Delirium after Cardiac Surgery-A Narrative Review.

Postoperative delirium (POD) after cardiac surgery is a well-known phenomenon which carries a higher risk of morbidity and mortality. Multiple patient-specific risk factors and pathophysiologic mechanisms have been identified and therapies have been proposed to mitigate risk of delirium development postoperatively. Notably, cardiac surgery frequently involves the use of an intraoperative cardiopulmonary bypass (CPB), which may contribute to the mechanisms responsible for POD. Despite our greater understanding of these causative factors, a substantial reduction in the incidence of POD remains high among cardiac surgical patients. Multiple therapeutic interventions have been implemented intraoperatively and postoperatively, many with conflicting results. This review article will highlight the incidence and impact of POD in cardiac surgical patients. It will describe some of the primary risk factors associated with POD, as well as anesthetic management and therapies postoperatively that may help to reduce delirium.

Central Skull Base Osteomyelitis: A Case Series from a Tertiary Care Center Over 5 Years.

OBJECTIVE: Skull base osteomyelitis may rarely present in the sphenoid bone or clivus without an otologic source. This is referred to as central skull base osteomyelitis (CSBO). Knowledge regarding CSBO is limited to case reports and small case series. Here we present a case series to further describe typical patient characteristics, clinical presentation, and clinical course associated with this rare infection. METHODS: All patients treated at a single academic tertiary care institution for CSBO from 2016 through 2020 were identified. Inclusion criteria included culture proven CSBO without an otologic or iatrogenic source. Data were extracted via patient chart review and qualitatively analyzed. RESULTS: Seven patients were identified with CSBO, 5 male and 2 female. Age ranged from 63 to 87 (average 76). Risk factors included advanced age, diabetes, and history of radiation. The most common presenting symptom was headache (6), followed by otalgia (4). Two patients presented with cranial neuropathies. Diagnosis was facilitated by history and exam (including flexible laryngoscope exam), imaging (MRI), and labs (ESR). All patients received endoscopic biopsy and culture (most commonly polymicrobial, with diverse species). Treatment involved IV antibiotics, with a limited role for surgery. All patients survived and achieved resolution of infection. CONCLUSIONS: CSBO remains a diagnostic challenge due to its rarity and vague presenting symptoms that overlap with presentation of sinonasal malignancies. A high index of suspicion is required by the evaluating provider to ensure a timely diagnosis with early treatment in order to limit the significant morbidity which can be associated with this infection. LEVEL OF EVIDENCE: 4.

Quantifying warfighter performance during a bounding rush (prone-sprinting-prone) maneuver.

A single sacrum mounted inertial measurement unit (IMU) was employed to analyze warfighter performance on a bounding rush (prone-sprinting-prone) task. Thirty-nine participants (23M/16F) performed a bounding rush task consisting of four bounding rush cycles. The sacrum mounted IMU recorded angular velocity and acceleration data were used to provide estimates of sacral velocity and position. Individual rush cycles were parsed into three principal movement phases; namely, the get up, sprint, and get down phases. The timing of each phase was analyzed, averaged for each participant, and compared to the overall rush cycle time using regression analysis. A cluster analysis further reveals differences between high and low performers. Get down time was most predictive of bounding rush performance (R2 = 0.75) followed by get up time (R2 = 0.58) and sprint time (R2 = 0.40). Comparing high and low performers, the get down time exhibited nearly twice the effect on mean rush cycle time compared to get up time (effect size of -2.61 to -1.46, respectively). Overall, this IMU-based method reveals key features of the bounding rush that govern performance. Consequently, this objective method may support future training regimens and performance standards for military recruits, and parallel applications for athletes.

Body-worn IMU array reveals effects of load on performance in an outdoor obstacle course.

This study introduces a new method to understand how added load affects human performance across a broad range of athletic tasks (ten obstacles) embedded in an outdoor obstacle course. The method employs an array of wearable inertial measurement units (IMUs) to wirelessly record the movements of major body segments to derive obstacle-specific metrics of performance. The effects of load are demonstrated on (N = 22) participants who each complete the obstacle course under four conditions including unloaded (twice) and with loads of 15% and 30% of their body weight (a total of 88 trials across the group of participants). The IMU-derived performance metrics reveal marked degradations in performance with increasing load across eight of the ten obstacles. Overall, this study demonstrates the significant potential in using this wearable technology to evaluate human performance across multiple tasks and, simultaneously, the adverse effects of body-borne loads on performance. The study addresses a major need of military organizations worldwide that frequently employ standardized obstacle courses to understand how added loads influence warfighter performance. Importantly, the findings and conclusions drawn from IMU data would not be possible using traditional timing metrics used to evaluate task performance.

