The strain distribution and microstructure at the crack nucleation sites in martensitic steel with fine- and coarse-prior austenite grains subjected to tensile deformation were characterized using ...the digital image correlation method on replica films. Although the tensile properties of the fine- and coarse-prior austenite grain specimens were approximately identical, the total strain was certainly improved in the coarse-prior austenite grain specimen. The crack size increased with the coarsening prior austenite grains, whereas the number of cracks decreased. An inhomogeneous strain was introduced in both the specimens by tensile deformation. The accumulated strain when crack nucleates was approximately the same in both specimens, independent of the prior austenite grain size. In low-strain regions, there were no cracks even though the accumulated strain was comparable to that when crack nucleates in high-strain regions. The strain at the crack nucleation sites was high even before crack nucleation occurred. Cracks primarily nucleated on packet and prior austenite grain boundaries, even in the coarse-prior austenite grain specimen, which confirmed that the prior austenite grain boundary should be a preferential crack nucleation site. It can be concluded that the high local strain and the presence of packet or prior austenite grain boundaries are responsible for crack nucleation in martensitic steel subjected to tensile deformation.
The purpose of this study was to examine whether the temperature difference between the jugular bulb and pulmonary artery (ΔTjb-pa) is associated with the neurological outcome of patients with severe ...traumatic brain injury (TBI).
We conducted a post hoc analysis of a multicenter randomized controlled trial of mild therapeutic hypothermia (TH, 32.0-34.0°C) or fever control (FC, 35.5-37.0°C) for the patients with severe TBI. ΔTjb-pa averaged every 12 h and the variation in ΔTjb-pa were compared between patients with favorable (n = 39) and unfavorable (n = 37) neurological outcomes. These values were also compared in the TH and FC subgroups.
The average ΔTjb-pa values in patients with favorable and unfavorable outcomes were 0.24 ± 0.23 and 0.06 ± 0.36°C, respectively (P < 0.001). ΔTjb-pa trended significantly higher in the favorable outcome patients than in the unfavorable outcome patients throughout the 120 h after onset of severe TBI (P < 0.001). The variation in ΔTjb-pa from 0 to 72 h was significantly lower in the favorable outcome patients than in the unfavorable outcome patients (0.8 ± 0.8 vs 1.8 ± 2.5°C, respectively, P = 0.013). From 72 to 120 h, there was no significant difference in the variation in ΔTjb-pa. Significant differences between patients with favorable and unfavorable outcomes in ΔTjb-pa and the variation in ΔTjb-pa were similar in the TH subgroup, but not evident in the FC subgroup.
A reduction in ΔTjb-pa and greater variation in ΔTjb-pa were associated with an unfavorable outcome in patients with severe TBI, especially those treated with TH. When treating severe TBI patients, it is important to understand that there will be differences in temperature reflecting the brain environment and the systemic temperature, depending on the severity and outcome of TBI during TH.
Objectives Coronavirus disease 2019 (COVID-19) reportedly causes thromboembolic complications due to coagulopathy with hypercoagulability and a hypofibrinolytic state. We evaluated the time-course of ...coagulopathy in patients with severe COVID-19 from admission to discharge from our intensive-care unit (ICU). Methods We conducted a retrospective study of adults with severe COVID-19 admitted to our ICU between January 20, 2021, and March 31, 2022. We obtained clinical information, laboratory data, and rotational thromboelastometry (ROTEM) parameters at admission and discharge. Results Fifteen patients were included. Fibrinogen and D-dimer values did not change significantly but were above the normal ranges at admission and discharge. Regarding ROTEM parameters, the maximum clot firmness in fibrinogen function (FIBTEM), a marker of hypercoagulability, did not change significantly but was above the normal range at admission and discharge median (interquartile range), admission vs. discharge: 31 (25-34) mm vs. 31 (27-32) mm, p=0.589. The maximum lysis at 60 minutes in the extrinsic coagulation pathway (EXTEM) and intrinsic coagulation pathway (INTEM), as markers of the fibrinolytic function, were both significantly lower at discharge than at admission median (interquartile range), admission vs. discharge: EXTEM, 3 (2-4) vs. 1 (0-2), p=0.011; INTEM, 3 (1-6) vs. 1 (0-2), p=0.008. Conclusion This study revealed a persistent hypercoagulable state at ICU discharge and a worse hypofibrinolytic state at discharge than at admission. These results may contribute to a better understanding of coagulopathies in the acute to subacute phases of severe COVID-19.
