Management of invasive candidiasis in critically ill patients

Intra-abdominal infection and sepsis in immunocompromised intensive care unit patients: Disease expression, microbial aetiology, and clinical outcomes

We compared epidemiology of intra-abdominal infection (IAI) between immunocompromised and non-immunocompromised ICU patients and identified risk factors for mortality. We performed a secondary analysis on the "AbSeS" database, a prospective, observational study with IAI patients from 309 ICUs in 42 countries. Immunocompromised status was defined as either neutropenia or prolonged corticosteroids use, chemotherapy or radiotherapy in the past year, bone marrow or solid organ transplantation, congenital immunodeficiency, or immunosuppressive drugs use. Mortality was defined as ICU mortality at any time or 28-day mortality for those discharged earlier. Associations with mortality were assessed by logistic regression. The cohort included 2589 patients of which 239 immunocompromised (9.2 %), most with secondary peritonitis. Among immunocompromised patients, biliary tract infections were less frequent, typhlitis more frequent, and IAIs were more frequently healthcare-associated or early-onset hospital-acquired compared with immunocompetent patients. No difference existed in grade of anatomical disruption, disease severity, organ failure, pathogens, and resistance patterns. Septic shock was significantly more frequent in the immunocompromised population. Mortality was similar in both groups (31.1% vs. 28.9 %; p = 0.468). Immunocompromise was not a risk factor for mortality (OR 0.98, 95 % CI 0.66-1.43). Independent risk factors for mortality among immunocompromised patients included septic shock at presentation (OR 6.64, 95 % CI 1.27-55.72), and unsuccessful source control with persistent inflammation (OR 5.48, 95 % CI 2.29-12.57). In immunocompromised ICU patients with IAI, short-term mortality was similar to immunocompetent patients, despite the former presented more frequently with septic shock, and septic shock and persistent inflammation after source control were independent risk factors for death.

Relationship between SARS-CoV-2 infection and ICU-acquired candidemia in critically ill medical patients: a multicenter prospective cohort study

BACKGROUND

While SARS-CoV2 infection has been shown to be a significant risk-factor for several secondary bacterial, viral and Aspergillus infections, its impact on intensive care unit (ICU)-acquired candidemia (ICAC) remains poorly explored.

METHOD

Using the REA-REZO network (French surveillance network of ICU-acquired infections), we included all adult patients hospitalized for a medical reason of admission in participating ICUs for at least 48 h from January 2020 to January 2023. To account for confounders, a non-parsimonious propensity score matching was performed. Rates of ICAC according to SARS-CoV2 status were compared in matched patients. Factors associated with ICAC in COVID-19 patients were also assessed using a Fine-Gray model.

RESULTS

A total of 55,268 patients hospitalized at least 48 h for a medical reason in 101 ICUs were included along the study period. Of those, 13,472 were tested positive for a SARS-CoV2 infection while 284 patients developed an ICAC. ICAC rate was higher in COVID-19 patients in both the overall population and the matched patients' cohort (0.8% (107/13,472) versus 0.4% (173/41,796); p < 0.001 and 0.8% (93/12,241) versus 0.5% (57/12,241); p = 0.004, respectively). ICAC incidence rate was also higher in those patients (incidence rate 0.51 per 1000 patients-days in COVID-19 patients versus 0.32 per 1000 patients-days; incidence rate ratio: 1.58 [95% CI:1.08-2.35]; p = 0.018). Finally, patients with ICAC had a higher ICU mortality rate (49.6% versus 20.2%; p < 0.001).

CONCLUSION

In this large multicenter cohort of ICU patients, although remaining low, the rate of ICAC was higher among COVID-19 patients.

Severe Candida infections in critically ill patients with COVID-19

The frequency of co-infections with bacterial or fungal pathogens has constantly increased among critically ill patients with coronavirus disease 2019 (COVID-19) during the pandemic. Candidemia was the most frequently reported invasive fungal co-infection. The onset of candidemia in COVID-19 patients was often delayed compared to non-COVID-19 patients. Additionally, Candida invasive infections in COVID-19 patients were more often linked to invasive procedures (e.g., invasive mechanical ventilation or renal replacement therapy) during the intensive care stay and the severity of illness rather than more "classic" risk factors present in patients without COVID-19 (e.g., underlying diseases and prior hospitalization). Moreover, apart from the increased incidence of candidemia during the pandemic, a worrying rise in fluconazole-resistant strains was reported, including a rise in the multidrug-resistant Candida auris. Regarding outcomes, the development of invasive Candida co-infection had a negative impact, increasing morbidity and mortality compared to non-co-infected COVID-19 patients. In this narrative review, we present and critically discuss information on the diagnosis and management of invasive fungal infections caused by Candida spp. in critically ill COVID-19 patients.

