Management of invasive candidiasis in critically ill patients

Gastrointestinal perforation and the acute abdomen

The acute abdomen accounts for up to 40% of all emergency-surgical hospital admissions and is considered in the differential in the more than 7 million visits to the emergency department annually for abdominal pain in the United States. A large percentage of these cases are secondary to perforation or impending gastrointestinal perforation. Gastrointestinal perforation causes considerable mortality and usually requires emergency surgery.Rapid diagnosis and treatment of these conditions is essential to reduce the high morbidity and mortality of late-stage presentation. Successful treatment requires a thorough understanding of the anatomy, microbiology, and pathophysiology of this disease process and in-depth knowledge of the therapy, including resuscitation,antibiotics, source control, and physiologic support.

Measuring the impact of multidrug resistance in nosocomial infection

PURPOSE OF REVIEW

The review examines potential confounders hampering measurement of the impact of multidrug resistance in nosocomial infections. Methodological techniques dealing with the problem of confounding are discussed and current findings in how multidrug resistance affects outcome in patients with nosocomial infection are highlighted.

RECENT FINDINGS

Outcome comparisons between patients infected with multidrug-resistant pathogens and patients infected with susceptible microorganisms are hampered by confounders such as differences in disease severity, prolonged hospitalization prior to onset of infection (exposure time), the causative pathogen, the type of infection, and the rate of appropriate empirical antimicrobial therapy. The confounding effect can be countered by means of either multivariable regression techniques or matched cohort studies, or a combination of both. Recent literature on the impact of multidrug resistance (methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase producing Enterobacteriaceae, etc) is conflicting and highly dependable on the way disturbing variables are accounted for.

SUMMARY

Recent data underscore that the impact of multidrug resistance on the outcome of nosocomial infection might differ depending on the study population, type of infection, type of pathogen and appropriateness of therapy, and hence, that any conclusion drawn prior to accurate accounting for imbalanced confounders is premature and potentially false.

Microevolution in genomic short sequence repeats of Candida albicans in non-neutropenic patients

The genome of the yeast Candida albicans harbours many genomic short sequence repeats (SSRs). These are stable upon transition of colonization to infection in immune-compromised patients. We show here that in non-neutropenic patients this transition may coincide with variation in several of the SSRs. This may have implications for stage-specific expression of C. albicans pathogenicity factors.

Candida peritonitis

PURPOSE OF REVIEW

The review highlights current insights in the epidemiology, diagnosis and therapy of Candida peritonitis, focusing on complicated secondary and tertiary peritonitis.

RECENT FINDINGS

Candida peritonitis is still associated with poor prognosis. Antifungal prophylaxis is therefore recommended in patients with an overt risk profile for invasive candidiasis (immunodeficiency and prior antibiotic exposure). The clinical and microbiological diagnosis of Candida peritonitis remains problematic. It is still unclear which peritonitis patients may benefit from antifungal treatment. Antifungal therapy can be suggested in critically ill patients with nosocomial peritonitis where Candida is diagnosed based on perioperatively sampled peritoneal fluid. Patients with prior exposure to fluconazole are at risk for Candida nonalbicans spp. involvement with possible reduced susceptibility.

SUMMARY

The main challenge in Candida peritonitis remains the interpretation of Candida cultured from the peritoneal cavity. Future research should focus on more conclusive diagnosis and on factors potentially confounding outcome, such as site of the perforation and failure of surgical source control. While awaiting progress to discriminate Candida colonization from invasive infection, antifungal therapy is recommended in high-risk critically ill surgical patients. Rapid detection of Candida might be beneficial in this regard. Besides antifungal therapy, adequate source control is of key importance.

Surgical critical care: Fungal infections in surgical patients

OBJECTIVE

To review the epidemiology, risk factors, diagnosis, treatment, and prevention of Candida infections in surgical intensive care unit patients.

DESIGN

: Selected review of the literature.

SETTING

Critically ill patients either in an intensive care unit or having undergone a major surgical procedure.

INTERVENTIONS

None.

MAIN RESULTS

Candida infections are the third most common cause of bloodstream infection in the intensive care unit, with increasing numbers of infections due to nonalbicans species. The diagnosis of an invasive fungal infection is difficult, and the risk factors must be recognized and minimized. There is no general consensus about what signs, symptoms, and cultures define a fungal infection. A new 1,3 beta-glucan blood test may assist is the definition of invasive fungal infection. Treatment of fungal infections is now possible with a variety of antifungal agents, with different spectrums of activity, mechanisms of action, and adverse events. Prevention (prophylaxis) is a reasonable strategy in highly selected patients with a significant risk of fungal infection.

