Vincenzo Russotto

Bacterial contamination of inanimate surfaces and equipment in the intensive care unit

Intensive care unit (ICU)-acquired infections are a challenging health problem worldwide, especially when caused by multidrug-resistant (MDR) pathogens. In ICUs, inanimate surfaces and equipment (e.g., bedrails, stethoscopes, medical charts, ultrasound machine) may be contaminated by bacteria, including MDR isolates. Cross-transmission of microorganisms from inanimate surfaces may have a significant role for ICU-acquired colonization and infections. Contamination may result from healthcare workers’ hands or by direct patient shedding of bacteria which are able to survive up to several months on dry surfaces. A higher environmental contamination has been reported around infected patients than around patients who are only colonized and, in this last group, a correlation has been observed between frequency of environmental contamination and culture-positive body sites. Healthcare workers not only contaminate their hands after direct patient contact but also after touching inanimate surfaces and equipment in the patient zone (the patient and his/her immediate surroundings). Inadequate hand hygiene before and after entering a patient zone may result in cross-transmission of pathogens and patient colonization or infection. A number of equipment items and commonly used objects in ICU carry bacteria which, in most cases, show the same antibiotic susceptibility profiles of those isolated from patients. The aim of this review is to provide an updated evidence about contamination of inanimate surfaces and equipment in ICU in light of the concept of patient zone and the possible implications for bacterial pathogen cross-transmission to critically ill patients.

Bloodstream infections in intensive care unit patients: distribution and antibiotic resistance of bacteria

Bloodstream infections (BSIs) are among the leading infections in critically ill patients. The case-fatality rate associated with BSIs in patients admitted to intensive care units (ICUs) reaches 35%–50%. The emergence and diffusion of bacteria with resistance to antibiotics is a global health problem. Multidrug-resistant bacteria were detected in 50.7% of patients with BSIs in a recently published international observational study, with methicillin resistance detected in 48% of Staphylococcus aureus strains, carbapenem resistance detected in 69% of Acinetobacter spp., in 38% of Klebsiella pneumoniae, and in 37% of Pseudomonas spp. Prior hospitalization and antibiotic exposure have been identified as risk factors for infections caused by resistant bacteria in different studies. Patients with BSIs caused by resistant strains showed an increased risk of mortality, which may be explained by a higher incidence of inappropriate empirical therapy in different studies. The molecular genetic characterization of resistant bacteria allows the understanding of the most common mechanisms underlying their resistance and the adoption of surveillance measures. Knowledge of epidemiology, risk factors, mechanisms of resistance, and outcomes of BSIs caused by resistant bacteria may have a major influence on global management of ICU patients. The aim of this review is to provide the clinician an update on BSIs caused by resistant bacteria in ICU patients.

The paradox of the evidence about invasive fungal infection prevention

Invasive fungal infections (IFIs) are characterized by high morbidity and mortality in non-neutropenic critically ill patients. Attributable mortality due to Candida spp. infections ranges from about 42 to 63 % [1, 2]. Data from large observational and retrospective studies show an association between early antifungal treatment and improved survival [3, 4]. Updated clinical practice guidelines for the management of candidiasis have been recently published [5].

Use of Cepheid Xpert Carba-R® for Rapid Detection of Carbapenemase-Producing Bacteria in Abdominal Septic Patients Admitted to Intensive Care Unit

