Overview of catheter-related infections with special emphasis on prevention based on educational programs

Microorganism colonization of peripheral venous catheters in a small animal clinical setting

OBJECTIVE

To compare the incidence of microorganism colonization of peripheral venous catheters (PVCs) placed in the Emergency Department (ED) to those placed in a routine preoperative setting. The relationship between catheter tip colonization and patient urgency (as assessed by triage priority) was also evaluated.

DESIGN

Prospective, observational study from January 2021 to October 2021.

SETTING

Emergency room and clinical areas of a large, urban, tertiary referral center.

ANIMALS

Three hundred dogs and 94 cats with a PVC in place for a minimum of 24 hours were enrolled in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred and eighty-eight PVCs were placed in the ED and 106 were placed preoperatively. The overall colonization rate was 10.4% (41/394). Sixteen bacterial and 1 fungal genera were cultured. Eight of these bacterial genera (25/51 [49%] bacterial isolates) were resistant to at least 1 antimicrobial class. Twenty-nine of 288 (10.1%) catheters positive for colonization were placed in the ED, whereas 12 of 106 (11.3%) were placed preoperatively. There was no association between microorganism growth on catheters and clinical area of catheter placement. There was also no association between ED patient urgency and positive catheter tip culture. No significant risk factors were identified predisposing to colonization of PVCs.

CONCLUSIONS

The overall incidence of microorganism colonization of PVCs in this study population was equivalent to, or lower than, previously reported in veterinary literature. There was no statistical difference between the catheters placed in the ED and those placed for routine surgical procedures. Patient urgency did not affect the incidence of positivity of peripheral catheter tip cultures.

The Evaluation of Central Venous Catheter-related Complications in Pediatric Acute Leukemia Patients: Single Center Experience

Central venous catheters (CVCs) are important for maintenance of childhood leukemia treatment but CVCs may develop complications. The aim of this study was to retrospectively evaluate the CVC-related complication rate, complication types, and outcome in children with acute leukemia. Complications developing in 310 CVCs (ports n=250, Hickman catheters n=60) inserted in 262 patients were evaluated. A total of 225,296 catheter days were screened. Median (range) CVC in-dwelling time was 661.5 (1 to 2636) days. In total, 157 complications developed of which 91 (58%) were infectious complications, 35 (22.3%) were vascular, 19 (12.1%) were surgical, and 12 (7.6%) were mechanical. Hickman catheters had a higher complication rate and were more prone to mechanical complications ( P <0.01) but there was no difference for other complications. A lower absolute neutrophil count at insertion was observed in children with infectious complications ( P <0.01). Seventy-eight of 136 catheters (57.3%) had to be removed prematurely. The overall complication rate was 0.65 per 1000 catheter days. In multivariate analysis, relapse leukemia, Hickman catheter and low absolute neutrophil count increased complication risk by 4.00, 1.97, and 1.92 times, respectively. Five (1.9%) deaths occurred because of catheter complications. Safe use of CVCs can be improved by early detection of complications and an experienced catheter care team.

Colonization and Infection of Indwelling Medical Devices by Staphylococcus aureus with an Emphasis on Orthopedic Implants

The use of indwelling medical devices has constantly increased in recent years and has revolutionized the quality of life of patients affected by different diseases. However, despite the improvement of hygiene conditions in hospitals, implant-associated infections remain a common and serious complication in prosthetic surgery, mainly in the orthopedic field, where infection often leads to implant failure. Staphylococcus aureus is the most common cause of biomaterial-centered infection. Upon binding to the medical devices, these bacteria proliferate and develop dense communities encased in a protective matrix called biofilm. Biofilm formation has been proposed as occurring in several stages-(1) attachment; (2) proliferation; (3) dispersal-and involves a variety of host and staphylococcal proteinaceous and non-proteinaceous factors. Moreover, biofilm formation is strictly regulated by several control systems. Biofilms enable staphylococci to avoid antimicrobial activity and host immune response and are a source of persistent bacteremia as well as of localized tissue destruction. While considerable information is available on staphylococcal biofilm formation on medical implants and important results have been achieved on the treatment of biofilms, preclinical and clinical applications need to be further investigated. Thus, the purpose of this review is to gather current studies about the mechanism of infection of indwelling medical devices by S. aureus with a special focus on the biochemical factors involved in biofilm formation and regulation. We also provide a summary of the current therapeutic strategies to combat biomaterial-associated infections and highlight the need to further explore biofilm physiology and conduct research for innovative anti-biofilm approaches.

Inflammatory, Mechanical and Infectious Complications Associated with Peripheral Intravenous Catheters in Dogs and Cats: A Risk Factor Analysis

The placement of peripheral intravenous catheters (PIVC) is potentially associated with complications that negatively impact healthcare. Our study investigated factors associated with the occurrence of PIVC-related complications in dogs and cats at a Veterinary Teaching Hospital. The second aim was to determine the prevalence of PIVC bacterial colonization. A total of 76 dogs and 40 cats with PIVCs were evaluated for the occurrence of phlebitis and mechanical complications. The devices were removed when they ceased to be functional or when complications occurred, and the content was submitted for bacterial cultures and antimicrobial susceptibility tests. Both multivariable linear regression models and ROC analysis were employed. Complications were recorded in 46.6% of cases, and 20.7% of catheters yielded a positive culture. Among the isolates, 45% were classified as multi-resistant. In dogs, a ≥36-h indwelling time was associated with an increased risk of complications. Male cats seem more prone to developing complications, while the insertion of PIVCs under sedation may represent a protective factor in this species. In conclusion, PIVC-associated complications were frequently observed, and the high rate of positive culture for PIVCs, together with the presence of multi-resistant isolates, is a cause of concern in a hospital setting.

Central line-related bloodstream infections and microbiological study in an Egyptian Ministry of Health Hospital

BACKGROUND

Central line-associated bloodstream infections continue to be one of the most important health problems in ICU.

OBJECTIVES

To identify the central line-related bloodstream infections and their microbiological characteristics Specific objectives to the identify the incidence, predisposing factors of central line-related bloodstream Infections and study the antibiotic sensitivity patterns of the isolated organisms.

MATERIAL AND METHODS

Patients' demographic, clinical data, central venous catheter related data,and blood culture specimen collection data were collected utilizing a descriptive exploratory design from a purposive sample of 120 ICU patients underwent insertion central venous catheter.

RESULTS

out of 120 central line catheters sent for culture from patients immediately and seven days after insertion., 13(10.83%) were positive seven days after insertion. Of the 13 infection cases, 10 cases were Staphylococcus epidermis and the others were Staphylococcus aureus. In addition, most infected patients were overweight and obese, diabetic, had sub-clavian route, and their length of hospital stayed more than7 days.

CONCLUSION

10.83 % developed bacterial blood stream infection 7 days after insertion of central venous catheters, and most of bacterial isolates were Staphylococcus epidermis and were sensitive to Vancomycin and Amikain.

