Performance Of Critical Tasks Research Articles

Mitochondria-Targeted Human Catalase in the Mouse Longevity MCAT Model Mitigates Head-Tilt Bedrest-Induced Neuro-Inflammation in the Hippocampus.

Microgravity (modeled by head-tilt bedrest and hind-limb unloading), experienced during prolonged spaceflight, results in neurological consequences, central nervous system (CNS) dysfunction, and potentially impairment during the performance of critical tasks. Similar pathologies are observed in bedrest, sedentary lifestyle, and muscle disuse on Earth. In our previous study, we saw that head-tilt bedrest together with social isolation upregulated the milieu of pro-inflammatory cytokines in the hippocampus and plasma. These changes were mitigated in a MCAT mouse model overexpressing human catalase in the mitochondria, pointing out the importance of ROS signaling in this stress response. Here, we used a head-tilt model in socially housed mice to tease out the effects of head-tilt bedrest without isolation. In order to find the underlying molecular mechanisms that provoked the cytokine response, we measured CD68, an indicator of microglial activation in the hippocampus, as well as changes in normal in-cage behavior. We hypothesized that hindlimb unloading (HU) will elicit microglial hippocampal activations, which will be mitigated in the MCAT ROS-quenching mice model. Indeed, we saw an elevation of the activated microglia CD68 marker following HU in the hippocampus, and this pathology was mitigated in MCAT mice. Additionally, we identified cytokines in the hippocampus, which had significant positive correlations with CD68 and negative correlations with exploratory behaviors, indicating a link between neuroinflammation and behavioral consequences. Unveiling a correlation between molecular and behavioral changes could reveal a biomarker indicative of these responses and could also result in a potential target for the treatment and prevention of cognitive changes following long space missions and/or muscle disuse on Earth.

Avatar-based patient monitoring in critical anaesthesia events: a randomised high-fidelity simulation study

BackgroundFailures in situation awareness cause two-thirds of anaesthesia complications. Avatar-based patient monitoring may promote situation awareness in critical situations. MethodsWe conducted a prospective, randomised, high-fidelity simulation study powered for non-inferiority. We used video analysis to grade anaesthesia teams managing three 10 min emergency scenarios using three randomly assigned monitoring modalities: only conventional, only avatar, and split-screen showing both modalities side by side. The primary outcome was time to performance of critical tasks. Secondary outcomes were time to verbalisation of vital sign deviations and the correct cause of the emergency, perceived workload, and usability. We used mixed Cox and linear regression models adjusted for various potential confounders. The non-inferiority margin was 10%, or hazard ratio (HR) 0.9. ResultsWe analysed 52 teams performing 154 simulations. For performance of critical tasks during a scenario, split-screen was non-inferior to conventional (HR=1.13; 95% confidence interval [CI], 0.96–1.33; not significant in test for superiority); the result for avatar was inconclusive (HR=0.98; 95% CI, 0.83–1.15). Avatar was associated with a higher probability for verbalisation of the cause of the emergency (HR=1.78; 95% CI, 1.13–2.81; P=0.012). We found no evidence for a monitor effect on perceived workload. Perceived usability was lower for avatar (coefficient=–23.0; 95% CI, –27.2 to –18.8; P<0.0001) and split-screen (–6.7; 95% CI, –10.9 to –2.4; P=0.002) compared with conventional. ConclusionsThis study showed non-inferiority of split-screen compared with conventional monitoring for performance of critical tasks during anaesthesia crisis situations. The patient avatar improved verbalisation of the correct cause of the emergency. These results should be interpreted considering participants' minimal avatar but extensive conventional monitoring experience.

Impact of Critical Event Checklists on Anaesthetist Performance in Simulated Operating Theatre Emergencies.

