Candida in the respiratory tract secretions of critically ill patients and the impact of antifungal treatment: a randomized placebo controlled pilot trial (CANTREAT study)

Practical Lessons on Antimicrobial Therapy for Critically Ill Patients

Sepsis stands as a formidable global health challenge, with persistently elevated mortality rates in recent decades. Each year, sepsis not only contributes to heightened morbidity but also imposes substantial healthcare costs on survivors. This narrative review aims to highlight the targeted measures that can be instituted to alleviate the incidence and impact of sepsis in intensive care. Here we discuss measures to reduce nosocomial infections and the prevention of equipment and patient colonisation by resilient pathogens. The overarching global crisis of bacterial resistance to newly developed antimicrobial agents intensifies the imperative for antimicrobial stewardship and de-escalation. This urgency has been accentuated in recent years, notably during the COVID-19 pandemic, as high-dose steroids and opportunistic infections presented escalating challenges. Ongoing research into airway colonisation's role in influencing disease outcomes among critically ill patients underscores the importance of tailoring treatments to disease endotypes within heterogeneous populations, which are important lessons for intensivists in training. Looking ahead, the significance of novel antimicrobial delivery systems and drug monitoring is poised to increase. This narrative review delves into the multifaceted barriers and facilitators inherent in effectively treating critically ill patients vulnerable to nosocomial infections. The future trajectory of intensive care medicine hinges on the meticulous implementation of vigilant stewardship programs, robust infection control measures, and the continued exploration of innovative and efficient technological solutions within this demanding healthcare landscape.

Heterogeneity of surrogate outcome measures used in critical care studies: A systematic review

BACKGROUND

The choice of outcome measure is a critical decision in the design of any clinical trial, but many Phase III clinical trials in critical care fail to detect a difference between the interventions being compared. This may be because the surrogate outcomes used to show beneficial effects in early phase trials (which informed the design of the subsequent Phase III trials) are not valid guides to the differences between the interventions for the main outcomes of the Phase III trials. We undertook a systematic review (1) to generate a list of outcome measures used in critical care trials, (2) to determine the variability in the outcome reporting in the respiratory subgroup and (3) to create a smaller list of potential early phase endpoints in the respiratory subgroup.

METHODS

Data related to outcomes were extracted from studies published in the six top-ranked critical care journals between 2010 and 2020. Outcomes were classified into subcategories and categories. A subset of early phase endpoints relevant to the respiratory subgroup was selected for further investigation. The variability of the outcomes and the variability in reporting was investigated.

RESULTS

A total of 6905 references were retrieved and a total of 294 separate outcomes were identified from 58 studies. The outcomes were then classified into 11 categories and 66 subcategories. A subset of 22 outcomes relevant for the respiratory group were identified as potential early phase outcomes. The summary statistics, time points and definitions show the outcomes are analysed and reported in different ways.

CONCLUSION

The outcome measures were defined, analysed and reported in a variety of ways. This creates difficulties for synthesising data in systematic reviews and planning definitive trials. This review once again highlights an urgent need for standardisation and validation of surrogate outcomes reported in critical care trials. Future work should aim to validate and develop a core outcome set for surrogate outcomes in critical care trials.

Respiratory Fungal Communities are Associated with Systemic Inflammation and Predict Survival in Patients with Acute Respiratory Failure

Rationale

Disruption of respiratory bacterial communities predicts poor clinical outcomes in critical illness; however, the role of respiratory fungal communities (mycobiome) is poorly understood.

Objectives

We investigated whether mycobiota variation in the respiratory tract is associated with host-response and clinical outcomes in critically ill patients.

Methods

To characterize the upper and lower respiratory tract mycobiota, we performed rRNA gene sequencing (internal transcribed spacer) of oral swabs and endotracheal aspirates (ETA) from 316 mechanically-ventilated patients. We examined associations of mycobiome profiles (diversity and composition) with clinical variables, host-response biomarkers, and outcomes.

Measurements and Main Results

ETA samples with >50% relative abundance for C. albicans (51%) were associated with elevated plasma IL-8 and pentraxin-3 (p=0.05), longer time-to-liberation from mechanical ventilation (p=0.04) and worse 30-day survival (adjusted hazards ratio (adjHR): 1.96 [1.04-3.81], p=0.05). Using unsupervised clustering, we derived two clusters in ETA samples, with Cluster 2 (39%) showing lower alpha diversity (p<0.001) and higher abundance of C. albicans (p<0.001). Cluster 2 was significantly associated with the prognostically adverse hyperinflammatory subphenotype (odds ratio 2.07 [1.03-4.18], p=0.04) and predicted worse survival (adjHR: 1.81 [1.03-3.19], p=0.03). C. albicans abundance in oral swabs was also associated with the hyperinflammatory subphenotype and mortality.

Conclusions

Variation in respiratory mycobiota was significantly associated with systemic inflammation and clinical outcomes. C. albicans abundance emerged as a negative predictor in both the upper and lower respiratory tract. The lung mycobiome may play an important role in the biological and clinical heterogeneity among critically ill patients and represent a potential therapeutic target for lung injury in critical illness.

Staphylococcus aureus hitchhiking from colonization to bacteremia via Candida within ICU infection prevention studies: a proof of concept modelling

Whether Candida within the patient microbiome drives the pathogenesis of Staphylococcus aureus bacteremia, described as microbial hitchhiking, cannot be directly studied. Group-level observations from studies of various decontamination and non-decontamination-based ICU infection prevention interventions and studies without study interventions (observational groups) collectively enable tests of this interaction within causal models. Candidate models of the propensity for Staphylococcus aureus bacteremia to arise with versus without various antibiotic, anti-septic, and antifungal exposures, each identified as singleton exposures, were tested using generalized structural equation modelling (GSEM) techniques with Candida and Staphylococcus aureus colonization appearing as latent variables within the models. Each model was tested by confrontation against blood and respiratory isolate data, obtained from 467 groups within 284 infection prevention studies. Introducing an interaction term between Candida colonization and Staphylococcus aureus colonization substantially improved GSEM model fit. Model-derived coefficients for singular exposure to anti-septic agents (- 1.28; 95% confidence interval; - 2.05 to - 0.5), amphotericin (- 1.49; - 2.3 to - 0.67), and topical antibiotic prophylaxis (TAP; + 0.93; + 0.15 to + 1.71) as direct effects versus Candida colonization were similar in magnitude but contrary in direction. By contrast, the coefficients for singleton exposure to TAP, as with anti-septic agents, versus Staphylococcus colonization were weaker or non-significant. Topical amphotericin would be predicted to halve both candidemia and Staphylococcus aureus bacteremia incidences versus literature derived benchmarks for absolute differences of < 1 percentage point. Using ICU infection prevention data, GSEM modelling validates the postulated interaction between Candida and Staphylococcus colonization facilitating bacteremia.

