Predicting Blood Pressure After Nitroglycerin Infusion Dose Titration in Critical Care Units: A Multicenter Retrospective Study.

Critical care nurses use physiological indicators, such as blood pressure, to guide their decision-making regarding the titration of nitroglycerin infusions. A retrospective study was conducted to determine the accuracy of systolic blood pressure predictions during nitroglycerin infusions. Data were extracted from the publicly accessible eICU program database. The accuracy of a linear model, least absolute shrinkage and selection operator, ridge regression, and a stacked ensemble model trained using the AutoGluon-Tabular framework were investigated. A persistence model, where the future value in a time series is predicted as equal to its preceding value, was used as the baseline comparison for model accuracy. Internal-external validation was used to examine if heterogeneity among hospitals could contribute to model performance. The sample consisted of 827 patients and 2541 nitroglycerin dose titrations with corresponding systolic blood pressure measurements. The root-mean-square error on the test set for the stacked ensemble model developed using the AutoGluon-Tabular framework was the lowest of all models at 15.3 mm Hg, equating to a 22% improvement against the baseline. Internal-external validation revealed consistent accuracy across hospitals. Further studies are needed to determine the impact of using systolic blood pressure predictions to inform nurses' clinical decision-making regarding nitroglycerin infusion titration in critical care.

High flow nasal oxygen during procedural sedation for cardiac implantable electronic device procedures: A randomised controlled trial.

BACKGROUND: High flow nasal oxygen may better support the vulnerable respiratory state of patients during procedural sedation. OBJECTIVE: The objective of this study was to investigate the effects of high flow nasal oxygen in comparison to facemask oxygen on ventilation during cardiac implantable electronic device procedures performed with procedural sedation. DESIGN: A randomised controlled trial. SETTING: The study was conducted at one academic hospital in Canada. PARTICIPANTS: Adults undergoing elective cardiac implantable electronic device procedures with sedation administered by an anaesthesia assistant, supervised by an anaesthesiologist from August 2019 to March 2020. INTERVENTIONS: Participants were randomised 1 : 1 to facemask (≥ 8 l ·â€Šmin-1) or high flow nasal oxygen (50 l ·â€Šmin-1 and a 50 : 50 oxygen to air ratio). MAIN OUTCOME MEASURES: The primary outcome was peak transcutaneous carbon dioxide. Outcomes were analysed using Bayesian statistics. RESULTS: The 129 participants who were randomised and received sedation were included. The difference in peak transcutaneous carbon dioxide was 0.0 kPa (95% CI -0.17 to 0.18). Minor adverse sedation events were 6.4 times more likely to occur in the high flow nasal oxygen group. This estimate is imprecise (95% CI 1.34 to 42.99). The odds ratio for oxygen desaturation for the high flow nasal oxygen group compared with the facemask group was 1.2 (95% CI 0.37 to 3.75). The difference in satisfaction with sedation scores between groups was 0.0 (95% CI -0.33 to 0.23). CONCLUSIONS: Ventilation, as measured by TcCO2, is highly unlikely to differ by a clinically important amount between high flow nasal oxygen at 50 l min-1 or facemask oxygen at 8 l min-1. Further research with a larger sample size would be required to determine the optimal oxygen:air ratio when using high flow nasal oxygen during cardiac implantable electronic device procedures performed with sedation. TRIAL REGISTRATION NUMBER: NCT03858257.

Accuracy and precision of zero-heat-flux temperature measurements with the 3M™ Bair Hugger™ Temperature Monitoring System: a systematic review and meta-analysis.

Zero-heat-flux thermometers provide clinicians with the ability to continuously and non-invasively monitor body temperature. These devices are increasingly being used to substitute for more invasive core temperature measurements during surgery and in critical care. The aim of this review was to determine the accuracy and precision of zero-heat-flux temperature measurements from the 3M™ Bair Hugger™ Temperature Monitoring System. Medline and EMBASE were searched for studies that reported on a measurement of core or peripheral temperature that coincided with a measurement from the zero-heat-flux device. Study selection and quality assessment was performed independently using the Revised Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2). The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to summarize the strength of the evidence. Pooled estimates of the mean bias and limits of agreement with outer 95% confidence intervals (population limits of agreement) were calculated. Sixteen studies were included. The primary meta-analysis of zero-heat-flux versus core temperature consisted of 22 comparisons from 16 individual studies. Data from 952 participants with 314,137 paired measurements were included. The pooled estimate for the mean bias was 0.03 °C. Population limits of agreement, which take into consideration the between-study heterogeneity and sampling error, were wide, spanning from - 0.93 to 0.98 °C. The GRADE evidence quality rating was downgraded to moderate due to concerns about study limitations. Population limits of agreement for the sensitivity analysis restricted to studies rated as having low risk of bias across all the domains of the QUADAS-2 were similar to the primary analysis. The range of uncertainty in the accuracy of a thermometer should be taken into account when using this device to inform clinical decision-making. Clinicians should therefore consider the potential that a temperature measurement from a 3M™ Bair Hugger™ Temperature Monitoring System could be as much as 1 °C higher or lower than core temperature. Use of this device may not be appropriate in situations where a difference in temperature of less than 1 °C is important to detect.