Molecular analysis, biofilm formation, and susceptibility of methicillin-resistant Staphylococcus aureus strains causing community- and health care-associated infections in central venous catheters

INTRODUCTION

The behavior of methicillin-resistant Staphylococcus aureus (MRSA) isolated from central venous catheter-related infection was evaluated to determine its biofilm potential, antimicrobial resistance, and adhesion genes.

METHODS

A total of 1,156 central venous catheters (CVC) were evaluated to screen for pathogens. Antimicrobial sensitivity, biofilm formation potential, and molecular analysis of MRSA were examined following standard guidelines.

RESULTS

Of the 1,156 samples, 882 (76%) were colonized by bacteria or candida. Among the infected patients, 69% were male and 36% were female with median age of 32 years. Staphylococcus aureus infected 39% (344/882) of CVCs in patients. Of the 59% (208/344) of patients with MRSA, 57% had community acquired MRSA and 43% had hospital acquired MRSA. Linezolid and vancomycin killed 100% of MRSA; resistance levels to fusidic acid, doxycycline, clindamycin, azithromycin, amikacin, trimethoprim-sulfamethoxazole, gentamycin, tobramycin, and ofloxacin were 21%, 42%, 66%, 68%, 72%, 85%, 95%, 97%, and 98% respectively. Strong biofilm was produced by 23% of samples, moderate by 27%, and weak by 50% of MRSA. The presence of adhesion genes, sdrC and sdrD (90%), eno (87%), fnbA (80%), clfA and sdrE (67%), fnbB, sdrD (61%), and cna (51%), in most MRSA samples suggested that the adhesion genes are associated with biofilm synthesis.

CONCLUSIONS

The superbug MRSA is a major cause of CVC-related infection. Antibiotic resistance to major classes of antibiotics and biofilm formation potential enhanced superbug MRSA virulence, leading to complicated infection. MRSA causes infection in hospitals, communities, and livestock.

Colonization of medical devices by staphylococci

The use of medical devices in modern medicine is constantly increasing. Despite the multiple precautionary strategies that are being employed in hospitals, which include increased hygiene and sterilization measures, bacterial infections on these devices still happen frequently. Staphylococci are among the major causes of medical device infection. This is mostly due to the strong capacity of those bacteria to form device-associated biofilms, which provide resistance to chemical and physical treatments as well as attacks by the host's immune system. Biofilm development is a multistep process with specific factors participating in each step. It is tightly regulated to provide a balance between biofilm expansion and detachment. Detachment from a biofilm on a medical device can lead to severe systemic infection, such as bacteremia and sepsis. While our understanding of staphylococcal biofilm formation has increased significantly and staphylococcal biofilm formation on medical devices is among the best understood biofilm-associated infections, the extensive effort put in preclinical studies with the goal to find novel therapies against staphylococcal device-associated infections has not yet resulted in efficient, applicable therapeutic options for that difficult-to-treat type of disease.

Incidence of and associated factors for bacterial colonization of intravenous catheters removed from dogs in response to clinical complications

BACKGROUND

Infection rate associated with intravenous (IV) catheter placement is emerging as an important issue in small animal veterinary medicine, mostly because of the economic costs associated with these infections. Identification of possible associated factors may provide useful information for the surveillance and prevention of such infections.

OBJECTIVES

To determine the incidence of positive bacterial cultures obtained from IV catheters used in dogs hospitalized for at least 48 hours and removed because of clinical complication. To identify the bacteria involved and factors associated with bacterial colonization.

ANIMALS

One-hundred eighty-two dogs that underwent IV catheterization from January 2015 to July 2015 at the Veterinary Teaching Hospital of Alfonso X el Sabio University of Madrid were enrolled in the study.

RESULTS

The bacterial colonization rate of all IV catheters removed in response to clinical complications was 39.6%, the cumulative proportion of catheters that remained in place at 24, 48, and 72 hours after placement was 89.5, 78, and 59.4%, respectively. Multivariable Cox proportional hazards regression indicated significant associations for staff who performed catheterization (junior, P = .002; student, P = .034) and use of steroidal anti-inflammatory drugs (P = .036). The most frequently isolated bacterium was Acinetobacter spp. (21.7%).

CONCLUSIONS AND CLINICAL IMPORTANCE

The bacterial colonization incidence related to IV catheter placement was slightly higher than the incidence described in other veterinary studies. Associated factors not previously described in veterinary medicine were found. The most frequently isolated organism was Acinetobacter spp., indicating its importance as an emerging pathogen in catheter colonization.

Evaluation of the placement and maintenance of central venous jugular catheters in critically ill dogs and cats

OBJECTIVE

To describe problems noted during central venous jugular catheter (CVJC) placement, conditions associated with unsuccessful catheterization, and CVJC maintenance complications.

DESIGN

Prospective observational study from September 2014 to September 2015.

SETTING

University veterinary teaching hospital.

ANIMALS

Twenty-seven dogs and 20 cats hospitalized in a veterinary ICU. Patients were excluded if previously hospitalized with a CVJC or lacked sufficient data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Ninety-one percent of indwelling CVJCs were placed successfully (43/47, 95% CI: 80%, 98%). Procedural-related difficulties that resulted in the inability to place a CVJC totaled 18/63 (28.6%, 95% CI: 18%, 41%) and included the inability to puncture the vessel (10), hematoma (6), malposition (1), and dislodgement (1). Procedural complications occurred in 24/47 patients (51%, 95% CI: 36%, 66%) and included cardiac dysrhythmias (13), hematoma (6), CVJC placement failure (4), and malposition (1). Risk factors associated with multiple catheterization attempts included increased age (7.5 years [± 4.2] vs 10.6 years [± 4.1], P = 0.04), smaller size (8.0 kg [0.6-51.9 kg] vs 4.4 kg [2.6-6.8 kg], P < 0.01) and thinner body condition score (median 5/9 [2/9-9/9] vs 4/9 [2/9-7/9], P = 0.04). The risk factor associated with dysrhythmias was smaller patient size (6.8 kg [2.6-51.9 kg] vs 4.8 kg [0.6-29.5 kg], P = 0.04). Eighteen indwelling complications occurred in 14 patients and included mechanical obstruction (7), skin irritation (6), malposition (4), and inflammation (1). Risk factors for indwelling complications included longer dwell time (5 days [2-30] vs 3 days [1-10], P < 0.01) and the administration of an irritant medication (P = 0.02).

CONCLUSIONS

Complications were documented in the placement and maintenance of CVJCs in critically ill patients with a low incidence of life-threatening sequelae. Risk factors associated with both unsuccessful CVJC placement and indwelling CVJC complications were identified.

Extravasation reactions associated with the administration of pamidronate: 11 cases (2008-2013)

Pamidronate is a bisphosphonate drug widely utilized in veterinary oncologic practice for the palliation of malignant osteolysis. Pamidronate has not been previously reported to cause tissue injury upon extravasation in dogs. The medical records of 11 client-owned dogs undergoing palliative treatment for primary bone tumors with known or suspected pamidronate extravasation reactions were reviewed. The majority of adverse events were low grade in nature, however in some cases, the reactions were severe and led to euthanasia in one instance. Time to complete resolution of lesions ranged from within several days to greater than one and a half months. Aside from the dog that was euthanized, no long-term sequelae of extravasation were identified. Treatments employed to address the reactions varied widely. Pamidronate extravasation reaction appears to be an uncommon, but potentially serious complication of intravenous administration.