IntroductionCrises in the operating theatre during a paediatric case are rare with the incidence of anesthesia-related cardiac arrest in non-cardiac patients being 1.4/10,000. In order to address this, the Society for Pediatric Anesthesia (SPA) developed cognitive aids (CAs) in the form of Critical Event Checklists (SPA CECs). Several studies have demonstrated the benefit of CAs in improving performance of critical tasks. Despite the presence of CAs, individuals often do not use the aids consistently. The objective of our study was to investigate whether the presence of SPA CECs, and orientation to these tools, improve the performance of trainees during simulated critical events.MethodsWith local Research Ethics Board (REB) approval we used a randomized, 2 x 2 factorial design. The first randomization was the participant orientation to the SPA CECs (e-module vs. didactic). The second randomization assigned participants to complete the simulations with or without SPA CECs available. The simulations were videoed and rated by two raters using a scenario-specific checklist and global rating scale (GRS).ResultsWe conducted 78 simulations. The SPA CEC was used in 17.9% of scenarios. The SPA CEC was used in 44.8% of diagnosis-based scenarios and only 2.0% of generic problem-based scenarios. Participants’ performance was superior with the SPA CEC present (GRS mean 3 [SD 1.27]) than without the SPA CEC available (GRS mean 2.43 [SD 0.89]) (p = 0.048).ConclusionOverall, we showed that uptake of the SPA CECs is poor. We also demonstrated that when the SPA CECs are utilized, they enhance the performance of trainees in simulated operating room (OR) critical events.

Design of a Wearable Stress Monitoring Tool for Intensive Care Unit Nursing: Functional Information Requirements Analysis

Nurses are the last line of defense to reduce preventable medical errors; however, they suffer from poor systems design and human factors issues (e.g., long shifts, dynamic workload, stressful situations, and fatigue), contributing to a reduced quality of care. A smart nursing system based on physiological monitoring is being designed to help nurses and their managers to efficiently communicate, reduce interruptions that affect critical task performance, and monitor acute stress and fatigue levels. This paper documents the systematic process of deriving information requirements through a group-participatory usability study, conducted with nurses working in various Southeastern Texas hospitals. Information requirements derived from these studies include: a need for accessing patients’ vital signs as well as laboratory results, memory aid tools for various critical nursing tasks, and options to call for help and to reduce interruptions for critical tasks. The system shows promise to meet these requirements.

Feasibility of an International Remote Simulation Training Program in Critical Care Delivery: A Pilot Study.

ObjectiveTo determine the feasibility and effectiveness of a video-enabled remote simulation training program to teach a systematic, standardized approach to the evaluation and management of the critically ill patients as part of an international quality improvement intervention.Patients and MethodsIn this pilot “train-the-trainer” prospective cohort study, we provided a remote simulation-based educational program for practicing clinicians from intensive care units involved in an international quality improvement project (www.icertain.org). Between February 21, 2014, and August 6, 2015, participants completed a self-guided online curriculum and participated in structured simulation training using web conference software with recording capabilities. The performance was assessed using a matched pair analysis at baseline and using standardized scenarios and a validated assessment tool postintervention. Participants rated their satisfaction with the training experience and confidence in implementing these skills in clinical practice.ResultsEighteen local champions from 8 hospitals in 7 countries in Asia, Europe, and South and Central America completed the educational program. Learners exhibited significant improvements in cumulative critical task performance during simulated critical care scenarios with training (60.3%-81.8%; P=.002). Most clinicians (94%) reported that they felt well prepared to manage the common critical care scenarios after training. These local champions have subsequently delivered this educational program to more than 800 international clinicians over a 4-year period.ConclusionInsufficient training is a major barrier to the delivery of cost-effective critical care in many areas of the world. Video-enabled remote simulation training is a low-cost, feasible, and effective method to disseminate clinical skills to critical care practitioners in diverse international settings.

EFT Fault Impact Analysis on Performance of Critical Tasks in Intravehicular Networks

Electrical fast transients (EFT) represent an important problem to intravehicular networks. Concerning this problem, this paper reports a study about the impact of EFT to the performance of communication protocols used in intravehicular networks. A method of fast transient injection has been applied to an experimental CAN network with the objective of verifying the EFT impact on jitter and how it influences the communication process. An experiment with a simulated control system distributed over a real CAN network was carried out. For this experiment, an active suspension system was chosen as a case study and a sequence of EFT injections was performed. As a result, it was verified that injected EFT bursts increase jitter of safety-critical control messages and may effectively influence and produce faults during the communication process.

