Vascular catheter-related infections: an endemic disease in healthcare institutions. An opinion paper of the Spanish Society of Cardiovascular Infections (SEICAV).

Catheter-related infections (CRI) are a serious healthcare problem due to their potential to cause serious complications, including bacteraemia or infective endocarditis, and to increase patient morbidity and mortality. In addition, these in fections significantly prolong hospital stay and cost. Preventing CRI is crucial and is considered a criterion for quality and safety in healthcare. For these reasons, the Spanish Society of Cardiovascular Infections (SEICAV) has considered it pertinent to review this topic, with experts in different areas including clinical microbiologists, infectious disease specialists, surgeons and nurses. The data were presented at a session held at the Ramón Areces Foundation, which was organised in the form of specific questions grouped into three round tables. The first panel analysed the scale of the problem including epidemiological, clinical and diagnostic aspects; the second panel addressed advances in the treatment of CRI; and the third panel reviewed developments in the prevention of CRI. The recorded session is available on the Areces Foundation website and we believe it maybe of interest not only to health professionals, but also to any non-expert citizen interested in the subject.

Struvite precipitation in wastewater treatment plants anaerobic digestion supernatants using a magnesium oxide by-product.

Struvite precipitation is a well-known technology to recover and upcycle phosphorus from municipal wastewater as a slow-release fertiliser. However, the economic and environmental costs of struvite precipitation are constrained by using technical-grade reagents as a magnesium source. This research evaluates the feasibility of using a low-grade magnesium oxide (LG-MgO) by-product from the calcination of magnesite as a magnesium source to precipitate struvite from anaerobic digestion supernatants in wastewater treatment plants. Three distinct LG-MgOs were used in this research to capture the inherent variability of this by-product. The MgO content of the LG-MgOs varied from 42 % to 56 %, which governed the reactivity of the by-product. Experimental results showed that dosing LG-MgO at P:Mg molar ratio close to stoichiometry (i.e. 1:1 and 1:2) favoured struvite precipitation, whereas higher molar ratios (i.e. 1:4, 1:6 and 1:8) favoured calcium phosphate precipitation due to the higher calcium concentration and pH. At a P:Mg molar ratio of 1:1 and 1:2, the percentage of phosphate precipitated was 53-72 % and 89-97 %, respectively, depending on the LG-MgO reactivity. A final experiment was performed to examine the composition and morphology of the precipitate obtained under the most favourable conditions, which showed that (i) struvite was the mineral phase with the highest peaks intensity and (ii) struvite was present in two different shapes: hopper and polyhedral. Overall, this research has demonstrated that LG-MgO is an efficient source of magnesium for struvite precipitation, which fits the circular economy principles by valorising an industrial by-product, reducing the pressure on natural resources, and developing a more sustainable technology for phosphorus recovery.

The optimal ethanol lock therapy regimen for treatment of biofilm-associated catheter infections: an in-vitro study.

BACKGROUND: Ethanol-based lock therapy (LT) solutions are used as an alternative to antibiotics for the conservative management of catheter-related bloodstream infection. However, no clear consensus on regimen or dose has been reached. AIM: To find the ethanol-based lock solution containing a sufficiently low concentration of ethanol for reduction of the metabolic activity of bacterial and fungal biofilms. METHODS: Using an in-vitro model, three concentrations of ethanol (25%, 40%, 70%) were tested, with and without 60 IU of heparin, at six different time-points and against 24 h preformed biofilms of Staphylococcus aureus ATCC29213, Staphylococcus epidermidis (clinical isolate), Enterococcus faecalis ATCC33186, Candida albicans ATCC14058, and Escherichia coli ATCC25922. The reduction in the metabolic activity of the biofilm was measured using the tetrazolium salt assay and LT was considered to be successful when metabolic activity fell by >90%. Regrowth inhibition was then tested within 24 h and seven days after each LT regimen only at the ethanol concentration of the most successful LT regimen. FINDINGS: The most successful LT was achieved with 40% ethanol + 60 IU of heparin only at 24, 72, and 24 h for seven-day regimens (P < 0.05). However, none of the regimens reached 45% RI within seven days of therapy. CONCLUSION: According to our in-vitro data, an ethanol-based lock solution with 40% ethanol + 60 IU heparin administered daily for 72 h is sufficient to almost eradicate the metabolic activity of bacterial and fungal biofilms. Future studies are needed to study cell regrowth after LT.