Early institution of effective antibiotic therapy and source control are pivotal to improve survival of abdominal septic patients. Xpert® Carba-R is a real time polymerase chain reaction assay for rapid detection and differentiation of five genes (blaKPC, blaVIM, blaOXA-48, blaIMP-1, blaNDM) responsible for carbapenem resistance. We performed an observational study investigating the clinical usefulness and applicability of Xpert® Carba-R to detect carbapenem resistance in abdominal septic patients admitted to intensive care unit. We compared the results of Xpert® Carba-R with standard microbiological culture. We collected a set of two rectal/stomia swabs and two swabs from abdominal drainage fluid for each patient. We included 20 patients for a total of 45 comparisons between the two methods. In our clinical setting, the overall performance of Xpert® Carba-R for detection of carbapenem resistance in the presence of genes detectable and non-detectable by the method was: sensitivity 50% (95% CI 24.6–75.3); specificity 93.1% (95% CI 77.2–99.1); positive predictive value (PPV) 80% (95% CI 44.4–97.5); negative predictive value (NPV) 77.1% (95% CI 56.9–89.6). The inter-rater agreement was 0.47 (SE 0.14; 95% CI 0.20–0.74). When considering the only 5 mechanisms of resistance detected by both methods, the overall diagnostic performance was: sensitivity 100% (95% CI 69.1–100), specificity 94.2 (95% CI 80.8–99.3), PPV 83.3 (95% CI 59.6–97.9) and NPV 100% (95% CI 89.4–100). The inter-rater agreement was 0.88 (SE 0.08; 95% CI 0.71–1). Xpert® Carba-R may be considered an additional diagnostic tool for early diagnosis of carbapenem resistance in abdominal septic patients. Clinicians should be aware of their epidemiology before its introduction in the diagnostic protocol of their intensive care units.

Effect of High-Fidelity Simulation on Medical Students' Knowledge about Advanced Life Support: A Randomized Study

High-fidelity simulation (HFS) is a learning method which has proven effective in medical education for technical and non-technical skills. However, its effectiveness for knowledge acquisition is less validated. We performed a randomized study with the primary aim of investigating whether HFS, in association with frontal lessons, would improve knowledge about advanced life support (ALS), in comparison to frontal lessons only among medical students. The secondary aims were to evaluate the effect of HFS on knowledge acquisition of different sections of ALS and personal knowledge perception. Participants answered a pre-test questionnaire consisting of a subjective (evaluating personal perception of knowledge) and an objective section (measuring level of knowledge) containing 100 questions about algorithms, technical skills, team working/early warning scores/communication strategies according to ALS guidelines. All students participated in 3 frontal lessons before being randomized in group S, undergoing a HFS session, and group C, receiving no further interventions. After 10 days from the end of each intervention, both groups answered a questionnaire (post-test) with the same subjective section but a different objective one. The overall number of correct answers of the post-test was significantly higher in group S (mean 74.1, SD 11.2) than in group C (mean 65.5, SD 14.3), p = 0.0017, 95% C.I. 3.34 – 13.9. A significantly higher number of correct answers was reported in group S than in group C for questions investigating knowledge of algorithms (p = 0.0001; 95% C.I 2.22–5.99) and team working/early warning scores/communication strategies (p = 0.0060; 95% C.I 1.13–6.53). Students in group S showed a significantly higher score in the post-test subjective section (p = 0.0074). A lower proportion of students in group S confirmed their perception of knowledge compared to group C (p = 0.0079). HFS showed a beneficial effect on knowledge of ALS among medical students, especially for notions of algorithms and team working/early warning scores/communication.

Use of a Real-Time Training Software (Laerdal QCPR®) Compared to Instructor-Based Feedback for High-Quality Chest Compressions Acquisition in Secondary School Students: A Randomized Trial

High-quality chest compressions are pivotal to improve survival from cardiac arrest. Basic life support training of school students is an international priority. The aim of this trial was to assess the effectiveness of a real-time training software (Laerdal QCPR®) compared to a standard instructor-based feedback for chest compressions acquisition in secondary school students. After an interactive frontal lesson about basic life support and high quality chest compressions, 144 students were randomized to two types of chest compressions training: 1) using Laerdal QCPR® (QCPR group– 72 students) for real-time feedback during chest compressions with the guide of an instructor who considered software data for students’ correction 2) based on standard instructor-based feedback (SF group– 72 students). Both groups had a minimum of a 2-minute chest compressions training session. Students were required to reach a minimum technical skill level before the evaluation. We evaluated all students at 7 days from the training with a 2-minute chest compressions session. The primary outcome was the compression score, which is an overall measure of chest compressions quality calculated by the software expressed as percentage. 125 students were present at the evaluation session (60 from QCPR group and 65 from SF group). Students in QCPR group had a significantly higher compression score (median 90%, IQR 81.9–96.0) compared to SF group (median 67%, IQR 27.7–87.5), p = 0.0003. Students in QCPR group performed significantly higher percentage of fully released chest compressions (71% [IQR 24.5–99.0] vs 24% [IQR 2.5–88.2]; p = 0.005) and better chest compression rate (117.5/min [IQR 106–123.5] vs 125/min [115–135.2]; p = 0.001). In secondary school students, a training for chest compressions based on a real-time feedback software (Laerdal QCPR®) guided by an instructor is superior to instructor-based feedback training in terms of chest compression technical skill acquisition. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12616000383460

Antifungal prophylaxis: update on an old strategy.

