Hospital-wide surveillance of catheter-related bloodstream infection: from the expected to the unexpected

Catheter-related bloodstream infections (CRBSIs) are among the most frequent healthcare-associated infections and cause considerable morbidity, mortality, and resource use. CRBSI surveillance serves quality improvement, but is often restricted to intensive care units (ICUs). We conducted a four-month prospective cohort study of all non-cuffed central venous catheters (CVCs) to design an efficient CRBSI surveillance and prevention programme. CVCs were assessed on a daily basis for ward exposure time, care parameters, and the occurrence of laboratory-confirmed CRBSI. Overall, 248 patients with 426 CVCs accounted for 3567 CVC-days (median: 5) and 15 CRBSI episodes. CVCs were inserted by anaesthetists, ICU physicians and internists in 45%, 47%, and 8% of cases, respectively. CVC utilisation rates for intensive care, internal medicine, non-abdominal surgery and abdominal surgery were 29.8, 3.8, 1.7 and 4.9 per 100 patient-days, respectively. Fourteen percent of patients changed wards while having a CVC in place, so spending CVC-days at risk within multiple departments. CRBSI incidence densities for ICU, internal medicine, surgery and abdominal surgery were 5.6, 1.9, 2.4 and 7.7 per 1000 CVC-days at risk, respectively. In a univariate Cox proportional hazards model, the high CRBSI rate in abdominal surgery was associated with longer CVC duration, frequent use of parenteral nutrition and CVC insertion by anaesthetists. CRBSI numbers were insufficient to perform a multivariate analysis. Our surveillance revealed similar CRBSI rates in both ICU and non-ICU departments, and when frequent ward transfers occurred. Hospital-wide CRBSI surveillance is advisable when a large proportion of CVC-days occur outside the ICU.     

Preventing catheter-associated bloodstream infections: a survey of policies for insertion and care of central venous catheters from hospitals in the prevention epicenter program.

OBJECTIVE: To determine the extent to which evidence-based practices for the prevention of central venous catheter (CVC)-associated bloodstream infections are incorporated into the policies and practices of academic intensive care units (ICUs) in the United States and to determine variations in the policies on CVC insertion, use, and care. DESIGN: A 9-page written survey of practices and policies for nontunneled CVC insertion and care. SETTING: ICUs in 10 academic tertiary-care hospitals. PARTICIPANTS: ICU medical directors and nurse managers. RESULTS: Twenty-five ICUs were surveyed (1-6 ICUs per hospital). In 80% of the units, 5 separate groups of clinicians inserted 24%-50% of all nontunneled CVCs. In 56% of the units, placement of more than two-thirds of nontunneled CVCs was performed in a single location in the hospital. Twenty units (80%) had written policies for CVC insertion. Twenty-eight percent of units had a policy requiring maximal sterile-barrier precautions when CVCs were placed, and 52% of the units had formal educational programs with regard to CVC insertion. Eighty percent of the units had a policy requiring staff to perform hand hygiene before inserting CVCs, but only 36% and 60% of the units required hand hygiene before accessing a CVC and treating the exit site, respectively. CONCLUSION: ICU policy regarding the insertion and care of CVCs varies considerably from hospital to hospital. ICUs may be able to improve patient outcome if evidence-based guidelines for CVC insertion and care are implemented.     

Device-associated infection rates for non-intensive care unit patients.