Invasive pulmonary aspergillosis in the ICU: tale of a broadening risk profile

PURPOSE OF REVIEW

In the absence of histopathological proof, the diagnosis of invasive pulmonary aspergillosis (IPA) is usually based on mycology (not on tissue), medical imaging, and the patient's risk profile for acquiring invasive fungal disease. Here, we review the changes in risk profile for IPA that took place over the past decades.

RECENT FINDINGS

In the early 2000s IPA was considered exclusively a disease of immunocompromised patients. Particularly in the context of critical illness, the risk profile has been broadened steadily. Acute viral infection by influenza or SARS-Cov-2 are now well recognized risk factors for IPA.

SUMMARY

The classic risk profile ('host factors') reflecting an immunocompromised status was first enlarged by a spectrum of chronic conditions such as AIDS, cirrhosis, and chronic obstructive pulmonary disease. In the presence of critical illness, especially characterized by sepsis and/or severe respiratory distress, any chronic condition could add to the risk profile. Recently, acute viral infections have been associated with IPA leading to the concepts of influenza-associated IPA and COVID-19-associated IPA. These viral infections may affect patients without underlying disease. Hence, the risk for IPA is now a reality for ICU patients, even in the absence of any chronic conditions.

Development and validation of a user-friendly risk nomogram for the prediction of catheter-associated urinary tract infection in neuro-intensive care patients

OBJECTIVE

This study aimed to develop a user-friendly nomogram model to evaluate the risk of catheter-associated urinary tract infections in neuro-critically ill patients.

METHODS

A retrospective cohort analysis was conducted on 537 patients with indwelling catheters admitted to the neuro-intensive care unit. Patients' general information, laboratory examination findings, and clinical characteristics were collected. Multivariate regression analysis was applied to develop the nomogram for the prediction of catheter-associated urinary tract infections in this group of patients. The discriminative capacity, calibration ability, and clinical effectiveness of the nomogram were evaluated.

RESULTS

The occurrence of catheter-associated urinary tract infections was 3.91 % and Escherichia coli was the major causative pathogen. Multivariate regression analysis showed that age ≥ 60 years (odds ratio: 35.2, 95 % confidence interval: 2.3-550.8), epilepsy (39.3, 5.1-301.4), a length of neuro-intensive care stay > 30 days (272.2, 8.3-8963.5), and low albumin levels (<35 g/L) (12.1, 2.1-69.9) were independent risk factors associated with catheter-associated urinary tract infection in neuro-intensive care patients. The nomogram demonstrated good calibration and discrimination in both the training and the validation sets. The model exhibited good clinical use since the decision curve analysis covered a large threshold probability.

CONCLUSIONS

We developed a user-friendly nomogram to predict catheter-associated urinary tract ibfection in neuro-intensive care patients. The nomogram incorporated clinical variables collected on admission (age, admission diagnosis, and albumin levels) and the length of stay and enabled the effective prediction of the likelihood of catheter-associated urinary tract infections.

Deciphering the epidemiology of invasive candidiasis in the intensive care unit: is it possible?

Invasive candidiasis (IC) has emerged in the last decades as an important cause of morbidity, mortality, and economic load in the intensive care unit (ICU). The epidemiology of IC is still a difficult and unsolved enigma for the literature. Accurate estimation of the true burden of IC is difficult due to variation in definitions and limitations inherent to available case-finding methodologies. Candidemia and intra-abdominal candidiasis (IAC) are the two predominant types of IC in ICU. During the last two decades, an increase in the incidence of candidemia has been constantly reported particularly in the expanding populations of elderly or immunosuppressed patents, with a parallel change in Candida species (spp.) distribution worldwide. Epidemiological shift in non-albicans spp. has reached worrisome trends. Recently, a novel, multidrug-resistant Candida spp., Candida auris, has globally emerged as a nosocomial pathogen causing a broad range of healthcare-associated invasive infections. Epidemiological profile of IAC remains imprecise. Though antifungal drugs are available for Candida infections, mortality rates continue to be high, estimated to be up to 50%. Increased use of fluconazole and echinocandins has been associated with the emergence of resistance to these drugs, which affects particularly C. albicans and C. glabrata. Crucial priorities for clinicians are to recognize the epidemiological trends of IC as well as the emergence of resistance to antifungal agents to improve diagnostic techniques and strategies, develop international surveillance networks and antifungal stewardship programmes for a better epidemiological control of IC.

