Development of a Decision Aid for Family Surrogate Decision Makers of Critically Ill Patients Requiring Renal Replacement Therapy in ICU: User-Centered Design for Rapid Prototyping.

Objectives Renal replacement therapy (RRT) is increasingly adopted for critically ill patients diagnosed with acute kidney injury, but the optimal time for initiation remains unclear and prognosis is uncertain, leading to medical complexity, ethical conflicts, and decision dilemmas in intensive care unit (ICU) settings. This study aimed to develop a decision aid (DA) for family surrogate of critically ill patients to support their engagement in shared decision-making process with clinicians. Methods Development of DA employed a systematic process with user-centered design (UCD) principle, which included: (i) competitive analysis: searched, screened, and assessed the existing DAs to gather insights for design strategies, developmental techniques, and functionalities; (ii) user needs assessment: interviewed family surrogates to explore target user group's decision-making experience and identify their unmet needs; (iii) evidence syntheses: integrate latest clinical evidence and pertinent information to inform the content development of DA.Results The competitive analysis included 16 relevant DAs, from which we derived valuable insights from existing resources. User decision needs were explored among a cohort of 15 family surrogates, revealing four thematic issues in decision-making, including stuck into dilemmas, sense of uncertainty, limited capacity, and delayed decision confirmation. A total of 27 articles were included for evidence syntheses. Relevant decision-making knowledge on disease and treatment, as delineated in the literature sourced from decision support system or clinical guidelines, were formatted as the foundational knowledge base. Twenty-one items of evidence were extracted and integrated into the content panels of benefits and risks of RRT, possible outcomes, and reasons to choose. The DA was drafted into a web-based phototype using the elements of UCD. This platform could guide users make preparation of decision-making through a sequential four-step progress: identifying treatment options, weighing the benefits and risks, clarifying personal preferences and values, and formulating a schedule for formal shared decision-making with clinicians.Conclusions We developed a rapid prototype of DA tailored for family surrogate decision makers of critically ill patients in need of RRT in ICU setting. Future studies are needed to evaluate its usability, feasibility, and clinical effects of this intervene.

Real-time amplitude spectrum area estimation during chest compression from the ECG waveform using a 1D convolutional neural network.

Introduction: Amplitude spectrum area (AMSA) is a well-established measure than can predict defibrillation outcome and guiding individualized resuscitation of ventricular fibrillation (VF) patients. However, accurate AMSA can only be calculated during cardiopulmonary resuscitation (CPR) pause due to artifacts produced by chest compression (CC). In this study, we developed a real-time AMSA estimation algorithm using a convolutional neural network (CNN). Methods: Data were collected from 698 patients, and the AMSA calculated from the uncorrupted signals served as the true value for both uncorrupted and the adjacent corrupted signals. An architecture consisting of a 6-layer 1D CNN and 3 fully connected layers was developed for AMSA estimation. A 5-fold cross-validation procedure was used to train, validate and optimize the algorithm. An independent testing set comprised of simulated data, real-life CC corrupted data, and preshock data was used to evaluate the performance. Results: The mean absolute error, root mean square error, percentage root mean square difference and correlation coefficient were 2.182/1.951 mVHz, 2.957/2.574 mVHz, 22.887/28.649% and 0.804/0.888 for simulated and real-life testing data, respectively. The area under the receiver operating characteristic curve regarding predicting defibrillation success was 0.835, which was comparable to that of 0.849 using the true value of the AMSA. Conclusions: AMSA can be accurately estimated during uninterrupted CPR using the proposed method.

Influence of oxygen concentration on the neuroprotective effect of hydrogen inhalation in a rat model of cardiac arrest.