BACKGROUND: Reference data from intensive care units (ICUs) are not applicable to non-ICU patients because of the differences in device use rates, length of stay, and severity of underlying diseases among the patient populations. In contrast to the huge amount of data available for ICU patients, appropriate surveillance data for non-ICU patients have been missing in Germany. OBJECTIVE: To establish a new module ("DEVICE-KISS") of the German Nosocomial Infection Surveillance System for generating stratified reference data for non-ICU wards. SETTING: Non-ICU patients from 42 German hospitals. METHODS: Monthly patient-days, device-days and nosocomial infections (NIs) (using Centers for Disease Control and Prevention definitions) were counted. Device use rates were calculated, and NI rates were stratified by different medical specialities. RESULTS: From July 2002 through June 2004, among the 77 wards, there were a total of 536,955 patient-days and 74,188 device-days (for CVC-associated primary bloodstream infections, there were 181,401 patient-days and 8,317 central vascular catheter [CVC]-days in 29 wards; for urinary catheter-associated urinary tract infections, there were 445,536 patient-days and 65,871 urinary catheter-days in 65 wards) and 483 NIs (36 bloodstream infections and 447 urinary tract infections). The mean device use rates were 4.6 device-days per 100 patient-days for CVCs (29 wards) and 14.8 device-days per 100 patient-days for urinary catheters (65 wards), respectively. Mean device-associated NI rates were 4.3 infections per 1,000 CVC-days for CVC-associated bloodstream infections and 6.8 infections per 1,000 urinary catheter-days for catheter-associated urinary tract infections. CONCLUSIONS: DEVICE-KISS allows non-ICUs to recognize an outlier position with regard to NIs by providing well-founded reference data for non-ICU patients.     

Hospital-wide survey of the use of central venous catheters

There are few data on indications for central venous catheter (CVC) use. We conducted an observational, hospital-wide prospective cohort study to quantify the indications for catheter placement over dwell time and to investigate agreement between healthcare workers (HCWs) on CVC use. Catheter use was observed by on-site visits, HCW interviews, and screening of patient charts. A total of 378 CVCs were inserted in 292 patients, accounting for 2704 catheter-days. Of these, 93% CVCs were multilumen catheters and 70% were placed in the intensive care unit (ICU). Median dwell time (interquartile range) was 5 (2-9) days overall, and 4 (2-7) and 8 (3-15) in the ICU and non-ICU settings, respectively. The mean number of specified indications for CVC use per day was 1.7 (1.9 for ICU and 1.5 for non-ICU; P<0.001). The most frequent reason (49%) for catheter use was prolonged (>7 days) antibiotic therapy followed by parenteral nutrition (22.3%). A total of 130 catheter-days (4.8%) were unnecessary with a higher proportion in non-ICU settings (6.6%). In 94% of cases, there was agreement among HCWs on indications for CVC use. However, 35 on-site visits (8.3%) in non-ICU settings revealed that neither the nurse nor the treating physician knew why the catheter was in place. ICU catheters have a short dwell time but are utilised more often, whereas catheters in non-ICU settings show a reverse characteristic. Prevention measures targeting catheter care are more likely to be successful in non-ICU settings.     

Catheter-associated bloodstream infections in general medical patients outside the intensive care unit: a surveillance study.

OBJECTIVE: To determine the incidence of central venous catheter (CVC)-associated bloodstream infection (CA-BSI) among patients admitted to general medical wards outside the intensive care unit (ICU). DESIGN: Prospective cohort study performed over a 13-month period, from April 1, 2002, through April 30, 2003. SETTING: Four selected general medical wards at Barnes-Jewish Hospital, a 1,250-bed teaching hospital in Saint Louis, Missouri. PATIENTS; All patients admitted to 4 general medical wards. RESULTS: A total of 7,337 catheter-days were observed during 33,174 patient-days. The device utilization ratio (defined as the number of catheter-days divided by the number of patient-days) was 0.22 overall and was similar among the 4 wards (0.21, 0.25, 0.19, and 0.24). Forty-two episodes of CA-BSI were identified (rate, 5.7 infections per 1,000 catheter-days). Twenty-four (57%) of the 42 cases of CA-BSI were caused by gram-positive bacteria: 10 isolates (24%) were coagulase-negative staphylococci, 10 (24%) were Enterococcus species, and 3 (7%) were Staphylococcus aureus. Gram-negative bacteria caused 7 infections (17%). Five CA-BSIs (12%) were caused by Candida albicans, and 5 infections (12%) had a polymicrobial etiology. Thirty-five patients (83%) with CA-BSI had nontunneled CVCs in place. CONCLUSIONS: Non-ICU medical wards in the study hospital had device utilization rates that were considerably lower than those of medical ICUs, but CA-BSI rates were similar to CA-BSI rates in medical ICUs in the United States. Studies of catheter utilization and on CVC insertion and care should be performed on medical wards. CA-BSI prevention strategies that have been used in ICUs should be studied on medical wards.     