Differential Functionality of Right and Left Parietal Activity in Controlling a Motor Vehicle.

Driving a motor vehicle is an inherently complex task that requires robust control to avoid catastrophic accidents. Drivers must maintain their vehicle in the middle of the travel lane to avoid high speed collisions with other traffic. Interestingly, while a vehicle’s lane deviation (LD) is critical, studies have demonstrated that heading error (HE) is one of the primary variables drivers use to determine a steering response, which directly controls the position of the vehicle in the lane. In this study, we examined how the brain represents the dichotomy between control/response parameters (heading, reaction time (RT), and steering wheel corrections) and task-critical parameters (LD). Specifically, we examined electroencephalography (EEG) alpha band power (8–13 Hz) from estimated sources in right and left parietal regions, and related this activity to four metrics of driving performance. Our results demonstrate differential task involvement between the two hemispheres: right parietal activity was most closely related to LD, whereas left parietal activity was most closely related to HE, RT and steering responses. Furthermore, HE, RT and steering wheel corrections increased over the duration of the experiment while LD did not. Collectively, our results suggest that the brain uses differential monitoring and control strategies in the right and left parietal regions to control a motor vehicle. Our results suggest that the regulation of this control changes over time while maintaining critical task performance. These results are interpreted in two complementary theoretical frameworks: the uncontrolled manifold and compensatory control theories. The central tenet of these frameworks permits performance variability in parameters (i.e., HE, RT and steering) so far as it does not interfere with critical task execution (i.e., LD). Our results extend the existing research by demonstrating potential neural substrates for this phenomenon which may serve as potential targets for brain-computer interfaces that predict poor driving performance.

The ELLIPTA® Dry Powder Inhaler: Design, Functionality, In Vitro Dosing Performance and Critical Task Compliance by Patients and Caregivers

Dry powder inhalers (DPIs) are commonly used for the delivery of inhaled medications, and should provide consistent, efficient dosing, be easy to use correctly, and be liked by patients; these attributes can all affect patient compliance and therefore treatment efficacy. The ELLIPTA® DPI was developed for the delivery of once-daily therapies for the treatment of asthma and chronic obstructive pulmonary disease. It has moderate resistance to airflow and can hold one or two blister strips, with each blister containing a sealed single dose of medication. Monotherapies can be delivered by the single-strip configuration and, in the two-strip configuration, one dose from each strip can be aerosolized simultaneously to allow combination therapies to be delivered, which enables the formulations for each product to be developed individually, since they are stored separately until the point of administration. There are three principal operating steps to administer a dose: open, inhale, close. This article summarizes the design, functionality, and in vitro dose-delivery characteristics of the ELLIPTA inhaler, and describes the results of human factors validation tests, designed to assess the performance of critical tasks required to use the inhaler. Results from the in vitro studies indicate that the ELLIPTA inhaler performs consistently with respect to in vitro dose delivery characteristics at a range of flow rates that can be achieved by the target population (≥30 L/min) and over its 30-day in-use life. Data from the human factors validation tests demonstrated that almost all participants (≥97%) were able to complete each of the steps required to prepare a dose for inhalation without error. Overall, the ELLIPTA inhaler has a versatile single- or two-strip design that allows it to be used for the delivery of a range of treatment options. It also improves patient ease-of-use when compared with the DISKUS® DPI.