Background: Post-cardiac arrest (CA) brain injury is the main cause of death in patients resuscitated from CA. Previous studies demonstrated that hydrogen inhalation mitigates post-CA brain injury. However, factors affecting the efficacy of hydrogen remain unknown. In the present study, we investigated the influence of oxygen concentration and targeted temperature on neuroprotective effect in a CA rat model of ventricular fibrillation (VF). Methods: Cardiopulmonary resuscitation (CPR) was initiated after 7 min of untreated VF in adult male Sprague-Dawley rats. Immediately following successful resuscitation, animals were randomized to be ventilated with 21% oxygen and 79% nitrogen (21%O2); 2% hydrogen, 21% oxygen, and 77% nitrogen (2%H2 + 21%O2); 2% hydrogen, 50% oxygen, and 48% nitrogen (2%H2 + 50%O2); or 2% hydrogen and 98% oxygen (2%H2 + 98%O2) for 3 h. For each group, the target temperature was 37.5°C for half of the animals and 35.0°C for the other half. Results: No statistical differences in baseline measurements and CPR characteristics were observed among groups. For animals with normothermia, 2%H2 + 50%O2 (123 [369] vs. 500 [393], p = 0.041) and 2%H2 + 98%O2 (73 [66] vs. 500 [393], p = 0.002) groups had significantly lower neurological deficit scores (NDSs) at 96 h and significantly higher survival (75.0 vs. 37.5%, p = 0.033 and 81.3 vs. 37.5%, p = 0.012) than 21%O2 group. For animals with hypothermia, no statistical difference in NDS among groups but 2%H2 + 98%O2 has significantly higher survival than the 21%O2 group (93.8 vs. 56.3%, p = 0.014). Conclusion: In this CA rat model, inhaling 2% hydrogen combined with a high concentration of oxygen improved 96-h survival, either under normothermia or under hypothermia.

Interaction between gender and post resuscitation interventions on neurological outcome in an asphyxial rat model of cardiac arrest.

PURPOSE: Previous clinical studies have suggested an effect of gender on outcome after out-of-hospital cardiac arrest, but the results are conflicting and there is no uniform agreement regarding gender differences in survival and prognosis. The present study was aimed to investigate the interaction between gender and post resuscitation interventions on neurological outcome in an asphyxial rat model of cardiac arrest. METHODS: Asphyxia was induced by blocking the endotracheal tube in 120 adult Sprague-Dawley rats (60 males and 60 females) at the same age. Cardiopulmonary resuscitation (CPR) was started after 5 min of untreated cardiac arrest. Animals were randomized into one of the three post resuscitation care intervention groups (n = 40, 20 males) immediately after resuscitation: (1) normothermic control (NC): ventilated with 2% N2/98% O2 for 1 h under normothermia; (2) targeted temperature management (TTM): ventilated with 2% N2/98% O2 for 1 h under hypothermia; (3) hydrogen inhalation (HI): ventilated with 2% H2/98% O2 for 1 h under normothermia. Physiological variables were recorded during the 5 h post resuscitation monitoring period. Neurological deficit score (NDS) and accumulative survival were used to assess 96 h outcomes. Mutual independence analysis and Mantel-Haenszel stratified analysis were used to explore the associations among gender, intervention and survival. RESULTS: The body weights of female rats were significantly lighter than males, but CPR characteristics did not differ between genders. Compared with male rats, females had significantly lower mean arterial pressure, longer onset time of the electroencephalogram (EEG) burst and time to normal EEG trace (TTNT) in the NC group; relatively longer TTNT in the TTM group; and substantially longer TTNT, lower NDSs, and higher survival in the HI group. Mutual independence analysis revealed that both gender and intervention were associated with neurological outcome. Mantel-Haenszel stratified analysis demonstrated that female rats had significantly higher survival rate than males when adjusted for the confounder intervention. CONCLUSION: In this rat model cardiac arrest and CPR, gender did not affect resuscitation but associated with neurological outcome. The superiority of female rats in neurological recovery was affected by post resuscitation interventions and female rats were more likely to benefit from hydrogen therapy.

A signal quality assessment-based ECG waveform delineation method used for wearable monitoring systems.

Identifying transient and nonpersistent abnormal electrocardiogram (ECG) waveforms by continuously monitoring the high-risk populations is of great importance for the diagnosis, treatment, and prevention of cardiovascular diseases. In recent years, fabric electrodes have been widely used in wearable devices because of their non-irritating properties and better comfort than traditional AgCl electrodes. However, the motion noise caused by the relative movement between the fabric electrodes and skin affects the quality of ECGs and reduces the accuracy of diagnosis. Therefore, delineating the ECG waveforms that are recorded from wearable devices with varying levels of noise is still challenging. In this study, a signal quality assessment (SQA)-based ECG waveform delineation method that is used for wearable systems was developed. The ECG signal was first preprocessed by a bandpass filter. Five indices, including the multiscale nonlinear amplitude statistical distribution (adSQI1, adSQI2), the proportion of energy-related to T wave (ptSQI), and heart rates computed from R waves and T waves (rHR and tHR, respectively), were then calculated from the preprocessed ECG signal. The signals were classified as good, acceptable, and unacceptable ECGs by combining these indices through the use of a neural network. Subsequently, the R waves or/and T waves were identified for the corresponding feature interpretations based on the SQA results. ECGs that were recorded from the chest belts from 29 volunteers at different activity statuses were divided into 4-s segments. A total of 7133 manually labeled segments were used to derive (4985 segments) and validate (2148 segments) the algorithm. The adSQI1, adSQI2, tHR, and rHR characteristics were significantly different among the good, acceptable, and unacceptable ECGs. The ptSQI value was considerably higher in the good ECGs than in the acceptable and unacceptable ECGs. The ECG segments of different quality levels were classified with an accuracy of 96.74% by using the proposed SQA method. The R waves and T waves were identified with accuracies of 99.95% and 99.57%, respectively, for segments that were classified as acceptable and/or good. The SQA-based ECG waveform delineation method can perform reliable analysis and has the potential to be applied in wearable ECG systems for the early diagnosis and prevention of cardiovascular diseases.

