Endotracheal tube biofilm in critically ill patients during the COVID-19 pandemic : description of an underestimated microbiological compartment.

Biofilm (BF) growth is believed to play a major role in the development of ventilator-associated pneumonia (VAP) in the intensive care unit. Despite concerted efforts to understand the potential implication of endotracheal tube (ETT)-BF dispersal, clinically relevant data are lacking to better characterize the impact of its mesostructure and microbiological singularity on the occurrence of VAP. We conducted a multicenter, retrospective observational study during the third wave of the COVID-19 pandemic, between March and May 2021. In total, 64 ETTs collected from 61 patients were included in the present BIOPAVIR study. Confocal microscopy acquisitions revealed two main morphological aspects of ETT-deposited BF: (1) a thin, continuous ribbon-shaped aspect, less likely monobacterial and predominantly associated with Enterobacter spp., Streptococcus pneumoniae or Viridans streptococci, and (2) a thicker, discontinuous, mushroom-shaped appearance, more likely characterized by the association of bacterial and fungal species in respiratory samples. The microbiological characterization of ETT-deposited BF found higher acquired resistance in more than 80% of analyzed BF phenotypes, compared to other colonization sites from the patient's environment. These findings reveal BF as a singular microbiological compartment, and are of added clinical value, with a view to future ETT-deposited BF-based antimicrobial stewardship in critically ill patients. Trial registration NCT04926493. Retrospectively registered 15 June 2021.

Candida spp. airway colonization could promote antibiotic-resistant bacteria selection in patients with suspected ventilator-associated pneumonia.

OBJECTIVE: Candida spp. airway colonization could promote development of ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa, a potentially multidrug-resistant (MDR) bacteria, and worsen the outcome of VAP regardless of pathogen. We therefore address the question of the risk of MDR bacteria isolation within the airway of patients with suspected VAP, whether Candida spp. is present or not. DESIGN AND SETTING: Prospective observational study in a teaching hospital. PATIENTS AND METHODS: Consecutive patients with suspected VAP were included. Respiratory tract secretions were seeded on specific medium for yeast isolation in addition to standard culture. Outcome as well as presence of MDR bacteria were assessed according to fungal colonization. RESULTS: 323 suspected VAP were analysed. Among these, 181 (56 %) cases presented with Candida spp. airway colonization. Colonized and noncolonized patients were similar regarding baseline characteristics, prior exposure to antibiotics and VAP severity. However, mortality rate was greater in patients with fungal airway colonization than in those without (44.2 versus 31.0 %, respectively; p = 0.02). In addition, MDR bacteria isolation was 31.5 % in patients with Candida spp. colonization versus 23.2 % in those without (p = 0.13). Moreover, Candida spp. airway colonization was one independent risk factor for MDR bacteria isolation [odds ratio (OR) = 1.79, 95 % confidence interval 1.05-3.05; p = 0.03], in addition to the time elapsed between intensive care unit (ICU) admission and VAP suspicion. CONCLUSIONS: In patients with suspected VAP, Candida spp. airway colonization is frequent and associated with increased risk for MDR bacteria isolation. This could worsen outcome and should therefore be considered when choosing an empiric antibiotic therapy.

Sodium citrate versus saline catheter locks for non-tunneled hemodialysis central venous catheters in critically ill adults: a randomized controlled trial.

PURPOSE: Sodium citrate has antibacterial and anticoagulant properties that are confined to the catheter when used as a catheter lock. Studies of its use as a catheter lock in chronic hemodialysis patients suggest it may be efficacious in preventing infection and thrombotic complications. We compared sodium citrate with saline catheter locks for non-tunneled hemodialysis central venous catheters in critically ill adult patients. Primary endpoint was catheter life span without complication. METHODS: This was a randomized, controlled, open-label trial involving intensive care patients with acute renal failure requiring hemodialysis. Events were defined as catheter-related bloodstream infection and catheter malfunction. RESULTS: Seventy-eight patients were included. Median catheter life span without complication was 6 days (saline group) versus 12 days (citrate group) [hazard ratio (HR) 2.12 (95% CI 1.32-3.4), p = 0.0019]. There was a significantly higher rate of catheter malfunction in the saline group compared with in the citrate group (127 catheter events/1,000 catheter-days, saline group vs. 26 events/1,000 catheter-days, citrate group, p < 0.00001). There was no significant difference in incidence of infections between groups. We observed a significantly longer time to occurrence of infection in the citrate group (20 days vs. 14 days, HR 2.8, 95% CI 1.04-7.6, p = 0.04). By multivariate analysis, age and citrate group were the only independent factors that influenced catheter life span. CONCLUSIONS: This study shows for the first time that citrate lock reduced catheter complications and increased catheter life span as compared to saline lock in critically ill adults requiring hemodialysis.

Benefits of computer screen-based simulation in learning cardiac arrest procedures.

OBJECTIVES: What is the best way to train medical students early so that they acquire basic skills in cardiopulmonary resuscitation as effectively as possible? Studies have shown the benefits of high-fidelity patient simulators, but have also demonstrated their limits. New computer screen-based multimedia simulators have fewer constraints than high-fidelity patient simulators. In this area, as yet, there has been no research on the effectiveness of transfer of learning from a computer screen-based simulator to more realistic situations such as those encountered with high-fidelity patient simulators. METHODS: We tested the benefits of learning cardiac arrest procedures using a multimedia computer screen-based simulator in 28 Year 2 medical students. Just before the end of the traditional resuscitation course, we compared two groups. An experiment group (EG) was first asked to learn to perform the appropriate procedures in a cardiac arrest scenario (CA1) in the computer screen-based learning environment and was then tested on a high-fidelity patient simulator in another cardiac arrest simulation (CA2). While the EG was learning to perform CA1 procedures in the computer screen-based learning environment, a control group (CG) actively continued to learn cardiac arrest procedures using practical exercises in a traditional class environment. Both groups were given the same amount of practice, exercises and trials. The CG was then also tested on the high-fidelity patient simulator for CA2, after which it was asked to perform CA1 using the computer screen-based simulator. Performances with both simulators were scored on a precise 23-point scale. RESULTS: On the test on a high-fidelity patient simulator, the EG trained with a multimedia computer screen-based simulator performed significantly better than the CG trained with traditional exercises and practice (16.21 versus 11.13 of 23 possible points, respectively; p<0.001). CONCLUSIONS: Computer screen-based simulation appears to be effective in preparing learners to use high-fidelity patient simulators, which present simulations that are closer to real-life situations.