Development of artificial synapse organizers liganded with a peptide tag for molecularly inducible neuron-microelectrode interface.

It has been proposed that cell-type-specific bioelectronic interfaces for neuronal circuits could be established by utilizing the function of synapse organizers. For this purpose, using neurexin-1ß and a peptide tag, we engineered compact synapse organizers that do not interact with the naturally occurring receptors but induce presynaptic differentiation upon contact with nanobody-decorated objects in cultured mammalian and chick forebrain neurons. In chick neurons, the engineered organizer exerted synaptogenesis typically in ∼4 h after the contact, even under an air atmosphere at room temperature, thereby providing a useful cellular model for establishing the molecularly inducible neuron-microelectrode interface.

Impact of the failure of initial insertion of a peripheral intravascular catheter on the development of adverse events in patients admitted to the intensive care unit from the emergency room: A post hoc analysis of the AMOR-VENUS study.

Aim: To investigate an association between failure of initial peripheral intravascular catheter (PIVC) insertion and adverse events in patients admitted to the intensive care unit (ICU) from the emergency room (ER). Methods: This study was a post hoc analysis of the AMOR-VENUS study, a multicenter cohort study that included 22 institutions and 23 ICUs in Japan between January and March of 2018. Study participants included consecutive adult patients admitted to the ICU with PIVCs inserted in ICU during the study period exclusively from the ER. The primary outcome was adverse events. Adverse events were composite of arterial puncture, hematoma, extravasation, nerve injury, tendon injury, compartment syndrome, pain, redness, bad location, and effusion. Multivariate logistic regression analyses were performed to assess the association between adverse events and the failure of initial PIVC insertion. Results: In total, 363 patients and 1121 PIVCs were analyzed. Moreover, 199 catheters failed to insert properly, and 36 patients and 107 catheters experienced adverse events. After performing multivariate logistic regression analysis, there were statistically significant associations in the odds ratio (OR) and 95% confidence interval (CI) for the failure of initial insertion (OR, 1.66 [1.02-2.71]; p = 0.04). Conclusion: Failure of initial insertion may be a risk factor for adverse events. We could potentially provide various interventions to avoid failure of initial PIVC insertion. For example, PIVC insertion could be performed by experienced practitioners.

Risk factors for peripheral venous catheter-related phlebitis stratified by body mass index in critically ill patients: A post-hoc analysis of the AMOR-VENUS study.

Introduction: Phlebitis is an important complication in patients with peripheral intravascular catheters (PIVCs). Although an association between body mass index (BMI) and phlebitis has been suggested, the risk of phlebitis according to BMI has not been well elucidated. Therefore, in this study, we analyzed the risk of phlebitis according to BMI in patients in the intensive care unit (ICU). Materials and methods: This study undertook a secondary analysis of the data from a prospective multicenter observational study assessing the epidemiology of phlebitis at 23 ICUs in Japan. Patients admitted into the ICU aged ≥18 years with a new PIVC inserted after ICU admission were consecutively enrolled and stratified into the following groups based on BMI: Underweight (BMI < 18.5 kg/m2), normal weight (18.5 ≤ BMI < 25.0 kg/m2), and overweight/obese (BMI ≥ 25.0 kg/m2). The primary outcome was phlebitis. The risk factors for phlebitis in each BMI-based group were investigated using a marginal Cox regression model. In addition, hazard ratios and 95% confidence intervals were calculated. Results: A total of 1,357 patients and 3,425 PIVCs were included in the analysis. The mean BMI for all included patients was 22.8 (standard deviation 4.3) kg/m2. Among the eligible PIVCs, 455; 2,041; and 929 were categorized as underweight, normal weight, and overweight/obese, respectively. In the underweight group, catheter size ≥ 18 G and amiodarone administration were independently associated with the incidence of phlebitis. Drug administration standardization was associated with the reduction of phlebitis. In the normal weight group, elective surgery as a reason for ICU admission, and nicardipine, noradrenaline, and levetiracetam administration were independently associated with the incidence of phlebitis. Heparin administration was associated with the reduction of phlebitis. In the overweight/obese group, the Charlson comorbidity index, catheter size ≥ 18 G, and levetiracetam administration were independently associated with the incidence of phlebitis. Catheters made from PEU-Vialon (polyetherurethane without leachable additives) and tetrafluoroethylene were associated with the reduction of phlebitis. Conclusion: We investigated the risk factors for peripheral phlebitis according to BMI in ICU and observed different risk factors in groups stratified by BMI. For example, in underweight or overweight patients, large size PIVCs could be avoided. Focusing on the various risk factors for phlebitis according to patients' BMIs may aid the prevention of phlebitis.

A burden of fluid, sodium, and chloride due to intravenous fluid therapy in patients with respiratory support: a post-hoc analysis of a multicenter cohort study.

BACKGROUND: Fluid creep, including fluids administered as drug diluents and for the maintenance of catheter patency, is the major source of fluid intake in critically ill patients. Although hypoxemia may lead to fluid restriction, the epidemiology of fluid creep in patients with hypoxemia is unclear. This study aimed to address the burden due to fluid creep among patients with respiratory support according to oxygenation status. METHODS: We conducted a post-hoc analysis of a prospective multicenter cohort study conducted in 23 intensive care units (ICUs) in Japan from January to March 2018. Consecutive adult patients who underwent invasive or noninvasive ventilation upon ICU admission and stayed in the ICU for more than 24 h were included. We excluded the following patients when no fluids were administered within 24 h of ICU admission and no records of the ratio of arterial oxygen partial pressure to fractional inspired oxygen. We investigated fluid therapy until 7 days after ICU admission according to oxygenation status. Fluid creep was defined as the fluids administered as drug diluents and for the maintenance of catheter patency when administered at ≤ 20 mL/h. RESULTS: Among the 588 included patients, the median fluid creep within 24 h of ICU admission was 661 mL (25.2% of the total intravenous-fluid volume), and the proportion of fluid creep gradually increased throughout the ICU stay. Fluid creep tended to decrease throughout ICU days in patients without hypoxemia and in those with mild hypoxemia (p < 0.001 in both patients), but no significant trend was observed in those with severe hypoxemia (p = 0.159). Similar trends have been observed in the proportions of sodium and chloride caused by fluid creep. CONCLUSIONS: Fluid creep was the major source of fluid intake among patients with respiratory support, and the burden due to fluid creep was prolonged in those with severe hypoxemia. However, these findings may not be conclusive as this was an observational study. Interventional studies are, therefore, warranted to assess the feasibility of fluid creep restriction. Trial registration UMIN-CTR, the Japanese clinical trial registry (registration number: UMIN 000028019, July 1, 2017).