Computational Drug Repurposing Resources and Approaches for Discovering Novel Antifungal Drugs against Candida albicans N-Myristoyl Transferase

Candida albicans is a yeast that is an opportunistic fungal pathogen and also identified as ubiquitous polymorphic species that is mainly linked with major fungal infections in humans, particularly in the immunocompromised patients including transplant recipients, chemotherapy patients, HIV-infected patients as well as in low-birth-weight infants. Systemic Candida infections have a high mortality rate of around 29 to 76%. For reducing its infection, limited drugs are existing such as caspofungin, fluconazole, terbinafine, and amphotericin B, etc. which contain unlikable side effects and also toxic. This review intends to utilize advanced bioinformatics technologies such as Molecular docking, Scaffold hopping, Virtual screening, Pharmacophore modeling, Molecular dynamics (MD) simulation for the development of potentially new drug candidates with a drug-repurpose approach against Candida albicans within a limited time frame and also cost reductive.

Effect of an acrylic terpolymer barrier film beneath transparent catheter dressings on skin integrity, risk of dressing disruption, catheter colonisation and infection

OBJECTIVES

We assessed the effect of a skin-protective terpolymer barrier film around the catheter insertion site on frequency of dressing disruptions and skin integrity issues (hyperaemia, skin irritation, residues of adhesives and moisture under the dressing). Secondary outcomes included colonisation of the central venous catheter (CVC) and rates of central line-associated bloodstream infection.

RESEARCH METHODOLOGY

A monocentric, open-label, randomised controlled trial was performed comparing a control group receiving standard transparent catheter dressings without the skin-protecting barrier film and an intervention group receiving a transparent chlorhexidine-impregnated dressing with use of the skin-protective acrylic terpolymer barrier film (3M™ Cavilon™ No - Sting Barrier Film, 3 M Health Care, St. Paul, MN, USA).

RESULTS

Sixty patients were enrolled and randomised in the study accounting for 60 central venous catheters and a total of 533 catheter days. Dressing disruptions occurred more frequently and at sooner time point in the control group. Skin integrity issues were significantly less observed in the intervention group. No differences in CVC colonisation or central line-associated bloodstream infection were observed.

CONCLUSIONS

The application of a barrier film creating a skin-protective polymer layer beneath transparent catheter dressings is associated with less dressing disruptions and skin integrity issues without altering the risk of infectious complications if used in combination with a chlorhexidine-impregnated catheter dressing.

The effects of major burn related pathophysiological changes on the pharmacokinetics and pharmacodynamics of drug use: An appraisal utilizing antibiotics

Patients suffering major burn injury represent a unique population of critically ill patients. Widespread skin and tissue damage causes release of systemic inflammatory mediators that promote endothelial leak, extravascular fluid shifts, and cardiovascular derangement. This phase is characterized by relative intra-vascular hypovolaemia and poor peripheral perfusion. Large volume intravenous fluid resuscitation is generally required. The patients' clinical course is then typically complicated by ongoing inflammation, protein catabolism, and marked haemodynamic perturbation. At all times, drug distribution, metabolism, and elimination are grossly distorted. For hydrophilic agents, changes in volume of distribution and clearance are marked, resulting in potentially sub-optimal drug exposure. In the case of antibiotics, this may then promote treatment failure, or the development of bacterial drug resistance. As such, empirical dose selection and pharmaceutical development must consider these features, with the application of strategies that attempt to counter the unique pharmacokinetic changes encountered in this setting.

Persistent spontaneous fungal peritonitis secondary to Candida albicans in a patient with alcoholic cirrhosis and review of the literature

Candida albicans is a common human pathogen. Occasionally, it can cause peritonitis in immunocompromised and postsurgical patients. We report a case of a male patient who presented with abdominal pain and distention. He had a history of end-stage liver disease secondary to alcoholism. His peritoneal fluid culture revealed C albicans, and (1-3)-β-d glucan (BDG) level was elevated. His hospital course was complicated by sepsis and renal failure. He was treated with antifungals for spontaneous fungal peritonitis. Fungal peritonitis should be suspected in patients with chronic liver disease particularly with elevated BDG levels.