A cohort autopsy study defines COVID-19 systemic pathogenesis.

Severe COVID-19 disease caused by SARS-CoV-2 is frequently accompanied by dysfunction of the lungs and extrapulmonary organs. However, the organotropism of SARS-CoV-2 and the port of virus entry for systemic dissemination remain largely unknown. We profiled 26 COVID-19 autopsy cases from four cohorts in Wuhan, China, and determined the systemic distribution of SARS-CoV-2. SARS-CoV-2 was detected in the lungs and multiple extrapulmonary organs of critically ill COVID-19 patients up to 67 days after symptom onset. Based on organotropism and pathological features of the patients, COVID-19 was divided into viral intrapulmonary and systemic subtypes. In patients with systemic viral distribution, SARS-CoV-2 was detected in monocytes, macrophages, and vascular endothelia at blood-air barrier, blood-testis barrier, and filtration barrier. Critically ill patients with long disease duration showed decreased pulmonary cell proliferation, reduced viral RNA, and marked fibrosis in the lungs. Permanent SARS-CoV-2 presence and tissue injuries in the lungs and extrapulmonary organs suggest direct viral invasion as a mechanism of pathogenicity in critically ill patients. SARS-CoV-2 may hijack monocytes, macrophages, and vascular endothelia at physiological barriers as the ports of entry for systemic dissemination. Our study thus delineates systemic pathological features of SARS-CoV-2 infection, which sheds light on the development of novel COVID-19 treatment.

Repetitive anodal transcranial direct current stimulation improves neurological recovery by preserving the neuroplasticity in an asphyxial rat model of cardiac arrest.

BACKGROUND: Non-shockable rhythms present an increasing proportion of out-of-hospital cardiac arrest (CA) patients, but are associated with poor prognosis and received limited therapeutic effect of targeted temperature management (TTM). Previous study showed repetitive anodal transcranial direct current stimulation (tDCS) improved neurological outcomes in animals with ventricular fibrillation. Here, we examine the effectiveness of tDCS on neurological recovery and the potential mechanisms in a rat model of asphyxial CA. METHOD: Cardiopulmonary resuscitation was initiated after 5 min of untreated asphyxial CA. Animals were randomized to three experimental groups immediately after successful resuscitation (n = 12/group, 6 males): no-treatment control (NTC) group, TTM group, and tDCS group. Post resuscitation hemodynamics, quantitative electroencephalogram (EEG), neurological deficit score, and 96-h survival were evaluated. Brain tissues of additional animals undergoing same experimental procedure was harvested for enzyme-linked immunoassay-based quantification assays of neuroplasticity-related biomarkers and compared with the sham-operated rats (n = 6/group). RESULTS: We observed that after resuscitation tDCS-treated animals exhibited significantly higher mean arterial pressure and left ventricular ejection fraction than NTC group and showed greatly improved EEG characteristics including weighted-permutation entropy and gamma band power, and neurologic deficit scores and 96-h survival rates compared to NTC and TTM groups. Furthermore, neuroplastic biomarkers including microtubule-associated protein 2, growth-associated protein 43, postsynaptic density protein 95 and synaptophysin, were significantly higher in tDCS group when compared with NTC and TTM groups. CONCLUSION: In this rat model of asphyxial CA, repetitive anodal tDCS commenced after resuscitation improved neurological recovery, and it may exert a neuroprotective effect by preserving the neuroplasticity.