Diagnosis and treatment of catheter-related bloodstream infection: Clinical guidelines of the Spanish Society of Infectious Diseases and Clinical Microbiology and (SEIMC) and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC).

Catheter-related bloodstream infections (CRBSI) constitute an important cause of hospital-acquired infection associated with morbidity, mortality, and cost. The aim of these guidelines is to provide updated recommendations for the diagnosis and management of CRBSI in adults. Prevention of CRBSI is excluded. Experts in the field were designated by the two participating Societies (the Spanish Society of Infectious Diseases and Clinical Microbiology and [SEIMC] and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units [SEMICYUC]). Short-term peripheral venous catheters, non-tunneled and long-term central venous catheters, tunneled catheters and hemodialysis catheters are covered by these guidelines. The panel identified 39 key topics that were formulated in accordance with the PICO format. The strength of the recommendations and quality of the evidence were graded in accordance with ESCMID guidelines. Recommendations are made for the diagnosis of CRBSI with and without catheter removal and of tunnel infection. The document establishes the clinical situations in which a conservative diagnosis of CRBSI (diagnosis without catheter removal) is feasible. Recommendations are also made regarding empirical therapy, pathogen-specific treatment (coagulase-negative staphylococci, Staphylococcus aureus, Enterococcus spp., Gram-negative bacilli, and Candida spp.), antibiotic lock therapy, diagnosis and management of suppurative thrombophlebitis and local complications.

Diagnosis and treatment of catheter-related bloodstream infection: Clinical guidelines of the Spanish Society of Infectious Diseases and Clinical Microbiology and (SEIMC) and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC) / Diagnóstico y tratamiento de la bacteriemia relacionada con catéter: guía de práctica clínica de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC) y de la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias (SEMICYUC)

Catheter-related bloodstream infections (CRBSI) constitute an important cause of hospital-acquired infection associated with morbidity, mortality, and cost. The aim of these guidelines is to provide updated recommendations for the diagnosis and management of CRBSI in adults. Prevention of CRBSI is excluded. Experts in the field were designated by the two participating Societies (the Spanish Society of Infectious Diseases and Clinical Microbiology and [SEIMC] and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units [SEMICYUC]). Short-term peripheral venous catheters, non-tunneled and long-term central venous catheters, tunneled catheters and hemodialysis catheters are covered by these guidelines. The panel identified 39 key topics that were formulated in accordance with the PICO format. The strength of the recommendations and quality of the evidence were graded in accordance with ESCMID guidelines. Recommendations are made for the diagnosis of CRBSI with and without catheter removal and of tunnel infection. The document establishes the clinical situations in which a conservative diagnosis of CRBSI (diagnosis without catheter removal) is feasible. Recommendations are also made regarding empirical therapy, pathogen-specific treatment (coagulase-negative staphylococci, Staphylococcus aureus, Enterococcus spp., Gram-negative bacilli, and Candida spp.), antibiotic lock therapy, diagnosis and management of suppurative thrombophlebitis and local complications (AU)