Prognostic factors for candidaemia in intensive care unit patients: a retrospective analysis

INTRODUCTION

Candidaemia, recognised as a fairly common disease among intensive care unit (ICU) patients, carries a poor prognosis. However, as studies on the prognostic factors associated with candidaemia in ICU patients are limited, this study aimed to establish the best prognostic factor for ICU patients with candidaemia in a tertiary care hospital in Japan.

METHODS

We conducted a retrospective cohort study of patients with candidaemia in the emergency ICU at Fukuoka University Hospital, Fukuoka, Japan, from April 2010 to March 2015. Demographic and clinical data was collected from the patients' medical records and laboratory databases.

RESULTS

A total of 25 patients were included in the study. However, 18 patients died during hospitalisation, resulting in an in-hospital mortality rate of 72.0%. The variables of Sequential Organ Failure Assessment (SOFA) score and cumulative number of risk factors for invasive candidiasis showed significant differences between patients in the survivor and non-survivor groups (p < 0.05). The areas under the receiver operating characteristic curves for the SOFA score and cumulative number of risk factors for invasive candidiasis were 0.873 (95% confidence interval [CI] 0.72-1.00) and 0.937 (95% CI 0.84-1.00), respectively.

CONCLUSION

Our results suggest that the cumulative number of risk factors for invasive candidiasis was the most useful prognostic indicator for candidaemia in ICU patients.

The effect of pathophysiology on pharmacokinetics in the critically ill patient--concepts appraised by the example of antimicrobial agents

Critically ill patients are at high risk for development of life-threatening infection leading to sepsis and multiple organ failure. Adequate antimicrobial therapy is pivotal for optimizing the chances of survival. However, efficient dosing is problematic because pathophysiological changes associated with critical illness impact on pharmacokinetics of mainly hydrophilic antimicrobials. Concentrations of hydrophilic antimicrobials may be increased because of decreased renal clearance due to acute kidney injury. Alternatively, antimicrobial concentrations may be decreased because of increased volume of distribution and augmented renal clearance provoked by systemic inflammatory response syndrome, capillary leak, decreased protein binding and administration of intravenous fluids and inotropes. Often multiple conditions that may influence pharmacokinetics are present at the same time thereby excessively complicating the prediction of adequate concentrations. In general, conditions leading to underdosing are predominant. Yet, since prediction of serum concentrations remains difficult, therapeutic drug monitoring for individual fine-tuning of antimicrobial therapy seems the way forward.

How to select an antifungal agent in critically ill patients

Fungal infections are common in critically ill patients and are associated with increased morbidity and mortality. Candida spp are the most commonly isolated fungal pathogens. The last 2 decades have seen an increased incidence of fungal infections in critical illness and the emergence of new pathogenic fungal species and also the development of more effective (better bioavailability) and safer (less toxicity, fewer drug interactions) drugs. The distinction between colonization and infection can be difficult, and problems diagnosing infection may delay initiation of antifungal treatment. A number of factors have been identified that can help to distinguish patients at high risk for fungal infection. The antifungal agents that are most frequently used in the intensive care unit are the first- and second-generation azoles and the echinocandins; amphotericin B derivatives (mainly the liposomal agents) are less widely used because of adverse effects. The choice of antifungal agent in critically ill patients will depend on the aim of therapy (prophylaxis, pre-emptive, empiric, definitive), as well as on local epidemiology and specific properties of the drug (antifungal spectrum, efficacy, toxicity, pharmacokinetic/pharmacodynamic properties, cost). In this article we will review all these aspects and propose an algorithm to guide selection of antifungal agents in critically ill patients.

Invasive fungal infections in the ICU: how to approach, how to treat

Invasive fungal infections are a growing problem in critically ill patients and are associated with increased morbidity and mortality. Most of them are due to Candida species, especially Candida albicans. Invasive candidiasis includes candidaemia, disseminated candidiasis with deep organ involvement and chronic disseminated candidiasis. During the last decades rare pathogenic fungi, such as Aspergillus species, Zygomycetes, Fusarium species and Scedosporium have also emerged. Timely diagnosis and proper treatment are of paramount importance for a favorable outcome. Besides blood cultures, several laboratory tests have been developed in the hope of facilitating an earlier detection of infection. The antifungal armamentarium has also been expanded allowing a treatment choice tailored to individual patients' needs. The physician can choose among the old class of polyenes, the older and newer azoles and the echinocandins. Factors related to patient's clinical situation and present co-morbidities, local epidemiology data and purpose of treatment (prophylactic, pre-emptive, empiric or definitive) should be taken into account for the appropriate choice of antifungal agent.