Development and evaluation of a decision aid for family surrogate decision-makers for patients with acute kidney injury requiring renal replacement therapy (RRT) in ICUs: a study protocol.

INTRODUCTION: Shared decision making is endorsed by guidelines for both acute kidney injury and critical care medicine. However, there is still a huge need for effective interventions, especially those focusing on decisions about renal replacement therapy for intensive care unit (ICU) patients with acute kidney injury. The decision aids provide evidence-based support for shared decision making, to achieve better decisions through enhanced knowledge of treatment options and treatment aligns with patients' preferences and values. Therefore, our objectives are to develop and evaluate a decision aid systematically and rigorously for family surrogate decision makers of ICU patients with acute kidney injury who need renal replacement therapy. METHODS AND ANALYSIS: We will use a systematic development process that focuses on user-centred design to develop and evaluate the decision aid in three phases: (1) development of a draft prototype for the decision aid based on extensive literature reviews, interviews with key stakeholders and evidence synthesis; (2) alpha testing ('near live' usability) the decision aid during simulated clinical encounters to test its comprehensibility, acceptability and usability and (3) beta testing ('live' usability) to examine the aid's clinical feasibility. User testing will be conducted using mixed-methods approach to support iterative revision of the decision aid. The IPDASi (V.4.0) will be used for following qualitative assessment. All interviews will be analysed by Colaizzi's seven-step approach to qualitative analysis. The coding scheme will use to analyse user interactions. Questionnaire surveys will be analysed using paired sample t-tests when related to the before-and-after survey, otherwise using one-sample t-test. ETHICS AND DISSEMINATION: Ethical approval for this research was obtained from the Ethics Committee of the First Affiliated Hospital of Army Medical University, PLA (Ref: KY2020104). All participants will sign a formal informed consent form. The findings will be published in peer-reviewed journals and reported in appropriate meetings. TRIAL REGISTRATION NUMBER: ChiCTR2000031613.

A framework of current based defibrillation improves defibrillation efficacy of biphasic truncated exponential waveform in rabbits.

Defibrillation is accomplished by the passage of sufficient current through the heart to terminate ventricular fibrillation (VF). Although current-based defibrillation has been shown to be superior to energy-based defibrillation with monophasic waveforms, defibrillators with biphasic waveforms still use energy as a therapeutic dosage. In the present study, we propose a novel framework of current-based, biphasic defibrillation grounded in transthoracic impedance (TTI) measurements: adjusting the charging voltage to deliver the desired current based on the energy setting and measured pre-shock TTI; and adjusting the pulse duration to deliver the desired energy based on the output current and intra-shock TTI. The defibrillation efficacy of current-based defibrillation was compared with that of energy-based defibrillation in a simulated high impedance rabbit model of VF. Cardiac arrest was induced by pacing the right ventricle for 60 s in 24 New Zealand rabbits (10 males). A defibrillatory shock was applied with one of the two defibrillators after 90 s of VF. The defibrillation thresholds (DFTs) at different pathway impedances were determined utilizing a 5-step up-and-down protocol. The procedure was repeated after an interval of 5 min. A total of 30 fibrillation events and defibrillation attempts were investigated for each animal. The pulse duration was significantly shorter, and the waveform tilt was much lower for the current-based defibrillator. Compared with energy-based defibrillation, the energy, peak voltage, and peak current DFT were markedly lower when the pathway impedance was > 120 Ω, but there were no differences in DFT values when the pathway impedance was between 80 and 120 Ω for current-based defibrillation. Additionally, peak voltage and the peak current DFT were significantly lower for current-based defibrillation when the pathway impedance was < 80 Ω. In sum, a framework of adjusting the charging voltage and shock duration to deliver constant energy for low impedance and constant current for high impedance via pre-shock and intra-shock impedance measurements, greatly improved the defibrillation efficacy of high impedance by lowering the energy DFT.

[Construction of CAR-T cells targeting CS1 and analysis of their antitumor activity in vitro].