Human crawling performance and technique revealed by inertial measurement units.

Human crawling performance and technique are of broad interest to roboticists, biomechanists, and military personnel. This study explores the variables that define crawling performance in the context of an outdoor obstacle course used by military organizations worldwide to evaluate the effects of load and personal equipment on warfighter performance. Crawling kinematics, measured from four body-worn inertial measurement units (IMUs) attached to the upper arms and thighs, are recorded for thirty-three participants. The IMU data is distilled to four metrics of crawling performance; namely, crawl speed, crawl stride time, ipsilateral limb coordination, and contralateral limb coordination. We hypothesize that higher performance (as identified by higher crawl speeds) is associated with more coordinated limbs and lower stride times. A cluster analysis groups participants into high and low performers exhibiting statistically significant differences across the four performance metrics. In particular, high performers exhibit superior limb coordination associated with a "diagonal gait" in which contralateral limbs move largely in-phase to produce faster crawl speeds and shorter crawl stride times. In contrast, low performers crawl at slower speeds with longer crawl stride times and less limb coordination. Beyond these conclusions, a major contribution of this study is a method for deploying wearable IMUs to study crawling in contextually relevant (i.e. non-laboratory) environments.

Load-embedded inertial measurement unit reveals lifting performance.

Manual lifting of loads arises in many occupations as well as in activities of daily living. Prior studies explore lifting biomechanics and conditions implicated in lifting-induced injuries through laboratory-based experimental methods. This study introduces a new measurement method using load-embedded inertial measurement units (IMUs) to evaluate lifting tasks in varied environments outside of the laboratory. An example vertical load lifting task is considered that is included in an outdoor obstacle course. The IMU data, in the form of the load acceleration and angular velocity, is used to estimate load vertical velocity and three lifting performance metrics: the lifting time (speed), power, and motion smoothness. Large qualitative differences in these parameters distinguish exemplar high and low performance trials. These differences are further supported by subsequent statistical analyses of twenty three trials (including a total of 115 total lift/lower cycles) from fourteen healthy participants. Results reveal that lifting time is strongly correlated with lifting power (as expected) but also correlated with motion smoothness. Thus, participants who lift rapidly do so with significantly greater power using motions that minimize motion jerk.

Estimating Stair Running Performance Using Inertial Sensors.

Stair running, both ascending and descending, is a challenging aerobic exercise that many athletes, recreational runners, and soldiers perform during training. Studying biomechanics of stair running over multiple steps has been limited by the practical challenges presented while using optical-based motion tracking systems. We propose using foot-mounted inertial measurement units (IMUs) as a solution as they enable unrestricted motion capture in any environment and without need for external references. In particular, this paper presents methods for estimating foot velocity and trajectory during stair running using foot-mounted IMUs. Computational methods leverage the stationary periods occurring during the stance phase and known stair geometry to estimate foot orientation and trajectory, ultimately used to calculate stride metrics. These calculations, applied to human participant stair running data, reveal performance trends through timing, trajectory, energy, and force stride metrics. We present the results of our analysis of experimental data collected on eleven subjects. Overall, we determine that for either ascending or descending, the stance time is the strongest predictor of speed as shown by its high correlation with stride time.

Quantifying performance on an outdoor agility drill using foot-mounted inertial measurement units.

Running agility is required for many sports and other physical tasks that demand rapid changes in body direction. Quantifying agility skill remains a challenge because measuring rapid changes of direction and quantifying agility skill from those measurements are difficult to do in ways that replicate real task/game play situations. The objectives of this study were to define and to measure agility performance for a (five-cone) agility drill used within a military obstacle course using data harvested from two foot-mounted inertial measurement units (IMUs). Thirty-two recreational athletes ran an agility drill while wearing two IMUs secured to the tops of their athletic shoes. The recorded acceleration and angular rates yield estimates of the trajectories, velocities and accelerations of both feet as well as an estimate of the horizontal velocity of the body mass center. Four agility performance metrics were proposed and studied including: 1) agility drill time, 2) horizontal body speed, 3) foot trajectory turning radius, and 4) tangential body acceleration. Additionally, the average horizontal ground reaction during each footfall was estimated. We hypothesized that shorter agility drill performance time would be observed with small turning radii and large tangential acceleration ranges and body speeds. Kruskal-Wallis and mean rank post-hoc statistical analyses revealed that shorter agility drill performance times were observed with smaller turning radii and larger tangential acceleration ranges and body speeds, as hypothesized. Moreover, measurements revealed the strategies that distinguish high versus low performers. Relative to low performers, high performers used sharper turns, larger changes in body speed (larger tangential acceleration ranges), and shorter duration footfalls that generated larger horizontal ground reactions during the turn phases. Overall, this study advances the use of foot-mounted IMUs to quantify agility performance in contextually-relevant settings (e.g., field of play, training facilities, obstacle courses, etc.).