The Role of Nontechnical Skills in Simulated Trauma Resuscitation

Trauma team training provides instruction on crisis management through debriefing and discussion of teamwork and leadership skills during simulated trauma scenarios. The effects of team leader's nontechnical skills (NTSs) on technical performance have not been thoroughly studied. We hypothesized that team's and team leader's NTSs correlate with technical performance of clinical tasks. Retrospective cohort study. Brigham and Women's Hospital, STRATUS Center for Surgical Simulation A total of 20 teams composed of surgical residents, emergency medicine residents, emergency department nurses, and emergency services assistants underwent 2 separate, high-fidelity, simulated trauma scenarios. Each trauma scenario was recorded on video for analysis and divided into 4 consecutive sections. For each section, 2 raters used the Non-Technical Skills for Surgeons framework to assess NTSs of the team. To evaluate the entire team's NTS, 2 additional raters used the Modified Non-Technical Skills Scale for Trauma system. Clinical performance measures including adherence to guidelines and time to perform critical tasks were measured independently. NTSs performance by both teams and team leaders in all NTS categories decreased from the beginning to the end of the scenario (all p < 0.05). There was significant correlation between team's and team leader's cognitive skills and critical task performance, with correlation coefficients between 0.351 and 0.478 (p < 0.05). The NTS performance of the team leader highly correlated with that of the entire team, with correlation coefficients between 0.602 and 0.785 (p < 0.001). The NTSs of trauma teams and team leaders deteriorate as clinical scenarios progress, and the performance of team leaders and teams is highly correlated. Cognitive NTS scores correlate with critical task performance. Increased attention to NTSs during trauma team training may lead to sustained performance throughout trauma scenarios. Decision making and situation awareness skills are critical for both team leaders and teams and should be specifically addressed to improve performance.

Efficacy of a template creation approach for performance improvement

This article presents the training and performance improvement approach, performance templates (P-T), and provides empirical evidence to support the efficacy of P-T. This approach involves a partnership among managers, trainers, and employees in the creation, use, and improvement of guides to affect the performance of critical tasks in the operating environment. The P-T approach requires much involvement and hands-on activities by training participants, and, as a result, training groups are not large. Given that limitation, a comparison of employees trained with P-T methods and employees trained in more conventional methods indicates that the P-T approach can lead to improved performance to some extent over a fairly short period.

Negative mood endures after completion of high-altitude military training

Associations between physical and emotional stress and negative mood states have been documented in a variety of populations. In military personnel, more physical symptoms and decrements in ability to perform critical tasks have been shown to accompany such stress-induced negative mood. Most research in this area has focused on immediate effects of stress on mood. We wondered what immediate mood effects strenuous training would have on Marines, what mood effects would endure 30 and 90 days after completion of training, and how mood scores would compare with normative data. Sixty male Marines (M age = 19 years, range = 18-28) completed the Profile of Mood States (POMS) at multiple time points before and after participating in a 30-day, cold weather, high-altitude field training exercise. Anthropometric measurements were taken at the same time points. The Marines reported significant increases in POMS scores from baseline to completion of training, most of which endured up to 90 days. The anger and fatigue scores reported by the Marines were comparable to adult male psychiatric outpatient norms. Rigorous training in challenging environments may result in enduring negative moods that approach levels of clinical significance and may have implications for readiness for duty and performance of critical tasks. Behavioral medicine interventions may be helpful in military populations to reduce the impact of negative mood.

A Comparison of Fast and Low Overhead Distributed Priority Locks

Distributed synchronization is necessary to coordinate the diverse activities of a distributed system. Priority synchronization is needed for real-time systems or to improve the performance of critical tasks. Practical synchronization techniques require fast response and low overhead. In this paper, we present three priority synchronization algorithms that sendO(logn) messages per critical section request on average and useO(logn) bits of storage per processor. Previous algorithms required 2(n− 1) messages per critical section entry andO(n) bits of storage per processor. Two of the algorithms are based on Li and Hudak's path compression techniques, and the third algorithm uses Raymond's fixed-tree structure. Since each of the algorithms have the same theoretical complexity, we make a performance comparison to determine which of the algorithms is best under different loads and different request priority distributions. We find that when the request priority distribution is stationary, the path-compression algorithm that uses a singly linked list is best overall, but the fixed-tree algorithm requires fewer messages when the number of processors is small and the load is high (100% or greater). When the request priority distribution is nonstationary, the fixed-tree algorithm requires the fewest messages when the load is 100% or greater.