Insights and advances in multidisciplinary critical care: a review of recent research

The intensive care unit is a work environment where superior dedication is pivotal to optimize patients' outcomes. As this demanding commitment is multidisciplinary in nature, it requires special qualities of health care workers and organizations. Thus research in the field covers a broad spectrum of activities necessary to deliver cutting-edge care. However, given the abundance of research articles and education activities available, it is difficult for modern critical care clinicians to keep up with the latest progress and innovations in the field. This article broadly summarizes new developments in multidisciplinary intensive care, providing elementary information about advanced insights in the field by briefly describing selected articles bundled in specific topics. Issues considered include cardiovascular care, monitoring, mechanical ventilation, infection and sepsis, nutrition, education, patient safety, pain assessment and control, delirium, mental health, ethics, and outcomes research.

Occurrence, presentation and treatment of candidemia

Candida is one of the most common causes of nosocomial bloodstream infections. Candidemia is not confined to hematological patients, intensive care units or abdominal surgery wards, but it is remarkably frequent in the internal medicine setting. High mortality associated with candidemia can be reduced by prompt, appropriate antifungal therapy. The epidemiology of species has been shifting toward non-albicans strains. Significant improvements in nonculture-based diagnostic methods, such as serological markers, have been made in recent years, and novel diagnostic techniques should be further studied to enable early pre-emptive therapy. Treatment guidelines indicate that echinocandins are at present the best choice for patients who are severely ill or possibly infected with fluconazole-resistant strains.

A review of Candida prophylaxis in the neonatal intensive care population

OBJECTIVE

To review the efficacy and safety of antifungal prophylaxis in the neonatal intensive care setting.

DATA SOURCES

English-language literature was accessed using MEDLINE (January 1988- December 2010). The following Medical Subject Heading (MeSH) search terms were used: "amphotericin B," "fluconazole," "nystatin," "itraconazole," "caspofungin," "voriconazole," "Candida," "prevention and control," and "critically ill." Literature was further limited to studies focusing on patient birth to 6 months of age. Abstracts and original research articles were included. Preference was given to published controlled trials. Articles providing descriptions of the safety and effectiveness of antifungal prophylaxis in neonatal intensive care patients were also used in this review.

RESULTS

Twenty-two studies have evaluated the impact of antifungal prophylaxis on Candida colonization or invasive infections in the Neonatal Intensive Care Unit (NICU). The two antifungal agents most commonly studied were nystatin and fluconazole. All of the nystatin studies demonstrated that nystatin is effective at reducing fungal colonization and invasive fungal infections. All of the studies designed to evaluate the impact of fluconazole prophylaxis on fungal colonization demonstrated a reduction in the incidence of fungal colonization with fluconazole prophylaxis. A total of 12 of 16 studies that evaluated the impact of fluconazole prophylaxis on the incidence of invasive fungal infections demonstrated a reduction in invasive fungal infections with fluconazole prophylaxis. Two studies found no difference between fluconazole and nystatin when used for prophylaxis.

CONCLUSION

Antifungal prophylaxis appears to be effective in reducing the incidence of Candida colonization and invasive Candida infections in the NICU. Antifungal prophylaxis also appears to be safe in the NICU population. The impact of antifungal prophylaxis on resistance patterns could be significant and needs to be evaluated long term before widespread prophylaxis can be recommended.