Structural equation modelling the impact of antimicrobials on the human microbiome. Colonization resistance versus colonization susceptibility as case studies

The impact of antimicrobials on the human microbiome and its relationship to human health are of great interest. How antimicrobial exposure might drive change within specific constituents of the microbiome to effect clinically relevant endpoints is difficult to study. Clinical investigation of each step within a network of causation would be challenging if done 'step-by-step'. An analytic tool of great potential to clinical microbiome research is structural equation modelling (SEM), which has a long history of applications to research questions arising within subject areas as diverse as psychology and econometrics. SEM enables postulated models based on a network of causation to be tested en bloc by confrontation with data derived from the literature. Case studies for the potential application of SEM techniques are colonization resistance (CR) and its counterpart, colonization susceptibility (CS), wherein specific microbes within the microbiome are postulated to either impede (CR) or facilitate (CS) invasive infection with pathogenic bacteria. These postulated networks have three causation steps: exposure to specific antimicrobials are key drivers, clinically relevant infection endpoints are the measurable observables and the activity of key microbiome constituents mediating CR or CS, which may be unobservable, appear as latent variables in the model. SEM methods have potential application towards evaluating the activity of specific antimicrobial agents within postulated networks of causation using clinically derived data.

Candida and the Gram-positive trio: testing the vibe in the ICU patient microbiome using structural equation modelling of literature derived data

Background

Whether Candida interacts with Gram-positive bacteria, such as Staphylococcus aureus, coagulase negative Staphylococci (CNS) and Enterococci, to enhance their invasive potential from the microbiome of ICU patients remains unclear. Several effective anti-septic, antibiotic, anti-fungal, and non-decontamination based interventions studied for prevention of ventilator associated pneumonia (VAP) and other ICU acquired infections among patients receiving prolonged mechanical ventilation (MV) are known to variably impact Candida colonization. The collective observations within control and intervention groups from numerous ICU infection prevention studies enables tests of these postulated microbial interactions in the clinical context.

Methods

Four candidate generalized structural equation models (GSEM), each with Staphylococcus aureus, CNS and Enterococci colonization, defined as latent variables, were confronted with blood culture and respiratory tract isolate data derived from 460 groups of ICU patients receiving prolonged MV from 283 infection prevention studies.

Results

Introducing interaction terms between Candida colonization and each of S aureus (coefficient + 0.40; 95% confidence interval + 0.24 to + 0.55), CNS (+ 0.68; + 0.34 to + 1.0) and Enterococcal (+ 0.56; + 0.33 to + 0.79) colonization (all as latent variables) improved the fit for each model. The magnitude and significance level of the interaction terms were similar to the positive associations between exposure to topical antibiotic prophylaxis (TAP) on Enterococcal (+ 0.51; + 0.12 to + 0.89) and Candida colonization (+ 0.98; + 0.35 to + 1.61) versus the negative association of TAP with S aureus (− 0.45; − 0.70 to − 0.20) colonization and the negative association of anti-fungal exposure and Candida colonization (− 1.41; − 1.6 to − 0.72).

Conclusions

GSEM modelling of published ICU infection prevention data enables the postulated interactions between Candida and Gram-positive bacteria to be tested using clinically derived data. The optimal model implies interactions occurring in the human microbiome facilitating bacterial invasion and infection. This interaction might also account for the paradoxically high bacteremia incidences among studies of TAP in ICU patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12982-022-00116-9.

GSEM modelling of published ICU infection prevention data from > 250 studies enables a test of and provides support to the interaction between Candida and Gram-positive bacteria.

The various ICU infection prevention interventions may each broadly impact the patient microbiome.

Structural equation modelling the relationship between anti-fungal prophylaxis and Pseudomonas bacteremia in ICU patients

Purpose

Animal models implicate candida colonization facilitating invasive bacterial infections. The clinical relevance of this microbial interaction remains undefined and difficult to study directly. Observations from studies of anti-septic, antibiotic, anti-fungal, and non-decontamination-based interventions to prevent ICU acquired infection collectively serve as a natural experiment.

Methods

Three candidate generalized structural equation models (GSEM), with Candida and Pseudomonas colonization as latent variables, were confronted with blood culture and respiratory tract isolate data derived from 464 groups from 279 studies including studies of combined antibiotic and antifungal exposures within selective digestive decontamination (SDD) interventions.

Results

Introducing an interaction term between Candida colonization and Pseudomonas colonization substantially improved GSEM model fit. Model derived coefficients for singular exposure to anti-septic agents (− 1.23; − 2.1 to − 0.32), amphotericin (− 1.78; − 2.79 to − 0.78) and topical antibiotic prophylaxis (TAP; + 1.02; + 0.11 to + 1.93) versus Candida colonization were similar in magnitude but contrary in direction. By contrast, the model-derived coefficients for singular exposure to TAP, as with anti-septic agents, versus Pseudomonas colonization were weaker or non-significant. Singular exposure to amphotericin would be predicted to more than halve candidemia and Pseudomonas bacteremia incidences versus literature benchmarks for absolute differences of approximately one percentage point or less.

Conclusion

GSEM modelling of published data supports the postulated interaction between Candida and Pseudomonas colonization towards promoting bacteremia among ICU patients. This would be difficult to detect without GSEM modelling. The model indicates that anti-fungal agents have greater impact in preventing Pseudomonas bacteremia than TAP, which has no impact.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40635-022-00429-8.

Candida Pneumonia: An Innocent Bystander or a Silent Killer?

Invasive candidiasis is predominantly seen in immunosuppressed patients and carries a significant mortality. The clinical spectrum of invasive candidiasis encompasses candidemia and disseminated infection (intra-abdominal abscess, osteomyelitis, endophthalmitis, and Candida meningitis). The existence of Candida pneumonia has been largely debated over the years due to its rarity and presence of frequent colonization. Demonstration of Candida species by lung biopsy along with evidence of inflammation is the only way to confirm this entity. The interpretation of Candida in respiratory specimens and the decision to initiate antifungal therapy is controversial due to the lack of clinical evidence. In this mini-review, we discuss the currently available clinical data from the literature on Candida pneumonia and future perspectives regarding the need for antifungal therapy in such patients.

Candida spp. isolation from critically ill patients' respiratory tract. Does antifungal treatment affect survival?

INTRODUCTION

Isolation of Candida spp. from bronchial samples of patients on mechanical ventilation is common. Even though it may not always reflect infection, it may induce immunological changes that can facilitate bacterial pneumonia. In this case, antifungal treatment is of uncertain value. This study examined the impact of antifungal treatment on the outcome of intensive care unit (ICU)-acquired respiratory tract infection (RTI) of critically ill, immunocompetent patients, with Candida isolation from their respiratory tract.