Validation of a Sampling Method to Collect Exposure Data for Central-Line–Associated Bloodstream Infections

OBJECTIVE

Surveillance of central-line–associated bloodstream infections requires the labor-intensive counting of central-line days (CLDs). This workload could be reduced by sampling. Our objective was to evaluate the accuracy of various sampling strategies in the estimation of CLDs in intensive care units (ICUs) and to establish a set of rules to identify optimal sampling strategies depending on ICU characteristics.

DESIGN

Analyses of existing data collected according to the European protocol for patient-based surveillance of ICU-acquired infections in Belgium between 2004 and 2012.

SETTING AND PARTICIPANTS

CLD data were reported by 56 ICUs in 39 hospitals during 364 trimesters.

METHODS

We compared estimated CLD data obtained from weekly and monthly sampling schemes with the observed exhaustive CLD data over the trimester by assessing the CLD percentage error (ie, observed CLDs – estimated CLDs/observed CLDs). We identified predictors of improved accuracy using linear mixed models.

RESULTS

When sampling once per week or 3 times per month, 80% of ICU trimesters had a CLD percentage error within 10%. When sampling twice per week, this was >90% of ICU trimesters. Sampling on Tuesdays provided the best estimations. In the linear mixed model, the observed CLD count was the best predictor for a smaller percentage error. The following sampling strategies provided an estimate within 10% of the actual CLD for 97% of the ICU trimesters with 90% confidence: 3 times per month in an ICU with >650 CLDs per trimester or each Tuesday in an ICU with >480 CLDs per trimester.

CONCLUSION

Sampling of CLDs provides an acceptable alternative to daily collection of CLD data.

Infect Control Hosp Epidemiol 2016;37:549–554

Incidence, risk factors, microbiology of venous catheter associated bloodstream infections--a prospective study from a tertiary care hospital

PURPOSE

Central venous catheters (CVCs) though indispensable in current medical and intensive care treatment, also puts patients at risk of catheter related infection (CRI) resulting in increased morbidity and mortality. We analysed the incidence, risk factors, bacteriological profile and antimicrobial susceptibility pattern of the isolates in central venous catheter associated bloodstream infection (CVC-BSI) in the intensive care unit (ICU) patients and studied the formation of biofilm in CVCs.

MATERIALS AND METHODS

The following case control study included 115 patients with CVC in situ. Quantitative blood cultures (QBC) and catheter tip cultures were performed for the diagnoses. Direct catheter staining was done for an early diagnosis by acridine orange (AO) and Gram staining methods. Biofilm production in catheters was detected by 'tissue culture plate' (TCP) method. The results were analysed using the computer-based program statistical package for the social sciences (SPSS).

RESULTS

In 25/115 patients, definite diagnosis of CVC-BSI was made. The mean age was 48.44 ± 17.34 years (cases) vs 40.10 ± 18.24 years (controls) and the mean duration of catheterisation was 25.72 ± 8.73 days (cases) vs 11.89 ± 6.38 days (controls). Local signs of infection (erythema, tenderness and oozing) were found more significantly in CVC-BSI cases. The AO staining was more sensitive and Gram staining of catheters showed higher specificity. Staphylococcus aureus followed by Pseudomonas aeruginosa and non-albicans Candida were common CVC-BSI pathogens. Multidrug-resistant (MDR) strains were isolated in bacterial agents of CVC-BSI. Non-albicans Candida and Enterococcus faecalis showed strong biofilm production.

CONCLUSION

The incidence of CVC-BSI was 21.73% and the rate was 14.59 per 1000 catheter days. Prolonged ICU stay and longer catheterisation were major risk factors. S. aureus was isolated most commonly in CVC-BSI cases. The menace of multidrug resistance and biofilm formation in CVCs is associated with CVC-BSI.

Accuracy of using automated methods for detecting adverse events from electronic health record data: a research protocol

Background

Adverse events are associated with significant morbidity, mortality and cost in hospitalized patients. Measuring adverse events is necessary for quality improvement, but current detection methods are inaccurate, untimely and expensive. The advent of electronic health records and the development of automated methods for encoding and classifying electronic narrative data, such as natural language processing, offer an opportunity to identify potentially better methods. The objective of this study is to determine the accuracy of using automated methods for detecting three highly prevalent adverse events: a) hospital-acquired pneumonia, b) catheter-associated bloodstream infections, and c) in-hospital falls.

Methods/design

This validation study will be conducted at two large Canadian academic health centres: the McGill University Health Centre (MUHC) and The Ottawa Hospital (TOH). The study population consists of all medical, surgical and intensive care unit patients admitted to these centres between 2008 and 2014. An automated detection algorithm will be developed and validated for each of the three adverse events using electronic data extracted from multiple clinical databases. A random sample of MUHC patients will be used to develop the automated detection algorithms (cohort 1, development set). The accuracy of these algorithms will be assessed using chart review as the reference standard. Then, receiver operating characteristic curves will be used to identify optimal cut points for each of the data sources. Multivariate logistic regression and the areas under curve (AUC) will be used to identify the optimal combination of data sources that maximize the accuracy of adverse event detection. The most accurate algorithms will then be validated on a second random sample of MUHC patients (cohort 1, validation set), and accuracy will be measured using chart review as the reference standard. The most accurate algorithms validated at the MUHC will then be applied to TOH data (cohort 2), and their accuracy will be assessed using a reference standard assessment of the medical chart.

Discussion

There is a need for more accurate, timely and efficient measures of adverse events in acute care hospitals. This is a critical requirement for evaluating the effectiveness of preventive interventions and for tracking progress in patient safety through time.

Health care workers' knowledge and practices regarding the prevention of central venous catheter-related infection

BACKGROUND

Central venous catheter-related infection (CVC-RI) is considered a common cause of increased morbidity, mortality, and medical care costs in intensive care units (ICUs). The objective in this descriptive study was to assess the knowledge of health care workers in ICUs about guidelines for the prevention of CVC-RI and their adherence to these guidelines in practices.

METHODS

Health care workers were assessed for their actual practices during central venous catheter (CVC) insertion and care. Then a questionnaire was distributed to the health care workers to assess their knowledge regarding the prevention of CVC-RI.

RESULTS

All the health care workers (N = 100; 40 physicians, 60 nurses) in the ICUs (levels I and III and triage) of Alexandria Main University Hospital participated in the present study. The response rate was 100%. The total percentage of correct answers of the health care workers about the guidelines for the prevention of CVC-RI was low. There was no significant difference between physicians' and nurses' knowledge regarding the total score on the questionnaire (P = .134). However, physicians had a significantly higher knowledge about the pathophysiology of CVC-RI and skin antisepsis items than nurses. There were no significant differences between the knowledge of physicians and nurses in other items except for CVC care, where nurses showed significantly higher knowledge than physicians (P = .001).