CONCLUSION

New antifungal agents and diagnostic tests may improve the outcome of surgical intensive care unit patients with invasive fungal infections. However, agreement about definitions of fungal infection makes study and conclusions of prevention and treatment trials difficult to interpret.

Candidaemia and antifungal therapy in a French University Hospital: rough trends over a decade and possible links

Background

Evidence for an increased prevalence of candidaemia and for high associated mortality in the 1990s led to a number of different recommendations concerning the management of at risk patients as well as an increase in the availability and prescription of new antifungal agents. The aim of this study was to parallel in our hospital candidemia incidence with the nature of prescribed antifungal drugs between 1993 and 2003.

Methods

During this 10-year period we reviewed all cases of candidemia, and collected all the data about annual consumption of prescribed antifungal drugs

Results

Our centralised clinical mycology laboratory isolates and identifies all yeasts grown from blood cultures obtained from a 3300 bed teaching hospital. Between 1993 and 2003, 430 blood yeast isolates were identified. Examination of the trends in isolation revealed a clear decrease in number of yeast isolates recovered between 1995–2000, whereas the number of positive blood cultures in 2003 rose to 1993 levels. The relative prevalence of Candida albicans and C. glabrata was similar in 1993 and 2003 in contrast to the period 1995–2000 where an increased prevalence of C. glabrata was observed. When these quantitative and qualitative data were compared to the amount and type of antifungal agents prescribed during the same period (annual mean defined daily dose: 2662741; annual mean cost: 615629 €) a single correlation was found between the decrease in number of yeast isolates, the increased prevalence of C. glabrata and the high level of prescription of fluconazole at prophylactic doses between 1995–2000.

Conclusion

Between 1993 and 2000, the number of cases of candidemia halved, with an increase of C. glabrata prevalence. These findings were probably linked to the use of Fluconazole prophylaxis. Although it is not possible to make any recommendations from this data the information is nevertheless interesting and may have considerable implications with the introduction of new antifungal drugs.

Critical issues in the clinical management of complicated intra-abdominal infections

Intra-abdominal infections differ from other infections through the broad variety in causes and severity of the infection, the aetiology of which is often polymicrobial, the microbiological results that are difficult to interpret and the essential role of surgical intervention. From a clinical viewpoint, two major types of intra-abdominal infections can be distinguished: uncomplicated and complicated. In uncomplicated intra-abdominal infection, the infectious process only involves a single organ and no anatomical disruption is present. Generally, patients with such infections can be managed with surgical resection alone and no antimicrobial therapy besides perioperative prophylaxis is necessary. In complicated intra-abdominal infections, the infectious process proceeds beyond the organ that is the source of the infection, and causes either localised peritonitis, also referred to as abdominal abscess, or diffuse peritonitis, depending on the ability of the host to contain the process within a part of the abdominal cavity. In particular, complicated intra-abdominal infections are an important cause of morbidity and are more frequently associated with a poor prognosis. However, an early clinical diagnosis, followed by adequate source control to stop ongoing contamination and restore anatomical structures and physiological function, as well as prompt initiation of appropriate empirical therapy, can limit the associated mortality. The biggest challenge with complicated intra-abdominal infections is early recognition of the problem. Antimicrobial management is generally standardised and many regimens, either with monotherapy or combination therapy, have proven their efficacy. Routine coverage against enterococci is not recommended, but can be useful in particular clinical conditions such as the presence of septic shock in patients previously receiving prolonged treatment with cephalosporins, immunosuppressed patients at risk for bacteraemia, the presence of prosthetic heart valves and recurrent intra-abdominal infection accompanied by severe sepsis. In patients with prolonged hospital stay and antibacterial therapy, the likelihood of involvement of antibacterial-resistant pathogens must be taken into account. Antimicrobial coverage of Candida spp. is recommended when there is evidence of candidal involvement or in patients with specific risk factors for invasive candidiasis such as immunodeficiency and prolonged antibacterial exposure. In general, antimicrobial therapy should be continued for 5-7 days. If sepsis is still present after 1 week, a diagnostic work up should be performed, and if necessary a surgical reintervention should be considered.

Biología molecular en el diagnóstico de la candidiasis profunda en el paciente crítico no neutropénico

Candida infections are an important cause of morbidity and mortality in critically ill patients. Rapid detection of the yeast in blood and other tissues by molecular biology methods has been the goal of some recent studies. An analysis of the sensitivity and specificity of these methods assayed in clinical specimens from critically ill and other patients is carried out. PCR amplification of ribosomal genes and their internal spacers showed a higher sensitivity than culture based methods. A standardization of most of the methodological steps in molecular methods is needed. Real time PCR with fluorescent probes seems to be the most interesting proposal. It has the advantage of the possible quantification of fungal presence in tissues and minimizes the samples' contamination risk.