La bacteriemia relacionada con catéteres (BRC) es una causa importante de infección hospitalaria y se asocia con elevados morbilidad, mortalidad y costes. El objetivo de esta guía de práctica clínica es proporcionar recomendaciones actualizadas para el diagnóstico y tratamiento de la BRC en pacientes adultos. De este documento se excluye la prevención de la BRC. Expertos en la materia fueron designados por las dos Sociedades participantes (Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica y Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias). Los catéteres venosos periféricos a corto plazo, los catéteres venosos centrales no tunelizados y de largo plazo, los catéteres tunelizados y los catéteres de hemodiálisis están incluidos en estas guías. El panel identificó 39 temas clave que fueron formulados de acuerdo con el formato PICO. La fuerza de las recomendaciones y la calidad de la evidencia se clasificaron de acuerdo con las directrices de la ESCMID. Se dan recomendaciones para el diagnóstico de BRC con extracción de catéter y sin él, y de la infección en túnel. El documento establece las situaciones clínicas en que es factible un diagnóstico conservador de CRBSI (diagnóstico sin retirada de catéter). También se dan recomendaciones respecto a la terapia empírica, el tratamiento específico según el patógeno identificado (estafilococos coagulasa-negativos, Staphylococcus aureus, Enterococcus spp., bacilos gramnegativos y Candida spp.), la terapia con sellado del catéter y el diagnóstico, así como tratamiento de la tromboflebitis supurativa y las complicaciones locales (AU)

Biofilm production is not associated with poor clinical outcome in 485 patients with Staphylococcus aureus bacteraemia.

OBJECTIVES: Staphylococcus aureus biofilm may constitute a major cause of virulence. Our main objective was to analyse whether there was an association between biofilm production and poor outcome in patients with S. aureus bacteraemia. METHODS: We studied 485 S. aureus strains isolated from the blood of patients with bacteraemia from 2012 to 2015. We assessed in vitro biomass production using crystal violet assay and metabolic activity using tetrazolium salt assay. Strains were classified in tertile ranks as follows: low biomass producers, moderate biomass producers, high biomass producers, low metabolic activity, moderate metabolic activity and high metabolic activity. We excluded from analysis strains with moderate crystal violet and tetrazolium salt values. We defined poor outcome as fulfillment of one or more of the following conditions: 30-day attributable mortality, infective endocarditis, persistent bacteraemia and recurrent bacteraemia. RESULTS: Outcome was poor in 199 (41.0%) of 485 S. aureus bacteraemia episodes. The distribution of poor outcome with respect to biomass production and metabolic activity was as follows: low biomass producers, 36.6% vs. high biomass producers, 43.2% (p 0.26); and low metabolic activity, 43.5% vs. high metabolic activity, 36.2% (p 0.91). The presence of methicillin-resistant S. aureus was the only characteristic that was more likely to be present in the high metabolic activity group (17.4% vs. 39.3%, p < 0.001). CONCLUSIONS: Biofilm production, as determined by any of the methods used in the present study, is not associated with poor outcome in patients with S. aureus bacteraemia.

Should non-bacteraemic patients with a colonized catheter receive antimicrobial therapy?

OBJECTIVES: The impact of antimicrobial therapy on the outcomes of patients with colonized catheters and no bacteraemia has not been assessed. This study assessed whether targeted antibiotic therapy is related to a poor outcome in patients with positive cultures of blood drawn through a non-tunnelled central venous catheter (CVC) and without concomitant bacteraemia. METHODS: This was a retrospective study involving adult patients with positive blood cultures drawn through a CVC and negative peripheral vein blood cultures. Patients were classified into two groups: those with clinical improvement and those with a poor outcome. These two groups were compared. The outcome was considered poor in the presence of one or more of the following: death, bacteraemia or other infection due to the same microorganism, and evidence of catheter-related bloodstream infection. RESULTS: A total of 100 patients were included (31 with a poor outcome). The only independent predictors of a poor outcome were a McCabe and Jackson score of 1-2 and a median APACHE score of 5. No association was found between the use of targeted antimicrobial therapy and a poor outcome when its effect was adjusted for the rest of the variables. CONCLUSIONS: This study showed that antimicrobial therapy was not associated with a poor outcome in non-bacteraemic patients with positive blood cultures drawn through a CVC.

Nationwide study on peripheral-venous-catheter-associated-bloodstream infections in internal medicine departments.