We constructed the CS1-targeted second- and third-generation CAR-T cells with genetic engineered 4-1BB or/and ICOS as a costimulatory signaling molecule by use of lentiviral platform. The CS1-targeted second-generation CAR-T cells with ICOS or 4-1BB had similar anti-neoplastic activity. When effector/target ratio was 1:1, the CAR-T cells with ICOS showed better killing effect on IM9-lucgfp cells than those with 4-1BB. However, The CS1-targeted third-generation CAR-T cells exihibited lower cytolytic capacity against IM9-lucgfp cells than the CS1-targeted second-generation CAR-T cells when the ratio of effector/target was 1:1, 2:1 or 5:1. When the ratio of effector/target was 10:1, the killing efficacy of both the second- and third-generation CAR-T cells against IM9-lucgfp cells was more than 85%, significantly higher than that of the control T cells. Taken together, both the CS1-targeted second- and third-generation CAR-T cells with ICOS or/and 4-1BB could efficiently kill CS1-positive multiple myeloma cells, but the CS1-targeted second-generation CAR-T cells had more potent killing effect on CS1-positive multiple myeloma cells than the CS1-targeted third-generation CAR-T cells.

High incidence of stroke in COVID-19 patients.

A retrospective analysis of 11 COVID-19 patients complicated with stroke was performed. It was found that the incidence of stroke in patients with COVID-19 was significantly higher than the average level of the general population (P=0.003), and the D-dimer levels of 11 stroke patients were significantly higher than other patients (P=0.004). The significant increase of D-dimer can be used as an early warning indicator of cerebral infarction. It is critical to have a response plan for treating acute stroke in COVID-19 patients.

Chinese Trauma Surgeon Association for management guidelines of vacuum sealing drainage application in abdominal surgeries-Update and systematic review.

Vacuum sealing drainage (VSD) is frequently used in abdominal surgeries. However, relevant guidelines are rare. Chinese Trauma Surgeon Association organized a committee composed of 28 experts across China in July 2017, aiming to provide an evidence-based recommendation for the application of VSD in abdominal surgeries. Eleven questions regarding the use of VSD in abdominal surgeries were addressed: (1) which type of materials should be respectively chosen for the intraperitoneal cavity, retroperitoneal cavity and superficial incisions? (2) Can VSD be preventively used for a high-risk abdominal incision with primary suture? (3) Can VSD be used in severely contaminated/infected abdominal surgical sites? (4) Can VSD be used for temporary abdominal cavity closure under some special conditions such as severe abdominal trauma, infection, liver transplantation and intra-abdominal volume increment in abdominal compartment syndrome? (5) Can VSD be used in abdominal organ inflammation, injury, or postoperative drainage? (6) Can VSD be used in the treatment of intestinal fistula and pancreatic fistula? (7) Can VSD be used in the treatment of intra-abdominal and extra-peritoneal abscess? (8) Can VSD be used in the treatment of abdominal wall wounds, wound cavity, and defects? (9) Does VSD increase the risk of bleeding? (10) Does VSD increase the risk of intestinal wall injury? (11) Does VSD increase the risk of peritoneal adhesion? Focusing on these questions, evidence-based recommendations were given accordingly. VSD was strongly recommended regarding the questions 2-4. Weak recommendations were made regarding questions 1 and 5-11. Proper use of VSD in abdominal surgeries can lower the risk of infection in abdominal incisions with primary suture, treat severely contaminated/infected surgical sites and facilitate temporary abdominal cavity closure.

Repetitive anodal transcranial direct current stimulation improves neurological outcome and survival in a ventricular fibrillation cardiac arrest rat model.

BACKGROUND: Transcranial direct current stimulation (tDCS) modulates neuronal activity and is a potential therapeutic tool for many neurological diseases. However, its beneficial effects on post cardiac arrest syndrome remains uncertain. OBJECTIVE/HYPOTHESIS: We investigated the effects of repetitive anodal tDCS on neurological outcome and survival in a ventricular fibrillation (VF) cardiac arrest rat model. METHODS: Cardiopulmonary resuscitation was initiated after 6 min of VF in 36 Sprague-Dawley rats. The animals were randomized into three groups immediately after resuscitation (n = 12 each): no-treatment control (NTC) group, targeted temperature management (TTM) group, and tDCS group. For tDCS, 1 mA anodal tDCS was applied on the dorsal scalp for 0.5 h. The stimulation was repeated for four sessions with 1-h resting interval under normothermia. Post-resuscitation hemodynamic, cerebral, and myocardial injuries, 96-h neurological outcome, and survival were evaluated. RESULTS: Compared with the NTC group, post-resuscitation serum astroglial protein S100 beta and cardiac troponin T levels and 96-h neuronal and myocardial damage scores were markedly reduced in the tDCS and TTM groups. Myocardial ejection fraction, neurological deficit score, and 96-h survival rate were also significantly better for the tDCS and TTM groups. The period of post-resuscitation arrhythmia with hemodynamic instability was considerably shorter in the tDCS group, but no differences were observed in neurological outcome and survival between the tDCS and TTM groups. CONCLUSIONS: In this cardiac arrest rat model, repeated anodal tDCS commenced after resuscitation improves 96-h neurological outcome and survival to an extent comparable to TTM by attenuating post-resuscitation cerebral and cardiac injuries.

