Optimal Time of Collapse to Return of Spontaneous Circulation to Apply Targeted Temperature Management for Cardiac Arrest: A Bayesian Network Meta-Analysis

Background: Both the American Heart Association (AHA) and European Resuscitation Council (ERC) have strongly recommended targeted temperature management (TTM) for patients who remain in coma after return of spontaneous circulation (ROSC). However, the role of TTM, especially hypothermia, in cardiac arrest patients after TTM2 trials has become much uncertain.Methods: We searched four online databases (PubMed, Embase, CENTRAL, and Web of Science) and conducted a Bayesian network meta-analysis. Based on the time of collapse to ROSC and whether the patient received TTM or not, we divided this analysis into eight groups (<20 min + TTM, <20 min, 20–39 min + TTM, 20–39 min, 40–59 min + TTM, 40–59 min, ≥60 min + TTM and ≥60 min) to compare their 30-day and at-discharge survival and neurologic outcomes.Results: From an initial search of 3,023 articles, a total of 9,005 patients from 42 trials were eligible and were included in this network meta-analysis. Compared with other groups, patients in the <20 min + TTM group were more likely to have better survival and good neurologic outcomes (probability = 46.1 and 52.5%, respectively). In comparing the same time groups with and without TTM, only the survival and neurologic outcome of the 20–39 min + TTM group was significantly better than that of the 20–39 min group [odds ratio = 1.41, 95% confidence interval (1.04–1.91); OR = 1.46, 95% CI (1.07–2.00) respectively]. Applying TTM with <20 min or more than 40 min of collapse to ROSC did not improve survival or neurologic outcome [ <20 min vs. <20 min + TTM: OR = 1.02, 95% CI (0.61–1.71)/OR = 1.03, 95% CI (0.61–1.75); 40–59 min vs. 40–59 min + TTM: OR = 1.50, 95% CI (0.97–2.32)/OR = 1.40, 95% CI (0.81–2.44); ≧60 min vs. ≧60 min + TTM: OR = 2.09, 95% CI (0.70–6.24)/OR = 4.14, 95% CI (0.91–18.74), respectively]. Both survival and good neurologic outcome were closely related to the time from collapse to ROSC.Conclusion: Survival and good neurologic outcome are closely associated with the time of collapse to ROSC. These findings supported that 20–40 min of collapse to ROSC should be a more suitable indication for TTM for cardiac arrest patients. Moreover, the future trials should pay more attention to these patients who suffer from moderate injury.Systematic Review Registration: [https://inplasy.com/?s=202180027], identifier [INPLASY202180027]

Long-Term Assessment of Temperature Management in an Industrial Scale Biogas Plant

Temperature management is one of the primary considerations of biogas plant operation, and influences physical and biochemical processes. An increase in the temperature leads to an increase in the hydrolysis rate of the feedstock, while it can inhibit microorganisms taking part in different stages of anaerobic digestion. Because of the complexity of the biochemical processes within the anaerobic digestion process, there is a lack of knowledge about the effects of temperature and temperature change on efficiency. Moreover, the impact of stirring directly affects the temperature distribution in the anaerobic digestion reactors. In this study, the temperature management in an industrial-scale biogas plant was examined, and the effect of small temperature changes (from the operation temperature 42 °C) on the efficiency was studied in a laboratory under two different conditions: with stirring (at 40 and 44 °C) and without stirring (at 40 and 44 °C). The examination results from the biogas plant showed that heat transfer in the reactor was not sufficient at the bottom of the digester. Adaptation of the post-digester samples to the temperature changes was more challenging than that of the digester samples. From digestate samples, higher biomethane generation could be obtained, resulting from sufficient contact between microorganisms, enzymes, and substrates. Overall, differences between these changing conditions (approx. 6 NmL CH4 g VS−1) were not significant and could be adapted by the process.

