Hospital-acquired Bloodstream Infection Caused By Gram-negative Bacilli

Objective To investigate the risk factors of patients with hospital-acquired bloodstream infections (BSI) caused by Gram-negative bacilli through analyzing the clinical data,discuss this regional distribution of pathogenic bacteria and sensitivity characteristics,analysis of treatment and prognosis factors during hospitalization,to provide clinicians with evidence-based early intervention and rational use of drugs.Methods During the study perod from January 2012 to December 2013,clinical dates of 432 patients with BSI caused by gram-negative bacilli were retrospectively reviewed. [Including name, gender, age and other general information, basic medical history, mainly the diagnosis and prognosis of patients admitted to hospital, where sections and bloodstream infections occur when the use of antibiotics, and to collect blood culture isolates, susceptibility results and other laboratory parameters, Severity were evaluated APACHE II score (the acute physiology and chronic health evaluation Ⅱ) J. Data collection unified entry, using SPSS 16.0 statistical software.Results1. During the period from January 2012 to December 2013,432 pations stayed longer than 48 hours and their blood cultures showed positive gram-negative bacilli BSI in our hospital.The incidence of 61-70 age group is highest, accounting for 29.9%.Use immunosuppressant, Vascular catheter for too long,and 14 days have invasive treatment operation as risk factors lead to bloodstream infections.2.432 boold samples were composed by Escherichia coli 227 cases, accounted for 52.5%, Klebsiella pneumoniae 108 cases, accounted for 25.0%, Pseudomonas aeruginosa 32 cases, accounted for 7.4%, Acinetobacter baumannii 15 cases, accounted for 3.5%.50 cases of other gram-negative bacilli..accounted for 10.9%.;and mainly collected from departments of internal medicine and ICU, which is more prominent in gastroenterology,especially thedetection rate of E. coli was highest in all department.3. Susceptibility test showed carbapenem antibiotics, piperacillin/tazobactam and amikacin Enterobacteriaceae preferred antimicrobial agents, third generation cephalosporin and fourth generation cephalosporin have varying degrees drug resistance. Pseudomonas aeruginosa is sensitive to meropenem, resistance rate less than 10%, followed by cefoperazone sulbactam and amikacin, resistance rate less than 20%, lower than ceftazidime, cefepime. Acinetobacter baumannii resistance is severe, the most for a variety of drug-resistant or pan-drug resistant.4. Treatment and outcome for the patient:before the results of blood culture returned, 429 patients were started more than one kind of antibiotic treatment, then adjust medication based on susceptibility results.119 cases (27.5%) died, survival 313 cases (72.5%),. The average hospital stay (18.32±15.54) d. Treatment within the two weeks beofor blood cultuer returned showed that the death group receiving cephalosporin and quinolones was more (49.6% vs 34.2%; 62.2% vs 51.5%, P<0.05).and the survival group receiving (3-lactamase inhibitor was more (46.3% vs 26.9%, P< 0.05).In death group the underlying diseases mainly wre solid tumors, followed by hematological malignancies, chronic renal insuficiency.5. Compared to the survival group, more people in the death group had the relevant factors,such as eld(54.6% vs.42.4%, x2=5.387, P<0.05), Multi-drug resistant infections (41.2% vs 19.2%, x2=22.135, P<0.05), used of immunosuppressant (42.0% vs 30.7%, x2=4.961, P<0.05)、Unconsciousness (16.0% vs 3.5%, x2=20.687, P<0.05) Agranulocytosis (35.3% vs 18.2%, x2=14.244, P<0.05),and received central venous catheter≥7d (45.8% vs 25.6%, x2=16.327, P<0.05). Logistic regression analysis showed that independent risk factors for death.were Unconsciousness (OR=3.871, 95%CI:1.607-9.327)、Multi-drug resistant infections (OR=2.56,95%CI:1.439-4.190)、 received central venous catheter≥7d (OR=2.675,95%CI:1.677-4.268),P<0.05. The death group had significantly higher Acute Physiology and Chronic Health Evaluation Ⅱ score (27.83±6.34 vs 15.26±5.81,p<0.01)than the survival group.Conclusions From the monitoring we can understand that the most pathogens were Escherichia coli, followed by Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii, many of whom were MDR and XDR, even PDR. ICU and gastroenterology were the departments which have higher incidence,. The group during 61-70 years old had highest incidence.The prognosis of patients diagnosed Gram-negative bacilli BSI may be significantly associated with using immunosuppressant、invasive procedures and the disease severity. Clinicians should actively assess risk factors and give interventions. Once find pathogens, the patients still need treatment timely.The initial drug to treatment BSI caused by Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa should be carbapenem antibiotics, β-lactamase inhibitor and amikacin. Acinetobacter baumannii resistant was severe in our hospital.Meanwhile, monitoringvof prognostic factors and APACHE Ⅱ score has an important clinical significance.