Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 Update by the Infectious Diseases Society of America

Role of mannose-binding lectin in nosocomial sepsis in critically ill neonates

We investigated the association of mannose-binding lectin (MBL) serum levels with nosocomial sepsis (NS), their changes overtime during infection, their relation with pathogens, with the MBL2 genotype and their relationship with mortality. In a prospective observational study, we included 365 critically ill neonates: 261 had no infection and 104 had at least 1 septic event. The median MBL serum concentration was significantly lower in infected than in noninfected neonates (p < 0.001). Low MBL levels on admission increased the risk of infection, independently from gestational age and invasive procedures. The median peak MBL level during infection was higher than the median level on admission (p < 0.001) and was correlated with it (r(2) = 0.83, p < 0.001). Moreover, MBL levels on admission were not associated with death (OR = 0.80, 95% CI = 0.56-1.14, p = 0.21). Similarly, no association was found between MBL peak levels during infection and death among infected neonates (OR = 1.10, 95% CI = 0.78-1.57, p = 0.57). In 127 neonates (42 infected) genotyped for exon-1 and -221 promoter MBL2 variants, we did not find significant difference in the frequencies of MBL2 genotypes between infected and noninfected neonates. Moreover, no association was found between MBL2 genotypes and death.

Catheter management

OBJECTIVES

To review the care and maintenance of the central venous access device (VAD), including dressing management, practice of accessing, swabbing, deaccessing and flushing, specific IV connectors, and practice considerations when sampling blood and VAD removal.

DATA SOURCES

Journal articles, compendiums and standards, case reports, manufacturers' product information, personal experience.

CONCLUSION

The available data on VAD care and maintenance depends on data from a variety of sources. VAD care is product-dependent and, while some basic actions are universal to dressing management, septum swabbing, and catheter flushing, it is important to understand the idiosyncrasies of various products to provide the best and safest care.

IMPLICATIONS FOR NURSING PRACTICE

Critical thinking skills and individualized care planning are necessary for the care and maintenance of VADs, which is a primary role of the nurse.

Infectious and thrombotic complications of central venous catheters

OBJECTIVE

To provide a review of the pathogenesis, prevention, and management strategies of infectious and thrombotic complications of central venous access devices (CVADs).

DATA SOURCE

Journal articles, case reports, product information, personal experience, professional guidelines.

CONCLUSION

Infectious and thrombotic catheter-related complications are common and serious complications that can negatively impact patient outcomes. There has been significant national attention on patient safety, and in particular, the prevention of catheter-related bloodstream infections.

IMPLICATIONS FOR NURSING PRACTICE

Clinicians have a crucial role in preventing and identifying CVAD-related complications. Understanding the pathogenesis of infectious and thrombotic complications, the principles of best practice, and adhering to these practices consistently, in all practice settings, are critical in order to minimize unnecessary risks to patients with an indwelling CVAD.

Candida albicans biofilm on titanium: effect of peroxidase precoating

The present study aimed to document Candida albicans biofilm development on titanium and its modulation by a peroxidase-precoated material which can generate antimicrobials, such as hypoiodite or hypothiocyanite, from hydrogen peroxide, iodide, or thiocyanate. For this purpose, titanium (powder or foil) was suspended in Sabouraud liquid medium inoculated with C. albicans ATCC10231. After continuous stirring for 2-21 days at room temperature, the supernatant was monitored by turbidimetry at 600 nm and titanium washed three times in sterile Sabouraud broth. Using the tetrazolium salt MTT-formazan assay, the titanium-adherent fungal biomass was measured as 7.50 ± 0.60 × 10(6) blastoconidia per gram of titanium powder (n = 30) and 0.50 ± 0.04 × 10(6) blastoconidia per cm(2) of titanium foil (n = 12). The presence of yeast on the surface of titanium was confirmed by microscopy both on fresh preparations and after calcofluor white staining. However, in the presence of peroxidase systems (lactoperoxidase with substrates such as hydrogen peroxide donor, iodide, or thiocyanate), Candida growth in both planktonic and attached phases appeared to be inhibited. Moreover, this study demonstrates the possible partition of peroxidase systems between titanium material (peroxidase-precoated) and liquid environment (containing peroxidase substrates) to limit C. albicans biofilm formation.