BACKGROUND: The use of peripheral venous catheters (PVCs) has increased outside intensive care units, as has the rate of PVC-associated-bloodstream infection (PVC-BSI). PVCs are widely used in internal medicine departments (IMDs), but data on the incidence of PVC-BSI and its characteristics in IMDs are scarce. AIM: To assess the incidence of PVC-BSI episodes detected in IMDs in Spain. METHODS: A one-year multi-centre prospective observational cohort study in 14 Spanish IMDs was undertaken. Adult patients admitted with at least one PVC and bacteraemia were included in the study. Demographic and clinical data were provided by local coordinators. FINDINGS: Seventy episodes of PVC-BSI were recorded, representing an overall rate of 1.64 PVC-BSI episodes/1000 IMD admissions. The mean age of patients was 67.44 (standard deviation 16.72) years. It was estimated that 25.7% of PVCs were no longer necessary. Staphylococcus aureus was the most frequently isolated micro-organism (41.7%). Phlebitis was clinically evident in 44 (62.9%) episodes, and proved to be an independent predictor of catheter insertion in emergency departments (odds ratio 5.44). The crude and attributable mortality rates were 12.9% and 5.7%, respectively. CONCLUSIONS: PVCs carry a significant risk for bacteraemia in Spanish IMDs. Phlebitis is not always clinically evident in patients with bacteraemia in this population. The study findings support the need for educational and interventional preventive measures in both IMDs and emergency departments to reduce the rate of PVC-BSI and associated comorbidities, and costs.

Improved method for the detection of catheter colonization and catheter-related bacteremia in newborns.

Accurate diagnosis of catheter-related bloodstream infection (CRBSI) is mandatory for hospital infection control. Peripherally inserted central venous catheters (PICCs) are widely used in intensive care units, but studies about procedures for detection of colonization are scarce in neonates. We sequentially processed 372 PICCs by 2 methods, first by the standard roll-plate (RP) technique and then by rubbing catheters on a blood agar plate after being longitudinally split (LS). With both techniques, we detected 133 colonized PICCs. Ninety-four events of CRBSI were diagnosed. The sensitivity, specificity, positive predictive value, and negative predictive value for detection of CRBSI were 58.5%, 92.8%, 73.3%, and 86.9%, respectively, for RP technique and 96.8%, 88.5%, 74.0%, and 98.8%, respectively, for LS technique. The LS technique increased the proportion of detected CRBSI by 38.3%. Neonatal PICC tips should be cultured after cutting them open. This technique is simple and sensitive to detect catheter colonization and also to diagnose CRBSI.

Slicing silicone neonatal vascular catheter tips improves colonization detection by the roll-plate technique.

OBJECTIVE: Silicone neonatal peripherally inserted central catheters (SN-PICCs) are a common cause of catheter-related bloodstream infection (C-RBSI) in neonates. Our objective was to compare the yield of traditional roll-plate technique (TRP), roll-plate after slicing (RPS), and sonication after slicing (SS) for the detection of colonization and C-RBSI in SN-PICCs. METHODS: We prospectively cultured tips from SN-PICCs withdrawn from paediatric patients admitted to our institution with suspicion of infection. We first cultured the catheter tip using TRP and then divided the catheter into two segments. RPS was performed by longitudinally slicing one segment and the fragments were cultured. SS was performed by transversally slicing the other segment followed by culture after sonication. We calculated the validity values of each technique individually by comparing them with the diagnostic standard of colonization and C-RBSI. RESULTS: We included 162 SN-PICCs, 46 of which were colonized. Sensitivity rates for colonization and C-RBSI with TRP, RPS and SS were, respectively, 71.7%, 80.4% and 67.4%; and 74.2%, 90.3% and 77.4%. CONCLUSION: Catheter slicing should be performed before the roll-plate technique to ensure optimal diagnosis on SN-PICCs.

2016 Expert consensus document on prevention, diagnosis and treatment of short-term peripheral venous catheter-related infections in adult.