Method for Estimating Three-Dimensional Knee Rotations Using Two Inertial Measurement Units: Validation with a Coordinate Measurement Machine.

Three-dimensional rotations across the human knee serve as important markers of knee health and performance in multiple contexts including human mobility, worker safety and health, athletic performance, and warfighter performance. While knee rotations can be estimated using optical motion capture, that method is largely limited to the laboratory and small capture volumes. These limitations may be overcome by deploying wearable inertial measurement units (IMUs). The objective of this study is to present a new IMU-based method for estimating 3D knee rotations and to benchmark the accuracy of the results using an instrumented mechanical linkage. The method employs data from shank- and thigh-mounted IMUs and a vector constraint for the medial-lateral axis of the knee during periods when the knee joint functions predominantly as a hinge. The method is carefully validated using data from high precision optical encoders in a mechanism that replicates 3D knee rotations spanning (1) pure flexion/extension, (2) pure internal/external rotation, (3) pure abduction/adduction, and (4) combinations of all three rotations. Regardless of the movement type, the IMU-derived estimates of 3D knee rotations replicate the truth data with high confidence (RMS error < 4 ° and correlation coefficient r ≥ 0.94 ).

Quantifying warfighter performance in a target acquisition and aiming task using wireless inertial sensors.

An array of inertial measurement units (IMUS) was experimentally employed to analyze warfighter performance on a target acquisition task pre/post fatigue. Eleven participants (5M/6F) repeated an exercise circuit carrying 20 kg of equipment until fatigued. IMUs secured to the sacrum, sternum, and a rifle quantified peak angular velocity magnitude (PAVM) and turn time (TT) on a target acquisition task (three aiming events with two 180° turns) within the exercise circuit. Turning performance of two turns was evaluated pre/post fatigue. Turning performance decreased with fatigue. PAVMs decreased during both turns for the sternum (p < 0.001), sacrum (p = 0.007) and rifle (p = 0.002). TT increased for the sternum (p = 0.001), sacrum (p = 0.003), and rifle (p = 0.02) during turn 1, and for the rifle (p = 0.04) during turn 2. IMUs detected and quantified changes in warfighter aiming performance after fatigue. Similar methodologies can be applied to many movement tasks, including quantifying movement performance for load, fatigue, and equipment conditions.

Quantifying performance and effects of load carriage during a challenging balancing task using an array of wireless inertial sensors.

We utilize an array of wireless inertial measurement units (IMUs) to measure the movements of subjects (n=30) traversing an outdoor balance beam (zigzag and sloping) as quickly as possible both with and without load (20.5kg). Our objectives are: (1) to use IMU array data to calculate metrics that quantify performance (speed and stability) and (2) to investigate the effects of load on performance. We hypothesize that added load significantly decreases subject speed yet results in increased stability of subject movements. We propose and evaluate five performance metrics: (1) time to cross beam (less time=more speed), (2) percentage of total time spent in double support (more double support time=more stable), (3) stride duration (longer stride duration=more stable), (4) ratio of sacrum M-L to A-P acceleration (lower ratio=less lateral balance corrections=more stable), and (5) M-L torso range of motion (smaller range of motion=less balance corrections=more stable). We find that the total time to cross the beam increases with load (t=4.85, p<0.001). Stability metrics also change significantly with load, all indicating increased stability. In particular, double support time increases (t=6.04, p<0.001), stride duration increases (t=3.436, p=0.002), the ratio of sacrum acceleration RMS decreases (t=-5.56, p<0.001), and the M-L torso lean range of motion decreases (t=-2.82, p=0.009). Overall, the IMU array successfully measures subject movement and gait parameters that reveal the trade-off between speed and stability in this highly dynamic balance task.

Failure to notify reportable test results: significance in medical malpractice.