Susceptibility of Candida albicans biofilms to azithromycin, tigecycline and vancomycin and the interaction between tigecycline and antifungals

Despite growing data on antimicrobial lock therapy (ALT) in treating bacterial catheter-related bloodstream infections (CR-BSIs), ALT has not been established as a treatment option for CR-BSI caused by Candida albicans. Based on our finding that high-dose doxycycline exhibited antifungal activity against mature C. albicans biofilms, we evaluated additional antibacterial agents with Gram-positive activity [azithromycin, tigecycline (TIG) and vancomycin]. After screening these antibiotics, it was found that TIG had substantial antifungal activity against mature C. albicans biofilms. Therefore, TIG was assayed alone and in combination with fluconazole (FLC), amphotericin B (AmB) or caspofungin (CAS). TIG at 2048 μg/mL resulted in a >50% reduction in the growth of planktonic C. albicans cells. TIG inhibited the formation of biofilms from 128 μg/mL. Against mature biofilms, 2048 μg/mL TIG reduced metabolic activity by 84.2%. Furthermore, addition of 512 μg/mL TIG to FLC at all concentrations tested provided additional reduction in the metabolic activity of mature biofilms. However, this was not superior to 512 μg/mL TIG alone. TIG at 512 μg/mL increased the antifungal effect of lower concentrations of AmB (0.03125-0.25 μg/mL), but at 0.03125 μg/mL and 0.0625 μg/mL this effect was not superior to 512 μg/mL TIG alone. TIG inhibited the antifungal effect of higher concentrations of AmB (≥ 2 μg/mL). TIG at 512 μg/mL inhibited the antifungal activity of CAS at lower concentrations (0.25-8 μg/mL). These data indicate that high-dose TIG is highly active in vitro against planktonic cells, forming biofilms and mature biofilms of C. albicans.

Placing of tunneled central venous catheters prior to induction chemotherapy in children with acute lymphoblastic leukemia

BACKGROUND

Tunneled central venous catheters (CVCs) are inevitable in children with acute lymphoid leukemia (ALL). The aim of this study was to evaluate the risk of CVC-related complications in children with ALL in relation to timing of catheter placement and type of catheter.

PROCEDURE

All children hospitalized from January 2000 to March 2008 with newly diagnosed ALL and with double-lumen total implantable devices (TIDs) or tunneled external catheters (TEs) were included retrospectively. We only used data related to the patient's first catheter.

RESULTS

We included 98 children; 35 received a TID and the remaining 63 received a TE. A total number of 29,566 catheter days and 93 catheter-associated blood stream infections (CABSI) was identified. We found a CABSI rate of 3.1/1,000 catheter days (5.4/1,000 catheter days for TEs and 1.4/1,000 catheter days for TIDs, incidence rate ratio (IRR) 3.82 (95% CI 2.37-6.35) P = 0.0001). No difference was found in CABSI between neither early versus later placed TIDs (IRR = 0.99 (95% CI 0.41-2.45) P = 0.98) nor early versus later placed TEs (IRR = 0.81 (95% CI 0.40-1.86) P = 0.54). We found no difference between early and later placed catheters regarding non-elective removal (RR = 0.86 (95% CI 0.72-1.03) P = 0.09). TEs had a higher risk of non-elective removal compared with TIDs (RR = 3.95 (95% CI 1.88-8.29) P < 0.001).

CONCLUSIONS

The study did not find that children with ALL and with early placed CVCs experienced significantly more complications compared with children with late placed catheters. This study found that children with ALL and TEs experienced more complications than children with TIDs.

The value of infectious diseases consultation in Staphylococcus aureus bacteremia

BACKGROUND

Staphylococcus aureus bacteremia results in substantial mortality. Infectious diseases specialist consultation can improve adherence to evidence-based management of S. aureus bacteremia, but its effect on mortality is unclear.

METHODS

A 2-year prospective cohort study of patients with S. aureus bacteremia was performed at a large tertiary care hospital. Patients who died within 2 days of diagnosis were excluded. Independent risk factors for 28-day mortality were determined.

