Effect of Nebulized Amphotericin B in Critically ill Patients With Respiratory Candida spp. De-colonization: A Retrospective Analysis

Clinical outcomes of antifungal therapy on Candida pulmonary colonisation in immunocompetent patients with invasive ventilation: a systematic review and meta-analysis

OBJECTIVE

This study aimed to use systematic review and meta-analysis to establish the influence of antifungal therapy on pulmonary Candida colonisation of patients with mechanical ventilation (MV).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

An extensive search was undertaken on publications from inception to 25 July 2023, through PubMed, Web of Science, Medline, Embase, China National Knowledge Infrastructure, Wanfang Data and VIP Databases.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised trials, cohort studies and case-control studies comparing the efficacy of antifungal treatment in immunocompetent patients with pulmonary Candida colonisation after invasive ventilation.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted the data and assessed the quality of studies. Dichotomous outcomes were expressed as ORs with 95% CIs. Continuous outcomes were expressed as standardised mean differences (SMD) with 95% CIs.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes included intensive care unit (ICU), hospital, 28-day, and 90-day mortality. The secondary outcomes included ICU length of stay, MV duration and ventilator-associated pneumonia (VAP).

RESULTS

Nine high-quality studies were included. According to the data collected from these nine studies, there is no significant evidence showing a difference between the therapy group treated with antifungal drugs and the control group without antifungal drugs in clinical outcomes, including ICU mortality (OR: 1.37; 95% CI 0.84 to 2.22), hospital mortality (OR: 1.17; 95% CI 0.57 to 2.38), 28-day mortality (OR: 0.71; 95% CI 0.45 to 1.14), 90-day mortality (OR: 0.76; 95% CI 0.35 to 1.63), ICU length of stay (SMD: -0.15; 95% CI -0.88 to 0.59), MV duration (SMD: 0.11; 95% CI -0.88 to 1.10) and VAP (OR: 1.54; 95% CI 0.56 to 4.20). Subgroup analysis of different treatment types indicates that the combined effect size is stable and unaffected by different treatment types including inhalation (OR: 2.32; 95% CI 0.30 to 18.09) and intravenous (OR: 0.65; 95% CI 0.13 to 3.34).

CONCLUSION

The application of antifungal treatment did not improve clinical outcomes in patients with MV. We do not suggest initiating antifungal treatment in patients with Candida pulmonary colonisation after invasive ventilation.

TRIAL REGISTRATION NUMBER

International Prospective Register of Systematic Reviews, CRD42020161138.

A new model of endotracheal tube biofilm identifies combinations of matrix-degrading enzymes and antimicrobials able to eradicate biofilms of pathogens that cause ventilator-associated pneumonia

Ventilator-associated pneumonia is defined as pneumonia that develops in a patient who has been on mechanical ventilation for more than 48 hours through an endotracheal tube. It is caused by biofilm formation on the indwelling tube, which introduces pathogenic microbes such as Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans into the patient's lower airways. Currently, there is a lack of accurate in vitro models of ventilator-associated pneumonia development. This greatly limits our understanding of how the in-host environment alters pathogen physiology and the efficacy of ventilator-associated pneumonia prevention or treatment strategies. Here, we showcase a reproducible model that simulates the biofilm formation of these pathogens in a host-mimicking environment and demonstrate that the biofilm matrix produced differs from that observed in standard laboratory growth medium. In our model, pathogens are grown on endotracheal tube segments in the presence of a novel synthetic ventilated airway mucus medium that simulates the in-host environment. Matrix-degrading enzymes and cryo-scanning electron microscopy were employed to characterize the system in terms of biofilm matrix composition and structure, as compared to standard laboratory growth medium. As seen in patients, the biofilms of ventilator-associated pneumonia pathogens in our model either required very high concentrations of antimicrobials for eradication or could not be eradicated. However, combining matrix-degrading enzymes with antimicrobials greatly improved the biofilm eradication of all pathogens. Our in vitro endotracheal tube model informs on fundamental microbiology in the ventilator-associated pneumonia context and has broad applicability as a screening platform for antibiofilm measures including the use of matrix-degrading enzymes as antimicrobial adjuvants.