Effect of nurse staffing and antimicrobial-impregnated central venous catheters on the risk for bloodstream infections in intensive care units.

BACKGROUND: Defining risk factors for central venous catheter (CVC)-associated bloodstream infections (BSIs) is critical to establishing prevention measures, especially for factors such as nurse staffing and antimicrobial-impregnated CVCs. METHODS: We prospectively monitored CVCs, nurse staffing, and patient-related variables for CVC-associated BSIs among adults admitted to eight ICUs during 2 years. RESULTS: A total of 240 CVC-associated BSIs (2.8%) were identified among 4,535 patients, representing 8,593 CVCs. Antimicrobial-impregnated CVCs reduced the risk for CVC-associated BSI only among patients whose CVC was used to administer total parenteral nutrition (TPN, 2.6 CVC-associated BSIs per 1,000 CVC-days vs no TPN, 7.5 CVC-associated BSIs per 1,000 CVC-days; P = .006). Among patients not receiving TPN, there was an increase in the risk of CVC-associated BSI in patients cared for by "float" nurses for more than 60% of the duration of the CVC. In multivariable analysis, risk factors for CVC-associated BSIs were the use of TPN in non-antimicrobial-impregnated CVCs (P = .0001), patient cared for by a float nurse for more than 60% of CVC-days (P = .0019), no antibiotics administered to the patient within 48 hours of insertion (P = .0001), and patient unarousable for 70% or more of the duration of the CVC (P = .0001). Peripherally inserted central catheters (PICCs) were associated with a lower risk for CVC-associated BSI (P = .0001). CONCLUSIONS: Antimicrobial-impregnated CVCs reduced the risk of CVC-associated BSI by 66% in patients receiving TPN. Limiting the use of float nurses for ICU patients with CVCs and the use of PICCs may also reduce the risk of CVC-associated BSI.     

Prevalence of healthcare-associated infection in Scottish intensive care units

A national point prevalence survey of healthcare-associated infection (HCAI) in all acute hospitals, including intensive care units (ICUs), was carried out in Scotland from October 2005 to October 2006. The survey measured the prevalence of HCAIs to determine the burden on ICU resources. HCAI prevalence in ICUs was compared with HCAI prevalence in patients outside ICU. The prevalence of HCAI in ICU patients was 27.1%, significantly higher than HCAI prevalence in patients outside ICU, which was 9.3%. The prevalence of specific infections, namely pneumonia and lower respiratory tract, bloodstream and surgical site infections, was also significantly higher in ICU patients compared with non-ICU patients. These results highlight the burden on ICU resources from all HCAIs, regardless of site of infection. High HCAI prevalence in Scottish ICUs has major implications for patient safety and ICU resources and emphasises the need for continuing strong collaboration between intensivists and infection control teams.     

Preventing central venous catheter-associated primary bloodstream infections: characteristics of practices among hospitals participating in the Evaluation of Processes and Indicators in Infection Control (EPIC) study.