RESULTS

Among 341 patients with S. aureus bacteremia, 189 (55%) were male, 196 (58%) were Caucasian, 185 (54%) had methicillin-resistant S. aureus, 108 (32%) had nosocomial bacteremia, and 231 (68%) had a central venous catheter at the time of diagnosis. The median age was 56 years (range 22-95 years). A total of 111 patients (33%) had an infectious diseases consultation. Fifty-four patients (16%) died within 28 days after diagnosis. Factors associated with mortality were intensive care unit admission 48 hours or less after the first positive blood culture (adjusted hazard ratio, 4.65; 95% confidence interval [CI], 2.65-8.18), cirrhosis (adjusted hazard ratio, 4.44; 95% CI, 2.40-8.20), and advanced age (adjusted hazard ratio, 1.27 per every 10 years of age; 95% CI, 1.08-1.50). Infectious diseases consultation was associated with a 56% reduction in 28-day mortality (adjusted hazard ratio, 0.44; 95% CI, 0.22-0.89).

CONCLUSION

Only one third of patients with S. aureus bacteremia in this cohort had an infectious diseases specialist consultation. Infectious diseases consultation was independently associated with a reduction in 28-day mortality. Routine infectious diseases consultation should be considered for patients with S. aureus bacteremia, especially those with greater severity of illness or multiple comorbidities.

Epidemiology, diagnosis, and antimicrobial treatment of acute bacterial meningitis

The epidemiology of bacterial meningitis has changed as a result of the widespread use of conjugate vaccines and preventive antimicrobial treatment of pregnant women. Given the significant morbidity and mortality associated with bacterial meningitis, accurate information is necessary regarding the important etiological agents and populations at risk to ascertain public health measures and ensure appropriate management. In this review, we describe the changing epidemiology of bacterial meningitis in the United States and throughout the world by reviewing the global changes in etiological agents followed by specific microorganism data on the impact of the development and widespread use of conjugate vaccines. We provide recommendations for empirical antimicrobial and adjunctive treatments for clinical subgroups and review available laboratory methods in making the etiological diagnosis of bacterial meningitis. Finally, we summarize risk factors, clinical features, and microbiological diagnostics for the specific bacteria causing this disease.

Incidence, characteristics, and outcomes of Staphylococcus lugdunensis bacteremia

Of 63 patients with Staphylococcus lugdunensis bacteremia, 15 (23.8%) had clinically significant bacteremia, with an incidence of 1.3 cases per 100,000 admissions. Of the five patients with community-acquired S. lugdunensis bacteremia, three had endocarditis. Catheters were the most common portal of entry for health-care-associated or hospital-acquired bacteremia. Only one patient died of bacteremia-related causes.

Clinical outcomes of antimicrobial lock solutions used in a treatment modality: a retrospective case series analysis

BACKGROUND

Antimicrobial lock therapy (ALT) may be considered as adjunctive therapy in the treatment of catheter-related bloodstream infections (CRBSI) when catheter removal is not a favorable option.

OBJECTIVE

To evaluate the outcomes associated with ALT as adjunctive treatment of CRBSI.

METHODS

This was a 24-month retrospective case series analysis evaluating patients treated for more than 24 hours with ALT. The primary outcome was blood culture sterilization for 30 days posttherapy. The impact of ALT duration and time to initiation on central venous catheter (CVC) salvage were evaluated. Logistic regression modeled the association between ALT and sterilization rates, with a prespecified level of significance (α) of 0.1.

RESULTS

Twenty-six cases were included in data analysis. Patients included ranged from 5 months to 82 years of age; 77% of patients were receiving total parenteral nutrition or chemotherapy. The majority of patients received vancomycin, daptomycin, or gentamicin combined with heparin in a lock solution. Blood culture sterilization was achieved in 69.2% of cases, and sterilization plus CVC retention was achieved in 11 cases (42.3%). Longer durations of ALT (≥9 days) were significantly correlated with blood culture sterilization (odds ratio = 1.367, P = 0.077).

CONCLUSION

ALT used as an adjunct to systemic therapy for adequate duration in CRBSI can achieve CVC sterilization and retainment without subsequent infectious complications.

A potential role for daptomycin in enterococcal infections: what is the evidence?

