External ventricular drain(EVD) exposes the patient to infectious complications which are associated with significant morbidity and economic burden. Biomaterials impregnated with various antimicrobial agents have been developed to decrease the rate of bacterial colonization and subsequent infection. While promising, antibiotics and silver-impregnated EVD showed conflicting clinical results. The aim of the present review is to discuss the challenges associated with the development of antimicrobial EVD catheters and their effectiveness from the bench to the bedside.

In clinical studies, the partial pressure of oxygen (PaO₂) and oxygen pulse saturation are the main variables used to assess blood oxygenation and define the threshold of hypoxia/hyperoxia and hypoxemia/hyperoxemia. Determination of the optimal oxygenation target has generated a lot of interest in recent years, mainly because of the potential risk of worse outcomes associated with hyperoxia, whereas the risk associated with hypoxia has been already well known. In this short narrative review, we recall some fundamental elements of physiology regarding the meaning of PaO₂, the diffusion of oxygen to cells, the definitions of hyperoxemia and hyperoxia and the mechanisms of oxygen toxicity to provide a better understanding of these concepts, to which intensive care clinicians are frequently confronted. PaO₂ provides only limited information about oxygen concentration carried by blood and does not allow to determine whether cells are exposed to hyperoxia. This should be considered for the design of future studies that aim to determine optimal oxygenation target and by clinicians for their daily practice.

Inappropriate fluid administration can impact patient outcome. Intraoperative advanced haemodynamic monitoring coupled with a treatment protocol based on stroke volume optimisation can help determine the appropriate timing for fluid boluses. Although recommended by several anaesthesia societies, this strategy is rarely implemented because protocols are complex and compliance is often poor. The Acumen Assisted Fluid Management (AFM) software is a decision support system that uses machine learning to predict fluid responsiveness and individualise fluid therapy. AFM reportedly predicts fluid responsiveness better than clinicians, decreases preload-dependent states, and improves both macro- and microcirculatory variables. The goal of this international multicentre stepped-wedge cluster randomised trial is to test whether implementing AFM during high-risk surgery improves patient outcome. The trial is ongoing in 16 academic hospitals in France, Belgium, Canada, and the USA. All centres (clusters) deliver routine care (control arm) at the start of the study and crossed over (one way) to AFM-guided fluid therapy (intervention arm). The time when different centres switch to AFM is randomised by an independent statistician. At the end of the trial, all centres will cross over to the intervention group. The primary outcome is a composite of major complications and death 30 days after surgery that will be analysed as intention-to-treat. A total of 2000 patients are required to detect a relative 20% differences in the primary outcome between groups. This trial is powered to provide evidence on whether implementing AFM is effective in reducing postoperative complications in high-risk patients after high-risk abdominal surgery. NCT06011187.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) exposes the patient to infectious complications related to the cannulas or the site of insertion. The aim of the current study was to investigate and compare the prevalence of cannula and membrane oxygenators colonization using three different methods: microbiological culture, scanning electron microscopy, and metagenomic (rRNA 16S analysis). A monocentric prospective study was conducted between December 2017 and June 2018. Consecutive patients undergoing VA-ECMO support for refractory cardiac arrest or cardiogenic shock were included. Ten patients were included with a median age of 64 (52–62) years. Venoarterial extracorporeal membrane oxygenation was inserted for refractory cardiac arrest in five (50%), cardiogenic shock in four (40%), and self-poisoning in one (10%) cases. Microbiological culture of all (8/8, 100%) membrane oxygenators was negative, whereas all (10/10, 100%) were colonized by biofilm, and eight (8/9, 89%) presented bacterial DNA. Three (3/9, 33%) arterial and venous cannulas were positive in culture and seven (7/9, 78%) were colonized by biofilm, respectively. Seven (7/9, 78%) arterial and four (4/9, 44%) venous cannulas presented bacterial DNA. Colonization of cannulas and membranes is more frequent when assessed by electron microscopy or metagenomic analysis than with culture. Membrane oxygenators are more often colonized than cannulas.