In this study, we aimed to develop and validate a machine learning-based mortality prediction model for hospitalized heat-related illness patients. After 2393 hospitalized patients were extracted ...from a multicentered heat-related illness registry in Japan, subjects were divided into the training set for development (n = 1516, data from 2014, 2017-2019) and the test set (n = 877, data from 2020) for validation. Twenty-four variables including characteristics of patients, vital signs, and laboratory test data at hospital arrival were trained as predictor features for machine learning. The outcome was death during hospital stay. In validation, the developed machine learning models (logistic regression, support vector machine, random forest, XGBoost) demonstrated favorable performance for outcome prediction with significantly increased values of the area under the precision-recall curve (AUPR) of 0.415 95% confidence interval (CI) 0.336-0.494, 0.395 CI 0.318-0.472, 0.426 CI 0.346-0.506, and 0.528 CI 0.442-0.614, respectively, compared to that of the conventional acute physiology and chronic health evaluation (APACHE)-II score of 0.287 CI 0.222-0.351 as a reference standard. The area under the receiver operating characteristic curve (AUROC) values were also high over 0.92 in all models, although there were no statistical differences compared to APACHE-II. This is the first demonstration of the potential of machine learning-based mortality prediction models for heat-related illnesses.
Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease. A 91-year-old woman was admitted to our intensive-care unit with SFTS, and she developed dyspnea with wheezes 5 ...days after admission. Bronchoscopy showed scattered white mold in her central airway. An airway tissue biopsy and culture of bronchial lavage fluid revealed fungal hyphae in the necrotic tissue, confirmed as Aspergillus fumigatus. She was thus diagnosed with pseudomembranous aspergillus tracheobronchitis. She had no common risk factors for invasive aspergillosis (IA). Patients with SFTS, even those without apparent risk factors for IA, may be at risk of developing IA.
Guanfacine hydrochloride extended-release (GXR) is used to treat attention deficit hyperactivity disorder. It is a selective α2A-adrenorecepor agonist that was reported to cause QT prolongation and ...hypotension in the event of overdosing. We report the case of a 17-year-old man who took 226 tablets of GXR 3 mg for attempted suicide. He was found complaining of dyspnea, and emergency medical services were called. When the patient was transferred to our hospital, his Glasgow coma scale was 12 (E4V3M5). He was agitated and hypoxemic. He was intubated for invasive mechanical ventilation under sedation. His chest X-ray and computed tomography scan showed pulmonary edema. Transthoracic echocardiography showed markedly reduced cardiac function. His serum guanfacine concentration peaked on day 3 after admission. His pulmonary edema improved quickly after a decrease in serum guanfacine concentration, but cardiac decompensation persisted for about 1 month. This case reveals that the decline in cardiac function after guanfacine intoxication is prolonged even after its serum concentration has decreased.
Guideline‐based management approaches for pain, agitation, and delirium (PAD) in critically ill adult patients are widely believed to result in good outcomes. However, there are some differences in ...the recommendations and evidence levels among the management guidelines established for PAD. To identify and compare the current management guidelines, we used the PubMed database. The PAD guidelines and Federación Panamericana e Ibérica de Sociedades de Medicina Crítica y Terapia Intensiva (FEPIMCTI) guidelines were identified from our search. We compared the main aspects of these two guidelines as well as the Japanese guidelines for the management of PAD (J‐PAD guidelines). The PAD, FEPIMCTI, and J‐PAD guidelines contained a total of 4, 12, and 5 sections, having 32, 138, and 37 recommendations, respectively, pertaining to routine monitoring of pain in adult patients in the intensive care unit. Intravenous opioids were recommended as the first‐line drug of choice for treating pain. Sedative titrated to maintain a light, rather than deep, level of sedation can be given unless clinically contraindicated. Although neither the PAD nor J‐PAD guidelines recommend use of a pharmacologic delirium prevention protocol or treatment with any pharmacological agent to reduce the duration of delirium, the FEPIMCTI guidelines provide such recommendations. The FEPIMCTI guidelines provide suggestions on which analgesics to use for several different cases and present algorithms for sedation and analgesia. The outlines of the three guidelines are similar, and all reinforce the management of PAD to improve patient outcomes.