METHODS

This is a retrospective cohort study of adult patients hospitalized in the ICU of the University Hospital of Heraklion, Greece, from 2014 through 2016 with ICU-acquired RTI and Candida spp. isolated from their bronchial secretions. Data regarding medical history, demographics (gender, age), reason for ICU admission, previous antimicrobial use or hospitalization, SOFA and APACHE II score, clinical outcomes (primary clinical outcome: overall mortality during hospitalization; secondary clinical outcome: mortality during the ICU stay and duration of ICU and hospital stay) at the end of their ICU stay and at the end of their hospital stay were recorded and consequently evaluated. A logistic regression analysis model evaluated the effect of the recorded parameters in association with ICU mortality and overall mortality during hospitalization.

RESULTS

A total of 90 individuals were enrolled. Of them, 47 (52.2%) were treated with antifungals during their hospitalization around the time of Candida isolation. Patients treated with antifungals had higher SOFA and APACHE II scores, longer duration of stay in the ICU, more days on ventilator and higher total mortality during hospitalization. Multivariate logistic regression analysis identified antifungal use to be independently associated with total mortality during hospitalization.

CONCLUSIONS

Antifungal use in patients with ICU-acquired RTI was associated with higher overall mortality as compared to those not receiving such agents.

Respiratory Candida in Patients with Bronchitis, Mucus Plugging, and Atelectasis

Background

The significance of Candida in pulmonary secretions is unclear, and usually is regarded as colonization, not contributing to symptoms or disease. Yet, in our experience, Candida seemed associated with chronic sputum, mucus plugging, atelectasis, and poor outcome.

Objective

The aim of this study is to describe the clinical findings of patients with Candida in pulmonary (sputum or bronchoscopy) secretions and the significance of Candida.

Methods

Retrospective study of inpatients and outpatients referred for pulmonary consultation with Candida in pulmonary secretions. Clinical parameters and estimates of whether Candida was likely clinically significant, were determined.

Results

82 inpatients and 11 outpatients were identified, of which 61 (66%) had atelectasis and 68 (73%) bronchoscopies. Of patients having bronchoscopies, 56 (82%) had mucus, and 43 (63%) mucus plugging. Of the inpatients death (or probable death) occurred in 43 (63%), 42 (98%) of which were from definite or probable respiratory failure, with 13 (31%) likely related to mucus plugging, 16 (38%) possibly from mucus plugging, 6 (14%) unknown, and 7 (17%) not due to mucus plugging. Candida was felt likely clinically significant in 57 patients (61%), uncertain significance in 23 (25%), and not significant in 13 (14%). All outpatients had exacerbations, including 7 (64%) within a year.

Conclusion

Patients requiring pulmonary consultation with Candida in pulmonary secretions often have chronic sputum production, exacerbations, mucus plugging, atelectasis, and death from respiratory failure. Candida was likely clinically significant in most patients. Recommendations to consider Candida in pulmonary secretions as colonization should be reconsidered.

Candida-Acinetobacter-Pseudomonas Interaction Modelled within 286 ICU Infection Prevention Studies

BACKGROUND

Whether Candida interacts to enhance the invasive potential of Acinetobacter and Pseudomonas bacteria cannot be resolved within individual studies. There are several anti-septic, antibiotic, anti-fungal, and non-decontamination-based interventions to prevent ICU acquired infection. These effective prevention interventions would be expected to variably impact Candida colonization. The collective observations within control and intervention groups from numerous ICU infection prevention studies simulates a multi-centre natural experiment with which to evaluate Candida, Acinetobacter and Pseudomonas interaction (CAPI).

METHODS

Eight Candidate-generalized structural equation models (GSEM), with Candida, Pseudomonas and Acinetobacter colonization as latent variables, were confronted with blood culture and respiratory tract isolate data derived from >400 groups derived from 286 infection prevention studies.

RESULTS

Introducing an interaction term between Candida colonization and each of Pseudomonas and Acinetobacter colonization improved model fit in each case. The size of the coefficients (and 95% confidence intervals) for these interaction terms in the optimal Pseudomonas (+0.33; 0.22 to 0.45) and Acinetobacter models (+0.32; 0.01 to 0.5) were similar to each other and similar in magnitude, but contrary in direction, to the coefficient for exposure to topical antibiotic prophylaxis (TAP) on Pseudomonas colonization (-0.45; -0.71 to -0.2). The coefficient for exposure to topical antibiotic prophylaxis on Acinetobacter colonization was not significant.

CONCLUSIONS

GSEM modelling of published ICU infection prevention data supports the CAPI concept. The CAPI model could account for some paradoxically high Acinetobacter and Pseudomonas infection incidences, most apparent among the concurrent control groups of TAP studies.

The relationship between immune status as measured by stimulated ex-vivo tumour necrosis factor alpha levels and the acquisition of nosocomial infections in critically ill mechanically ventilated patients

Introduction

Immunological dysfunction is common in critically ill patients but its clinical significance and the optimal method to measure it are unknown. The level of tumor necrosis factor alpha (TNF-α) after ex-vivo whole blood stimulation with lipopolysaccharide (LPS) has been proposed as a possible method to quantify immunological function. We hypothesized that in a cohort of critically ill patients, those with a lower post-stimulation TNF-α level would have increased rates of nosocomial infections (NIs) and worse clinical outcomes.

Methods

A secondary analysis of a phase 2 randomized, multi-centre, double-blinded placebo-controlled trial. As there was no difference between treatment and control arms in outcomes and NI rate, all the patients were analyzed as one cohort. On enrolment, day 4, 7, and weekly until day 28, whole blood was incubated with LPS ex-vivo and subsequent TNF-α level was measured. Patients were grouped in tertiles according to delta and peak TNF-α level. The primary outcome was the association between NIs and tertiles of TNF-α level post LPS stimulation; secondary outcomes included ICU and 90-day mortality, and ICU and hospital length of stay.

Results

Data was available for 201 patients. Neither the post LPS stimulation delta TNF-α group nor the peak TNF-α post-stimulation group were associated with the development of NIs or clinical outcomes. Patients in the highest tertile for post LPS stimulation delta TNF-α compared to the lowest tertile were younger [61.1 years ± 15.7 vs. 68.6 years ± 12.8 standard deviations (SD) in the lowest tertile], had lower acuity of illness (APACHE II 25.0 ± 9.7 vs. 26.7 ± 6.1) and had lower baseline TNF-α (9.9 pg/mL ± 19.0 vs. 31.0 pg/mL ± 68.5). When grouped according to peak post-stimulation TNF-α levels, patients in the highest tertile had higher serum TNF-α at baseline (21.3 pg/mL ± 66.7 compared to 6.5 pg/mL ± 9.0 in the lowest tertile).

