Objective To investigate the value of bronchial mucosa biopsy and quantitative culture in the differential diagnosis of lower airway bacterial colonization and infection. Methods A prospective observational cohort survey onMDR Pseudomonas aeruginosa and Acinetobacter baumannii was carried out in intubed or tracheotomized patients with invasive ventilation in respiratory intensive care unite ( RICU) . A total of 50 ICU patients were followed for the detection of MDR pathogen colonization or infection from June 2008 to October 2009. All subjects were divided into an infection group and a colonization group according to the outcome of patients discharged fromthe RICU. Baseline information, APACHEⅡ scores, and CPIS scores were recorded on individual forms for each patient untill discharge or death. Bronchial mucosa biopsy was conducted on appropriate time to identify whether the patient was comfirmed as infection. Microbiological diagnosis was performed with quantitative culture. Results Fifty patients were enrolled in this study, of which infected in 23 cases and colonized in 27 cases. The time of invasive mechanical ventilation, length ofICU stay, catheter indwelling time, and the kinds of disease were significantly different between the two groups( P lt; 0. 05) . The kinds of using antibiotics before onset of multi-drug resistance of bacteria showed that cefoxitin/ cefmetazole and mezlocillin also had significant difference between the infection group and the colonization group. The results of dynamic CPIS score of the infection group showed that scores at each timepoint were higher than those in the colonization group. However, the results of t-test showed that there was higher score in the infection group than that in the colonization group on 14 days after intubation ( P lt;0. 05) . The bronchial mucosa biopsy showed that airway inflammation was detected in 19 cases in the infection group and 9 cases in colonization group. The positive rate in the infection and the colonization group were 55. 6% and 25. 0% , respectively assessed by traditional threshold of 103 cfu/mL for PSB in quantitative bacterial culture. In addition, there was more inflammatory cells in the patients with drug-resistant pathogens infection than that in the patients without nosocomial infection. The combination of bronchial mucosa biopsy and microorganism quantitative cultures had the highest sensitivity and specificity and the highest diagnostic accuracy. Conclusions Bronchial mucosa biopsy combining microorganism quantitative culture is feasible in identifying colonized or infected bacteria. Invasive mechanical ventilation time, length of ICU stay and the catheter indwelling time extending are risk factors for bacterial colonization.
医院感染是指住院患者在医院内获得的感染,包括在住院期间发生的感染和在医院内获得出院后发生的感染。重症加强治疗病房( ICU) 是医院感染的高发科室, 其中又以肺部感染最为常见, 导致患者死亡率增加及治疗成本上升。随着医疗技术的发展, 器官移植、有创检查及治疗手段的不断推广, 以及广谱抗生素、糖皮质激素和免疫抑制剂在临床治疗中的广泛应用, 下呼吸道感染病原菌的种类不断发生变迁, 由多重耐药菌( MDR) 及真菌引起的感染不断增多, 成为下呼吸道感染的主要病原菌之一。在大多数情况下, 这类条件致病菌在合适的部位定植而不引起感染, 当机体因各种因素造成的抵抗力下降、菌群失调或天然屏障结构破坏时可引起感染发生。 由于定植菌的致病性是相对的, 临床上无法通过患者的临床表现经验诊断至属或种, 实验室亦无法单纯依赖培养鉴定技术确定其是感染病原菌还是定植菌。在呼吸机相关性肺炎( VAP) 患者中, 下呼吸道的真菌定植率较高, 但真正出现真菌性肺炎的患者比例并不高, 以致对患者的结局无显著影响。如果仅仅根据真菌定植结果制定治疗方案就容易造成抗真菌药物的过度使用。因此, 判断肺部感染的病原学是定植还是感染成为目前医院感染治疗中的难点问题之一。
0bjective To compare the effect of closed airway management system and open suction system on distribution and drug susceptibility of pathogenic bacteria in lower respiratory tract of mechanical ventilated patients.Methods Fifty-nine cases in ICU who received mechanical ventilation for more than 48 h from May 2006 to Dec 2006 were randomly divided into two groups.Group A(29 patients)received closed—tracheal suction and Group B(30 patients)received open-tracheal suction.Quantitative bacteriological culture and sensitivity of antibacterial drugs were conducted on lower respiratory tract secretion samples.Results In group A，a total of 91 strains were isolated，in which a single pathogen infection(41.4％)was the most frequent，followed by mixed infection of two pathogens(34.5％)and three or more pathogens(24.1％).In group B，a total of 141 strains were isolated，in which three or more pathogen infection(53.33％)was the most frequent，followed by two pathogen infection(30％)and a single pathogen infection(16.7％ ).Pathogen distribution between the two groups was not significantly different(Pgt;0.05).Drug susceptibility test did not show significant difference in main pathogens between the two groups(Pgt;0.05).Conclusions Closed airway management system can reduce the infection or colonization of mixed pathogens，but can not change the distribution and drug susceptibility of pathogens.