The outlines of the three guidelines are similar, and all reinforce the management of PAD to improve patient outcomes.
In the experimental setting several investigators have recently reported exacerbations of the burden of axonal damage and other neuropathological changes following repetitive traumatic brain injuries ...(TBI) that were sustained at intervals from hours to days following the initial insult. These same studies also revealed that prolonging the interval between the first and second insult led to a reduction in the burden of neuropathological changes and/or their complete elimination. Although demonstrating the capability of repetitive TBI to evoke increased axonal and other neuropathological changes, these studies did not address the potential for concomitant microvascular dysfunction or damage, although vascular dysfunction has been implicated in the second-impact syndrome. In this study we revisit the issue of repetitive injury in a well-controlled animal model in which the TBI intensity was bracketed from subthreshold to threshold insults, while the duration of the intervals between the injuries varied. Employing cranial windows to assess vascular reactivity and post-mortem amyloid precursor protein (APP) analysis to determine the burden of axonal change, we recognized that subthreshold injuries, even when administered in repeated fashion over a short time frame, evoked neither axonal nor vascular change. However, with an elevation of insult intensity, repetitive injuries administered within 3-h time frames caused dramatic axonal damage and significant vascular dysfunction bordering on a complete loss of vasoreactivity. If, however, the interval between the repetitive injury was extended to 5 h, the burden of axonal change was reduced, as was the overall magnitude of the ensuing vascular dysfunction. With the extension of the interval between injuries to 10 h, neither axonal nor vascular changes were found. Collectively, these studies reaffirm the existence of significant axonal damage following repetitive TBI administered within a relatively short time frame. Additionally, they also demonstrate that these axonal changes parallel changes in the cerebral microcirculation, which also may have adverse consequences for the injured brain.
The purpose of this study was to clarify the practical clinical treatment for acute carbon monoxide (CO) poisoning in Japan and to investigate the efficacy of hyperbaric oxygen (HBO.sub.2) therapy in ...preventing delayed neurological sequelae (DNS) in the acute phase of CO poisoning. We conducted a multicenter, prospective, observational study of acute CO poisoning in Japan. Patients with acute CO poisoning were enrolled and their treatment details were recorded. The primary endpoint was the onset of DNS within 2 months of CO exposure. Factors associated with DNS were assessed with logistic regression analysis. A total of 311 patients from 57 institutions were registered and 255 were analyzed: 171 received HBO.sub.2 therapy (HBO.sub.2 group) and 84 did not (normobaric oxygen NBO.sub.2 group). HBO.sub.2 therapy was performed zero, once, twice, or three times within the first 24 h in 1.8%, 55.9%, 30.9%, and 11.3% of the HBO.sub.2 group, respectively. The treatment pressure in the first HBO.sub.2 session was 2.8 ATA (47.9% of the HBO.sub.2 group), 2.0 ATA (41.8%), 2.5 ATA (7.9%), or another pressure (2.4%). The incidence of DNS was 13/171 (7.6%) in the HBO.sub.2 group and 3/84 (3.6%) in the NBO.sub.2 group (P = 0.212). The number of HBO.sub.2 sessions in the first 24 h was one of the factors associated with the incidence of DNS (odds ratio, 2.082; 95% confidence interval, 1.101-3.937; P = 0.024). The practical clinical treatment for acute CO poisoning, including HBO.sub.2 therapy, varied among the institutions participating in Japan. HBO.sub.2 therapy with inconsistent protocols showed no advantage over NBO.sub.2 therapy in preventing DNS. Multiple HBO.sub.2 sessions was associated with the incidence of DNS.
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