Nosocomial infections caused by enterococci present a challenge for clinicians because treatment options are often limited due to the widespread occurrence of strains resistant to multiple antibiotics, including vancomycin. Daptomycin is a first-in-class cyclic lipopeptide that has proven efficacy for the treatment of Gram-positive infections. Although methicillin-resistant Staphylococcus aureus has been the most prominent target in the clinical development of daptomycin, this agent has demonstrated potent bactericidal activity in enterococcal infection models and has been used for the treatment of enterococcal infections in humans. In recent years, large-scale susceptibility studies have shown that daptomycin is active against >98% of enterococci tested, irrespective of their susceptibility to other antibacterial agents. This lack of cross-resistance reflects the fact that daptomycin has a mode of action distinct from those of other antibiotics, including glycopeptides. While there are limited data available from randomized controlled trials, extensive clinical experience with daptomycin in enterococcal infections (including bacteraemia, endocarditis, skin and soft tissue infections, bone and joint infections and urinary tract infections) has been reported. This growing body of evidence provides useful insights regarding the efficacy of daptomycin against enterococci in clinical settings.

Prevention of catheter-related bacteremia with a daily ethanol lock in patients with tunnelled catheters: a randomized, placebo-controlled trial

BACKGROUND

Catheter-related bloodstream infection (CRBSI) results in significant attributable morbidity and mortality. In this randomized, double-blind, placebo-controlled trial, we studied the efficacy and safety of a daily ethanol lock for the prevention of CRBSI in patients with a tunnelled central venous catheter (CVC).

METHODOLOGY

From 2005 through 2008, each lumen of the CVC of adult hematology patients was locked for 15 minutes per day with either 70%-ethanol or placebo, where after the lock solution was flushed through. As a primary endpoint, the incidence rates of endoluminal CRBSI were compared.

PRINCIPAL FINDINGS

The intent-to-treat analysis was based on 376 patients, accounting for 448 CVCs and 27,745 catheter days. For ethanol locks, the incidence of endoluminal CRBSI per 1000 CVC-days was 0.70 (95%-CI, 0.4-1.3), compared to 1.19 (95% confidence interval, 0.7-1.9) for placebo (incidence rate-ratio, 0.59; 95% confidence interval, 0.27-1.30; P = .19). For endoluminal CRBSI according to the strictest definition (positive hub culture and identical bacterial strain in blood), a 3.6-fold, non-significant, reduction was observed for patients receiving ethanol (2 of 226 versus 7 of 222; P = .103). No life-threatening adverse events were observed. More patients receiving ethanol discontinued lock-therapy (11 of 226 versus 1 of 222; P = .006) or continued with decreased lock-frequency (10 of 226 versus 0 of 222; P = .002), due to non-severe adverse events.

CONCLUSIONS

In this study, the reduction in the incidence of endoluminal CRBSI using preventive ethanol locks was non-significant, although the low incidence of endoluminal CRBSI precludes definite conclusions. Therefore, the lack of statistical significance may partially reflect a lack of power. Significantly more patients treated with ethanol locks discontinued their prophylactic treatment due to adverse effects, which were non-severe but reasonably ethanol related. Additional studies should be performed in populations with higher incidence of (endoluminal) CRBSI. Alternative sources of bacteremia, like exoluminal CRBSI or microbial translocation during chemotherapy-induced mucositis may have been more important in our patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00122642.

PREFABL: predictors of failure of antibiotic locks for the treatment of catheter-related bacteraemia

BACKGROUND

Antibiotic lock (ABL) solutions can effectively treat catheter-related bacteraemia (CRB) without the need for catheter exchange. This approach does not increase secondary infectious complications. We evaluated the risk factors that contribute to failure when CRB is treated with ABLs and systemic antibiotics in paediatric haemodialysis patients.

METHODS

A retrospective chart review of 72 children on haemodialysis between January 2004 and June 2006 was performed. We evaluated risk factors for ABL treatment using patients' characteristics, CRB/catheter characteristics and patients' biochemical profiles. The first CRB of each catheter was included in the statistical analysis. Our end points were outcome at 2 weeks of treatment and at 6 weeks following treatment. Compound symmetry covariance structure was employed for statistical analysis.