OBJECTIVES: To describe the conceptual framework and methodology of the Evaluation of Processes and Indicators in Infection Control (EPIC) study and present results of CVC insertion characteristics and organizational practices for preventing BSIs. The goal of the EPIC study was to evaluate relationships among processes of care, organizational characteristics, and the outcome of BSI. DESIGN: This was a multicenter prospective observational study of variation in hospital practices related to preventing CVC-associated BSIs. Process of care information (eg, barrier use during insertions and experience of the inserting practitioner) was collected for a random sample of approximately 5 CVC insertions per month per hospital during November 1998 to December 1999. Organization demographic and practice information (eg, surveillance activities and staff and ICU nurse staffing levels) was also collected. SETTING: Medical, surgical, or medical-surgical ICUs from 55 hospitals (41 U.S. and 14 international sites). PARTICIPANTS: Process information was obtained for 3,320 CVC insertions with an average of 58.2 (+/- 16.1) insertions per hospital. Fifty-four hospitals provided policy and practice information. RESULTS: Staff spent an average of 13 hours per week in study ICU surveillance. Most patients received nontunneled, multiple lumen CVCs, of which fewer than 25% were coated with antimicrobial material. Regarding barriers, most clinicians wore masks (81.5%) and gowns (76.8%); 58.1% used large drapes. Few hospitals (18.1%) used an intravenous team to manage ICU CVCs. CONCLUSIONS: Substantial variation exists in CVC insertion practice and BSI prevention activities. Understanding which practices have the greatest impact on BSI rates can help hospitals better target improvement interventions.     

Effect of central venous catheter type on infections: a prospective clinical trial

This study reports on a block clinical trial of two types of central venous catheters (CVCS): antiseptic-impregnated catheters (AIC) and non-impregnated catheters (non-AIC), on catheter tip colonization and bacteraemia. In total, 500 catheters were inserted in 390 patients over the 18 month study period, 260 (52.0%) AIC and 240 (48.0%) non-AIC. Of these, 460 (92.0%) tips (237 AIC and 223 non-AIC) were collected. While significantly fewer AIC, 14 (5.9%), than non-AIC, 30 (13.5%), catheters were colonized (P<0.01), there was no difference in the rates of bacteraemias in the two groups (0.8% vs. 2.7%, respectively, P=0.16). There were 6.87 (95% CI 3.38-14.26) and 16.92 (95% CI 10.61-27.12) colonized AIC and non-AIC catheters, respectively, per 1000 catheter days, a difference that was significant (P<0.01). However, no difference emerged between bacteraemias in AIC and non-AIC catheters per 1000 catheter days measured at 0.98 (95% CI 0.24-5.54) and 3.38 (95% CI 1.29-9.34), respectively (P=0.10). Of the 444 CVCs that were sited in the subclavian or jugular veins and had tips collected, significantly more catheters were colonized in the jugular group, 19 (20%), compared with the subclavian group, 24 (6.9%; P< or =0.01). Overall, the low rates of colonization and bacteraemia may be explained by the population studied, the policies used and the employment of a clinical nurse dedicated to CVC management.     

Value of performing active surveillance cultures on intensive care unit discharge for detection of methicillin-resistant Staphylococcus aureus.

OBJECTIVE: To quantify the value of performing active surveillance cultures for detection of methicillin-resistant Staphylococcus aureus (MRSA) on intensive care unit (ICU) discharge. DESIGN: Prospective cohort study. SETTING: Medical ICU (MICU) and surgical ICU (SICU) of a tertiary care hospital. PARTICIPANTS: We analyzed data on adult patients who were admitted to the MICU or SICU between January 17, 2001, and December 31, 2004. All participants had a length of ICU stay of at least 48 hours and had surveillance cultures of anterior nares specimens performed on ICU admission and discharge. Patients who had MRSA-positive clinical cultures in the ICU were excluded. RESULTS: Of 2,918 eligible patients, 178 (6%) were colonized with MRSA on ICU admission, and 65 (2%) acquired MRSA in the ICU and were identified by results of discharge surveillance cultures. Patients with MRSA colonization confirmed by results of discharge cultures spent 853 days in non-ICU wards after ICU discharge, which represented 27% of the total number of MRSA colonization-days during hospitalization in non-ICU wards for patients discharged from the ICU. CONCLUSIONS: Surveillance cultures of nares specimens collected at ICU discharge identified a large percentage of MRSA-colonized patients who would not have been identified on the basis of results of clinical cultures or admission surveillance cultures alone. Furthermore, these patients were responsible for a large percentage of the total number of MRSA colonization-days during hospitalization in non-ICU wards for patients discharged from the ICU.     