To the Editor We read with interest the Review by Lagunes et al. about invasive candidiasis [1]. We focused our attention on the data and arguments about antifungal prophylaxis reported by the authors. Our group has recently published an updated Cochrane Systematic Review investigating the effect of untargeted antifungal treatment in non-neutropenic critically ill patients [2]. Untargeted antifungal treatment encompasses prophylaxis, pre-emptive and empiric treatment. Prophylaxis has been defined as the administration of antifungal agents in patients without proven or suspected fungal infections, but, possibly, with risk factors for its development [3]. Authors have described the results of a meta-analysis investigating the effect of prophylaxis with fluconazole in critically ill surgical patients only [4]. This meta-analysis included four trials, and 626 patients were enrolled. Notably, the study was performed more than a decade ago. In our systematic review, we included 12 studies in which antifungal prophylaxis was tested, enrolling 1,609 patients. With regard to mortality, there was no statistically significant difference between the intervention and control group (relative risk 0.92, 95 % CI 0.78 to 1.90). However, a statistically significant difference was found for the outcome of proven invasive fungal infections (relative risk 0.39, 95 % CI 0.26 to 0.60). In view of the high mortality associated with invasive fungal infections, the contrast between the absence of effect on mortality and a reduced incidence of invasive fungal infections may be considered a paradox [5]. We agree with the authors about the possible increased risk of resistance development and excessive costs associated with the widespread use of antifungal prophylaxis. In our review, we advocated the need for investigating incidence of antifungal resistance and costs as study endpoints in future trials. We also agree on the proposed strategy of better patient selection based on predictive scores and determination of biomarkers (i.e., pre-emptive strategy). The last point is supported by two factors: 1) the need for evidence coming from randomized controlled trials studying the pre-emptive approach, and 2) recent evidence supporting strategies based on risk factors and biomarkers in terms of diagnostic performance and the sparing of antifungal drugs [6, 7]. As far as antifungal treatments is concerned, Bbetter tailoring for better care^ should be our aim for the future!

Is it time to combine untargeted antifungal strategies to reach the goal of ‘early’ effective treatment?

A recently published retrospective study by Posteraro et al. [1] investigated the use of (1–3)-β-D-glucan (BDG) as a strategy for antifungal drug administration in patients at high risk of candidemia. The strategy consisted of the administration of antifungals (anidulafungin in most cases) to septic patients with a Candida score ≥ 3a nd a positive BDG result (≥80 pg/ml). This untargeted strategy led to better selection of patients, avoiding exposure to antifungals in approximately 73 % of patients with negative BDG results and leading to shortened treatment duration in another 20 % of patients. Untargeted antifungal treatments (including prophylaxis, pre-emptive and empiric approaches) are the mainstay of early invasive fungal infection (IFI) management [2]. We recently published a Cochrane systematic review investigating the effects of untargeted antifungal treatment in terms of mortality and incidence of IFI in nonneutropenic critically ill patients [3]. Notably, prophylaxis resulted in IFI reduction but it may lead to exposure to antifungals for an unacceptably high proportion of patients, with associated potential adverse effects of antifungals, increased risk of resistance and costs. On the contrary, empiric treatment showed no benefit in terms of IFI reduction and mortality. We hypothesized that this observation may be due to inclusion of patients with a more advanced disease stage [4]. Moreover, many patients receiving antifungals may not need them, leading to the observed lack of benefit. The pre-emptive strategy was less investigated, with only one published randomized controlled study included in the systematic review. According to the findings of Posteraro et al. [1], a surrogate marker-driven strategy, in association with risk factors, might represent an adequate and cost-effective approach to tailor antifungal treatment to patients who may benefit most. Is it time to abandon classic antifungal treatments to shift towards more pliant ‘early’ antifungal strategies based on risk factors and biomarkers? Data from non-randomized studies suggested that this kind of antifungal strategy might combine advantages of classic treatments with improved selection of patients and reduced exposure to antifungals, also being able to help clinicians to decide when to stop treatments [5]. There is a need for further randomized trials to answer the question of whether surrogate marker/risk factorbased antifungal strategies could be beneficial to our critically ill patients, in comparison with other (old?) untargeted treatments, in terms of efficacy, exposure to antifungals and costs.