Process-adapted temperature application within a two-stage rivet forming process for high nitrogen steel

Mechanical joining technologies like self-piercing riveting are gaining importance with regard to environmental protection, as they enable multi-material design and lightweight construction. A new approach is the use of high nitrogen steel as rivet material, which allows to omit the usually necessary heat treatment and coating and thus leads to a shortening of the process chain. Due to the high strain hardening, however, high tool loads must be expected. Thus, appropriate forming strategies are needed. Within this contribution, the influence of applying different temperatures for each forming stage in a two-stage rivet forming process using the high nitrogen steel 1.3815 is investigated. The findings provide a basic understanding of the influence of the temperature management when forming high nitrogen steel. For this purpose, the rivets are not formed at the same temperature in each stage, but an elevated temperature is applied selectively. Different process routes are investigated. First, cups are manufactured in stage 1 at room temperature, followed by stage 2 at 200°C. Second, cups are formed in stage 1 at 200°C and used for stage 2 at room temperature. By comparing the findings with results when applying the same temperature in both stages, it is shown that the temperature during the first forming operation has an effect on the forming behaviour during the second forming stage. The required forming forces and the resulting rivet hardness can be influenced by process-adapted temperature application. Furthermore, the causes for the temperature impact on the residual cup thickness in stage 1 are evaluated by a cause and effect analysis, which provides a deeper process understanding. The thermal expansion of the tool and the billet as well as the improved forming behaviour at 200°C are identified as the main influencing causes on the achieved residual cup thickness.

Withdrawal of Life-Sustaining Therapy in Intensive Care Unit Patients Following Out-Of-Hospital Cardiac Arrest: An Australian Metropolitan ICU Experience

Objective: To determine factors associated with withdrawal of life-sustaining therapy (WLST) in intensive care unit (ICU) patients following out-of-hospital cardiac arrest (OHCA).Methods: A retrospective review of ICU data from patient clinical records following OHCA was conducted from January 2010 to December 2015. Demographic features, cardiac arrest characteristics, clinical attributes and targeted temperature management were compared between patients with and without WLST. We dichotomised WLST into early (ICU length of stay <72 hours) and late (ICU length of stay ≥72 hours). Factors independently associated with WLST were determined by multivariable binary logistic regression using a backward elimination method, and results were depicted as odds ratios (OR) with 95% confidence intervals (CI).Results: The study selection criteria resulted in a cohort of 260 ICU patients post-OHCA, with a mean age of 58 years and the majority were males (178, 68%); 151 patients (58%) died, of which 145 (96%) underwent WLST, with the majority undergoing early WLST (89, 61%). Status myoclonus was the strongest independent factor associated with early WLST (OR 38.90, 95% CI 4.55–332.57; p < 0.001). Glasgow Coma Scale (GCS) motor response of <4 on day 3 post-OHCA was the strongest factor associated with delayed WLST (OR 91.59, 95% CI 11.66–719.18; p < 0.0001).Conclusion: The majority of deaths in ICU patients post-OHCA occurred following early WLST. Status myoclonus and a GCS motor response of <4 on day 3 post-OHCA are independently associated with WLST.

Review of novel therapeutics in cardiac arrest (ReNTICA): systematic review protocol

IntroductionCardiac arrest remains a common and devastating cause of death and disability worldwide. While targeted temperature management has become standard of care to improve functional neurologic outcome, few pharmacologic interventions have shown similar promise.Methods/analysisThis systematic review will focus on prospective human studies from 2015 to 2020 available in PubMed, Web of Science and EMBASE with a primary focus on impact on functional neurologic outcome. Prospective studies that include pharmacologic agents given during or after cardiac arrest will be included. Study selection will be in keeping with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. If sufficient data involving a given agent are available, a meta-analysis will be conducted and compared with current evidence for therapies recommended in international practice guidelines.Ethics and disseminationFormal ethical approval will not be required as primary data will not be collected. The results will be disseminated through peer-reviewed publication, conference presentation and lay press.PROSPERO registration numberInternational Prospective Register for Systematic Reviews (CRD42021230216).