A one-year prospective study of nosocomial bacteraemia in ICU and non-ICU patients and its impact on patient outcome

A one-year, prospective, two-observational cohort study was performed to evaluate the incidence and outcome in hospitalized patients (ICU and non-ICU) of nosocomial bacteraemia, and to assess its prognostic value in the ICU group. A group of 18 098 hospitalized patients and a group of 291 consecutive ICU patients were followed. Prognostic factors were determined using single and multivariable analyses. 109 (90 non-ICU and 19 ICU) patients developed 118 nosocomial bacteraemic episodes. The incidence of nosocomial bacteraemia was 6.0 per 1000 admissions (95% confidence interval (CI): 5-7%) and 65 per 1000 admissions in ICU patients (95% CI: 4.5-8.5%). Gram-positive and Gram-negative bacteria were 63/133 (47%) and 70/133 (53%) of the isolated micro-organisms respectively. Crude mortality rates were 41/109 (38%) with adverse outcome associated with mechanical ventilation (OR: 3.6; 95% CI: 1.4-9.2, P =0.01), neutropenia (OR: 7.7; 95% CI: 0.8-73.1;P =0.07) while gastro-intestinal surgery was associated with an improved outcome (OR: 0.4; 95% CI: 0.16-0.96;P =0.04). Of the 291 ICU patients, 19 acquired 22 episodes of nosocomial bacteraemia, and 18 were referred from the wards with documented nosocomial bacteraemia. Of these 37 bacteraemic patients, 17 (46%) died. When adjusting for predictors of death (SAPS II>/=40, cardiac and neurological failure), nosocomial bacteraemia markedly influence the outcome in ICU patients (OR: 3.4; 95% CI: 1.3-8.7;P =0.010). This study suggests that the outcome of nosocomial bacteraemia in hospitalized patients is poor in ventilated and neutropenic patients and that nosocomial bacteraemia per se influenced outcome in ICU patients.     

The changing epidemiology of vancomycin-resistant enterococci.

OBJECTIVE: To determine the distribution of vancomycin-resistant enterococci (VRE) cases in our hospital and those from outside of our hospital from 1993 through 1998. METHODS: Weekly rectal surveillance was instituted whenever there were two or more cases present in the units. Cases were divided into acquired in our hospital, acquired outside of our hospital (VRE positive after and within 72 hours of admission, respectively), and indeterminate. Hospital cases were attributed to the originating ward or intensive care unit (ICU) if patients were noted to be positive within 72 hours of transfer. RESULTS: From 1993 to 1998, the rate of VRE per 1,000 admissions increased threefold, from 3.2 to 9.8, for the hospital. VRE cases acquired outside of the hospital increased by approximately 5% per year (r = 0.87; P = .03). The rate of VRE per 1,000 admissions increased 1.7-fold in the ICUs and 3.6-fold in the wards. The ICUs had an average of 75.3 cases per year, with the number of new cases per year increasing by approximately 9 (r = 0.80; P = .028). In the wards, there were an average of 22.0 new cases per year, with a slight upward trend of 3 additional new cases per year (r = 0.69; P = .64). There was a highly significant increasing linear trend (P = .0007) for VRE colonization and infection. CONCLUSION: Although VRE still predominate in the ICUs, cases originating from outside of our hospital and the wards are becoming more common. VRE colonization remained more frequent than infection.     

Compliance with routine use of gowns by healthcare workers (HCWs) and non-HCW visitors on entry into the rooms of patients under contact precautions.