The use of endovascular catheters is a routine practice in secondary and tertiary care level hospitals. Short peripheral catheters have been found to be associated with the risk of nosocomial bacteremia resulting in morbidity and mortality. Staphyloccus aureus is mostly associated with peripheral catheter insertion. This Consensus Document has been elaborated by a panel of experts of the Spanish Society of Cardiovascular Infections in cooperation with experts from the Spanish Society of Internal Medicine, Spanish Society of Chemotherapy and Spanish Society of Thoracic-Cardiovascular Surgery and aims at define and establish the norm for management of short duration peripheral vascular catheters. The document addresses the indications for insertion, catheter maintenance and registry, diagnosis and treatment of infection, indications for removal and stresses on continuous education as a driver for quality. Implementation of this norm will allow uniformity in usage thus minimizing the risk of infection and its complications.

The Tego™ needleless connector for hemodialysis catheters may protect against catheter colonization.

Catheter connectors used in hemodialysis patients are those with open caps to manage high blood flows. However, current guidelines for the prevention of catheter infections recommend closed connectors. Tego™ is a closed connector designed to enable high blood flows. We used an in vitro model to compare the efficacy of Tego™ against contamination with that of standard caps in a real-life practice scenario. The model consisted of 200 blood culture bottles (BCB) with an inserted cannula closed either with Tego™ (100) or with open caps (100). BCB were manipulated using two different methods: under aseptic conditions and with gloves contaminated with a 0.05 McFarland Staphylococcus aureus solution. The BCB were incubated at 37 °C under continuous shaking for up to 7 days or until positive. When a BCB turned positive, 100 µL of the fluid was cultured. The positivity rate and time to positivity of the BCB in each method were compared. Overall, 4.0 % of BCB with Tego™ and 52.0 % of BCB with open caps were positive in the sterile model (p < 0.001), whereas all BCB in the contamination model were positive. We did not find differences regarding the median time (hours) to positivity between Tego™ and the standard cap in the contamination model (19.04 vs. 17.87, p = 0.465). In our model, Tego™ proved to be better than the standard cap for the prevention of contamination when the device was handled under optimal conditions. Moreover, it was as efficient as the standard catheter cap in the contamination model.

Effectiveness of a training program in compliance with recommendations for venous lines care.

BACKGROUND: The impact of training programs on the care and maintenance of venous lines (VL) has been assessed mainly in patients admitted to the intensive care unit (ICU). Data on the impact of such programs in a whole general hospital are scarce. The objective of this study was to assess compliance with VL care after an extensive training program aimed at nurses caring for adult ICU and non-ICU patients. METHODS: We performed 2 point prevalence studies in a general hospital. A specialized nurse visited all hospitalized adult patients, performed a bedside inspection, and reviewed the nursing records for patients with a VL before and after a 1-year training program. The program included an interactive on-line teaching component and distribution of pocket leaflets and posters with recommendations on VL care. RESULTS: Data recorded for the first and second prevalence studies were as follows: number of patients visited, 753 vs. 682; total number of patients with ≥ 1 VL implanted on the visit day, 653 (86.7%) vs 585 (85.8%); catheters considered unnecessary on the study day, 183 (22.9%) vs 48 (7.1%) (p < 0.001); number of catheters with local clinical evidence of infection on the study day, 18 (2.2%) vs 12 (1.8%) (p = 0.52); registration of insertion day (42.3% vs 50.1%; p = 0.003); and registration of day of dressing change (41.2% vs 49.1%; p = 0.003). Maintenance parameters improved more in non-ICU than in ICU patients. CONCLUSION: A multidisciplinary teaching program to improve VL care and compliance with recommendations is effective. Point prevalence studies are easy to carry out and effective at demonstrating increases in compliance, mainly in non-ICU patients.

Nationwide study on the use of intravascular catheters in internal medicine departments.