Essentials for selecting antimicrobial therapy for intra-abdominal infections

Intra-abdominal infection (IAI) is a complex disease entity in which different aspects must be balanced in order to select the proper antimicrobial regimen and determine duration of therapy. A current classification indicates different faces of peritonitis. Primary peritonitis implies an intact gastrointestinal tract without overt barrier disruption. Secondary peritonitis refers to localized or diffuse peritoneal inflammation and abscess formation due to disruption of the anatomical barrier. Tertiary peritonitis includes cases that cannot be solved by a single or even sequential surgical intervention, often in combination with sequential courses of antimicrobial therapy. The most frequently used classification distinguishes ‘uncomplicated’ and ‘complicated’ IAI. In uncomplicated IAI, the infectious process is contained within a single organ, without anatomical disruption. In complicated IAI, disease is extended, with either localized or generalized peritonitis. However, there exists more than a single dimension of complexity in IAI, including severity of disease expression through systemic inflammation. As the currently used classifications of IAI often incite confusion by mixing elements of anatomical barrier disruption, severity of disease expression and (the likelihood of) resistance involvement, we propose an alternative for the current widely accepted classification. We suggest abandoning the terms ‘uncomplicated’ and ‘complicated’ IAI, as they merely confuse the issue. Furthermore, the term ‘tertiary peritonitis’ should likewise be discarded, as this simply refers to treatment failure of secondary peritonitis resulting in a state of persistent infection and/or inflammation. Hence, anatomical disruption and disease severity should be separated into different phenotypes for the same disease in combination with either presence or absence of risk factors for involvement of pathogens that are not routinely covered in first-line antimicrobial regimens (Pseudomonas aeruginosa, enterococci, Candida species and resistant pathogens). Generally, these risk factors can be brought back to recent exposure to antimicrobial agents and substantial length of stay in healthcare settings (5–7 days). As such, we developed a grid based on the different components of the classification: (i) anatomical disruption; (ii) severity of disease expression; and (iii) either community-acquired/early-onset healthcare-associated origin or healthcare-associated origin and/or recent antimicrobial exposure. The grid allows physicians to define the index case of IAI in a more unequivocal way and to select the most convenient empirical antimicrobial regimens. The grid advises on the necessity of covering nosocomial Gram-negative bacteria (including P. aeruginosa), enterococci and yeasts. The basis of antimicrobial therapy for IAI is that both Gram-negative and anaerobic bacteria should always be covered.

In recent years, some newer agents such as doripenem, moxifloxacin and tigecycline have been added to the antimicrobial armamentarium for IAI. For patients in whom the source can be adequately controlled, antimicrobial therapy should be restricted to a short course (e.g. 3–7 days in peritonitis).

Antifungal effect of 4-arylthiosemicarbazides against Candida species. Search for molecular basis of antifungal activity of thiosemicarbazide derivatives

The in vitro antifungal potency of six series of 4-arylthiosemicarbazides was evaluated. Two isoquinoline derivatives with an ortho-methoxy or ortho-methyl group at the phenyl ring were the most potent antifungal agents. Molecular modeling studies and docking of all 4-arylthiosemicarbazides into the active sites of sterol 14α-demethylase (CYP51), topoisomerase II (topo II), l-glutamine: d-fructose-6-phosphate amidotransferase (GlcN-6-P), secreted aspartic proteinase (SAP), N-myristoyltransferase (NMT), and UDP-N-acetylmuramoyl-l-alanine:d-glutamate ligase (MurD) indicated the importance of both structural and electronic factors in ligand recognition and thus for the antifungal effectiveness of 4-arylthiosemicarbazides. A possible antifungal target was identified (NMT) and isoquinoline-thiosemicarbazides showed more favorable affinity than the native ligand.

Figure

Azole antimycotics and drug interactions in the perioperative period

PURPOSE OF REVIEW

A beneficial effect of antifungal prophylaxis on the prevention of invasive fungal infections has increased the use of azole antimycotics in intensive care and during the perioperative period. At the same time more severe illnesses are treated and multiple drug therapies are employed. Thus, the potential for severe drug-drug interactions has increased. Previous studies have shown that azole antimycotics increase the risk of many clinically significant drug interactions with potentially hazardous consequences.

RECENT FINDINGS

A recent pharmacoepidemiological study has found a more than five-fold incidence ratio in the adjusted rate of sudden death from cardiac diseases among those patients who were given simultaneously inhibitors of cytochrome P450 (CYP) enzymes and their substrates. Although new triazole antifungals are well tolerated, they still cause significant inhibition of CYP enzymes.

SUMMARY

This review focuses on azole antimycotics and anesthetic drugs being used during the perioperative period and discusses the possible clinically significant drug-drug interactions. Azole antimycotics are amongst the strongest inhibitors of CYP-mediated drug metabolism. Anesthesiologists must be aware of the interaction potential of azole antimycotics to be able to adjust their perioperative strategies according to the patient's condition and concomitant medication.