An Exploration of How Persons Receiving In-Center Hemodialysis Describe How Access to Transportation for Treatment Influences Their Overall Health.

Individuals having in-center hemodialysis treatment re quire transportation services on average six trips a week (three roundtrips for three treatment days), making access to transportation an important component for sustaining the health and well-being of these individuals. This qualitative study aimed to explore how persons receiving in-center hemodialysis treatment explain ways in which access to transportation for such treatment influences their overall health using the World Health Organization's definition of health. Purposive sampling was used to recruit eight participants from a community hemodialysis center in a suburban region of Southwestern Ontario, Canada. Data were obtained using semi-structured individual interviews and analyzed using inductive analysis. Three interrelated themes revealed each patient's experience: reliability, choice, and personal safety.

Unveiling the Potential of an Fe Bis(terpyridine) Complex for Precise Development of an Fe-N-C Electrocatalyst to Promote the Oxygen Reduction Reaction.

Improvements in highly efficient precious-metal-free electrocatalysts for the oxygen reduction reaction (ORR) are extremely important but still a significant challenge. Herein, we report a novel catalyst design strategy integrating a bis(terpyridine) (hexadentate chelating ligand) with Fe which acts as nitrogen, a self-supporting carbon source, and a potent metal-ligand active site binding structure (Fe-btpy) and promotes the formation of Fe-Nx/C active sites, bypassing the complications induced during Fe-N-C catalyst synthesis. The resulting Fe-N/C(H,P) electrocatalyst shows a very high ORR onset (Eonset) and half-wave potential (E1/2) of 1.05 and 0.89 V (vs reversible hydrogen electrode), respectively, outperforming the commercial Pt/C catalyst in alkaline medium. Most importantly, the Fe-N/C(H,P) catalyst displays decent stability and remarkable methanol tolerance in comparison to the Pt/C catalyst. A fabricated rechargeable zinc-air battery with an Fe-N/C(H,P) cathode catalyst demonstrated an excellent peak power density of 225 mW cm-2 at a current density of 240 mA cm-2, in comparison to the Pt/C cathode catalyst. This work illuminates blueprints utilizing a new long-chain one-dimensional macromolecule that could be viable to produce Fe-N/C-based carbon electrocatalysts toward energy conversion applications.

A No-Sweat Strategy for Graphene-Macrocycle Co-assembled Electrocatalyst toward Oxygen Reduction and Ambient Ammonia Synthesis.

Toward the realm of sustainable energy, the development of efficient methods to enhance the performance of electrocatalysts with molecular level perception has gained immense attention. Inspite of untiring attempts, the production cost and scaling-up issues have been a step back toward the commercialization of the electrocatalysts. Herein, we report a one-pot electrophoretic exfoliation technique with minimum time and power input to synthesize iron phthalocyanine functionalized high-quality graphene sheets (G-FePc). The π-stacked co-assembly excels in oxygen reduction performance (major criterion for fuel cells) with a high positive E1/2 of 0.91 V (vs RHE) and a reproducible reduction peak potential of 0.90 V (vs RHE). An overpotential as low as 29 mV dec-1 and complete tolerance toward the methanol crossover effect confirm the authentication of the catalytic performance of our designed catalyst G-FePc. The catalyst simultaneously exhibits hydrogen storage efficacy by means of nitrogen fixation, yielding 27.74 µg h-1 mgcat-1 NH3 at a potential of -0.3 V (vs RHE) in an acidic electrolyte. The structure-function relationship of the catalyst is revealed via molecular orbital chemistry for the bonding of the Fe(II) active center with O2 and N2 during catalysis.

Unravelling the Role of Fe-Mn Binary Active Sites Electrocatalyst for Efficient Oxygen Reduction Reaction and Rechargeable Zn-Air Batteries.