CONCLUSION

The results of the present study revealed health care worker's low knowledge regarding the prevention of CVC-RI and low compliance with the standard guidelines of CVC care. Therefore, health care workers should be periodically evaluated for their knowledge and practices regarding guidelines for the prevention of CVC-RI.

Complications Related to Insertion and Use of Central Venous Catheters (CVC)

Introduction:

Central Venous Catheters (CVC) are essential in everyday medical practice, especially in treating patients in intensive care units (ICU). The application of these catheters is accompanied with the risk of complications, such as the complications caused during the CVC insertion, infections at the location of the insertion, and complications during the use of the catheter, sepsis and other metastatic infections.

Patients and methods:

This study is a retrospective-prospective and it was implemented in the period 1^st January 2011- 31^st December 2012. It included 108 examinees with CVC placed for more than 7 days.

Results:

The most common complications occurring in more than 2 attempts of CVC applications are: hearth arrhythmias in both groups in 12 cases, 7 in multi-lumen (12.72%) and 5 in mono-lumen ones (9.43%). Artery puncture occurs in both groups in 7 cases, 5 in multi-lumen (9.09%) and 2 in mono-lumen ones (3.77%). Hematoma occurred in both groups in 4 cases, 3 in multi-lumen CVCs (5.45%) and 1 in mono-lumen ones (1.88%). The most common complication in multi-lumen catheters was heart arrhythmia, in 20 cases (36.37%). The most common complications in mono-lumen CVCs was hearth arrhythmias, in 20 cases as extrasystoles and they were registered in 16 catheter insertions (30.18%). Out of total number of catheters of both groups, out of 108 catheters the complications during insertion occurred in 49 catheters (45.40%). The most common complications in both groups were heart arrhythmias, artery punctures and hematomas at the place of catheter insertion.

Genotypic study documents divergence in the pathogenesis of bloodstream infection related central venous catheters in neonates

Objective

To investigate the pathogenesis of bloodstream infection by Staphylococcus epidermidis, using the molecular epidemiology, in high-risk neonates.

Methods

We conducted a prospective study of a cohort of neonates with bloodstream infection using central venous catheters for more than 24 h. “National Healthcare Safety Network” surveillance was conducted. Genotyping was performed by DNA fingerprinting and mecA genes and icaAD were detected by multiplex-PCR.

Results

From April 2006 to April 2008, the incidence of bloodstream infection and central venous catheter-associated bloodstream infection was 15.1 and 13.0/1000 catheter days, respectively, with S. epidermidis accounting for 42.9% of episodes. Molecular analysis was used to document the similarity among six isolates of bloodstream infection by S. epidermidis from cases with positive blood and central venous catheter tip cultures. Fifty percent of neonates had bloodstream infection not identified as definite or probable central venous catheter-related bloodstream infection. Only one case was considered as definite central venous catheter-related bloodstream infection and was extraluminally acquired; the remaining were considered probable central venous catheter-related bloodstream infections, with one probable extraluminally and another probable intraluminally acquired bloodstream infection. Additionally, among mecA+ and icaAD+ samples, one clone (A) was predominant (80%). A polyclonal profile was found among sensitive samples that were not carriers of the icaAD gene.

Conclusions

The majority of infections caused by S. epidermidis in neonates had an unknown origin, although 33.3% appeared to have been acquired intraluminally and extraluminally. We observed a polyclonal profile between sensitive samples and a prevalent clone (A) between resistant samples.

A prospective randomised trial to compare the efficacy of povidone-iodine 10% and chlorhexidine 2% for skin disinfection

Context:

Infectious complications of invasive procedures affect patient outcomes adversely. Choice of antiseptic solution at the time of insertion is one of the major factors affecting their incidence.

Aims:

This study was undertaken to compare efficacy of chlorhexidine 2% and povidone iodine 10% for skin disinfection prior to placement of epidural and central venous catheters (CVCs).

Settings and Design:

A prospective randomised trial in the operating rooms of a tertiary referral cancer centre.

Methods:

Sixty consecutive adult patients undergoing elective oncosurgery requiring placement of epidural and CVCs were enrolled. Paired skin swabs were collected before and after application of the antiseptic solution. The samples were incubated in McConkey's media and blood agar at 35°C for up to 24 h. Any bacterial growth was graded as: <10 colonies - poor growth, 10-50 colonies - moderate growth and >50 colonies as heavy growth. Data on demographics and antibiotic prophylaxis and costs was collected for all patients.

Statistical Analysis:

Student's t-test and Mann-Whitney tests were used to analyse data, P<0.05 was considered significant.

Results:

Demographics and antibiotic prophylaxis use was similar in both groups. Before application of antiseptic solution, a variety of micro-organisms were grown from most patients with growth ranging from none-heavy. No organism was grown after application of either antiseptic solution from any patient.

Conclusions:

We found no differences between 2% chlorhexidine and 10% povidone-iodine for skin disinfection in regard to costs, efficacy or side-effects.

Catheter-associated bloodstream infections in pediatric hematology-oncology patients

Catheter-associated bloodstream infections (CABSIs) are common complications encountered with cancer treatment. The aims of this study were to analyze the factors associated with recurrent infection and catheter removal in pediatric hematology-oncology patients. All cases of CABSIs in patients attending the Department of Pediatric Hematology-Oncology between January 2008 and December 2010 were reviewed. A total of 44 episodes of CABSIs, including multiple episodes involving the same catheter, were identified in 31 children with cancer. The overall CABSIs rate was 7.4 infections per 1000 central venous catheter (CVC) days. The most frequent organism isolated was coagulase-negative Staphylococcus (CONS). The CVC was removed in nine (20.4%) episodes. We found that hypotension, persistent bacteremia, Candida infection, exit-side infection, neutropenia, and prolonged duration of neutropenia were the factors for catheter removal. There were 23 (52.2%) episodes of recurrence or reinfection. Mortality rate was found to be 9.6% in children with CABSIs. In this study, we found that CABSIs rate was 7.4 infections per 1000 catheter-days. CABSIs rates in our hematology-oncology patients are comparable to prior reports. Because CONS is the most common isolated microorganism in CABSIs, vancomycin can be considered part of the initial empirical regimen.

[Venous catheter-related infections]

Central venous catheter-related infections can lead to a substantial increase in morbidity and mortality in patients. Nowadays, with the increase in multi-resistant bacteria, the recent appearance of new antibiotics, and the development of new treatment guidelines, means that this has to be constantly reviewed. The objective of this review is to briefly define the epidemiological and pathogenic concepts and to look in detail at the preventive and therapeutic measures of this type of infection. Practical aspects are presented of different clinical situations such as, antibiotic-lock of the central venous catheter, and the withdrawal or maintenance of the catheter.