Conclusion

In this prospective multicenter study, ex-vivo stimulated TNF-α level was not associated with the occurrence of NIs or clinical outcomes. Further study is required to better ascertain whether TNF levels and ex-vivo stimulation can be used to characterize immune function in critical illness and if other assays might be better suited to this task.

The impact of Candida spp airway colonization on clinical outcomes in patients with ventilator-associated pneumonia: A systematic review and meta-analysis

BACKGROUND

Previous studies have drawn different conclusions about the impact of Candida airway colonization on clinical outcomes in patients with ventilator-associated pneumonia (VAP).

METHODS

We searched PubMed, the Cochrane Library, Embase (via OVID), and Web of Science database. We included both retrospective and prospective observational studies. The mean difference (MD) or risk ratio (RR) with 95% confidence intervals (CI) were applied to assess the association between Candida colonization and clinical outcomes.

RESULTS

A total of 8 studies with 1,661 patients were pooled in our final studies. Compared with patients with VAP without Candida colonization, patients with Candida colonization had significantly longer durations of mechanical ventilation (MD, 1.93; 95% CI, 0.53-3.33). The intensive care unit (ICU) length of stay seems to be longer among Candida colonized patients than noncolonized patients, although the results were not so significant (MD, 1.15; 95% CI, -1.04 to 3.34). Patients with colonization had higher 28-day mortality and ICU mortality than those without colonization (28-day mortality: RR, 1.64; 95% CI, 1.27-2.12; ICU mortality: RR, 1.57; 95% CI, 1.26-1.94).

CONCLUSIONS

The presence of Candida spp airway colonization is associated with longer durations of mechanical ventilation, higher 28-day mortality, higher ICU mortality, and probably longer ICU length of stay compared with the absence of colonization in patients with VAP.

Safety and Outcomes of Early Enteral Nutrition in Circulatory Shock

Circulatory shock is one of the most common reasons for an intensive care unit admission, has been shown to impair gut barrier and immune functions, and promotes dysbiosis. The exact timing and dose of enteral nutrition (EN) in circulatory shock remains unclear. In fact, because of fear of complications such as nonocclusive mesenteric ischemia and bowel necrosis and splanchnic steal phenomenon, clinicians may hesitate to start EN in critically ill patients with circulatory shock. In this narrative review, we identify and appraise contemporary evidence evaluating the safety and outcomes of EN in circulatory shock.

Phase 3 Pilot Randomized Controlled Trial Comparing Early Trophic Enteral Nutrition With "No Enteral Nutrition" in Mechanically Ventilated Patients With Septic Shock

BACKGROUND

The optimal dose and timing of enteral nutrition (EN) in septic shock are unclear.

METHODS

We conducted a phase 3 single-center randomized controlled pilot trial comparing early trophic EN with "no EN" in mechanically ventilated adults with septic shock, with the hypothesis that implementing a protocol comparing early trophic EN with "no EN" in patients with septic shock would be feasible. Patients were randomized to early trophic EN or "no EN" until off vasopressor for 3 hours. The primary outcome was feasibility in achieving >75% consent and compliance rate and <10% contamination rate.

RESULTS

One hundred thirty-one patients were eligible for enrollment, and 49 were available for consent. Thirty-one (86%) consented and were randomized and 100% of patients in the early EN arm and 94% in the "no EN" arm completed their protocols. While on vasopressors, early EN group received median 384 kcal, and the "no EN" group received median 0 kcal. Contamination rate was 0 in the early trophic EN arm and 6% in the "no EN" arm. The early EN group had median 25 intensive care unit-free days, as compared with 12 in the "no EN" arm (P = .014). The early EN arm had median 27 ventilator-free days, compared with 14 in "no EN" arm (P = .009).

CONCLUSION

Our protocol comparing early trophic EN with "no EN" in septic shock was feasible. Early trophic EN may be beneficial, but a larger multicenter trial is warranted to confirm the observed clinical benefits seen in this trial.

Impact of bronchial colonization with Candida spp. on the risk of bacterial ventilator-associated pneumonia in the ICU: the FUNGIBACT prospective cohort study

INTRODUCTION

Respiratory tract Candida spp. colonization is associated with more frequent bacterial ventilator-associated pneumonia (VAP). However, this colonization could be causally related to VAP or simply reflect the immune paralysis associated with multiple organ failure.

OBJECTIVE

To prospectively evaluate the relationship between Candida spp. colonization and bacterial VAP in mechanically ventilated patients with multiple organ failure.

INCLUSION

Patients receiving mechanical ventilation for > 4 days and presenting multiple organ failure were included. Tracheal colonization with Candida spp. was evaluated at inclusion (day 0, D0) and every 4 days until extubation. Quantitative proximal and tracheal cultures were performed at each VAP episode. Monocyte human leukocyte antigen-DR isotype (mHLA-DR) expression and the ratio of polymononuclear leukocytes to lymphocytes were used to evaluate immunoparalysis at D0 and D7. The relationship between fungal colonization and VAP was modelled using cause-specific models for repeated events with adjustment for time-dependent confounders and immune factors.

RESULTS

A total of 213 patients, with a median age of 64, simplified acute physiology score II (SAPS II) score 55 and sequential organ failure assessment (SOFA) score 10, mainly admitted for medical reasons (n = 197, 92%), were enrolled in 2012-2015. The median ICU stay was 24 days and the mortality rate was 32% (69 cases). Median mHLA-DR was 5916 Ab-bound/cell [3863-8934]; median lymphocyte count, 0.9Giga/L [0.6-1.3]; neutrophil-to-lymphocyte ratio, 10.9 [6.5-19.7]. Overall, 146 cases (68.5%) had tracheal colonization with Candida spp. An episode of VAP occurred (either for the first or only time) in 62 (29.1%) cases 5.5 days (median) after D0; a second episode occurred in 12 (5.6%) cases, 15.5 days (median) after D0. After adjustment, bronchial colonization with Candida was not associated with VAP [adjusted cause-specific hazard ratio = 0.98 (0.59-1.65), p = 0.95].

CONCLUSION

In patients with mechanical ventilation for more than 4 days and multiple organ failure, bronchial colonization with Candida spp. was not associated with VAP, even after adjustment for immune function.