BACKGROUND: The use of intravascular catheters (IVCs) in intensive care units (ICUs) has been well assessed in recent years. However, a high proportion of these devices are placed in patients outside the ICU, particularly in internal medicine departments (IMDs), where data on the quality of care are scarce. AIM: To assess the use and management of IVCs in IMDs in Spain. METHODS: We performed a point prevalence study of all adult inpatients on 47 IMDs from hospitals of different sizes on one day in June 2013. A local co-ordinator was appointed to assess patients and collect data from each site. FINDINGS: Out of the 2080 adult patients hospitalized on the study day, 1703 (81.9%) had one or more IVCs (95.4% of which were peripheral devices). Infection was detected at the insertion site in 92 catheters (5.0%); 87 patients (5.2%) had signs of sepsis, but only one case was considered to be catheter-related. The local co-ordinators estimated that 19% of the catheters in place were no longer necessary. A daily record of the need for a catheter was available in only 40.6% of cases. CONCLUSION: Our study shows clear opportunities for improvement regarding catheter use and care in Spanish IMDs. Strategies similar to those applied in ICUs should be implemented in IMDs.

Performing Gram stain directly on catheter tips: assessment of the quality of the observation process.

A previous study performed in our institution showed that catheter tip (CT) staining by combining acridine orange and Gram stain (GS) before culture anticipated catheter colonization with exhaustive and careful observation by a highly trained technician. Our objective was to assess the validity values of GS without acridine orange on an external smear of CT for predicting catheter colonization and catheter-related bloodstream infection (C-RBSI). We compared different periods of observation and the results of two technicians with different levels of professional experience. Over a 5-month period, the roll-plate technique was preceded by direct GS of all CTs sent to the microbiology laboratory. The reading was taken at ×100 by two observers with different skill levels. Each observer performed a routine examination (3 min along three longitudinal lines) and an exhaustive examination (5 min along five longitudinal lines). The presence of at least one cell was considered positive. All slides were read before culture results were known. We included a total of 271 CTs from 209 patients. The prevalence of catheter colonization and C-RBSI was 16.2 % and 5.1 %, respectively. Routine and exhaustive examinations revealed only 29.5 % and 40.9 % of colonized catheters, respectively (p < 0.001). In contrast, they revealed high negative predictive values for C-RBSI (96.5 % and 96.3 %, respectively). Our study shows that the yield of GS performed directly on CTs is greater when staining is performed exhaustively. However, the decision to implement this approach in daily routine will depend on the prevalence rate of catheter colonization at each institution.

Micafungin at physiological serum concentrations shows antifungal activity against Candida albicans and Candida parapsilosis biofilms.

We assessed the in vitro activity of micafungin against preformed Candida biofilms by measuring the concentration of drug causing the most fungal damage and inhibition of regrowth. We studied 37 biofilm-producing Candida spp. strains from blood cultures. We showed that micafungin was active against planktonic and sessile forms of Candida albicans strains and moderately active against Candida parapsilosis sessile cells. Concentrations of micafungin above 2 µg/ml were sufficiently high to inactivate regrowth of Candida sessile cells.

The risk of catheter-related bloodstream infection after withdrawal of colonized catheters is low.

Most episodes of catheter-related bloodstream infection (C-RBSI) are documented before or at the time of catheter withdrawal. The risk of C-RBSI in the period after removing a colonized catheter in patients without bacteremia (late C-RBSI) is unknown. We assessed the risk of developing a late C-RBSI episode in an unselected population with positive catheter tip cultures and analyzed associated risk factors. We analyzed retrospectively all colonized catheter tips between 2003 and 2010 and matched them with blood cultures. C-RBSI episodes were classified as early C-RBSI (positive blood cultures were obtained ≤24 h after catheter withdrawal) or late C-RBSI (positive blood cultures were obtained ≥24 h after catheter withdrawal). We analyzed the risk factors associated with late C-RBSI episodes by comparison with a selected group of early C-RBSI episodes. We collected a total of 17,981 catheter tips: 4,533 (25.2 %) were colonized. Of them, 1,063 (23.5 %) were associated to early C-RBSI episodes and from the remaining 3,470, only 143 (4.1 %) were associated to late C-RBSI episodes. Then, they corresponded to 11.9 % of the total 1,206 C-RBSI episodes. After comparing early and late C-RBSI episodes, we found that late C-RBSI was significantly associated with the presence of methicillin-resistant Staphylococcus aureus (MRSA, p = 0.028) and with higher mortality (p = 0.030). According to our data, patients with colonized catheter tips had a 4.1 % risk of developing late C-RBSI, which was associated with higher crude mortality.