Catheter-related bloodstream infections in neonatal intensive care units

Central venous catheters (CVCs) are regularly used in intensive care units, and catheter-related bloodstream infection (CRBSI) remains a leading cause of healthcare-associated infections, particularly in preterm infants. Increased survival rate of extremely-low-birth-weight infants can be partly attributed to routine practice of CVC placement. The most common types of CVCs used in neonatal intensive care units (NICUs) include umbilical venous catheters, peripherally inserted central catheters, and tunneled catheters. CRBSI is defined as a laboratory-confirmed bloodstream infection (BSI) with either a positive catheter tip culture or a positive blood culture drawn from the CVC. BSIs most frequently result from pathogens such as gram-positive cocci, coagulase-negative staphylococci, and sometimes gram-negative organisms. CRBSIs are usually associated with several risk factors, including prolonged catheter placement, femoral access, low birth weight, and young gestational age. Most NICUs have a strategy for catheter insertion and maintenance designed to decrease CRBSIs. Specific interventions slightly differ between NICUs, particularly with regard to the types of disinfectants used for hand hygiene and appropriate skin care for the infant. In conclusion, infection rates can be reduced by the application of strict protocols for the placement and maintenance of CVCs and the education of NICU physicians and nurses.

Bacterial and fungal colonisation of peripheral intravenous catheters in dogs and cats

OBJECTIVES

The purposes of this study were to determine the prevalence of intravenous catheter colonisation in a routine clinical setting, to identify pathogens involved and to explore factors associated with an increased risk of colonisation.

METHODS

A prospective study of 100 peripherally placed intravenous catheters from 13 cats and 78 dogs was conducted. The distal two-thirds were removed and submitted for bacterial and fungal cultures. Antimicrobial susceptibility of each isolate was determined.

RESULTS

Nineteen peripheral catheters were positive for microbiologic culture from 14 animals. Twenty organisms were isolated among which Staphylococcus species was the most common. Isolates displayed lower levels of resistance against the antimicrobial agents amoxicillin-clavulanate, cephalosporins and gentamicin than against other agents tested. Major risk factors predisposing to catheter-related colonisation included dextrose infusion, duration of catheter placement, local complications and immunosuppressive diseases or drugs.

CLINICAL SIGNIFICANCE

In a routine clinical setting, the prevalence of microbial colonisation of peripheral intravenous catheters is comparable to that found in an intensive care unit. However, consequences on morbidity and mortality rates differ.

Preventing surgical site infections

The risk of surgical site infection (SSI) is approximately 1-3% for elective clean surgery. Apart from patient endogenous factors, the role of external risk factors in the pathogenesis of SSI is well recognized. However, among the many measures to prevent SSI, only some are based on strong evidence, for example, adequate perioperative administration of prophylactic antibiotics, and there is insufficient evidence to show whether one method is superior to any other. This highlights the need for a multimodal approach involving active post-discharge surveillance, as well as measures at every step of the care process, ranging from the operating theater to postoperative care. Multicenter or supranational intervention programs based on evidence-based guidelines, 'bundles' or safety checklists are likely to be beneficial on a global scale. Although theoretically reducible to zero, the maximal realistic extent by which SSI can be decreased remains unknown.

A prospective 7-year survey on central venous catheter-related complications at a single pediatric hospital

The aims of this study were to assess the incidence and risk factors of major central venous catheter (CVC)-related complications in a large cohort of children affected by oncological, hematological, or immunological diseases in a 7-year prospective observational study at a single center. Nine hundred fifteen CVCs were inserted in 748 children for a total period of 307,846 CVC-days. Overall, 298 complications were documented with a complication rate of 0.97/1,000 CVC-days: 105 mechanical complications (dislocations 0.30/1,000 CVC-days, ruptures 0.04/1,000 CVC-days), 174 infections (bloodstream infections 0.46/1,000 CVC-days, tunnel infections 0.10/1,000 CVC-days), and 19 thrombosis (0.06/1,000 CVC-days). Significant risk factors were: diagnosis of acute lymphoblastic leukemia (ALL) and age <or=3 years for dislocations; nonmalignant disease for ruptures; ALL for thrombosis; double-lumen and partially implanted CVCs for bloodstream infections; age <or=3 years for tunnel infections. In conclusion, the rate of CVC-related complications in children was lower than that usually reported.

Occurrence of bloodstream infection with different types of central vascular catheter in critically neonates

OBJECTIVE

The aim of this research was to assess the incidence of CVC-associated/related to bloodstream infection (BSI) to different types of CVC, by classes of neonatal birth weight.

METHODS

The research was conducted in the Neonatal Intensive Care Unit of Uberlandia University Hospital from April/2006 through April/2008. The population analyzed comprised neonates who had at least one CVC placed for longer than 24h, followed-up through epidemiologic vigilance "National Healthcare Safety Network". Patients were followed daily from their entry into the study to their discharge or death.

RESULTS

At birth, 50.7% of neonates had low weight (< or = 1500g), 24.5% between 1501 and 2500g and 24.8% over 2500g. The highest density of CVC use (0.96) was found in neonates with birth weight ranging from 751g to 1000g. The incidence of CVC-associated/related to BSI was 13.0 and 2.1 per 1000 days CVC, respectively, and the higher representativeness in the weight group of 1501-2500g (15.8) and < or = 750g (3.3), respectively. A higher proportion of CVC-associated to BSI was observed in PICC (6.0) than in the other CVCs (P<0.01). Coagulase negative Staphylococcus was the most common microorganism (39.7%) in BSI, followed by Staphylococcus aureus (24. 6%) and Gram-negative bacilli (19.2%).

CONCLUSION

Although neonates weighing less than 750g comprise the group with lower representativeness at the unit (5.4%), they reveal the highest CVC related to BSI incidence rate (3.3/1000 days CVC).

Foreign body infections due to Staphylococcus epidermidis

Staphylococcal infections are one of the main causes of complications in patients with implanted foreign prosthetic material. Implants are associated with a significant reduction of the threshold at which contaminating Gram-positive bacteria, particularly Staphylococcus epidermidis, become infectious and develop a biofilm with phenotypic resistance to almost all antibiotics. A 1000-fold increase in minimal bactericidal levels against most antibiotics except rifampin has been repeatedly observed. Since only removal of the foreign material reverses these phenomena, the clinical challenge consists in finding approaches to cure the infection without removal of the implanted device. Rifampin combinations with other antibiotics, administration of exceedingly high antibiotic concentrations in situ, and early therapy before biofilm development are efficacious. Although these strategies have dramatically improved the outcome of foreign body infections, an improved understanding of biofilm-grown S. epidermidis is necessary to develop new antibacterial agents. Here, we review the pathogenesis, prevention, and treatment of implant infections due to S. epidermidis and highlight some new compounds with already promising in vitro results.

[Intensive care nurses' knowledge about the evidence-based guidelines of preventing central venous catheter related infection]

OBJECTIVES

To determine intensive care unit (ICU) nurses' knowledge of evidence-based guidelines for preventing central venous catheter (CVC) related infection.

METHOD

We used a validated multiple-choice questionnaire which was distributed to intensive care units between October and December 2006. We collected demographic data, like gender, years of ICU experience, number of ICU beds and whether respondents hold a special degree in intensive care.