Candidemia and invasive candidiasis: a review of the literature for the burns surgeon

Advances in critical care, operative techniques, early fluid resuscitation, antimicrobials to control bacterial infections, nutritional support to manage the hypermetabolic response and early wound excision and coverage has improved survival rates in major burns patients. These advances in management have been associated with increased recognition of invasive infections caused by Candida species in critically ill burns patients. Candida albicans is the most common species to cause invasive Candida infections, however, non-albicans Candida species appear to becoming more frequent. These later species may be less fluconazole susceptible than Candida albicans. High crude and attributable mortality rates from invasive Candida sepsis are multi-factorial. Diagnosis of invasive candidiasis and candidemia remains difficult. Prophylactic and pre-emptive therapies appear promising strategies, but there is no specific approach which is well-studied and clearly efficacious in high-risk burns patients. Treatment options for invasive candidiasis include several amphotericin B formulations and newer less toxic antifungal agents, such as azoles and echinocandins. We review the currently available data on diagnostic and management strategies for invasive candidiasis and candidemia; whenever possible providing reference to the high-risk burn patients. We also present an algorithm for the management of candidemia and invasive candidiasis in burn patients.

Patterns of antimicrobial therapy in severe nosocomial infections: empiric choices, proportion of appropriate therapy, and adaptation rates--a multicentre, observational survey in critically ill patients

This prospective, observational multicentre (n=24) study investigated relationships between antimicrobial choices and rates of empiric appropriate or adequate therapy, and subsequent adaptation of therapy in 171 ICU patients with severe nosocomial infections. Appropriate antibiotic therapy was defined as in vitro susceptibility of the causative pathogen and clinical response to the agent administered. In non-microbiologically documented infections, therapy was considered adequate in the case of favourable clinical response <5 days. Patients had pneumonia (n=127; 66 ventilator-associated), intra-abdominal infection (n=23), and bloodstream infection (n=21). Predominant pathogens were Pseudomonas aeruginosa (n=29) Escherichia coli (n=26), Staphylococcus aureus (n=22), and Enterobacter aerogenes (n=21). In 49.6% of infections multidrug-resistant (MDR) bacteria were involved, mostly extended-spectrum beta-lactamase (EBSL)-producing Enterobacteriaceae and MDR non-fermenting Gram-negative bacteria. Prior antibiotic exposure and hospitalisation in a general ward prior to ICU admission were risk factors for MDR. Empiric therapy was appropriate/adequate in 63.7% of cases. Empiric schemes were classified according to coverage of (i) ESBL-producing Enterobacteriaceae and non-fermenting Gram-negative bacteria ("meropenem-based"), (ii) non-fermenting Gram-negative bacteria (schemes with an antipseudomonal agent), and (iii) first-line agents not covering ESBL-Enterobacteriaceae nor non-fermenting Gram-negative bacteria. Meropenem-based schemes allowed for significantly higher rates of appropriate/adequate therapy (p<0.001). This benefit remained when only patients without risk factors for MDR were considered (p=0.021). In 106 patients (61%) empiric therapy was modified: in 60 cases following initial inappropriate/inadequate therapy, in 46 patients in order to refine empiric therapy. In this study reflecting real-life practice, first-line use of meropenem provided significantly higher rates of the appropriate/adequate therapy, irrespective of presence of risk factors for MDR.

Delivery of Antifungal Agents Using Bioactive and Nonbioactive Bone Cements

Background:

Management of fungal osteomyelitis is prolonged and frequently unsuccessful. Antifungal-impregnated cement is sometimes used as adjunctive therapy.

Objective:

To examine the release of antifungals from biodegradable and nonbiodegradable cement carriers.

Methods:

In vitro methods were used to assess antifungal drug release and antifungal activity of impregnated cements commonly used as adjunctive treatment of osteomyelitis. Cements included thermoplastic, nonbioactive polymers (polymethylmethacrylate [PMMA]) or bioactive agents (hydroxyapatite [HAP], β-tricalcium phosphate [β-TCP]) and were formed into spheres (beads).

Results:

Amphotericin B provided consistent supernatant concentrations (release), between 1.75 and 2.0 ug/mL, over 110 days from all bone cements. Flucytosine and fluconazole were observed for 33–42 days before becoming undetectable from a nonbioactive sphere and 18–22 days from a bioactive sphere. Serum concentrations for micafungin, terbinafine, and anidulafungin impregnated into PMMA rapidly became undetectable, regardless of the matrix used. Investigational β-TCP spheres prolonged release for fluconazole and micafungin, but had no effect on amphotericin B. Serum calcium concentrations decreased 60–80% in all HAP-impregnated drug sphere supernatants. Only amphotericin B–impregnated PMMA impacted supernatant calcium, decreasing concentrations by 50–60%. The antifungal-impregnated beads did not appear to be toxic to osteoblasts during 72 hours of exposure in tissue culture medium.