Physiologically based pharmacokinetic model for the inhibition of acetylcholinesterase by organophosphate esters.

Organophosphate (OP) exposure can be lethal at high doses while lower doses may impair performance of critical tasks. The ability to predict such effects for realistic exposure scenarios would greatly improve OP risk assessment. To this end, a physiologically based model for diisopropylfluorophosphate (DFP) pharmacokinetics and acetylcholinesterase (AChE) inhibition was developed. DFP tissue/blood partition coefficients, rates of DFP hydrolysis by esterases, and DFP-esterase bimolecular inhibition rate constants were determined in rat tissue homogenates. Other model parameters were scaled for rats and mice using standard allometric relationships. These DFP-specific parameter values were used with the model to simulate pharmacokinetic data from mice and rats. Literature data were used for model validation. DFP concentrations in mouse plasma and brain, as well as AChE inhibition and AChE resynthesis data, were successfully simulated for a single iv injection. Effects of repeated, subcutaneous DFP dosing on AChE activity in rat plasma and brain were also well simulated except for an apparent decrease in basal AChE activity in the brain which persisted 35 days after the last dose. The psychologically based pharmacokinetic (PBPK) model parameter values specific for DFP in humans, for example, tissue/blood partition coefficients, enzymatic and nonenzymatic DFP hydrolysis rates, and bimolecular inhibition rate constants for target enzymes were scaled from rodent data or obtained from the literature. Good agreement was obtained between model predictions and human exposure data on the inhibition of red blood cell AChE and plasma butyrylcholinesterase after an intramuscular injection of 33 micrograms/kg DFP and at 24 hr after acute doses of DFP (10-54 micrograms/kg), as well as for repeated DFP exposures.(ABSTRACT TRUNCATED AT 250 WORDS)

Physiologically based pharmacokinetic and pharmacodynamic model for the inhibition of acetylcholinesterase by diisopropyfluorophosphate

Organophosphate (OP) exposure can be lethal at high doses while lower doses may impair performance of critical tasks. The ability to predict such effects for realistic exposure scenarios would expedite OP risk assessment. To this end, a physiologically based model for diisopropylfluorophosphate (DFP) pharmacokinetics and acetylcholinesterase (AChE) inhibition was developed in mammals. DFP tissue:blood partition coefficients, rates of DFP hydrolysis by esterases, and DFP-esterase bimolecular inhibition rate constants were determined in rat tissue homogenates. Other model parameters were scaled for rats and mice using standard allometric relationships. These DFP-specific parameter values were used with the model to simulate expected in vivo pharmacokinetic data from mice and rats. Literature data were used for model validation. DFP concentrations in mouse plasma and brain were successfully simulated after a single iv injection ( B. R. Martin, 1985, Toxicol. Appl. Pharmacol. 77, 275–284). AChE inhibition and AChE resynthesis data from this study were also simulated. Effects of repeated, subcutaneous DFP dosing on AChE activity in rat plasma and brain ( H. Michalek, A. Meneguz, and G. M. Bisso, 1982, Arch. Toxicol., Suppl. 5, 116–119; M. E. Traina and L. A. Serpietri, 1984, Biochem. Pharmacol. 33, 645–653) were also simulated well, but the return of brain AChE activity to basal levels after cessation of repeated dosing was not as well described. The initial model structure returned brain AChE activity to the original level, while in the laboratory studies brain AChE never returned to basal levels, even at 35 days after the last dose. These data suggest modulation of AChE synthesis with prolonged DFP exposure. This study demonstrated the possibility of using a model based on mammalian physiology and biochemistry to simulate in vivo data on DFP pharmacokinetics and AChE inhibition. Scaling of the model between rats and mice was also successful. The approach holds promise for predictive simulation of organophosphate-mediated AChE inhibition in humans.