RESULTS

We collected 178 questionnaires from 11 intensive care units; the mean score was 3.66 on 10 questions (37%). Eighteen per cent knew that CVCs should be replaced on indication only, and 61% knew that this recommendation concerns also replacement over a guidewire. Recommendations for replacing pressure transducers and tubing every 4 days, and for using coated devices in patients requiring a CVC < 5 days in settings with high infection rates were recognized only by 48% and 66%, respectively. Regarding CVC dressings, 15% knew that these should be changed only when indicated and at least once weekly, and 35% recognized that both poly-urethane and gauze dressings can be recommended. Only 20% checked 2% aqueous chlorhexidine as recommended disinfection solution; 14% knew antibiotic ointments are not recommended because they trigger resistance. The recommendation to replace administration sets within 24 hours after administering lipid emulsions was recognized by 85%, but it was known by 5% only that these sets should be replaced every 96 hours when administering neither lipid emulsions nor blood products. Professional seniority and the number of intensive care beds in the ICU where nurses work showed not to be associated with better scores on the test.

DISCUSSION

Knowledge regarding CVC-related infection is poor among Hungarian nurses. Prevention guidelines should be included in the nurse education curriculum as well as in continuing refresher nursing education programs.

Vascular catheter-associated infections: a microbiological and therapeutic update

The increasing incidence of central venous catheter (CVC)-related infections can be ascribed to the wider indications to central venous catheterization, to the higher attention to this issue paid by clinicians and microbiologists, and to the patient population referred to hospitals, increasingly characterized by different degrees of immunosuppression and often in critical clinical conditions. This phenomenon implies a higher health care burden and higher related costs, as well as a significant attributable mortality, that varies however according to the pathogen involved. The microorganisms most frequently involved in CVC-related infections are coagulase-negative staphylococci, Staphylococcus aureus, aerobic Gram-negative bacilli, and Candida albicans. In the management of suspected or proven central venous catheter-related infections, several issues need to be addressed: the need to remove the device or the possibility of salvage, the immediate start of calculated antibiotic therapy or the possibility of waiting for results of microbiological diagnostics and proceeding to etiologically-guided therapy. The preferred conservative method is the "Antibiotic-Lock technique" (ALT), based on the endoluminal application of antibacterials at extremely high concentrations in situ for a period of time long enough to ensure bactericidal activity. On the other hand, immediate catheter removal and initiation of appropriate calculated therapy immediately after an adequate diagnostic work-up are strongly recommended in a clinical setting of severe sepsis or septic shock.

Intensivist supervision of resident-placed central venous catheters decreases the incidence of catheter-related blood stream infections

Catheter-related blood stream infections (CRBSI) cause significant morbidity and mortality. A retrospective study of a performance improvement project in our teaching hospital's surgical intensive care unit (SICU) showed that intensivist supervision was important in reinforcing maximal sterile barriers (MSB) use during the placement of a central venous catheter (CVC) in the prevention of CRBSI. A historical control period, 1 January 2001-31 December 2003, was established for comparison. From 1 January 2003-31 December 2007, MSB use for central venous line placement was mandated for all operators. However, in 2003 there was no intensivist supervision of CVC placements in the SICU. The use of MSB alone did not cause a significant change in the CRBSI rate in the first year of the project, but close supervision by an intensivist in years 2004-2007, in conjunction with MSB use, demonstrated a significant drop in the CRBSI rate when compared to the years before intensivist supervision (2001-2003), p < .0001. A time series analysis comparing monthly rates of CRBSI (2001-2007) also revealed a significant downward trend, p = .028. Additionally, in the first year of the mandated MSB use (2003), 85 independently observed resident-placed CVCs demonstrated that breaks in sterile technique (34/85), as compared those placements that had no breaks in technique (51/85), had more CRBSI, 6/34 (17.6%) vs. 1/51 (1.9%), p < .01. Interventions to reduce CRBSI in our SICU needed emphasis on adequate supervision of trainees in CVC placement, in addition to use of MSB, to effect lower CRBSI rates.

Prevention of primary bacteraemia

This overview provides information on recent advances in the prevention of primary bacteraemia, commonly defined as bloodstream infection without a documented source of infection, but including those resulting from an intravenous or arterial line infection. The potential to prevent community-acquired, primary bacteraemia is still limited and may be targeted mainly at vaccines for high-risk groups. In contrast, the prevention of catheter-related bacteraemia has seen substantial progress within the last 10 years. Consequently, intravascular device-related bacteraemia has become largely preventable under routine working conditions. Independent of the use of antibiotic-coated catheters, the implementation of clinical pathways and multimodal preventive strategies directed at several risk factors of catheter-related bacteraemia is a successful strategy to reduce this potentially life-threatening infection and deserves future health services research.

Evidence-based guidelines for the prevention of ventilator-associated pneumonia: results of a knowledge test among intensive care nurses

OBJECTIVE

To determine intensive care nurses' knowledge of evidence-based guidelines for the prevention of ventilator-associated pneumonia (VAP).

DESIGN

A survey using a validated multiple-choice questionnaire, developed to evaluate nurses' knowledge of VAP prevention. The questionnaire was distributed and collected during the annual congress of the Flemish Society for Critical Care Nurses (Ghent, November 2005). Demographic data included were gender, years of intensive care experience, number of critical beds, and whether respondents hold a special degree in emergency and intensive care.

MAIN RESULTS

We collected 638 questionnaires (response rate 74.6%). Nineteen percent of the respondents recognized the oral route as the recommended way for intubation. It was known by 49% of respondents that ventilator circuits should be changed for each new patient. Heat and moisture exchangers were checked as the recommended type of humidifier by 55% of respondents, but only 13% knew that it is recommended to change them once weekly. Closed suctioning systems were identified as recommended by 17% of respondents, and 20% knew that these must be changed for each new patient only. Sixty percent and 49%, respectively, recognized subglottic drainage and kinetic beds to reduce the incidence of VAP. Semi-recumbent positioning is well known to prevent VAP (90%). The average knowledge level was higher among more experienced nurses (> 1 year experience) and those holding a special degree in emergency and intensive care.

CONCLUSION

Nurses lack knowledge regarding recommendations for VAP prevention. Nurses' schooling and continuing education should include support from current evidence-based guidelines.

Surveillance of infections associated with intravenous catheters in dogs and cats in an intensive care unit

Positive catheter-tip culture rates and risk factors associated with bacterial colonization of intravenous (i.v.) catheters were assessed in dogs and cats. Aerobic and anaerobic bacterial cultures were performed on 151 catheters, and 24.5% were positive. Of the positive cultures, 46.0% grew Enterobacter spp. The type of catheter used, blood sampling through the catheter, the type of i.v. infusate administered, the duration the catheter was in place, the catheter location, complications with the catheter, and the final outcome of the animal were not associated with an increased risk of a positive bacterial culture from the catheter tip.

Incidence and risk factors of device-associated infections and associated mortality at the intensive care in the Dutch surveillance system

OBJECTIVE

To examine the incidence of and risk factors for device-associated infections and associated mortality.

DESIGN AND SETTING

Prospective surveillance-based study in ICUs of 19 hospitals in The Netherlands.

PATIENTS

The study included 2,644 patients without infection at admission during 1997-2000, staying in the ICU for at least 48 h.

