ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo determine if nitric oxide production is associated with increased intestinal permeability after endotoxin challenge using the ex vivo Ussing chamber.SubjectsIleal mucosal membranes harvested from normal rats weighing 300 to 420 g.InterventionsEndotoxin (lipopolysaccharide), 1, 10, 100 [micro sign]g/mL, or saline was placed on the serosal side of ileal mucosal membranes mounted in Ussing chambers after 109Escherichia coli C-25 had been placed on the mucosal side of the ileal membranes (n = 6-7/group). In a second set of experiments, ileal membranes were exposed to 100 [micro sign]g/mL lipopolysaccharide with or without the addition of the nitric oxide synthase inhibitor, NG-monomethyl-L-arginineat a concentration of 10 mM (n = 7-8/group).Main Outcome MeasureBacterial translocation of E. coli C-25 from the mucosal to the serosal side of the ileal membrane was measured every hour during the 3-hr experimental period, as were serial measurements of the potential difference and resistance values of the ileal membranes. At the conclusion of the 3-hr period, the ileal membranes were harvested and levels of inducible nitric oxide synthase and constitutive nitric oxide synthase activity were measured.ResultsThe incidence of E. coli C-25 passage across the ileal membranes mounted in the Ussing chambers was significantly increased in the ileal membranes exposed to 10 or 100 [micro sign]g/mL of lipopolysaccharide (71% and 86%, respectively) vs. the control membranes (0%) or the membranes exposed to 1 [micro sign]g/mL of lipopolysaccharide (0%) (p < .05). This increase in E. coli C-25 passage in the ileal membranes exposed to 10 or 100 [micro sign]g/mL of lipopolysaccharide was associated with a decrease in ileal membrane resistance and an increase in inducible nitric oxide synthase activity (p < .05). The addition of NG-monomethyl-L-arginineprotected against lipopolysaccharide-induced bacterial translocation and prevented the lipopolysaccharide-induced increase in ileal membrane inducible nitric oxide synthase activity.ConclusionThese results indicate that lipopolysaccharide induction of increased ileal inducible nitric oxide synthase activity is necessary for lipopolysaccharide-induced E. coli C-25 translocation to occur in normal ileal mucosal membranes tested in the Ussing chamber system. (Crit Care Med 1999; 27:880-886)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo describe the epidemiology of nosocomial infections in medical intensive care units (ICUs) in the United States.DesignAnalysis of ICU surveillance data collected through the National Nosocomial Infections Surveillance (NNIS) System between 1992 and 1997.SettingMedical ICUs in the United States.PatientsA total of 181,993 patients.Measurements and Main ResultsNosocomial infections were analyzed by infection site and pathogen distribution. Urinary tract infections were most frequent (31%), followed by pneumonia (27%) and primary bloodstream infections (19%). Eighty-seven percent of primary bloodstream infections were associated with central lines, 86% of nosocomial pneumonia was associated with mechanical ventilation, and 95% of urinary tract infections were associated with urinary catheters. Coagulase-negative staphylococci (36%) were the most common bloodstream infection isolates, followed by enterococci (16%) and Staphylococcus aureus (13%). Twelve percent of bloodstream isolates were fungi. The most frequent isolates from pneumonia were Gram-negative aerobic organisms (64%). Pseudomonas aeruginosa (21%) was the most frequently isolated of these. S. aureus (20%) was isolated with similar frequency. Candida albicans was the most common single pathogen isolated from urine and made up just over half of the fungal isolates. Fungal urinary infections were associated with asymptomatic funguria rather than symptomatic urinary tract infections (p < .0001). Certain pathogens were associated with device use: coagulase-negative staphylococci with central lines, P. aeruginosa and Acinetobacter species with ventilators, and fungal infections with urinary catheters. Patient nosocomial infection rates for the major sites correlated strongly with device use. Device exposure was controlled for by calculating device-associated infection rates for bloodstream infections, pneumonia, and urinary tract infections by dividing the number of device-associated infections by the number of days of device use. There was no association between these device-associated infection rates and number of hospital beds, number of ICU beds, or length of stay. There is a considerable variation within the distribution of each of these infection rates.ConclusionsThe distribution of sites of infection in medical ICUs differed from that previously reported in NNIS ICU surveillance studies, largely as a result of anticipated low rates of surgical site infections. Primary bloodstream infections, pneumonia, and urinary tract infections associated with invasive devices made up the great majority of nosocomial infections. Coagulase-negative staphylococci were more frequently associated with primary bloodstream infections than reported from NNIS ICUs of all types in the 1980s, and enterococci were a more frequent isolate from bloodstream infections than S. aureus. Fungal urinary tract infections, often asymptomatic and associated with catheter use, were considerably more frequent than previously reported. Invasive device-associated infections were associated with specific pathogens. Although device-associated site-specific infection rates are currently our most useful rates for performing comparisons between ICUs, the considerable variation in these rates between ICUs indicates the need for further risk adjustment. (Crit Care Med 1999;27:887-892)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID