Clinical and neuroradiographic features of fentanyl inhalation-induced leukoencephalopathy.

A man in his late 40s with no known past medical history was unresponsive for an unknown period of time. Crushed pills and white residue were found on a nearby table. On presentation he was obtunded and unresponsive to verbal commands but withdrawing to painful stimuli. The initial urine drug screen was negative, but a urine fentanyl screen was subsequently positive with a level of 137.3 ng/mL. MRI of the brain showed reduced diffusivity and fluid attenuated inversion recovery (FLAIR) hyperintensity symmetrically in the bilateral supratentorial white matter, cerebellum and globus pallidus. Alternative diagnoses such as infection were considered, but ultimately the history and workup led to a diagnosis of fentanyl-induced leukoencephalopathy. Three days after admission the patient became able to track, respond to voice and follow basic one-step commands. The patient does not recall the mechanism of inhalation. While there are case reports of heroin-induced leukoencephalopathy following inhaled heroin use and many routes of fentanyl, this is the first reported case of a similar phenomenon due to fentanyl inhalation.

Implementation of a Nurse-Driven Medication Ordering Protocol to Improve Clinician and Nursing Experiences.

ABSTRACT: Paging and text messaging to request new orders remain common means of communication between clinicians and nurses in the hospital setting. However, sending and triaging multiple pages can lead to interruptions in other clinical duties. A medication order delegation protocol allowing for nurse-driven ordering of low-risk medications was developed with an objective of decreasing potentially avoidable pages. The aim of this study was to evaluate the impact of implementing this protocol on nurse and clinician perceptions of clerical burden and satisfaction. A survey assessing satisfaction with the process of obtaining medications in this protocol and the perception of clerical burden associated with ordering them before and after delegation protocol implementation was completed by over 160 clinicians and nurses. Survey respondents reported increased satisfaction and decreased clerical burden associated with the implementation of the delegation protocol. These results suggest the potential for delegation protocols to limit clerical burden associated with paging.

Ultrasonic Transducers Made From Freeze-Cast Porous Piezoceramics.

Porous and composite piezoelectric ceramics are of interest for underwater ultrasonic transducers due to their improved voltage sensitivity and acoustic matching with water, compared with their dense counterparts. Commonly, these materials are fabricated by dice-and-fill of sintered blocks of polycrystalline piezoceramic, which results in a high volume of waste. The freeze-casting technique offers a low waste and scalable alternative to the dice-and-fill method to produce porous piezoceramics with highly orientated, anisometric pores. In this article, we have fabricated underwater ultrasonic transducers from freeze-cast lead zirconate titanate (PZT) with a range of porosities. The porous PZT samples were characterized in terms of their piezoelectric and dielectric properties before being encapsulated for acoustic performance testing in water. Off resonance, the on- axis receive sensitivity of the manufactured devices was approximately [Formula: see text]; the transmit voltage response (TVR) was in the range of approximately [Formula: see text] at 60 kHz to [Formula: see text] at 180 kHz. The most porous transducer devices (0.51, 0.43, and 0.33 pore fraction) exhibited primarily a thickness mode resonance, whereas the least porous transducers (0.29 pore fraction and dense benchmark) exhibited an undesired radial mode, which was observed as an additional resonant peak in the electrical impedance measurements and lateral off-axis lobes in the acoustic beampatterns. Our results show that the acoustic sensitivities and TVRs of the porous freeze-cast transducers are comparable to those of a dense pressed transducer. However, the freeze-cast transducers with porosity exceeding 0.30 pore fraction were shown to achieve an effective structure with aligned porosity that suppressed undesired radial mode resonances.

A one-week internal medicine procedure rotation designed to increase procedural opportunities and competency.

Background: Mounting literature describes increased procedure volume and improvement in procedural skills following implementation of procedural curricula and standardized rotations, generally requiring at least two weeks and incorporating dedicated lecture and didactic efforts. It is unknown whether shorter rotations that feature self-directed curricula can achieve similar outcomes.Methods: House staff participated in a one-week procedure rotation that coincided with preexisting non-clinical blocks ('jeopardy'). It provided an online curriculum as well as opportunities to perform procedures under interprofessional supervision. Inpatient procedure volumes were tallied before and after implementation of the rotation. During the first year of the rotation (academic year 2013-2014), house staff completed a knowledge-based quiz and a Likert-based survey (range 1-5) addressing confidence in performing procedures and satisfaction in procedural training. Results: Ninety-five of 99 house staff participated in the intervention (96% response rate). The total number of procedures performed by the Division of Hospital Medicine increased from an average of 74 per year over the four years prior to the introduction of the rotation to 291 per year during the third year of the rotation. The knowledge-based quiz score improved from a pre-intervention mean value of 50% to a post-intervention mean value of 61% (P = 0.020). Confidence in performing procedures improved from a pre-intervention mean value of 2.37 to a post-intervention mean value of 2.59 (P < 0.001). Satisfaction with procedural training improved from a pre-intervention mean value of 2.48 to a post-intervention mean value of 2.69 (P < 0.001).Conclusions: A one-week procedure rotation with a self-directed curriculum was introduced into the curriculum of an internal medicine residency program and was associated with increased procedure volume and sustained improvement in house staff knowledge, confidence, and satisfaction with procedural training.

High-resolution, large-scale laboratory measurements of a sandy beach and dynamic cobble berm revetment.

High quality laboratory measurements of nearshore waves and morphology change at, or near prototype-scale are essential to support new understanding of coastal processes and enable the development and validation of predictive models. The DynaRev experiment was completed at the GWK large wave flume over 8 weeks during 2017 to investigate the response of a sandy beach to water level rise and varying wave conditions with and without a dynamic cobble berm revetment, as well as the resilience of the revetment itself. A large array of instrumentation was used throughout the experiment to capture: (1) wave transformation from intermediate water depths to the runup limit at high spatio-temporal resolution, (2) beach profile change including wave-by-wave changes in the swash zone, (3) detailed hydro and morphodynamic measurements around a developing and a translating sandbar.

Array processing of neural signals recorded from the peripheral nervous system for the classification of action potentials.

BACKGROUND: Recording from the peripheral nervous system is key in the development of implantable neural interfaces. Despite a long history of using implantable electrodes for neuro-stimulation, it is difficult to make recordings from the nerves as signal amplitudes are often too small to be detected. Methods exist that are suitable for recording evoked potentials, but these require artificial stimulation of the nerve and thus have limited use in implanted neural interfaces. NEW METHOD: In order to address these issues new methods are developed to analyse spontaneously occurring action potentials by extending an approach called velocity selective recording, which uses longitudinally spaced electrodes to record action potentials as they propagate. The new methods using image processing techniques to automatically identify and classify action potentials without any prior knowledge of their morphology. RESULTS: Simulations are developed to test the methods, and a detailed experimental validation is performed using in-vivo recordings from the L5 dorsal rootlet of rat. Results show that this new approach can discriminate action potentials from both simulated and real recordings and the experimental validation demonstrates an ability to detect dermal stimulation by changes in the firing patterns of different axons. COMPARISON TO EXISTING METHODS: This framework, unlike existing methods, is intrinsically suitable for recordings of spontaneous neural activity. Further it improves upon both the computational complexity and the overall performance of existing methods. CONCLUSION: It is possible to perform on-line discrimination and identification of action potentials without any prior knowledge of their morphology using new image processing inspired methods.

Disseminated Herpes Simplex Masquerading as Hemophagocytic Lymphohistiocytosis: A Case Report.

INTRODUCTION: Marked elevation in serum ferritin levels may be seen in disseminated infection or severe organ failure states, but it is also present in hemophagocytic lymphohistiocytosis (HLH). Herpes simplex virus (HSV) hepatitis has a high mortality rate, even in immunocompetent individuals, in whom it is rarely reported. We present a case of hyperferritinemia with features initially suggestive of a diagnosis of HLH but that ultimately proved to be fulminant HSV hepatitis. CASE PRESENTATION: A 56-year-old man with an indolent undiagnosed brain mass presented with progressive neurologic deficits and was found to have fevers, cytopenias, transaminitis, and hyperferritinemia. Initially, HLH was suspected; however, the ultimate diagnosis was HSV hepatitis with dissemination. Although the patient was treated with intravenous acyclovir, multiorgan failure developed, and he died. DISCUSSION: This case highlights the importance of considering alternative causes for a rise in ferritin levels when HLH is on the differential. Additionally, we discuss the diagnostic and therapeutic implications of HSV hepatitis, and we review the literature for cases presenting in immunocompetent hosts.

A 5-day intensive curriculum for interns utilizing simulation and active-learning techniques: addressing domains important across internal medicine practice.

OBJECTIVE: Simulation-based learning strategies have demonstrated improved procedural competency, teamwork skills, and acute patient management skills in learners. "Boot camp" curricula have shown immediate and delayed performance in surgical and medical residents. We created a 5-day intensive, simulation and active learning-based curriculum for internal medicine interns to address perceived gaps in cognitive, affective and psychomotor domains. Intern confidence and self-perceived competence was assessed via survey before and after the curriculum, along with qualitative data. RESULTS: A total of 33 interns completed the curriculum in 2014, 32 in 2015. Interns had a significant increase in confidence and self-perceived competence in procedural, cognitive and affective domains (all p values < .05).

The Strength of Transosseous Medial Meniscal Root Repair Using a Simple Suture Technique Is Dependent on Suture Material and Position.