IL-13 attenuates early local CXCL2-dependent neutrophil recruitment for Candida albicans clearance during a severe murine systemic infection

To investigate the role of IL-13 during a severe systemic Candida albicans infection, BALB/c control and IL-13^-/- mice were examined for colony forming units (CFU) in the kidneys and survival days after intravenous infection. Proinflammatory mediators and cell recruitment into the tissue were measured by quantitative real-time PCR, a multiple ELISA system, and morphological cell differentiation. The IL-13^-/- group exhibited a lower CFU number in the kidneys at 4 days and survived longer than the control mice, which was accompanied by significantly higher expression of C-X-C motif ligand 2 (CXCL2), IFN-γ, and polymorphonuclear neutrophils (PMNs) in the infected kidneys. By contrast, the expression of transforming growth factor β (TGF-β) and IL-17 A on day 10 were significantly higher in the control mice than in the IL-13^-/- group. When using an intratracheal infection model, the IL-13^-/- group recruited a greater number of PMNs in 6 h, with rapidly increased CXCL2 in the alveolar space. In vitro testing with cultured bone-marrow-derived cells demonstrated rapid CXCL2 mRNA upregulation at 3 h after contact with C. albicans, which decreased with recombinant IL-13 pretreatment, whereas rIL-13 retained TGF-β upregulation. In a murine model of Candida systemic infection, preexistent IL-13 limits both the rapid CXCL2 elevation and PMN aggregation in the target organ to suppress inflammatory mediators, which also attenuates local pathogen clearance within four days.

A Risk Prediction Model for Invasive Fungal Disease in Critically Ill Patients in the Intensive Care Unit

PURPOSE

Developing a risk prediction model for invasive fungal disease based on an analysis of the disease-related risk factors in critically ill patients in the intensive care unit (ICU) to diagnose the invasive fungal disease in the early stages and determine the time of initiating early antifungal treatment.

METHODS

Data were collected retrospectively from 141 critically ill adult patients with at least 4 days of general ICU stay at Sun Yat-sen Memorial Hospital, Sun Yat-sen University during the period from February 2015 to February 2016. Logistic regression was used to develop the risk prediction model. Discriminative power was evaluated by the area under the receiver operating characteristics (ROC) curve (AUC).

RESULTS

Sequential organ failure assessment (SOFA) score, antibiotic treatment period, and positive culture of Candida albicans other than normally sterile sites are the three predictors of invasive fungal disease in critically ill patients in the ICU. The model performs well with an ROC-AUC of .73.

CONCLUSION

The risk prediction model performs well to discriminate between critically ill patients with or without invasive fungal disease. Physicians could use this prediction model for early diagnosis of invasive fungal disease and determination of the time to start early antifungal treatment of critically ill patients in the ICU.

Respiratory Tract Colonization by Candida species Portends Worse Outcomes in Immunocompromised Patients

Background

The significance and clinical management of Candida colonization of the respiratory tract are ill-defined. We now report the frequency of Candida species from the lower respiratory tract in hematopoietic stem cell transplant recipients (HSCT) undergoing bronchoscopy with broncheoalveolar lavage (BAL) for pneumonitis post-HSCT.

Methods

The University of Michigan Clinical Microbiology Lab Database was queried for all respiratory cultures positive for Candida species between 2000-2012. We concurrently performed a retrospective analysis of 515 HSCT recipients with pneumonitis at our institution between 2001-2012.

Results

During this twelve-year period, there were 2524 unique Candida isolates (78% Candida albicans). Of the 515 HSCT patients with suspected pneumonitis,127 (24.7%) HSCT subjects were culture positive for a fungal pathogen, with Candida species identified in 27 cases (5.2%). When compared with other HSCT subjects, those cultures positive for Candida had significantly increased mortality (p=0.04).

Conclusions

Candida sp. are commonly cultured from the respiratory tract of HSCT recipients, with increased mortality in affected patients. While there is insufficient evidence for anti-fungal treatment of Candida species colonization, the presence of the yeast may be useful as a surrogate marker of disease severity.

The Effect of a Polysaccharide-Based Multinutrient Dietary Supplementation Regimen on Infections and Immune Functioning in Multiple Sclerosis

Multiple sclerosis (MS) is a progressive neurodegenerative disease associated with increased infection rates, chronic inflammation, and premature death. Optimization of nutritional status via dietary supplementation may improve immune function in people suffering from MS and lead to decreased rates of infection. Fifteen individuals with a diagnosis of relapsing-remitting MS for an average of 12.4 years (SD =7.4; R = 2, 25) were enrolled in a one-year open-label clinical trial. Participants consumed a broad-spectrum dietary supplement regimen containing polysaccharides, phytochemicals, antioxidants, vitamins, and minerals three times per day. The occurrence of infections and a panel of cytokines, growth factors, and T- and B-cell subsets were assessed at baseline and 12 months. Seven female and 8 male participants with an average age of 51.3 years (SD =7.2; R = 38, 65) completed the study. At the end of the intervention, participants had fewer total infections (M = 7.9, SD =8.1 at baseline and M = 2.5, SD =4.3 at 12-month follow-up). At 12 months, IL-2, TNF-α, EGF, and CD95 + CD34+ significantly increased, while IL-1β significantly decreased. No major adverse effects were reported; only mild gastrointestinal intolerance was reported in four cases. A decreased occurrence of infection was observed in MS patients treated with 12 months of a polysaccharide-based multinutrient dietary supplement. Significant changes were also noted in several key biomarkers that would be physiologically favorable to the MS population. Thus, the results of this study suggest an immunomodulatory effect of the dietary supplement regimen studied.

Choosing Optimal Antifungal Agents To Prevent Fungal Infections in Nonneutropenic Critically Ill Patients: Trial Sequential Analysis, Network Meta-analysis, and Pharmacoeconomic Analysis

The use of antifungal interventions in critically ill patients prior to invasive fungal infection (IFI) being microbiologically confirmed and the preferred drug are still controversial. A systematic literature search was performed to identify randomized controlled trials (RCTs) that compared untargeted antifungal treatments applied to nonneutropenic critically ill patients. The primary outcomes were all-cause mortality and proven IFI rates. A random-effects model was used with trial sequential analyses (TSA), a network meta-analysis (NMA) was conducted to obtain indirect evidence, and a cost-effectiveness analysis using a decision-analytic model was completed from the patient perspective over a lifetime horizon. In total, 19 RCTs involving 2,556 patients (7 interventions) were included. Untargeted antifungal treatment did not significantly decrease the incidence of all-cause mortality (odds ratio [OR] = 0.89, 95% confidence interval [95%CI] = 0.70 to 1.14), but it did reduce the incidence of proven IFI (OR = 0.45, 95%CI = 0.29 to 0.71) relative to placebo/no intervention. The TSA showed that there was sufficient evidence supporting these findings. In the NMA, the only significant difference found for both primary outcomes was between fluconazole and placebo/no intervention in preventing proven IFI (OR = 0.35, 95%CI = 0.19 to 0.65). Based on drug and hospital costs in China, the incremental cost-effectiveness ratios per life-year saved for fluconazole, caspofungin, and micafungin relative to placebo/no intervention corresponded to US$889, US$9,994, and US$10,351, respectively. Untargeted antifungal treatment significantly reduced proven IFI rates in nonneutropenic critically ill patients but with no mortality benefits relative to placebo/no intervention. Among the well-tolerated antifungals, fluconazole remains the only one that is effective for IFI prevention and significantly cheaper than echinocandins.