ObjectiveTo explore the value of bronchoscopy alveolar lavage cytology in diagnosis of pulmonary fungus infection and distinguishing colonization from true fungal infections. MethodsA retrospective analysis was conducted on the patients with positive fungi results in bronchoalveolar lavage cytology admitted in Shanghai Xinhua Hospital between January 2009 and December 2013.Clinical,radiological,bronchoalveolar lavage and histopathology findings were recorded and analyzed. ResultsFungi were found in alveolar lavage fluid in 60 cases.The most common fungal organism identified was Aspergillus,followed by Candida and Cryptococcosis.Twenty-seven cases (45.00%) by lung biopsy pathology were diagnosed as pulmonary fungal infection and 33 cases (55.00%) were diagnosed as lung bacteria colonization.Aspergillus was found in 35 cases (58.33%),as pathogenic bacteria in 12 cases (34.28%),and colonization bacteria in 23 cases (65.72%).Candida was found in 13 cases (21.67%),as pathogenic bacteria in 3 cases (23.08%),and colonization bacteria in 10 cases (76.92%).Ten cases of Cryptococcus and 2 cases of pulmonary sporozoan were all as pathogenic bacteria.Most cases of Aspergillus and Candida in cytological specimens presented as a pulmonary mass or endobrochial growth and were diagnosed as carcinomas in biopsy specimens,so bacteria colonization should be considered in these cases first of all.All cases of Pneumocystis with bilateral ground glass infiltrates and cryptococcosis with parenchymal mass lesion in radiology represented true infection.The coincidence rate of bronchoscopy alveolar lavage cytology and histopathology was 45%. ConclusionAspergillus and Candida species are the most common fungal organisms in the bronchoscopy alveolar lavage.Fluid cytological examination is an important diagnostic modality for pulmonary mycoses,however it is important to correlate with clinical,bronchoscopy and biopsy findings for accurate diagnosis and appropriate management.