BACKGROUND: Diagnostic physicians generally acknowledge their responsibility to notify referring clinicians whenever examinations demonstrate urgent or unexpected findings. During the past decade, clinicians have ordered dramatically greater numbers of diagnostic examinations. One study demonstrated that between 1996 and 2003, malpractice payments related to diagnosis increased by approximately 40%. Communication failures are a prominent cause of action in medical malpractice litigation. The aims of this study were to (1) define the magnitude of malpractice costs related to communication failures in test result notification and (2) determine if these costs are increasing significantly. EVALUATION: Linear regression analysis of National Practitioner Data Bank claims data from 1991 to 2009 suggested that claims payments increased at the national level by an average of $4.7 million annually (95% confidence interval, $2.98 million to $6.37 million). Controlled Risk Insurance Company/Risk Management Foundation claims data for 2004 to 2008 indicate that communication failures played a role, accounting for 4% of cases by volume and 7% of the total cost. DISCUSSION: Faile communication of clinical data constitutes an increasing proportion of medical malpractice payments. The increase in cases may reflect expectations of more reliable notification of medical data. Another explanation may be that the remarkable growth in diagnostic test volume has led to a corresponding increase in reportable results. If notification reliability remained unchanged, this increased volume would predict more failed notifications. CONCLUSIONS: There is increased risk for malpractice litigation resulting from diagnostic test result notification. The advent of semiautomated critical test result management systems may improve notification reliability, improve workflow and patient safety, and, when necessary, provide legal documentation.

Emergency department operations dictionary: results of the second performance measures and benchmarking summit.

The public, payers, hospitals, and Centers for Medicare and Medicaid Services (CMS) are demanding that emergency departments (EDs) measure and improve performance, but this cannot be done unless we define the terms used in ED operations. On February 24, 2010, 32 stakeholders from 13 professional organizations met in Salt Lake City, Utah, to standardize ED operations metrics and definitions, which are presented in this consensus paper. Emergency medicine (EM) experts attending the Second Performance Measures and Benchmarking Summit reviewed, expanded, and updated key definitions for ED operations. Prior to the meeting, participants were provided with the definitions created at the first summit in 2006 and relevant documents from other organizations and asked to identify gaps and limitations in the original work. Those responses were used to devise a plan to revise and update the definitions. At the summit, attendees discussed and debated key terminology, and workgroups were created to draft a more comprehensive document. These results have been crafted into two reference documents, one for metrics and the operations dictionary presented here. The ED Operations Dictionary defines ED spaces, processes, patient populations, and new ED roles. Common definitions of key terms will improve the ability to compare ED operations research and practice and provide a common language for frontline practitioners, managers, and researchers.

Emergency department operational metrics, measures and definitions: results of the Second Performance Measures and Benchmarking Summit.

There is a growing mandate from the public, payers, hospitals, and Centers for Medicare & Medicaid Services (CMS) to measure and improve emergency department (ED) performance. This creates a compelling need for a standard set of definitions about the measurement of ED operational performance. This Concepts article reports the consensus of a summit of emergency medicine experts tasked with the review, expansion, and update of key definitions and metrics for ED operations. Thirty-two emergency medicine leaders convened for the Second Performance Measures and Benchmarking Summit on February 24, 2010. Before arrival, attendees were provided with the original definitions published in 2006 and were surveyed about gaps and limitations in the original work. According to survey responses, a work plan to revise and update the definitions was developed. Published definitions from key stakeholders in emergency medicine and health care were reviewed and circulated. At the summit, attendees discussed and debated key terminology and metrics and work groups were created to draft the revised document. Workgroups communicated online and by teleconference to reach consensus. When possible, definitions were aligned with performance measures and definitions put forth by the CMS, the Emergency Nurses Association Consistent Metrics Document, and the National Quality Forum. The results of this work are presented as a reference document.

H1N1: communication patterns among emergency department staff during the H1N1 outbreak, April 2009.