Measuring (1,3)-β-D-glucan in tracheal aspirate, bronchoalveolar lavage fluid, and serum for detection of suspected Candida pneumonia in immunocompromised and critically ill patients: a prospective observational study

Background

While Candida pneumonia is life-threatening, biomarker measurements to early detect suspected Candida pneumonia are lacking. This study compared the diagnostic values of measuring levels of (1, 3)-β-D-glucan in endotracheal aspirate, bronchoalveolar lavage fluid, and serum to detect suspected Candida pneumonia in immunocompromised and critically ill patients.

Methods

This prospective, observational study enrolled immunocompromised, critically ill, and ventilated patients with suspected fungal pneumonia in mixed intensive care units from November 2010 to October 2011. Patients with D-glucan confounding factors or other fungal infection were excluded. Endotracheal aspirate, bronchoalveolar lavage fluid and serum were collected from each patient to perform a fungal smear, culture, and D-glucan assay.

Results

After screening 166 patients, 31 patients completed the study and were categorized into non-Candida pneumonia/non-candidemia (n = 18), suspected Candida pneumonia (n = 9), and non-Candida pneumonia/candidemia groups (n = 4). D-glucan levels in endotracheal aspirate or bronchoalveolar lavage were highest in suspected Candida pneumonia, while the serum D-glucan level was highest in non-Candida pneumonia/candidemia. In all patients, the D-glucan value in endotracheal aspirate was positively correlated with that in bronchoalveolar lavage fluid. For the detection of suspected Candida pneumonia, the predictive performance (sensitivity/specificity/D-glucan cutoff [pg/ml]) of D-glucan in endotracheal aspirate and bronchoalveolar lavage fluid was 67%/82%/120 and 89%/86%/130, respectively, accounting for areas under the receiver operating characteristic curve of 0.833 and 0.939 (both P < 0.05), respectively. Measuring serum D-glucan was of no diagnostic value (area under curve =0.510, P = 0.931) for the detection of suspected Candida pneumonia in the absence of concurrent candidemia.

Conclusions

D-glucan levels in both endotracheal aspirate and bronchoalveolar lavage, but not in serum, provide good diagnostic values to detect suspected Candida pneumonia and to serve as potential biomarkers for early detection in this patient population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2364-2) contains supplementary material, which is available to authorized users.

Pathophysiology of Pediatric Multiple Organ Dysfunction Syndrome

OBJECTIVE

To describe the pathophysiology associated with multiple organ dysfunction syndrome in children.

DATA SOURCES

Literature review, research data, and expert opinion.

STUDY SELECTION

Not applicable.

DATA EXTRACTION

Moderated by an experienced expert from the field, pathophysiologic processes associated with multiple organ dysfunction syndrome in children were described, discussed, and debated with a focus on identifying knowledge gaps and research priorities.

DATA SYNTHESIS

Summary of presentations and discussion supported and supplemented by relevant literature.

CONCLUSIONS

Experiment modeling suggests that persistent macrophage activation may be a pathophysiologic basis for multiple organ dysfunction syndrome. Children with multiple organ dysfunction syndrome have 1) reduced cytochrome P450 metabolism inversely proportional to inflammation; 2) increased circulating damage-associated molecular pattern molecules from injured tissues; 3) increased circulating pathogen-associated molecular pattern molecules from infection or endogenous microbiome; and 4) cytokine-driven epithelial, endothelial, mitochondrial, and immune cell dysfunction. Cytochrome P450s metabolize endogenous compounds and xenobiotics, many of which ameliorate inflammation, whereas damage-associated molecular pattern molecules and pathogen-associated molecular pattern molecules alone and together amplify the cytokine production leading to the inflammatory multiple organ dysfunction syndrome response. Genetic and environmental factors can impede inflammation resolution in children with a spectrum of multiple organ dysfunction syndrome pathobiology phenotypes. Thrombocytopenia-associated multiple organ dysfunction syndrome patients have extensive endothelial activation and thrombotic microangiopathy with associated oligogenic deficiencies in inhibitory complement and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13. Sequential multiple organ dysfunction syndrome patients have soluble Fas ligand-Fas-mediated hepatic failure with associated oligogenic deficiencies in perforin and granzyme signaling. Immunoparalysis-associated multiple organ dysfunction syndrome patients have impaired ability to resolve infection and have associated environmental causes of lymphocyte apoptosis. These inflammation phenotypes can lead to macrophage activation syndrome. Resolution of multiple organ dysfunction syndrome requires elimination of the source of inflammation. Full recovery of organ functions is noted 6-18 weeks later when epithelial, endothelial, mitochondrial, and immune cell regeneration and reprogramming is completed.

Antifungal use in immunocompetent, critically ill patients with pneumonia does not improve clinical outcomes

PURPOSE

To determine if treating bronchoalveolar lavage (BAL) culture-positive patients with antifungal therapy impacted mortality compared to not treating due to presumed colonization.

METHODS

We conducted a retrospective study of immunocompetent, critically ill adult patients from 2010 to 2014. Patients with a BAL culture-positive for Candida or unspeciated yeast and a clinical suspicion of pneumonia were included. The treatment group received an antifungal agent for at least 5 days, and the control group received either no antifungal therapy or an antifungal agent for less than 48 h. Recruitment occurred in a 2:1 ratio of untreated versus treated patients.

RESULTS

Seventy-five patients were included. In-hospital mortality was similar between treated and untreated groups (24% vs. 26%, P = 0.85). Length of stay and duration of mechanical ventilation also did not differ between the two groups.

CONCLUSION

We did not observe a difference in mortality or clinical outcomes in patients treated with antifungal agents. Presumptive antifungal therapy for BAL-positive Candida or yeast in immunocompetent patients did not result in improved clinical outcomes.

Characteristics, Clinical Relevance, and the Role of Echinocandins in Fungal-Bacterial Interactions

Fungal-bacterial interactions are common in the environment. The interactions between invasive fungi (eg, Candida species and Aspergillus species) and pathogenic bacteria can be particularly significant in the outcome of human infections. Study of these interactions in vivo using murine or invertebrate models, such as Caenorhabditis elegans or Galleria mellonella, has been very helpful in increasing our understanding of the pathogenesis of mixed infections and in identifying ways to use this between-kingdom interplay to our advantage. Based on their effect against fungal biofilms and their immunomodulatory properties, the newer class of antifungal agents, known as echinocandins, has the potential to be useful in polymicrobial infections and in high-risk complex infections such as ventilator-associated pneumonia or sepsis where colonization by fungi can lead to worse outcomes.