RESULTS

We treated 149 CRB in 50 patients. The incidence was 3.4 CRB/1000 catheter days. Thirty CRB failed to be cleared with the use of ABL and systemic antibiotics at 2 weeks of treatment (30/149, 20 vs 80%, P < 0.001). Twenty-four of these catheters required exchange. Thirty-nine of the treated catheters got re-infected within the next 6 weeks (39/125, 31 vs 69%, P < 0.001). CRB aetiology was the only statistically significant independent variable for 2-week outcome (P = 0.033). Coagulase-negative Staphylococcus CRB had higher odds of being cleared at 2 weeks compared with other CRB aetiologies. For the 6-week outcome, the statistically significant independent variables in the final model included age (P = 0.048) and serum phosphorous level (P < 0.001). Younger age and higher serum phosphorous levels were independent risk factors for failure at 6 weeks with re-infection. Area under the receiver operating characteristic (ROC) curve for the model of the 2-week outcome was 0.736 with the percentage of correct predictions at 81.2%. Area under the ROC curve for the model of the 6-week outcome was 0.689 with the percentage of correct predictions at 75.5%.

CONCLUSIONS

CRB can effectively be treated with ABLs and systemic antibiotics. CRB aetiology is the only independent variable of early treatment failure. Younger age and higher serum phosphorous levels are independent risk factors for re-infection at 6 weeks.

Current aspects of invasive candidiasis and aspergillosis in adult intensive care patients

Sepsis is a leading cause of death in the intensive care unit (ICU), with Candida spp. in the forefront among the important pathogens. As recent studies have shown, survival outcome is strongly influenced by adequate antifungal therapy at an early stage that is often delayed by the time lag associated with microbiological diagnosis. Risk factor-based prediction models have a high negative predictive value, but positive prediction of candidaemia in the individual patient remains elusive. New antigen- or DNA-based methods for early diagnosis still await clinical validation. Their routine use is hampered by methodological issues. Species distribution of invasive Candida isolates in the ICU appears to be influenced primarily by age, previous hospitalisation and colonising species. In the context of the importance of adequate first-line treatment, recent guidelines favour the use of echinocandins in critically ill patients with symptoms evoking high suspicion of invasive candidiasis. This is supported by robust clinical trial data, a few interactions and low toxicity. Fluconazole is characterised by reduced activity against some important Candida species, elevated rates of persistent infection seen in comparative trials. Amphotericin B deoxycholate should be considered obsolete in ICU patients because of its high toxicity. Invasive aspergillosis (IA) is a rare devastating infection in the general ICU population, but some centres have reported elevated incidences and underdiagnosis as determined in autopsy-controlled studies. Treatment with mould-active agents such as voriconazole must be initiated early in patients with suspected IA.

Clinical and molecular epidemiology of Staphylococcus aureus catheter-related bacteremia in children

BACKGROUND

Staphylococcus aureus (SA) is an important cause of catheter-related bacteremia (CRB). The USA300 clone increasingly causes healthcare associated infections. We compared children with SA-CRB due to USA300 versus non-USA300 isolates and identified risk factors for complications.

METHODS

Children at Texas Children's Hospital (TCH) with SA-CRB were identified from a prospective S. aureus surveillance study. S. aureus isolates were characterized by methicillin susceptibility and pulsed field gel electrophoresis.

RESULTS

From August 2001 to October 2007, 112 children with a first episode of SA-CRB and corresponding isolates were identified. USA300 accounted for 21 isolates. Metastatic infection complicated 10.7% of cases and was associated with methicillin resistance. Other complications were recurrence (n = 16), death (n = 13), thrombosis (n = 9), and intravascular "cast" (n = 6). Four patients with non-USA300 SA-CRB had endocarditis. Prolonged bacteremia was more common in methicillin-resistant SA (12/29) than in methicillin-susceptible SA SA-CRB (14/83) (P = 0.007). Complications were more common in patients with bacteremia > or =4 days (16/26 [61.5%]) versus patients with bacteremia <4 days (25/86 [29%]) (P = 0.003). The complication rate was lower in patients who had the catheter removed <4 days (22.5%) versus patients whose catheter was removed > or =4 days after infection or not removed (44.4%) (P = 0.02). Children with USA300 versus non-USA300 isolates did not differ with respect to frequency or type of complications.

CONCLUSIONS

At Texas Children's Hospital, the USA300 clone caused 19% of initial SA-CRB episodes and was associated with methicillin resistance. Complications occurred in 36.6% of the patients and were associated with prolonged bacteremia and catheter removal > or =4 days after infection or failure to remove the catheter.