BACKGROUND: Modified contact precautions (MCP), defined as routine donning of isolation gowns (along with routine gloving) on entry into the rooms of patients under contact precautions, regardless of the likelihood of direct exposure to the patient or their immediate environment, were instituted at our medical center to reduce nosocomial transmission of common hospital pathogens. OBJECTIVES: To study compliance with MCP policy regarding routine gowning in intensive care units (ICUs) and general wards and to determine the relationship between gown and glove use in the care of patients under MCP in ICUs. DESIGN: Prospective observational study from February 20, 2004, through January 8, 2005, involving 2,110 persons (1,504 healthcare workers [HCWs] and 606 non-HCW visitors). SETTING: A 900-bed tertiary care teaching community hospital. RESULTS: Overall compliance with routine gown use was observed for 1,542 persons (73%), including 1,150 HCWs (76%) and 392 visitors (65%) (odds ratio [OR], 1.8 [95% confidence interval {CI}, 1.4-2.2]; P<.001). Visitors in the ICUs (186 [91%] of 204) were more likely than visitors in the general wards (202 [51%] of 398) to comply with gown use (OR, 10 [95% CI, 6.0-17.0]; P<.001). In logistic regression analysis, independent predictors of gown compliance among HCWs were female sex (OR, 2.3 [95% CI, 1.8-3.0]; P<.001) and ICU setting (OR, 2.2 [95% CI, 1.7-2.9]; P<.001). In the ICUs, gown use was highly predictive of glove use among HCWs (positive predictive value, 95%). CONCLUSION: Improvement in compliance with gown use at our medical center will require more-intensive educational efforts targeted at male HCWs and at HCWs and visitors on general wards. In the care of ICU patients under MCP, HCW compliance with gown use may be used as a proxy for their compliance with glove use.     

Unnecessary use of central venous catheters: the need to look outside the intensive care unit.

We developed criteria for justifiable CVC use and evaluated CVC use in a public hospital. Unjustified CVC-days were more common for non-ICU patients compared with ICU patients. Also, insertion-site dressings were less likely to be intact on non-ICU patients. Interventions to reduce CVC-associated bloodstream infections should include non-ICU patients.     

Central venous catheter-related bacteremia due to gram-negative bacilli: significance of catheter removal in preventing relapse.

OBJECTIVE: To study the characteristics of catheter-related, gram-negative bacteremia (GNB) and the role of central venous catheter (CVC) removal. DESIGN: This retrospective study involved a search of the microbiological department records of CVC and blood cultures and patients' medical records. SETTING: University of Texas M. D. Anderson Cancer Center, a tertiary-care hospital in Houston, Texas. PATIENTS: Patients with cancer who had catheter-related GNB, defined as (1) a positive catheter tip culture with at least 15 colony-forming units semiquantitatively, (2) isolation of the same organism from the tip and peripheral blood cultures, (3) no other source for bacteremia except the CVC, and (4) clinical manifestations of infection (fever or chills). RESULTS: Between January 1990 and December 1996, 72 cases of catheter-related GNB were available for review. Most of the patients (67; 93%) had their CVCs removed in response to the bacteremia. Few patients (5; 7%) retained their CVCs and were treated with appropriate antibiotics. When CVCs were removed, only 1 patient (1%) relapsed with the same organism, whereas all 5 patients with retained CVCs relapsed after having responded (P < .001). The most commonly isolated organisms were Enterobacter, Klebsiella, Stenotrophomonas, Pseudomonas, and Acinetobacter species. Catheter removal within 72 hours of the onset of the catheter-related GNB was the only independent protective factor against relapse of the infection (odds ratio, 0.13; 95% confidence interval, 0.02-0.75; P = .02). CONCLUSION: In patients with documented catheter-related GNB, CVCs should be removed within 48 to 72 hours to prevent relapse.     

Ventilator-associated pneumonia in a multi-hospital system: differences in microbiology by location.