INTRODUCTION: The H1N1 influenza virus has been described by the World Health Organization (WHO) and the media as a disease that could rival the 1918 Spanish Influenza epidemic in deaths. During the spring of 2009, emergency departments across the world saw a spike in the number of influenza cases and by June 2009, the WHO had declared H1N1 a pandemic. In order to prevent emergency department staff from becoming ill and to provide up-to-date medical care to patients, information had to be disseminated quickly to emergency department staff. METHODS: An anonymous Internet survey was utilized to query emergency department staff regarding communication methods and overall attitudes regarding safety and treatment during the spring of 2009. RESULTS: The majority of emergency department staff (263; 88.3%) used multiple sources to obtain information about the H1N1 virus. There were 258 respondents (88.9%) that felt that the hospital was supplying them with the necessary information to protect themselves and their families and 280 (98.5%) felt confident that their emergency department was treating patients by the government-recommended guidelines. Statistically significant differences were noted in communication patterns between direct and indirect patient care providers. CONCLUSIONS: In general, H1N1 communication to emergency department staff was perceived as good during the initial H1N1 outbreak. However, because of the limitations associated with an online survey, these results do not allow for generalization to the total emergency department staff population. Hospital administrators may need to consider the differences in communication preferences of direct patient care providers and indirect patient care providers when distributing important information to emergency department staff during crisis and emergency situations.

Exploring new intake models for the emergency department.

The objective of this article was to explore new intake models for processing patients into the emergency department (ED) and disseminate these new ideas. In the fall of 2008, the Board of Directors of the Emergency Department Benchmarking Alliance (EDBA) identified intake as an area of focus and asked its members to submit new intake strategies alternative to traditional triage. All EDBA members were invited to participate via an e-mail survey. New models could be of their own design or developed by another organization and presented with permission. In all, 25 departments provided information on intake innovations. These submissions were collated into a document that outlines some of the new models. Collaborative methodology promoted the diffusion of innovation in this organization. The results of the project are presented here as an original article that outlines some of the new and mostly unpublished work occurring to improve the intake process into the ED.

Pharmacist improves timely administration of medications to boarded patients in the emergency department.

PURPOSE: Our purpose was to assess the variations in timely administration of medications based on differences in nursing staff (ED nurses who are responsible for emergency and boarded patients vs inpatient nurses who are responsible for only boarded patients) and to determine whether a pharmacist's interventions can improve the timely administration of medications to boarded patients in the emergency department. METHODS: This was a prospective observational study. Patients were included in the study if they were aged 18 years or older, were physically located in the emergency department but had already been admitted to the medical center, and had medication orders. The pharmacist documented the medication orders and the allotted time for administration. Once the upper limit of the allotted time frame for administration had passed, the pharmacist determined whether the medications were given and interventions were then carried out for those medications that were not administered. Successful interventions were documented when the medication was given within 1 hour from the time of intervention. RESULTS: Seventy-nine patients were included in the study, resulting in 266 medication administration opportunities (emergency department, 146; inpatient, 120). Inpatient nurses administered medications in a timely manner at a significantly greater rate than ED nurses (83.3% vs 63.7%, P < .0001). The greatest difference was observed during the evening hours (95.2% vs 53.8% of medications administered for inpatient vs ED nurses, P = .002). The most common reason for medications not being administered by ED nurses was insufficient time (51.4%), and for inpatient nurses, it was that the medication order was not verified (77.8%). The pharmacist's interventions were successful with both the ED and inpatient nurses (95.5% and 94.1%, respectively). CONCLUSION: This study illustrates that assigning nurses with varying workloads as a means to manage overcrowding is likely to result in boarded patients in the emergency department not receiving their medications. ED pharmacists' interventions may fill the gap, ensuring compliance with the administration of medication orders prescribed for boarded patients and ensuring more timely administration. A multidisciplinary team approach is needed to manage current overcrowding issues.

Evaluation of emergency medicine community educational program.

Out-of-hospital emergencies occur frequently, and laypersons are often the first to respond to these events. As an outreach to our local communities, we developed "Basic Emergency Interventions Everyone Should Know," a three-hour program addressing cardiopulmonary resuscitation and automated external defibrillator use, heart attack and stroke recognition and intervention, choking and bleeding interventions and infant and child safety. Each session lasted 45 minutes and was facilitated by volunteers from the emergency department staff. A self-administered 13-item questionnaire was completed by each participant before and after the program. A total of 183 participants completed the training and questionnaires. Average score pre-training was nine while the average score post-training was 12 out of a possible 13 (P< .0001). At the conclusion of the program 97% of participants felt the training was very valuable and 100% would recommend the program to other members of their community.

A primary care perspective on keloids.

Keloids are a common presenting complaint in the primary care clinic. This condition presents a formidable challenge, as recurrence is often difficult to prevent despite use of multiple therapeutic interventions. Part of the reason for the absence of a definitive treatment is the incomplete understanding of the pathogenesis of keloid formation, which creates a frustrating situation for both physician and patient. Here we review the most recent literature on the clinical features, pathogenesis, and management of keloids, with special emphasis on the unique challenges faced by primary care physicians.