Conclusions:

Elution characteristics of most antifungals from bone cement spheres are probably not optima) for treatment of deep-seated fungal infections if a similar phenomenon of antifungal release manifests in vivo. Ceramic nonabsorbable impregnated devices must be removed after their lifespan expires and may necessitate another surgical procedure that can increase surgical risk and cost. Bioactive osteoconductive materials may provide a surgical alternative to nonabsorbable matrices. However, there have been no controlled trials demonstrating improved therapeutic outcomes with local therapy and assessing whether biodegradable materials act as a new focus for infection.

Is Candida really a threat in the ICU?

PURPOSE OF REVIEW

The epidemiological and clinical relevance of Candida in the ICU is reviewed. Three issues were appraised. First is the prevalence of Candida. Second is the relevance of nonblood cultures positive for Candida and multisite colonization. Third is the importance of invasive candidiasis in terms of mortality.

RECENT FINDINGS

The diagnosis of invasive candidiasis remains problematic in nonblood cultures. Consequently, the true prevalence of invasive candidiasis is difficult to assess. Another result of the complicated diagnosis is the risk for delayed antifungal therapy in case of systemic Candida infection. Therefore, pre-emptive therapy has become increasingly popular in high-risk patients.

SUMMARY

Candida spp. cause a minority of nosocomial bloodstream infections ( approximately 4-9%). Yet, delayed initiation of appropriate antifungal therapy results in significant attributable mortality. Given the inability to efficiently discriminate colonization from invasive candidiasis, this is a problematic issue. The presence of Candida in tracheal aspirates, urine cultures or wound swabs frequently reflects colonization. Yet, multisite colonization frequently precedes systemic invasion. As such, multisite Candida colonization is a crucial element in the decision to start pre-emptive therapy. However, the predictive value of multisite colonization in the absence of an overt risk profile for invasive candidiasis appears to be low.

Discovery of a small-molecule inhibitor of {beta}-1,6-glucan synthesis

It is possible that antifungal drugs with novel modes of action will provide favorable options to treat fungal infections. In the course of our screening for antifungal compounds acting on the cell wall, a pyridobenzimidazole derivative with unique activities, named D75-4590, was discovered. During treatment of Saccharomyces cerevisiae with D75-4590, (i) incorporation of [(14)C]glucose into the beta-1,6-glucan component was selectively reduced, (ii) proteins released from the cell had lost the beta-1,6-glucan moiety, and (iii) cells tended to clump, resulting in impaired cell growth. Genetic analysis of a D75-4590-resistant mutant of S. cerevisiae indicated that its primary target was Kre6p, which is considered to be one of the beta-1,6-glucan synthases. These results strongly suggest that D75-4590 is a specific inhibitor of beta-1,6-glucan synthesis. D75-4590 showed potent activities against various Candida species. It inhibited hyphal elongation of C. albicans as well. KRE6 is conserved in various fungi, but no homologue has been found in mammalian cells. These lines of evidence indicate that D75-4590 is a promising lead compound for novel antifungal drugs. To our knowledge, this is the first report of a beta-1,6-glucan inhibitor.

[Tolerance of caspofungin in intensive care unit: a prospective study]

OBJECTIVE

Caspofungin has shown efficacy and very low toxicity in empirical antifungal therapy in refractory invasive Aspergillus infections and invasive candidiasis in neutropenic (or non) patients. To date, there is no data on tolerability of caspofungin in ICU patients. The aim of this study was to evaluate caspofungine tolerability in critical care patients.

PATIENTS AND METHOD

Over a 36-month period, 1430 patients were admitted in a general intensive care unit. All patients data were collected in a prospective database. All the clinical or biological side effects reported in the multicentric studies were required. The patients were laminated in two groups, according to the initial hepatic function.

RESULTS

Seventy-three patients were treated with caspofungin (5.1%) and 58% were immunocompromised. Immunosuppression was due to acute leukemia (30%), solid organ transplant (20%) or other causes of immunosuppression. In this group, SAPS2 was higher (51+/-20 versus 44+/-20; p<0.05) as mortality rate was (60% versus 23%). More than 90% of patients were ventilated and 55% needed extrarenal therapy. Caspofungin treatment was initiated for aspergillosis in 12 patients, candidiasis in 33 patients and others indications. Partial or complete response to treatment was 72%. Median duration of caspofungin administration was 11 days, no liver dysfunction or acute renal failure due to caspofungin was reported whatever initial liver function was.

CONCLUSION

This prospective open study demonstrate the very low toxicity of caspofungin even in critical care patients.