[Epidemiology of the primary and vascular catheter-related bacteriemias in critical patients admitted to an Intensive Medicine Department]

OBJECTIVE

In recent years, changes have occurred in the setting of bacteriemia related with the use of vascular catheters (BVC) and with the appearance of multiresistant gram positive cocci (MR-GPC), knowledge of the limitations regarding the antibiotics used most for their treatment (glycopeptides) and the appearance of new antibiotics active against these pathogens. This article analyzes the evolution of the rates, etiologies and markers of multiresistance of the most common pathogens in the BVC (including the primary bacteriemias) in the Spanish Intensive Medicine Departments (ICU).

MATERIAL AND METHODS

A multicenter, prospective, observational study of incidence, with voluntary participation, was conducted. A total of 74, 105, 112 and 121 ICUs belonging to 71, 97, 103 and 112 hospitals, respectively, collaborated including the years 2005-2008. The information included in the ENVIN-HELICS registry was used.

RESULTS

The rates of this complication have decreased and are now at about 5 episodes per 1,000 days of central venous catheter (CVC). One third of the episodes occur with significant systemic response (severe sepsis or septic shock). The MR-GPC were the most frequent, however Gram-negative bacilli (GNB) were identified in 30% of the cases and fungi (different species of Candida) in 6%. Staphylococcus epidermidis and coagulase-negative, methicillin-resistant staphylococci (CNS) persist in a proportion greater than 80%, while methicillin-resistance S. aureus have decreased to less than 40%.

CONCLUSIONS

The empirical treatment in situations of extreme seriousness should consider coverage of the most frequent pathogens such as the MR-GPC and GNB and in special conditions, the fungi.

Catheter duration and risk of CLA-BSI in neonates with PICCs

OBJECTIVE

To determine whether the risk of central line-associated bloodstream infections (CLA-BSIs) remained constant over the duration of peripherally inserted central venous catheters (PICCs) in high-risk neonates.

PATIENT AND METHODS

We performed a retrospective cohort study of NICU patients who had a PICC inserted between January 1, 2006, and December 31, 2008. A Poisson regression model with linear spline terms to model time since PICC insertion was used to evaluate potential changes in the risk of CLA-BSI while adjusting for other variables.

RESULTS

Six hundred eighty-three neonates were eligible for analysis. There were 21 CLA-BSIs within a follow-up period of 10 470 catheter-days. The incidence of PICC-associated CLA-BSI was 2.01 per 1 000 catheter-days (95% confidence interval [CI]: 1.24-3.06). The incidence rate of CLA-BSIs increased by 14% per day during the first 18 days after PICC insertion (incidence rate ratio [IRR]: 1.14 [95% CI: 1.04-1.25]). From days 19 through 35 after PICC insertion, the trend reversed (IRR: 0.8 [95% CI: 0.66-0.96]). From days 36 through 60 after PICC insertion, the incidence rate of CLA-BSI again increased by 33% per day (IRR: 1.33 [95% CI: 1.12-1.57]). There was no statistically significant association between the risk of CLA-BSI and gestational age groups, birth weight groups, or chronological age groups.

CONCLUSIONS

Our data suggest that catheter duration is an important risk factor for PICC-associated CLA-BSI in the NICU. A significant daily increase in the risk of CLA-BSI after 35 days may warrant PICC replacement if intravascular access is necessary beyond that period.

Decreasing central line associated bloodstream infection in neonatal intensive care

Central Line Associated Bloodstream Infections (CLABSIs) have come to be recognized as preventable adverse events that result from lapses in technique at multiple levels of care. CLABSIs are associated with increased mortality and adverse outcomes that may have lifelong consequences. This review provides a summary of evidence-based strategies to reduce CLABSI in the newborn intensive care unit that have been described in the literature over the past decades. Implementation of these strategies in "bundles" is also discussed, citing examples of successful quality improvement collaboratives. The methods of implementation require an understanding of the scientific data and technical developments, as well as knowledge of how to influence change within the unique and complicated milieu of the newborn intensive care unit.