ObjectiveTo evaluate the diagnostic value of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) level in bronchoalveolar lavage fluid (BALF) for discrimination of Acinetobacter baumannii (A. baumannii) colonization from infection.MethodsSixty patients with tracheal intubation or tracheotomy who were admitted in intensive care unit from July 2016 to July 2018, were divided into an infection group (n=20), a colonization group (n=20) and a control group (n=20). The serum and BALF samples were collected from the patients on the day when lower respiratory tract sample culture was positive so as to detect sTREM-1, serum procalcitonin (PCT) and interleukin-6 (IL-6). The value of serum PCT, IL-6, sTREM-1 and BALF sTREM-1 in differentiation of infection or colonization for A. baumannii was analyzed by mean of receiver operating characteristic (ROC) curve.ResultsThere were no significant differences in gender composition, age or Glasgow coma score among the three groups (P>0.05). The clinical pulmonary infection score (CPIS) of the infection group was higher than that in the control group (P<0.05). Compared with the control group, while the sTREM-1 concentration of BALF with A. baumannii colonization increased significantly but levels of PCT, IL-6 and sTREM-1 remained unchanged in serum. The levels of PCT, IL-6 and sTREM-1 in serum, and sTREM-1 in BALF increased significantly in the infection group (P<0.001). Compared with the colonization group, the levels of PCT, IL-6 and sTREM-1 in serum, and sTREM-1 in BALF increased significantly in the infection group (P<0.05). The area under the ROC curve (AUC) of serum PCT was 0.67 with the sensitivity of 0.55 and the specificity of 0.90 (95%CI 0.52 - 0.82). AUC of serum IL-6 was 0.72 with the sensitivity of 0.60 and the specificity of 0.95 (95%CI 0.58 - 0.85). AUC of serum sTREM-1 was 0.72 with the sensitivity of 0.75 and the specificity of 0.60 (95%CI 0.55 - 0.85). AUC of sTREM-1 in BALF was 0.92 with the sensitivity of 0.95 and the specificity of 0.70 (95%CI 0.79 - 0.98). The diagnostic accuracy of sTREM-1 in BALF was higher than that of PCT, IL-6 and sTREM-1 in serum (P<0.05).ConclusionssTREM-1 in BALF has good diagnostic performance in differentiating patients with infection of colonization for A. baumannii. Its sensitivity and specificity are higher than serum PCT, IL-6 and sTREM-1.
ObjectivesTo systematically review the risk factors of carbapenem-resistant enterobacteriaceae colonization or infection in neonates.MethodsPubMed, EMbase, The Cochrane Library, CNKI, WanFang Data, VIP and CBM databases were electronically searched to collect cohort or case-control studies on the risk factors of carbapenem-resistant enterobacteriaceae colonization or infection in neonates from inception to May 2020. Two reviewers independently screened literature, extracted data, and assessed risk of bias of included studies, and meta-analysis was performed by RevMan5.3 software.ResultsA total of 9 case-control studies involving 759 patients were included. The results of meta-analysis showed that, maternal factors like placental abruption (OR=6.25, 95%CI 1.47 to 26.61, P=0.01), premature rupture of fetal membranes of parturient (OR=5.62, 95%CI 2.63 to 12.00, P<0.000 01), pregnancy-induced hypertension (OR=2.04, 95%CI 1.49 to 2.80, P<0.000 01), carbapenem antibiotics used in mothers (OR=1.77, 95%CI 1.10 to 2.81, P=0.017), neonatal factors like premature delivery (OR=1.96, 95%CI 1.06 to 3.61, P=0.03), mechanical ventilation (OR=2.14, 95%CI 1.01 to 4.55, P=0.05), surgical procedure (OR=14.17, 95%CI 2.46 to 81.70, P=0.003), umbilical vein catheter (OR=1.93, 95%CI 1.20 to 3.11, P=0.007), peripherally inserted central catheter (OR=4.30, 95%CI 1.86 to 9.93, P=0.000 6), nasogastric feeding (OR=4.37, 95%CI 1.44 to 13.29, P=0.009), use of carbapenems (OR=3.04, 95%CI 1.91 to 4.84, P<0.000 01), and admission to NICU (OR=2.78, 95%CI 1.79 to 4.33, P<0.000 01) were the risk factors of carbapenem-resistant enterobacteriaceae colonization or infection in neonates. Breastfeeding (OR=0.30, 95%CI 0.13 to 0.70, P=0.005) was the protective factor of carbapenem-resistant enterobacteriaceae colonization or infection in neonates.ConclusionsThe current evidence shows that maternal factors like placental abruption, premature rupture of fetal membranes, pregnancy-induced hypertension, carbapenem antibiotics used in mothers, and neonatal factors like premature delivery, mechanical ventilation, surgical procedure, umbilical vein catheter, peripherally inserted central catheter, nasogastric feeding, use of carbapenems, and admission to NICU are the risk factors of carbapenem-resistant enterobacteriaceae colonization or infection in neonates; while breastfeeding is the protective factor of carbapenem-resistant enterobacteriaceae colonization or infection in neonates. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify the conclusions.