MEASUREMENTS AND RESULTS

The occurrence of ventilator-associated pneumonia (VAP), central venous catheter (CVC) related bloodstream infection (CR-BSI), urinary catheter-associated urinary tract infection (CA-UTI) and risk factors was monitored. Of the ventilated patients 19% developed pneumonia (25/1,000 ventilator days); of those with a central line 3% developed CR-BSI (4/1,000 CVC days,) and of catheterized patients 8% developed CA-UTI (9/1,000 catheter days). Longer device use increased the risk for all infections, especially for CR-BSI. Independent risk factors were sex, immunity, acute/elective admission, selective decontamination of the digestive tract, and systemic antibiotics at admission, dependent upon the infection type. Crude mortality significantly differed in patients with and without CR-BSI (31% vs. 20%) and CA-UTI (27% vs. 17%) but not for VAP (26% vs. 23%). Acquiring a device-associated infection was not an independent risk factor for mortality. Being in need of ventilation or a central line, and the duration of this, contributed significantly to mortality, after adjusting for other risk factors.

CONCLUSIONS

Device use was the major risk factor for acquiring VAP, CR-BSI and CA-UTI. Acquiring a device-associated infection was not an independent risk factor for mortality, but device use in itself was.

Implementation of a Written Protocol for Management of Central Venous Access Devices

The objectives of this study were to evaluate registered nurses' (RN) compliance with a local clinical central venous access device (CVAD) protocol after completing an educational program and to determine RNs' perception of the program. Seventy-five RNs working in hematology participated in the educational part of the program. Sixty-eight RNs were examined while changing CVAD dressings or placing a Huber needle into a port on actual patients. Sixty percent of the RNs passed the examination and reported that the program increased their knowledge. The results indicated that the educational program could be recommended for use when implementing a new clinical protocol.

Enhanced surveillance of meticillin-resistant Staphylococcus aureus bacteraemia in a London teaching hospital

In 2001, the UK Department of Health introduced mandatory surveillance of meticillin-resistant Staphylococcus aureus (MRSA) bacteraemias (blood-culture-positive episodes) in English hospitals. We performed enhanced surveillance in their hospital between April 2001 and March 2003 to determine the epidemiology of MRSA bacteraemia across different specialities. There were 267 MRSA-blood-culture-positive episodes, giving a rate of 0.37 per 1000 occupied bed-days (OBD). Thirty-three (12.4%) episodes were false positives due to contaminants and 15 (5.6%) originated in the community or at another institution. Thirty-one (11.6%) episodes were in outpatients or occurred after recent discharge and were designated 'hospital associated'. The remaining 188 cases were clinically significant hospital-acquired episodes in inpatients, with a rate of 0.26 per 1000 OBDs. The highest rates were in the intensive therapy unit (ITU; 2.74 per 1000 OBDs) and the high-dependency unit (HDU; 1.68 per 1000 OBDs). Fifty-five non-ITU, non-HDU episodes occurred in patients who had been discharged from ITU or HDU prior to the development of bacteraemia but during the same admission. The number of MRSA bacteraemias related to ITU/HDU suggests that these wards may be hubs of MRSA infection. Haematology, oncology and renal (HOR) patients had the greatest number of hospital-associated episodes. The most common source of MRSA bacteraemia was a vascular access device (VAD) (108 episodes, 57%, 64% of which were central lines). The high bacteraemia rates in ITU, HDU and HOR patients were associated with high usage of VADs. The majority of episodes occurred in patients who were newly colonized with MRSA after admission. Thus, in this hospital, VADs and stays in ITU or HDU are important risk factors for bacteraemia, and VAD care and prevention of cross-infection are priorities for intervention. We recommend that the mandatory national surveillance scheme should collect additional data on MRSA bacteraemia to provide information for a national strategy for MRSA control and to allow appropriate comparison between institutions.

Central venous access device infections in the critical care unit

Central venous access devices are indispensable tools in caring for the gravely ill patients in today's critical care units. Unfortunately, they are also one of the major sources for nosocomial infections in the hospital setting. This article explores the pathophysiology and risk factors related to central venous access devices infections, and examine prevention strategies. The critical care nurse, using evidence-based practice guidelines in the care of these lines, can be instrumental in preventing catheter-related infections.

Using real time process measurements to reduce catheter related bloodstream infections in the intensive care unit

PROBLEM

Measuring a process of care in real time is essential for continuous quality improvement (CQI). Our inability to measure the process of central venous catheter (CVC) care in real time prevented CQI efforts aimed at reducing catheter related bloodstream infections (CR-BSIs) from these devices.

DESIGN

A system was developed for measuring the process of CVC care in real time. We used these new process measurements to continuously monitor the system, guide CQI activities, and deliver performance feedback to providers.

SETTING

Adult medical intensive care unit (MICU).

KEY MEASURES FOR IMPROVEMENT

Measured process of CVC care in real time; CR-BSI rate and time between CR-BSI events; and performance feedback to staff.

STRATEGIES FOR CHANGE

An interdisciplinary team developed a standardized, user friendly nursing checklist for CVC insertion. Infection control practitioners scanned the completed checklists into a computerized database, thereby generating real time measurements for the process of CVC insertion. Armed with these new process measurements, the team optimized the impact of a multifaceted intervention aimed at reducing CR-BSIs.

EFFECTS OF CHANGE

The new checklist immediately provided real time measurements for the process of CVC insertion. These process measures allowed the team to directly monitor adherence to evidence-based guidelines. Through continuous process measurement, the team successfully overcame barriers to change, reduced the CR-BSI rate, and improved patient safety. Two years after the introduction of the checklist the CR-BSI rate remained at a historic low.

LESSONS LEARNT

Measuring the process of CVC care in real time is feasible in the ICU. When trying to improve care, real time process measurements are an excellent tool for overcoming barriers to change and enhancing the sustainability of efforts. To continually improve patient safety, healthcare organizations should continually measure their key clinical processes in real time.

Octenidine hydrochloride for the care of central venous catheter insertion sites in severely immunocompromised patients

OBJECTIVE

To determine the efficacy and tolerability of octenidine hydrochloride, a non-alcoholic skin antiseptic, for the care of central venous catheter (CVC) insertion sites.

DESIGN

Prospective, observational study.

SETTING

Bone marrow transplantation unit of a university hospital.

PATIENTS

All consecutive patients with a nontunneled CVC were enrolled prospectively after informed consent.

METHODS

Octenidine hydrochloride (0.1%) was applied for disinfection at the CVC insertion site during dressing changes. The following cultures were performed weekly as well as at the occurrence of any systemic inflammatory response syndrome criteria: cultures of the skin surrounding the CVC entry site, cultures of the three-way hub connected to the CVC, blood cultures, and cultures of the CVC tip on removal. Enhanced microbiological methods (skin swabs of a 24-cm2 standardized area, roll plate, and sonication of catheter tips) were applied.

RESULTS

One hundred thirty-five CVCs were inserted in 62 patients during the study period and remained for a mean period of 19.1 days, corresponding to 2,462 catheter-days. Bacterial density at the insertion site declined substantially over time, and most cultures became negative 2 weeks after insertion. Only 6 patients had a documented catheter-related bloodstream infection. The incidence density was 2.39 catheter infections per 1,000 catheter-days. No side effects were noted with application of the antiseptic.