Inflammation and innate immune function in critical illness

PURPOSE OF REVIEW

The purpose of review is to highlight the inflammatory response in critical illness and the importance of immune monitoring and modulation in the diagnosis and treatment of critical illness-induced innate immune suppression.

RECENT FINDINGS

The pro and anti-inflammatory responses are known to be concurrently activated in many patients requiring intensive care, with innate immune suppression emerging as an important, and potentially reversible, complication of critical illness.

SUMMARY

The initial inflammatory response to critical illness is typically driven by innate immune cells, including neutrophils, monocytes, and macrophages. The proinflammatory mediators made by these cells are responsible for many of the pathophysiologic features of critical illness. Concurrent with this, however, is a compensatory anti-inflammatory response, including the elaboration of anti-inflammatory mediators and impairment of innate immune cell function. This includes reduction of monocyte human leukocyte antigen-DR expression and impairment of the ability of innate immune cells to produce tumor necrosis factor alpha when stimulated ex vivo. In its most severe form this is referred to as immunoparalysis, and is associated with markedly increased risks for secondary infection and death in the ICU. Prospective testing can detect this phenomenon, and immunostimulatory strategies, including the use of granulocyte macrophage-colony stimulating factor, have the potential to restore innate immune function in this setting.

Impact of selective digestive decontamination on respiratory tract Candida among patients with suspected ventilator-associated pneumonia. A meta-analysis

The purpose here is to establish the incidence of respiratory tract colonization with Candida (RT Candida) among ICU patients receiving mechanical ventilation within studies in the literature. Also of interest is its relationship with candidemia and the relative importance of topical antibiotic (TA) use as within studies of selective digestive decontamination (SDD) versus other candidate risk factors towards it. The incidence of RT Candida was extracted from component (control and intervention) groups decanted from studies of various TA and non-TA ICU infection prevention methods with summary estimates derived using random effects. A benchmark RT Candida incidence to provide overarching calibration was derived using (observational) groups from studies without any prevention method under study. A multi-level regression model of group level data was undertaken using generalized estimating equation (GEE) methods. RT Candida data were sourced from 113 studies. The benchmark RT Candida incidence is 1.3; 0.9-1.8 % (mean and 95 % confidence intervals). Membership of a concurrent control group of a study of SDD (p = 0.02), the group-wide presence of candidemia risk factors (p < 0.001), and proportion of trauma admissions (p = 0.004), but neither the year of study publication, nor membership of any other component group, nor the mode of respiratory sampling are predictive of the RT Candida incidence. RT Candida and candidemia incidences are correlated. RT Candida incidence can serve as a basis for benchmarking. Several relationships have been identified. The increased incidence among concurrent control groups of SDD studies cannot be appreciated in any single study examined in isolation.

Antifungal agents for preventing fungal infections in non-neutropenic critically ill patients

BACKGROUND

Invasive fungal infections are important causes of morbidity and mortality among critically ill patients. Early institution of antifungal therapy is pivotal for mortality reduction. Starting a targeted antifungal therapy after culture positivity and fungi identification requires a long time. Therefore, alternative strategies (globally defined as 'untargeted antifungal treatments') for antifungal therapy institution in patients without proven microbiological evidence of fungal infections have been discussed by international guidelines. This review was originally published in 2006 and updated in 2016. This updated review provides additional evidence for the clinician dealing with suspicion of fungal infection in critically ill, non-neutropenic patients, taking into account recent findings in this field.

OBJECTIVES

To assess the effects of untargeted treatment with any antifungal drug (either systemic or nonabsorbable) compared to placebo or no antifungal or any other antifungal drug (either systemic or nonabsorbable) in non-neutropenic, critically ill adults and children. We assessed effectiveness in terms of total (all-cause) mortality and incidence of proven invasive fungal infections as primary outcomes.

SEARCH METHODS

We searched the following databases to February 2015: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OVID), and EMBASE (OVID). We also searched reference lists of identified studies and major reviews, abstracts of conference proceedings, scientific meetings and clinical trials registries. We contacted experts in the field, study authors and pharmaceutical companies as part of the search strategy.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) (irrespective of language or publication status) comparing the use of untargeted treatment with any antifungal drug (either systemic or nonabsorbable) to placebo, no antifungal, or another antifungal agent in non-neutropenic critically ill participants.

DATA COLLECTION AND ANALYSIS

Three authors independently applied selection criteria, extracted data and assessed the risk of bias. We resolved any discrepancies by discussion. We synthesized data using the random-effects model and expressed the results as risk ratios (RR) with 95% confidence intervals. We assessed overall evidence quality using the GRADE approach.

MAIN RESULTS

We included 22 studies (total of 2761 participants). Of those 22 studies, 12 were included in the original published review and 10 were newly identified. Eleven trials compared the use of fluconazole to placebo or no antifungal treatment. Three trials compared ketoconazole versus placebo. One trial compared anidulafungin with placebo. One trial compared caspofungin to placebo. Two trials compared micafungin to placebo. One trial compared amphotericin B to placebo. Two trials compared nystatin to placebo and one trial compared the effect of clotrimazole, ketoconazole, nystatin and no treatment. We found two new ongoing studies and four new studies awaiting classification. The RCTs included participants of both genders with wide age range, severity of critical illness and clinical characteristics. Funding sources from pharmaceutical companies were reported in 11 trials and one trial reported funding from a government agency. Most of the studies had an overall unclear risk of bias for key domains of this review (random sequence generation, allocation concealment, incomplete outcome data). Two studies had a high risk of bias for key domains. Regarding the other domains (blinding of participants and personnel, outcome assessment, selective reporting, other bias), most of the studies had a low or unclear risk but four studies had a high risk of bias.There was moderate grade evidence that untargeted antifungal treatment did not significantly reduce or increase total (all-cause) mortality (RR 0.93, 95% CI 0.79 to 1.09, P value = 0.36; participants = 2374; studies = 19). With regard to the outcome of proven invasive fungal infection, there was low grade evidence that untargeted antifungal treatment significantly reduced the risk (RR 0.57, 95% CI 0.39 to 0.83, P value = 0.0001; participants = 2024; studies = 17). The risk of fungal colonization was significantly reduced (RR 0.71, 95% CI 0.52 to 0.97, P value = 0.03; participants = 1030; studies = 12) but the quality of evidence was low. There was no difference in the risk of developing superficial fungal infection (RR 0.69, 95% CI 0.37 to 1.29, P value = 0.24; participants = 662; studies = 5; low grade of evidence) or in adverse events requiring cessation of treatment between the untargeted treatment group and the other group (RR 0.89, 95% CI 0.62 to 1.27, P value = 0.51; participants = 1691; studies = 11; low quality of evidence). The quality of evidence for the outcome of total (all-cause) mortality was moderate due to limitations in study design. The quality of evidence for the outcome of invasive fungal infection, superficial fungal infection, fungal colonization and adverse events requiring cessation of therapy was low due to limitations in study design, non-optimal total population size, risk of publication bias, and heterogeneity across studies.