Transition-metal atoms and/or heteroatom-doped carbon nanostructures is a crucial alternative to find a nonprecious metal catalyst for electrocatalytic oxygen reduction reaction (ORR). Herein, for the first time, we demonstrated the formation of binary (Fe-Mn) active sites in hierarchically porous nanostructure composed of Fe, Mn, and N-doped fish gill derived carbon (Fe,Mn,N-FGC). The Fe,Mn,N-FGC catalyst shows remarkable ORR performance with onset potential (Eonset) of 1.03 V and half-wave potential (E1/2) of 0.89 V, slightly better than commercial Pt/C (Eonset = 1.01 V, E1/2 = 0.88 V) in alkaline medium (pH > 13), which is attributed to the synergistic effect of Fe-Mn dual metal center as evidenced from X-ray absorption spectroscopic study. We proposed that the presence of Fe-Mn binary sites is actually beneficial for the O2 binding and boosting the ORR by weakening the O═O bonds. The homemade rechargeable Zn-air battery performance reveals the open-circuit voltage of 1.41 V and a large power density of 220 mW cm-2 at 260 mA cm-2 current density outperforming Pt/C (1.40 V, 158 mW cm-2) with almost stable charge-discharge voltage plateaus at high current density. The present strategy enriches a route to synthesize low-cost bioinspired electrocatalyst that is comparable to/better than any nonprecious-metal catalysts as well as commercial Pt/C.

Universal Approach for Electronically Tuned Transition-Metal-Doped Graphitic Carbon Nitride as a Conductive Electrode Material for Highly Efficient Oxygen Reduction Reaction.

The rational design of electronically tuned transition-metal-doped conductive carbon nanostructures has emerged as a potential substitution of a platinum-group-metal (PGM)-free electrocatalyst for oxygen reduction reaction (ORR). We report here a universal strategy using a one-step thermal polymerization reaction for transition-metal-doped graphitic carbon nitride (g-C3N4) without any conductive carbon support as a highly efficient ORR electrocatalyst. X-ray absorption spectroscopy evidences the presence of Fe-Nx active sites with a possible three-coordinated Fe atom with N atoms. The as-prepared Fe-g-C3N4 with improved surface area, graphitic nature, and conductive carbon framework exhibits a superior electrochemical performance toward ORR activity in an alkaline medium. Interestingly, it displays a 0.88 V (vs reversible hydrogen electrode, RHE) half-wave potential (E1/2) with a four-electron-transfer pathway and excellent stability outperforming platinum/carbon (Pt/C) in an alkaline medium. More impressively, when the Fe-g-C3N4 catalyst is used as a cathode material in a zinc-air battery, it presents a higher peak power density (148 mW cm-2) than Pt/C (133 mW cm-2), which further established the importance of the low-cost material synthesis approach toward the development of an earth-abundant PGM-free catalyst for fuel-cell and air battery fabrication.

Laser-irradiated carbonized polyaniline-N-doped graphene heterostructure improves the cyclability of on-chip microsupercapacitor.

Laser-irradiated graphene-based heterostructures have attracted significant attention for the fabrication of highly conducting and stable metal-free energy storage devices. Heteroatom doping on the graphene backbone has proven to have better charge storage properties. Among other heteroatoms, nitrogen-doped graphene (NG) has been extensively researched due to its several advanced properties while maintaining the original characteristics of graphene for energy storage applications. However, NG is generally prepared via chemical vapor deposition or high temperature pyrolysis method, which gives low yield and has a complex operation route. In this work, first a polyaniline-reduce graphene oxide (PANI-rGO) heterostructure was prepared via in situ electrochemical polymerization, followed by the deposition process. In the next step, laser-irradiation process was employed to carbonize polyaniline as well as doping of nitrogen on the graphene film, simultaneously. For the very first time, laser-irradiated carbonization of PANI on NG (cPANI-NG) heterostructure was utilized for microsupercapacitor (MSC). The as-prepared cPANI-NG-MSC shows extremely high cycling stability with a capacitance enhancement of 135% of its initial capacitance after 70 000 continuous charge-discharge cycles. It is very interesting to know the origin of the capacitance enhancement, which results from the change of pyrrolic N in NG-MSC to the pyridinic and graphitic N. An on-chip NG-MSC exhibits an excellent charge storage capacitance of 43.5 mF cm-2 at a current density of 0.5 mA cm-2 and shows impressive power delivery at a very high scan rate of 100 V s-1. The excellent rate capability of the MSC shows capacitance retention up to 70.1% with the variation of current density. This unique approach to fabricate NG-MSC can have a broad range of applications as energy storage devices in the electronics market, as demonstrated by glowing a commercial red LED.