Metabolomic Analysis of Plasma From Patients With Acute Mountain Sickness Using Chromatography-Mass Spectrometry.

Although acute mountain sickness (AMS) has long been recognized, little is known about this condition to date. The current study was conducted to explore changes in the metabolomic profiles of AMS patients and to further assess the potential of using these changes for the diagnosis of AMS. Plasma samples from 12 patients with AMS and 12 individuals without AMS were collected and used for further bioinformatics analysis by gas chromatography-mass spectrometry (GC-MS). The following analytical methods were used: gas chromatography-mass spectrometry data preprocessing, principal components analysis, partial least squares-discriminant analysis, model validation, orthogonal partial least squares-discriminant analysis, and the screening and identification of differences in metabolites. The results revealed a significantly difference between the subjects with AMS and those in the control group. Compared with plasma from the controls, plasma from the AMS patients contained significantly increased hypoxanthine, cysteinylglycine, D-arabitol, L-allothreonine, 2-ketobutyric acid, and succinate semialdehyde. The identification of metabolomic changes may be useful for the diagnosis of AMS in the future and may lay the foundation for further study of AMS pathogenesis.

Performance of cardiopulmonary resuscitation during prolonged basic life support in military medical university students: A manikin study.

BACKGROUND: The quality of chest compressions can be significantly improved after training of rescuers according to the latest national guidelines of China. However, rescuers may be unable to maintain adequate compression or ventilation throughout a response of average emergency medical services because of increased rescuer fatigue. In the present study, we evaluated the performance of cardiopulmonary resuscitation (CPR) in training of military medical university students during a prolonged basic life support (BLS). METHODS: A 3-hour BLS training was given to 120 military medical university students. Six months after the training, 115 students performed single rescuer BLS on a manikin for 8 minutes. The qualities of chest compressions as well as ventilations were assessed. RESULTS: The average compression depth and rate were 53.7±5.3 mm and 135.1±15.7 compressions per minute respectively. The proportion of chest compressions with appropriate depth was 71.7%±28.4%. The average ventilation volume was 847.2±260.4 mL and the proportion of students with adequate ventilation was 63.5%. Compared with male students, significantly lower compression depth (46.7±4.8 vs. 54.6±4.8 mm, P<0.001) and adequate compression rate (35.5%±26.5% vs. 76.1%±25.1%, P<0.001) were observed in female students. CONCLUSIONS: CPR was found to be related to gender, body weight, and body mass index of students in this study. The quality of chest compressions was well maintained in male students during 8 minutes of conventional CPR but declined rapidly in female students after 2 minutes according to the latest national guidelines. Physical fitness and rescuer fatigue did not affect the quality of ventilation.

Compressing with dominant hand improves quality of manual chest compressions for rescuers who performed suboptimal CPR in manikins.

OBJECTIVE: The question of whether the placement of the dominant hand against the sternum could improve the quality of manual chest compressions remains controversial. In the present study, we evaluated the influence of dominant vs nondominant hand positioning on the quality of conventional cardiopulmonary resuscitation (CPR) during prolonged basic life support (BLS) by rescuers who performed optimal and suboptimal compressions. METHODS: Six months after completing a standard BLS training course, 101 medical students were instructed to perform adult single-rescuer BLS for 8 minutes on a manikin with a randomized hand position. Twenty-four hours later, the students placed the opposite hand in contact with the sternum while performing CPR. Those with an average compression depth of less than 50 mm were considered suboptimal. RESULTS: Participants who had performed suboptimal compressions were significantly shorter (170.2 ± 6.8 vs 174.0 ± 5.6 cm, P = .008) and lighter (58.9 ± 7.6 vs 66.9 ± 9.6 kg, P < .001) than those who performed optimal compressions. No significant differences in CPR quality were observed between dominant and nondominant hand placements for these who had an average compression depth of greater than 50 mm. However, both the compression depth (49.7 ± 4.2 vs 46.5 ± 4.1 mm, P = .003) and proportion of chest compressions with an appropriate depth (47.6% ± 27.8% vs 28.0% ± 23.4%, P = .006) were remarkably higher when compressing the chest with the dominant hand against the sternum for those who performed suboptimal CPR. CONCLUSIONS: Chest compression quality significantly improved when the dominant hand was placed against the sternum for those who performed suboptimal compressions during conventional CPR.