AUTHORS' CONCLUSIONS

There is moderate quality evidence that the use of untargeted antifungal treatment is not associated with a significant reduction in total (all-cause) mortality among critically ill, non-neutropenic adults and children compared to no antifungal treatment or placebo. The untargeted antifungal treatment may be associated with a reduction of invasive fungal infections but the quality of evidence is low, and both the heterogeneity and risk of publication bias is high.Further high-quality RCTs are needed to improve the strength of the evidence, especially for more recent and less studied drugs (e.g. echinocandins). Future trials should adopt standardized definitions for microbiological outcomes (e.g. invasive fungal infection, colonization) to reduce heterogeneity. Emergence of resistance to antifungal drugs should be considered as outcome in studies investigating the effects of untargeted antifungal treatment to balance risks and benefit.

Prognostic potential of 1,3-beta-d-glucan levels in bronchoalveolar lavage fluid samples

OBJECTIVES

The objective of this study was to investigate the prognostic potential of 1,3-beta-d-glucan (BDG) testing in bronchoalveolar lavage fluid (BALF) samples.

METHODS

A total of 300 BALF samples from 252 patients were investigated for BDG (Fungitell(®) assay). Prognostic potential of BALF BDG was evaluated by using: i.) Kaplan-Meier analysis, and ii.) multivariable Cox hazard regression analyses.

RESULTS

BALF BDG levels were found to be significantly higher in samples with Candida spp. colonization (p < 0.001). A total of 61/252 patients (24.2%) died within 90-days of BALF sampling (18.1% of patients with BALF BDG <200 pg/mL, 32.4% with BALF BDG ≥200 pg/mL). Kaplan-Meier analysis revealed that overall cumulative 90-day mortality was significantly higher in those with BALF BDG levels ≥200 pg/mL when compared to those with levels <200 pg/mL (log-rank p = 0.006, Breslow p = 0.005 and Tarone-Ware p = 0.005). The multivariable Cox regression analysis showed that BALF BDG levels were a strong predictor of 90-day overall mortality, with a hazard ratio of 1.048 (per 100 pg/mL increase of BALF BDG).

CONCLUSION

False positive BALF BDG results in the presence of Candida spp. colonization of the lower respiratory tract may explain the limited diagnostic potential of BALF BDG testing. In contrast, prognostic potential of BALF BDG may be promising.

Fungal-bacterial interactions and their relevance in health

Cross-kingdom interactions between bacteria and fungi are a common occurrence in the environment. Recent studies have identified various types of interactions that either can take the form of a synergistic relationship or can result in an antagonistic interplay with the subsequent destruction or inhibition of growth of bacteria, fungi or both. This cross-kingdom communication is of particular significance in human health and disease, as bacteria and fungi commonly colonize various human surfaces and their interactions can at times alter the outcome of invasive infections. Moreover, mixed infections from both bacteria and fungi are relatively common among critically ill patients and individuals with weak immune responses. The purpose of this review is to summarize our knowledge on the type of interactions between bacteria and fungi and their relevance in human infections.

Antifungal therapy in patients with pulmonary Candida spp. colonization may have no beneficial effects

Background

In critically ill patients, Candida spp. can often be identified in pulmonary samples. The impact of prompt antifungal therapy in these patients is unknown.

Methods

In this retrospective study, 500 adult patients with pulmonary Candida spp. colonization admitted to the intensive care unit (ICU) between 2010 and 2012 were included. The patients were analyzed according to whether or not they received antifungal therapy, which was administered at the discretion of the attending physician. Logistic regression analysis was performed to investigate the impact of antifungal therapy on hospital mortality and new onset of ventilator-associated pneumonia. In a stepwise backward elimination, the impact of age, cancer as an underlying disease, Simplified Acute Physiology Score (SAPS) II, and Sequential Organ Failure Assessment (SOFA) score were considered.

Results

After excluding 178 patients with multifocal Candida spp., isolated pulmonary Candida spp. colonization was found in 322 patients (cohort 1). Pre-existing pneumonia was found in 147/322 patients. Out of the remaining 175 patients (cohort 2), 44 patients received any antifungal therapy, and 131 were defined as the control group. Patients who received antifungal therapy had higher hospital mortality (50 vs. 30 %, p = 0.02) and pneumonia rates (47.7 vs. 16.8 %; p < 0.001) than those who did not. In Cox regression analysis, antifungal therapy was not independently associated with favorable outcome (mortality: odds ratio 0.854 (95 % CI 0.467–1.561); new pneumonia: 1.048 (0.536–2.046)), but SAPS II and SOFA score were significantly (p < 0.05) independent covariates for worse outcome.

Conclusions

In critically ill patients with pulmonary Candida spp. colonization, antifungal therapy may not have an impact on the incidence of new pneumonia or in-hospital mortality after adjustment for confounders.

Electronic supplementary material

The online version of this article (doi:10.1186/s40560-015-0097-0) contains supplementary material, which is available to authorized users.

Outcomes associated with routine systemic antifungal therapy in critically ill patients with Candida colonization

PURPOSE

To assess the evolution of patient deep colonization by Candida spp. in a surgical ICU over an 8-year period.

METHODS

This retrospective, observational study included all patients hospitalized for more than 2 days in a surgical and trauma ICU of a university hospital, from 2005 to 2012. Mycological samples were monitored weekly from five sites (oropharyngeal, rectal, gastric, tracheal and urinary). Preemptive fluconazole therapy was started in patients highly colonized with Candida albicans. The evolution in Candida spp. involved in the deep colonization sites distribution over the study period (main outcome measure, trend chi-square and time-series analysis), antifungal consumption, ICU-acquired candidemia and mortality were determined.

RESULTS

Among the 3029 patients with ICU stay >48 h, 2651 had at least one set of mycological sampling. Thirty percent of the 31,171 samples were positive to Candida spp. Caspofungin consumption increased over the years, whereas fluconazole consumption decreased. No trend in C. albicans colonization was observed, after adjusting on colonization risk-factors. A significant increase of acquired C. glabrata colonization was observed, whereas the clearing of C. parapsilosis colonization significantly decreased. No significant shift of colonization to other Candida spp. and mortality was observed.

CONCLUSIONS

Preemptive strategy of antifungal drug prescriptions in highly colonized ICU patients induced an increase in C. glabrata colonization without significant shift of colonization to other Candida spp. in surgical ICU patients. However, the potential detrimental impact of fluconazole on Candida ecology in ICU and/or on Candida susceptibility to antifungal drugs should be considered, and deserves further studies.