OBJECTIVE: To determine whether there were differences in the microbiologic etiologies of ventilator-associated pneumonia in different clinical settings. DESIGN: Observational retrospective cohort study of microbiologic etiologies of ventilator-associated pneumonia from 1998 to 2001 in a multi-hospital system. Microbiologic results were compared between hospitals and between different intensive care units (ICUs) within hospitals. SETTING: Three hospitals--one pediatric teaching hospital, one adult teaching hospital, and one community hospital--in one healthcare system in the midwestern United States. PATIENTS: Patients at the target hospitals who developed ventilator-associated pneumonia and for whom microbiologic data were available. RESULTS: Seven hundred fifty-three episodes of ventilator-associated pneumonia had culture data available for review. The most common organisms at all hospitals were Staphylococcus aureus (28.4%) and Pseudomonas aeruginosa (25.2%). The pediatric hospital had higher proportions of Escherichia coli (9.5% vs 2.3%; P < .001) and Klebsiella pneumoniae (13% vs 3.1%; P < .001) than did the adult hospitals. In the pediatric hospital, the pediatric ICU had higher P aeruginosa rates than did the neonatal ICU (33.3% vs 17%; P = .01). In the adult hospitals, the surgical ICU had higher Acinetobacter baumannii rates (10.2% vs. 1.7%; P < .001) than did the other ICUs. CONCLUSIONS: Microbiologic etiologies of ventilator-associated pneumonia vary between and within hospitals. Knowledge of these differences can improve selection of initial antimicrobial regimens, which may decrease mortality.     

Surveillance and infection control in an intensive care unit.

OBJECTIVE: To evaluate the effect of an infection control program on the incidence of hospital-acquired infection (HAI) and associated mortality. DESIGN: Prospective study. SETTING: A 2000-bed, university-affiliated hospital in Italy. PATIENTS: All patients admitted to the general intensive care unit (ICU) for more than 48 hours between January 2000 and December 2001. METHODS: The infection control team (ICT) collected data on the following from all patients: demographics, origin, diagnosis, severity score, underlying diseases, invasive procedures, HAI, isolated microorganisms, and antibiotic susceptibility. INTERVENTIONS: Regular ICT surveillance meetings were held with ICU personnel. Criteria for invasive procedures, particularly central venous catheters (CVCs), were modified. ICU care was restricted to a team of specialist physicians and nurses and ICU antimicrobial therapy policies were modified. RESULTS: Five hundred thirty-seven patients were included in the study (279 during 2000 and 258 in 2001). Between 2000 and 2001, CVC exposure (82.8% vs 71.3%; P < .05) and mechanical ventilation duration (11.2 vs 9.6 days) decreased. The HAI rate decreased from 28.7% in 2000 to 21.3% in 2001 (P < .05). The crude mortality rate decreased from 41.2% in 2000 to 32.9% in 2001 (P < .05). The most commonly isolated microorganisms were nonfermentative gram-negative organisms and staphylococci (particularly MRSA). Mortality was associated with infection (relative risk, 2.11; 95% confidence interval, 1.72-2.59; P < .05). CONCLUSION: Routine surveillance for HAI, coupled with new measures to prevent infections and a revised policy for antimicrobial therapy, was associated with a reduction in ICU HAls and mortality.     

集束化干预策略在预防ICU中心静脉导管相关血流感染中的应用

目的探讨集束化干预策略预防重症监护室(ICU)中心静脉导管相关血流感染（CRBSI）的效果。方法采用前瞻性和回顾性调查相结合的方法,选择2011年3月-2012年2月某院ICU留置中心静脉导管, 实施集束化干预策略的179例患者作为试验组;2010年1-12月该ICU留置中心静脉导管, 未实施集束化干预策略的198例患者作为对照组,比较两组CRBSI发生情况。结果试验组 CRBSI发生率为3.34‰,显著低于对照组的9.42‰（χ2=5.340,P=0.021）;且试验组住院时间明显缩短［（26.43±7.16）d vs （33.25±8.51）d;t=8.35,P＜0.001］,发生CRBSI的时间显著延长［（10.11±2.34）d vs （6.23±1.92）d;t=17.703, P＜0.001］,手消毒液消耗量明显增加［41.2 mL/患者日 vs 3.5 mL/患者日;t=34.469,P＜0.001］。结论在ICU实施中心静脉导管集束化干预策略能有效降低CRBSI的发生率, 有利于CRBSI的防治。     

Impact of contact and droplet precautions on the incidence of hospital-acquired methicillin-resistant Staphylococcus aureus infection.