Association of arterial oxygen saturation and acute mountain sickness susceptibility: a meta-analysis.

Acute mountain sickness (AMS) is the most common high altitude illnesses experienced during rapid ascent to a higher altitude without prior acclimation. It is mainly characterized by a headache which may be accompanied with nausea, vomiting, anorexia, dizziness, lethargy, fatigue, and sleep disturbance. If not diagnosed and treated in a timely manner, AMS can develop into deadly high altitude pulmonary edema or high altitude cerebral edema. In the previous studies of individual variation in susceptibility to AMS, arterial oxygen saturation (SO2) was identified as being associated with AMS. However, other studies have reported no association between AMS and arterial oxygen saturation. In this study, the association between SO2 and AMS was assessed through a meta-analysis of published data. The literature databases PubMed, Web of Science, LWW, Science Direct, and Embase were queried for papers published before 15 April 2014. A fixed-effects model and a random-effects model were applied (Revman 5.0) on the basis of heterogeneity, and the study quality was assessed in duplicate. Twelve studies with 614 AMS patients and 1,025 control subjects were analyzed. There was a significant association with differences in SO2 and the risk of developing AMS. SO2 values are associated with AMS incidence.

The role of glioma stem cells in glioma tumorigenesis.

Malignant gliomas, the most common type of primary brain tumor, account for 80% of malignant tumors in the central nervous system (CNS). There are three principal types of glioma: astrocytomas, oligodendrogliomas, and oligoastrocytomas. Glioma stem cells (GSCs) have been found in all types; however, many fundamental questions about GSCs remain unanswered. This review will examine the current state of knowledge regarding GSC origin and the signaling pathways implicated in GSC tumorigenesis. The outstanding challenges for the study of GSCs in the context of glioma progression will also be discussed.

Retrospective evaluation of current-based impedance compensation defibrillation in out-of-hospital cardiac arrest.

OBJECTIVE: Transthoracic impedance (TTI) is a principal parameter that influences the intracardiac current flow and defibrillation outcome. In this study, we retrospectively evaluated the performance of current-based impedance compensation defibrillation in out-of-hospital cardiac arrest (OHCA) patients. METHODS: ECG recordings, along with TTI measurements were collected from multiple emergency medical services (EMSs) in the USA. All the EMSs in this study used automated external defibrillators (AEDs) which employing rectilinear biphasic (RLB) waveform. The distribution and change of TTI between successive shocks, the influence of preceding shock results on the subsequent shock outcome, and the performance of current-based impedance compensation defibrillation was evaluated. RESULTS: A total of 1166 shocks from 594 OHCA victims were examined in this study. The average TTI for the 1st shock was 134.8 Ω and a significant decrease in TTI was observed for the 2nd (p<0.001) and 3rd (p=0.033) sequential escalating shock. But TTI did not change after the 3rd shock. A higher success rate was observed for shocks with preceding defibrillation success. The success rate remained unchanged over the whole spectrum of TTI. CONCLUSION: The average TTI was relatively higher in this OHCA population treated with RLB defibrillation as compared with previously reported data. TTI was significantly decreased after 1st and 2nd successive escalating shock but kept constant after the 3rd shock. Preceding shock success was a better predictor of subsequent defibrillation outcome other than TTI. Current-based impedance compensation defibrillation resulted in equivalent success rate for high impedance patients when compared with those of low impedance.

Selective attention deficits in early and moderate stage Parkinson's disease.

Patients with Parkinson's disease (PD) often show impaired performance on visuospatial attentional tasks. The objective of the study was to examine the attentional function of PD patients performing the attentional network test (ANT). We used the ANT to compare PD patients with healthy controls with respect to the efficiency of 3 anatomically defined attentional networks: the alerting, orienting, and executive control networks. We found that PD patients showed a selective abnormality in the orienting network. Although the alerting and executive control networks apparently remained unaffected, the efficiencies of these networks in patients with PD negatively correlated with the Hoehn-Yahr stage. The results supported the idea that the orienting processes may be more dynamic in PD than in non-PD individuals.