Ultrafine Mix-Phase SnO-SnO2 Nanoparticles Anchored on Reduced Graphene Oxide Boost Reversible Li-Ion Storage Capacity beyond Theoretical Limit.

Tin-based materials with high specific capacity have been studied as high-performance anodes for Li-ion storage devices. Herein, a mix-phase structure of SnO-SnO2@rGO (rGO = reduced graphene oxide) was designed and prepared via a simple chemical method, which leads to the growth of tiny nanoparticles of a mixture of two different tin oxide phases on the crumbled graphene nanosheets. The three-dimensional structure of graphene forms the conductive framework. The as-prepared mix phase SnO-SnO2@rGO exhibits a large Brunauer-Emmett-Teller surface area of 255 m2 g-1 and an excellent ionic diffusion rate. When the resulting mix-phase material was examined for Li-ion battery anode application, the SnO-SnO2@rGO was noted to deliver an ultrahigh reversible capacity of 2604 mA h g-1 at a current density of 0.1 A g-1. It also exhibited superior rate capabilities and more than 82% retention of capacity after 150 charge-discharge cycles at 0.1 A g-1, lasting until 500 cycles at 1 A g-1 with very good retention of the initial capacity. Owing to the uniform defects on the rGO matrix, the formation of LiOH upon lithiation has been suggested to be the primary cause of this very high reversible capacity, which is beyond the theoretical limit. A Li-ion full cell was assembled using LiNi0.5Mn0.3Co0.2O2 (NMC-532) as a high-capacity cathodic counterpart, which showed a very high reversible capacity of 570 mA h g-1 (based on the anode weight) at an applied current density of 0.1 A g-1 with more than 50% retention of capacity after 100 cycles. This work offers a favorable design of electrode material, namely, mix-phase tin oxide-nanocarbon matrix, exhibiting adequate electrochemical performance for Li storage applications.

Development and validation of the nursing confidence in managing sedation complications scale.

AIM: To develop the Nursing Confidence in Managing Sedation Complications Scale. DESIGN: A multi-phased approach was used. METHODS: An initial bank of items was created based on the authors' experience and clinical practice guidelines. An expert panel assessed content validity. Exploratory factor analysis was used for item reduction and regression was used to explore construct validity. Responsiveness was evaluated using a pre-test post-test design. RESULTS: Criteria for content validity was met for 34 items. An 18-item, three-factor solution was identified from exploratory factor analysis performed using Nursing Confidence in Managing Sedation Complications Scale scores from 228 nurses. Subscales accounted for 66% of the variance. Cronbach's alpha for the scale (0.95) and subscales was high (>0.85). There were differences (p < .001) in Nursing Confidence in Managing Sedation Complications Scale scores relative to years of experience and work environment. NC-MSCS scores increased significantly from before to after sedation training (mean difference = 31.8; 95% CI = 24.4-39; N = 31).

Accuracy and precision of continuous non-invasive arterial pressure monitoring in critical care: A systematic review and meta-analysis.

OBJECTIVE: To summarize the evidence regarding the accuracy of continuous non-invasive arterial pressure measurements in adult critical care patients. RESEARCH METHODOLOGY: Medline, EMBASE, and CINAHL were searched for studies that included adult critical care patients reporting the agreement between continuous non-invasive and invasive arterial pressure measurements. The studies were selected and assessed for risk of bias using the Revised Quality Assessment of Diagnostic Accuracy Studies tool by two independent reviewers. The Grading of Recommendations, Assessment, Development and Evaluations approach was used. Pooled estimates of the mean bias and limits of agreement with outer 95% confidence intervals (termed population limits of agreement) were calculated. RESULTS: Population limits of agreement for systolic blood pressure were wide, spanning from -36.13 mmHg to 28.28 mmHg (18 studies; 785 participants). Accuracy of diastolic blood pressure measurements was highly inconsistent across studies, resulting in imprecise estimates for the population limits of agreement. Population limits of agreement for mean arterial pressure spanned from -39.96 mmHg to 44.36 mmHg (17 studies; 765 participants). The evidence was rated as very low-quality due to very serious concerns about heterogeneity and imprecision. CONCLUSION: Substantial differences in blood pressure were identified between measurements taken from continuous non-invasive and invasive monitoring devices. Clinicians should consider this broad range of uncertainty if using these devices to inform clinical decision-making in critical care.

Alteration of Electronic Band Structure via a Metal-Semiconductor Interfacial Effect Enables High Faradaic Efficiency for Electrochemical Nitrogen Fixation.