CONCLUSIONS

Disinfection with a skin antiseptic that contains octenidine hydrochloride is highly active and well tolerated. It leads to a decrease in skin colonization over time and may be a new option for CVC care.

[Infections and sepsis from intravascular catheters]

Intravascular catheters are an indispensable part of modern medicine, but also a frequent source for bloodstream infections. The incidence of infection depends on the catheter type, type of hospital setting (intensive care unit vs ward), and underlying diseases of the patient, and the type and resources for the prevention program. Initially, a common portal of bacterial entry is the insertion site. After prolonged catheterization, the hub (the connection between the catheter and the infusing tube) becomes the predominant source of bacterial entry. Basic surveillance data guide a risk-adjusted prevention program for an individual health care institution. The guidelines issued by the Robert-Koch-Institute are still an excellent framework: In cases of suspected catheter-related bloodstream infection, the catheter can be immediately removed and submitted to the laboratory, or -- in less severe cases -- blood cultures can be simultaneously drawn by venous cut-down and cultures through the catheter. Health care education, training and monitoring or insertion, maintenance are paramount to prevent catheter-related bloodstream infection. Coated catheters are indicated for special patient populations such as burn patients or transplant patients.

Transfusion practice and blood stream infections in critically ill patients

STUDY OBJECTIVE

To examine the relationship between packed RBC (pRBC) transfusion and the development of ICU-acquired bloodstream infections (BSIs)

DESIGN

Secondary analysis of a large, prospective, observational study of transfusion practice in critically ill patients.

SETTING

A total of 284 adult ICUs in the United States.

PATIENTS

Critically ill adults who lacked BSIs both at ICU admission and 48 h after ICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

BSIs were prospectively tracked in this study, and diagnosis of a new BSI represented the primary end point. Transfusions administered in the ICU prior to development of a BSI were also prospectively recorded. Of 4,892 patients enrolled in this investigation, 3,502 patients lacked BSIs both at ICU admission and 48 h later. Among these individuals, 117 patients (3.3%) had an ICU-acquired BSI. In multivariate analysis adjusting for severity of illness, primary diagnosis, use of mechanical ventilation, placement of central venous catheters, and ICU length of stay, three variables were independently associated with diagnosis of a new BSI: baseline treatment with cephalosporins (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.26 to 2.68), higher sequential organ failure assessment score measured on ICU days 3 to 4 (OR, 1.11; 95% CI, 1.06 to 1.16), and pRBC transfusion (OR, 2.23; 95% CI, 1.43 to 3.52). The relationship between pRBC transfusion and BSI was evident with both small transfusion volumes (OR with 1- to 2-U pRBC transfusion, 1.89; 95% CI, 1.10 to 3.23) and larger transfusion volumes (OR with > 4-U pRBC transfusion, 2.63; 95% CI, 1.52 to 4.53).

CONCLUSIONS

pRBC transfusion is associated with subsequent ICU-acquired BSI. Avoiding unnecessary transfusions may decrease the incidence of BSIs.

Infections associated with medical devices: pathogenesis, management and prophylaxis

The insertion or implantation of foreign bodies has become an indispensable part in almost all fields of medicine. However, medical devices are associated with a definitive risk of bacterial and fungal infections. Foreign body-related infections (FBRIs), particularly catheter-related infections, significantly contribute to the increasing problem of nosocomial infections. While a variety of micro-organisms may be involved as pathogens, staphylococci account for the majority of FBRIs. Their ability to adhere to materials and to promote formation of a biofilm is the most important feature of their pathogenicity. This biofilm on the surface of colonised foreign bodies is regarded as the biological correlative for the clinical experience with FBRI, that is, that the host defence mechanisms often seem to be unable to handle the infection and, in particular, to eliminate the micro-organisms from the infected device. Since antibacterial chemotherapy is also frequently not able to cure these infections despite the use of antibacterials with proven in vitro activity, removal of implanted devices is often inevitable and has been standard clinical practice. However, in specific circumstances, such as infections of implanted medical devices with coagulase-negative staphylococci, a trial of salvage of the device may be justified. All FBRIs should be treated with antibacterials to which the pathogens have been shown to be susceptible. In addition to systemic antibacterial therapy, an intraluminal application of antibacterial agents, referred to as the 'antibiotic-lock' technique, should be considered to circumvent the need for removal, especially in patients with implanted long-term catheters. To reduce the incidence of intravascular catheter-related bloodstream infections, specific guidelines comprising both technological and nontechnological strategies for prevention have been established. Quality assurance, continuing education, choice of the catheter insertion site, hand hygiene and aseptic techniques are aspects of particular interest. Furthermore, all steps in the pathogenesis of biofilm formation may represent targets against which prevention strategies may be directed. Alteration of the foreign body material surface may lead to a change in specific and nonspecific interactions with micro-organisms and, thus, to a reduced microbial adherence. Medical devices made out of a material that would be antiadhesive or at least colonisation resistant would be the most suitable candidates to avoid colonisation and subsequent infection. Another concept for the prevention of FBRIs involves the impregnation of devices with various substances such as antibacterials, antiseptics and/or metals. Finally, further studies are needed to translate the knowledge on the mechanisms of biofilm formation into applicable therapeutic and preventive strategies.

Biofilm: the microbial "bunker" for intravascular catheter-related infection

Catheter-related infection in cancer patients remains an important health-care problem with major financial implications. During the last few years a better understanding of the pathogenesis of catheter-related infections and the interaction between microorganisms and catheter surfaces has emerged. Recently the influence of biofilm formation in catheter-related infections has been established. The development of biofilm by the colonizing microbes permits attachment of the organisms to the vascular access device and confers resistance to antibiotics and host defense mechanisms. Strategies to overcome the development of biofilm are being developed to prevent catheter- and other medical device-related infections.

[Frequency and colonization rate of intravascular catheters]

Clinical signs are not sufficiently reliable for establishing diagnosis of intravascular catheter-related infection. Therefore, microbiological confirmation, based on the culture of the catheter tip after its removal, is necessary in diagnosing the infection. The aim of this study was to determine the frequency and the degree of microbial colonization of intravascular catheters (IVK), and the risk for the onset of sepsis, by using qualitative, semiquantitative (roll plate) and quantitative (vortexing) catheter culture techniques. During the period April 2001-December 2002, 289 intravascular catheters were cultured. A total of 284 microorganisms were isolated from 217 (75%) culture-positive catheters. The frequency of isolation of some organisms was the following: coagulase-negative staphylococci (CNS) 41%, Staphylococcus aureus 19%, Enterococci spp 6%, other gram-positive microorganisms 9%, gram-negative microorganisms 21%, and fungi 4%. In 35 catheters, cultures were polymicrobial; two microorganisms were found in 25 cultures and three were found to be in 10 cultures. There were 122 (46%) intravascular catheters, which were found significantly colonized. A high rate of positivity and a high rate of S. aureus isolates and gram-negative bacteria indicate the need of establishing the exact microbiological diagnosis of these infections, and the rigorous undertaking of adequate control and preventive measures.