Iodine in enteral and parenteral nutrition

Iodine deficiency (ID) has multiple adverse effects on growth and development due to inadequate thyroid hormone production. Methods for assessment of iodine nutrition in individuals include the urinary iodine concentration (UI), thyroid size and thyroid function tests. The UI measured in several repeat 24-h urine samples can detect inadequate iodine intake in individuals receiving enteral or parenteral nutrition (PN) and allow for iodine supplementation before the onset of hypothyroidism. A daily dose of 1 microg iodine/kg body weight is currently recommended for children receiving PN, but this is far below their requirements. Daily iodine requirements in adults receiving enteral nutrition or PN are estimated to be 70-150 microg, but most PN formulations do not contain iodine. Despite this, ID has been unlikely because absorption from iodine-containing skin antiseptics and other adventitious sources can provide sufficient iodine. However, if chlorhexidine replaces iodine-containing antiseptics for catheter care, ID may occur during long-term PN, and periodic testing of UI and thyroid function may be prudent. Infants may be particularly vulnerable to ID because of their small thyroidal iodine store. In this review, we describe three recent patients (an infant, a child and an adult) who developed ID and thyroid hypofunction during PN.

Clinical microbiology in the intensive care unit: strategic and operational characteristics

Infection is a major cause of morbidity and mortality among patients admitted in intensive care units (ICUs). The application of the principles and the practice of Clinical Microbiology for ICU patients can significantly improve clinical outcome. The present article is aimed at summarising the strategic and operational characteristics of this unique field where medical microbiology attempts to venture into the domain of direct clinical care of critically ill patients. The close and strategic partnership between clinical microbiologists and intensive care specialists, which is essential for this model of patient care have been emphasized. The article includes discussions on a variety of common clinical-microbiological problems faced in the ICUs such as ventilator-associated pneumonia, blood stream infections, skin and soft tissue infection, UTI, infection control, besides antibiotic management.

Simvastatin inhibits Candida albicans biofilm in vitro

By inhibiting the conversion of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) to mevalonate, statins impair cholesterol metabolism in humans. We reasoned that statins might similarly interfere with the biosynthesis of ergosterol, the major sterol of the yeast cell membrane. As assessed by spectrophotometric and microscopic analysis, significant inhibition of biofilm production was noted after 16-h incubation with 1, 2.5, and 5 muM simvastatin, concentrations that did not affect growth, adhesion, or hyphal formation by C. albicans in vitro. Higher concentrations (10, 20, and 25 muM simvastatin) inhibited biofilm by >90% but also impaired growth. Addition of exogenous ergosterol (90 muM) overcame the effects of 1 and 2.5 muM simvastatin, suggesting that at least one mechanism of inhibition is interference with ergosterol biosynthesis. Clinical isolates from blood, skin, and mucosal surfaces produced biofilms; biofilms from bloodstream isolates were similarly inhibited by simvastatin. In the absence of fungicidal activity, simvastatin's interruption of a critical step in an essential metabolic pathway, highly conserved from yeast to man, has unexpected effects on biofilm production by a eukaryotic pathogen.

Safety and Efficacy of Cefazolin Sodium in the Management of Bacterial Infection and in Surgical Prophylaxis

Cefazolin sodium is a first-generation cephalosporin antibiotic and has been used worldwide since the early 1970s. It is used for the treatment of bacterial infections in various organs, such as the respiratory tract, skin and skin structure, genital tract, urinary tract, biliary tract, and bone and joint infections. It has also been used for septicemia due to susceptible gram-positive cocci (except Enterococcus), some gram-negative bacilli including E. coli, Proteus, and Klebsiella may be susceptible, and for perioperative prophylaxis. After the introduction of penicillins and other cephalosporins, occasional outbreaks of methicillin-resistant Staphylococcus aureus were noted. As a result, vancomycin use was increased; however, very recently and most alarmingly, vancomycin-resistant strains have been described. In this setting, to avoid the risk of the development of vancomycin-resistant strains further, vancomycin use should be curtailed. In consideration of this historical background, the appropriate use of antibiotics, such as dosage, dosage intervals, and the duration of administration is required not only for the protection of patients’ health but also for the prevention of the development of drug resistance. Cefazolin has been used in clinical practice for about 40 years, and a large body of evidence has been accumulated, and its efficacy and safety are well established compared with other antibiotics. Therefore, cefazolin has been chosen as a first-line anti-microbial for prophylaxis after various surgical procedures, including cardiovascular surgery, hysterectomy, arthroplasty and so on. Based on these facts, especially for the prophylaxis of surgical site infections, the first-generation cephalosporin, cefazolin, is now being “re-visited”.