The interface engineering strategy has been an emerging field in terms of material improvisation that not only alters the electronic band structure of a material but also induces beneficial effects on electrochemical performances. Particularly, it is of immense importance for the environmentally benign electrochemical nitrogen reduction reaction (NRR), which is potentially impeded by the competing hydrogen evolution reaction (HER). The main problem lies in the attainment of the desired current density at a negotiable potential where the NRR would dominate over the HER, which in turn hampers the Faradaic efficiency for the NRR. To circumvent this issue, catalyst development becomes necessary, which would display a weak affinity for H-adsorption suppressing the HER at the catalyst surface. Herein, we have adopted the interfacial engineering strategy to synthesize our electrocatalyst NPG@SnS2, which not only suppressed the HER on the active site but yielded 49.3% F.E. for the NRR. Extensive experimental work and DFT calculations regarded that due to the charge redistribution, the Mott-Schottky effect, and the band bending of SnS2 across the contact layer at the interface of NPG, the d-band center for the surface Sn atoms in NPG@SnS2 lowered, which resulted in favored adsorption of N2 on the Sn active site. This phenomenon was driven even forward by the upshift of the Fermi level, and eventually, a decrease was seen in the work function of the heterostructure that increased the conductivity of the material as compared to pristine SnS2. This strategy thus provides a field to methodically suppress the HER in the realm of improving the Faradaic efficiency for the NRR.

Predicting Prolonged Apnea During Nurse-Administered Procedural Sedation: Machine Learning Study.

BACKGROUND: Capnography is commonly used for nurse-administered procedural sedation. Distinguishing between capnography waveform abnormalities that signal the need for clinical intervention for an event and those that do not indicate the need for intervention is essential for the successful implementation of this technology into practice. It is possible that capnography alarm management may be improved by using machine learning to create a "smart alarm" that can alert clinicians to apneic events that are predicted to be prolonged. OBJECTIVE: To determine the accuracy of machine learning models for predicting at the 15-second time point if apnea will be prolonged (ie, apnea that persists for >30 seconds). METHODS: A secondary analysis of an observational study was conducted. We selected several candidate models to evaluate, including a random forest model, generalized linear model (logistic regression), least absolute shrinkage and selection operator regression, ridge regression, and the XGBoost model. Out-of-sample accuracy of the models was calculated using 10-fold cross-validation. The net benefit decision analytic measure was used to assist with deciding whether using the models in practice would lead to better outcomes on average than using the current default capnography alarm management strategies. The default strategies are the aggressive approach, in which an alarm is triggered after brief periods of apnea (typically 15 seconds) and the conservative approach, in which an alarm is triggered for only prolonged periods of apnea (typically >30 seconds). RESULTS: A total of 384 apneic events longer than 15 seconds were observed in 61 of the 102 patients (59.8%) who participated in the observational study. Nearly half of the apneic events (180/384, 46.9%) were prolonged. The random forest model performed the best in terms of discrimination (area under the receiver operating characteristic curve 0.66) and calibration. The net benefit associated with the random forest model exceeded that associated with the aggressive strategy but was lower than that associated with the conservative strategy. CONCLUSIONS: Decision curve analysis indicated that using a random forest model would lead to a better outcome for capnography alarm management than using an aggressive strategy in which alarms are triggered after 15 seconds of apnea. The model would not be superior to the conservative strategy in which alarms are only triggered after 30 seconds.

Facile one step synthesis of Cu-g-C3N4 electrocatalyst realized oxygen reduction reaction with excellent methanol crossover impact and durability.

Non-precious metal doped carbonaceous materials are currently the most promising alternative towards oxygen reduction reaction (ORR) electrocatalysts in terms of cost, accessibility, efficiency and durability. In this work, a simple one-step pyrolysis process was used for the synthesis of copper doped graphitic carbon nitride (Cu-g-C3N4) as electrocatalyst. The as-synthesized Cu-g-C3N4 material is displaying excellent electrocatalytic response towards ORR in alkaline medium. In comparison to commercial Pt/C catalyst, Cu-g-C3N4 exhibits high methanol tolerance, long term stability, without compromising (4e-) electron transfer pathway process and attaining less than 4% H2O2 formation. The enhanced electrocatalytic behaviour may be ascribed to the formation of active sites strongly coupled into the nitrogen-rich carbon matrix. Such a low-cost, extremely durable and stable electrocatalyst can therefore be regarded as an efficient cathodic material, which can be utilized for several renewable energy conversion technologies such as fuel cell, biofuel cell and metal-air battery.