OBJECTIVE: To evaluate the efficacy of contact and droplet precautions in reducing the incidence of hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections. DESIGN: Before-after study.Setting. A 439-bed, university-affiliated community hospital. METHODS: To identify inpatients infected or colonized with MRSA, we conducted surveillance of S. aureus isolates recovered from clinical culture and processed by the hospital's clinical microbiology laboratory. We then reviewed patient records for all individuals from whom MRSA was recovered. The rates of hospital-acquired MRSA infection were tabulated for each area where patients received nursing care. After a baseline period, contact and droplet precautions were implemented in all intensive care units (ICUs). Reductions in the incidence of hospital-acquired MRSA infection in ICUs led to the implementation of contact precautions in non-ICU patient care areas (hereafter, "non-ICU areas"), as well. Droplet precautions were discontinued. An analysis comparing the rates of hospital-acquired MRSA infection during different intervention periods was performed. RESULTS: The combined baseline rate of hospital-acquired MRSA infection was 10.0 infections per 1,000 patient-days in the medical ICU (MICU) and surgical ICU (SICU) and 0.7 infections per 1,000 patient-days in other ICUs. Following the implementation of contact and droplet precautions, combined rates of hospital-acquired MRSA infection in the MICU and SICU decreased to 4.3 infections per 1,000 patient-days (95% confidence interval [CI], 0.17-0.97; P=.03). There was no significant change in hospital-acquired MRSA infection rates in other ICUs. After the discontinuation of droplet precautions, the combined rate in the MICU and SICU decreased further to 2.5 infections per 1,000 patient-days. This finding was not significant (P=.43). In the non-ICU areas that had a high incidence of hospital-acquired MRSA infection, the rate prior to implementation of contact precautions was 1.3 infections per 1,000 patient-days. After the implementation of contact precautions, the rate in these areas decreased to 0.9 infections per 1,000 patient-days (95% CI, 0.47-0.94; P=.02). CONCLUSION: The implementation of contact precautions significantly decreased the rate of hospital-acquired MRSA infection, and discontinuation of droplet precautions in the ICUs led to a further reduction. Additional studies evaluating specific infection control strategies are needed.     

Resistance in Enterobacteriaceae: results of a multicenter surveillance study, 1995-2000.

OBJECTIVES: To assess changes over time in susceptibility of Enterobacteriaceae from patients in ICUs, compare susceptibility rates of isolates from patients in ICUs with those from inpatients outside ICUs, and explore phenotypic patterns of cross-resistance and co-resistance. DESIGN: From 1995 to 2000, centers participating in the ICU Surveillance Study tested 100 to 200 consecutive nosocomial gram-negative bacilli by broth microdilution. SETTING: Each year, 42 to 97 U.S. hospitals tested isolates. RESULTS: In all years, imipenem was the most potent agent tested, followed by amikacin and ertapenem. Extended-spectrum beta-lactam and monobactam agents had good activity against Escherichia coli and Klebsiella species, but limited activity against Enterobacter species. Susceptibility to imipenem and amikacin did not fluctuate during the analysis period, whereas susceptibility to ceftazidime, ceftriaxone, and ciprofloxacin decreased 2% to 5%. The decline was most pronounced for susceptibility of Escherichia coli to ciprofloxacin: 98.7% of ICU isolates were susceptible in 1995 versus 93.2% in 2000. Susceptibility of ICU isolates was lower than that of non-ICU isolates, except for ciprofloxacin, for which the reverse was true. Cross-resistance was common among extended-spectrum cephalosporins and penicillins, but uncommon between imipenem and ertapenem. Only imipenem and ertapenem remained highly active against Enterobacteriaceae with a phenotype suggesting possible production of an extended-spectrum beta-lactamase and those with a phenotype suggesting possible Amp C hyperproduction. CONCLUSIONS: Imipenem was the most active agent against nosocomial Enterobacteriaceae. Susceptibility to ciprofloxacin decreased from 1995 to 2000, particularly in Escherichia coli, and, in contrast to other agents, was lower among non-ICU isolates.