Update on perioperative management of the child with asthma

Asthma represents the leading cause of morbidity from a chronic disease among children. Dealing with this disease during the perioperative period of pediatric surgical procedures is, therefore, quite common for the anesthesiologist and other professionalities involved. Preoperative assessment has a key role in detecting children at increased risk of perioperative respiratory complications. For children without an optimal control of symptoms or with a recent respiratory tract infection elective surgery should be postponed, if possible, after the optimization of therapy. According to clinical setting, loco-regional anesthesia represents the desirable option since it allows to avoid airway instrumentation. Airway management goals are preventing the increase of airflow resistance during general anesthesia along with avoiding triggers of bronchospasm. When their use is possible, face mask ventilation and laringeal mask are considered more reliable than tracheal intubation for children with asthma. Sevoflurane is the most commonly used anesthetic for induction and manteinance. Salbutamol seems to be useful in preventing airflow resistance rise after endotracheal intubation. Mechanical ventilation should be tailored according to pathophysiology of asthma: an adequate expiratory time should be setted in order to avoid a positive end-expiratory pressure due to expiratory airflow obstruction. Pain should be prevented and promptly controlled with a loco-regional anesthesia technique when it is possible. Potential allergic reactions to drugs or latex should always be considered during the whole perioperative period. Creating a serene atmosphere should be adopted as an important component of interventions in order to guarantee the best care to the asthmatic child.

Adenosine triphosphate bioluminescence in intensive care units: Be careful with its use

We read with interest the article by Whiteley et al1 investigating the use of adenosine triphosphate (ATP) bioluminescence for location of multidrug-resistant organisms (MDROs) in an intensive care unit (ICU). We agree with the authors that inanimate surfaces and equipment contamination, either in the patient zone or in the health care area, may significantly contribute to cross-transmission of pathogens, including MDROs.2 Indeed, we recently performed a review of the available evidence of bacterial contamination of high-touch objects (HTOs) in the ICU, with a contamination rate as high as 60%-80% of samples in most studies.3 However, we have some concerns about the use of ATP bioluminescence as a method to identify the locations of MDROs in the ICU. In 2010, the Centers for Disease Control and Prevention developed a toolkit providing guidance for programs aiming to improve environmental hygiene. In this document, ATP bioluminescence was included among methods for objective assessment of HTOs’ cleanliness and improvement of hygiene practices.4 In our opinion, and according to available recommendations, a culture method should be adopted instead, when the aim is the identification of MDROs locations.5,6 Another questionable point is the search for a correlation between values of ATP bioluminescence readings and MDRO contamination. Very low values of relative light units (RLUs) have been associated with low aerobic colonic counts.7 However, this is not always true, and MDROs have been detected also in sampled surfaces with low RLUs, as also observed in this study.1,2 Very high RLU values may indicate a viable bioburden, organic debris (including dead bacteria), or a combination of both, and a relationship between RLU values and risk of MDRO detection cannot be established with reliability.2 For these reasons, previous authors recommended to identify benchmark values corresponding to what, in a given setting, may be considered clean, and to use the ATP bioluminescence to monitor an intervention which would reduce the bioburden under a predefined level.4,8 In other words, ATP bioluminescence is not a reliable method for identification and surveillance of potentially contaminated HTOs but rather a tool to assess the efficacy of a cleaning procedure or other infection control measures.2 We appreciate the authors’ interests in investigating the contamination of HTOs in the ICU and we thank them for providing another occasion to remind us: clean your hands!