Bloodstream infections in patients with kidney disease: risk factors for poor outcome and mortality.

BACKGROUND: Information regarding bloodstream infections (BSIs) in patients with kidney diseases is scarce and mainly derived from selected groups of patients. AIM: To assess the characteristics of BSI in an unselected population of patients with kidney disease, including renal transplant recipients and patients with chronic kidney failure who were receiving or not receiving dialysis. METHODS: A retrospective cohort study of all patients who presented with BSI in the nephrology department of a large teaching hospital. Clinical records were reviewed according to a pre-established protocol. Standard definitions were used. FINDINGS: In all, 155 episodes of BSI were recorded in 108 patients. The incidence of BSI was 77.3 episodes per 1000 admissions, and 4.5 episodes per 100 patient-years. Haemodialysis patients had the highest incidence of BSI. The distribution of micro-organisms was as follows: Gram-negative, 52.3%; Gram-positive, 46.5%; fungi, 1.2%. Escherichia coli was the most frequently isolated micro-organism (27%). The BSI was classed as bacteraemia of unknown source (29.7%), urinary tract infection (23.2%), vascular access infection (17.4%), and other (29.7%). Eighteen patients (11.6%) developed septic shock or multi-organ failure, and the same proportion had persistent bacteraemia. The crude mortality rate was 14.6%. The risk factors for mortality were high Charlson index, persistent bacteraemia, and absence of fever. CONCLUSION: Nephrology patients have a high incidence of BSI, particularly patients undergoing haemodialysis. The predominant micro-organisms causing BSI episodes were Gram-negative bacilli. Patients with kidney disease have high BSI-related morbidity and mortality. Risk factors for mortality were high Charlson comorbidity index and persistent BSI. The presence of fever during the BSI episodes was found to be a protective factor.

Value of superficial cultures for prediction of catheter-related bloodstream infection in long-term catheters: a prospective study.

Cultures taken from the skin and from the hubs of short-term central venous catheters can help us to predict catheter-related bloodstream infections (C-RBSIs). The value of these cultures for such predictions has not been assessed in long-term catheters. Our objective was to assess the value of superficial cultures for the prediction of C-RBSI among patients with long-term catheters. Over a 2-year period, we prospectively obtained cultures from the skin overlying reservoir ports (group A) and from the skin insertion site and hubs of all tunneled catheters (group B). This routine was performed by vascular and interventional radiologists immediately before catheter removal (irrespective of the reason for withdrawal). Swabs were processed semiquantitatively. Catheter tips from both groups were cultured using Maki's semiquantitative technique and sonication. We also performed cultures of the reservoir ports at different sites. C-RBSI was defined as the isolation of the same species of microorganism(s) both in the colonized catheter and in at least 1 peripheral blood culture. We included 372 catheters (group A, 223; group B, 149) during the study period. The catheter colonization rate was 23.4% (87/372), and 28 patients had C-RBSI. Validity index values for the capacity of surface cultures to predict C-RBSI in groups A and B were, respectively, as follows: sensitivity, 23.5% and 45.5%; specificity, 59.7% and 63.0%; positive predictive value, 4.6% and 8.9%; and negative predictive value, 90.4% and 93.5%. Superficial cultures of patients with long-term catheters could help us to rule out the catheter as the portal of entry of bloodstream infections. Superficial cultures (from skin and hubs) proved to be a useful conservative diagnostic tool for ruling out C-RBSI among patients with long-term tunneled catheters and totally implantable venous access ports.