BACKGROUND: A simple suture technique in transosseous meniscal root repair can provide equivalent resistance to cyclic load and is less technically demanding to perform compared with more complex suture configurations, yet maximum yield loads are lower. Various suture materials have been investigated for repair, but it is currently not clear which material is optimal in terms of repair strength. Meniscal root anatomy is also complex; consisting of the ligamentous mid-substance (root ligament), the transition zone between the meniscal body and root ligament; the relationship between suture location and maximum failure load has not been investigated in a simulated surgical repair. HYPOTHESES: (A) Using a knottable, 2-mm-wide, ultra-high-molecular-weight polyethylene (UHMWPE) braided tape for transosseous meniscal root repair with a simple suture technique will give rise to a higher maximum failure load than a repair made using No. 2 UHMWPE standard suture material for simple suture repair. (B) Suture position is an important factor in determining the maximum failure load. STUDY DESIGN: Controlled laboratory study. METHODS: In part A, the posterior root attachment of the medial meniscus was divided in 19 porcine knees. The tibias were potted, and repair of the medial meniscus posterior root was performed. A suture-passing device was used to place 2 simple sutures into the posterior root of the medial meniscus during a repair procedure that closely replicated single-tunnel, transosseous surgical repair commonly used in clinical practice. Ten tibias were randomized to repair with No. 2 suture (Suture group) and 9 tibias to repair with 2-mm-wide knottable braided tape (Tape group). The repair strength was assessed by maximum failure load measured by use of a materials testing machine. Micro-computed tomography (CT) scans were obtained to assess suture positions within the meniscus. The wide range of maximum failure load appeared related to suture position. In part B, 10 additional porcine knees were prepared. Five knees were randomized to the Suture group and 5 to the Tape group. All repairs were standardized for location, and the repair was placed in the body of the meniscus. A custom image registration routine was created to coregister all 29 menisci, which allowed the distribution of maximum failure load versus repair location to be visualized with a heat map. RESULTS: In part A, higher maximum failure load was found for the Tape group (mean, 86.7 N; 95% CI, 63.9-109.6 N) compared with the Suture group (mean, 57.2 N; 95% CI, 30.5-83.9 N). The 3D micro-CT analysis of suture position showed that the mean maximum failure load for repairs placed in the meniscus body (mean, 104 N; 95% CI, 81.2-128.0 N) was higher than for those placed in the root ligament (mean, 35.1 N; 95% CI, 15.7-54.5 N). In part B, the mean maximum failure load was significantly greater for the Tape group, 298.5 N ( P = .016, Mann-Whitney U; 95% CI, 183.9-413.1 N), compared with that for the Suture group, 146.8 N (95% CI, 82.4-211.6 N). Visualization with the heat map revealed that small variations in repair location on the meniscus were associated with large differences in maximum failure load; moving the repair entry point by 3 mm could reduce the failure load by 50%. CONCLUSION: The use of 2-mm braided tape provided higher maximum failure load than the use of a No. 2 suture. The position of the repair in the meniscus was also a highly significant factor in the properties of the constructs. CLINICAL RELEVANCE: The results provide insight into material and location for optimal repair strength.

Platypnea-Orthodeoxia Syndrome: A Case of Chronic Paroxysmal Hypoxemia.

A 75-year-old man with chronic (30-year) unexplained paroxysmal hypoxemia presented with postural hypoxemia and desaturation consistent with a clinical manifestation of platypnea-orthodeoxia syndrome. His history included a lack of significant past pulmonary disease, yet with intermittent need for oxygen supplementation. On admission he was found to have an interatrial shunt through a patent foramen ovale. Device closure by percutaneous catheterization led to sustained resolution of symptoms. Platypnea-orthodeoxia syndrome is a rare but important consideration in the differential diagnosis of hypoxemia, as it represents a potentially curable cause of hypoxemia, with missed diagnosis leading to possible patient morbidity if untreated. Even more importantly, an astute and careful history and physical examination are integral to the diagnosis of this rare but likely under-recognized syndrome.

Cotton Fever: Does the Patient Know Best?

Fever and leukocytosis have many possible etiologies in injection drug users. We present a case of a 22-year-old woman with fever and leukocytosis that were presumed secondary to cotton fever, a rarely recognized complication of injection drug use, after an extensive workup. Cotton fever is a benign, self-limited febrile syndrome characterized by fevers, leukocytosis, myalgias, nausea and vomiting, occurring in injection drug users who filter their drug suspensions through cotton balls. While this syndrome is commonly recognized amongst the injection drug user population, there is a paucity of data in the medical literature. We review the case presentation and available literature related to cotton fever.

Sonar target enhancement by shrinkage of incoherent wavelet coefficients.

Background reverberation can obscure useful features of the target echo response in broadband low-frequency sonar images, adversely affecting detection and classification performance. This paper describes a resolution and phase-preserving means of separating the target response from the background reverberation noise using a coherence-based wavelet shrinkage method proposed recently for de-noising magnetic resonance images. The algorithm weights the image wavelet coefficients in proportion to their coherence between different looks under the assumption that the target response is more coherent than the background. The algorithm is demonstrated successfully on experimental synthetic aperture sonar data from a broadband low-frequency sonar developed for buried object detection.

Impact of hyponatremia and the syndrome of inappropriate antidiuresis on mortality in elderly patients with aspiration pneumonia.

BACKGROUND: Hyponatremia is associated with pneumonia, and aspiration pneumonia is common in the elderly, however, there has been no study of hyponatremia in this population. OBJECTIVE: To determine the impact of hyponatremia on mortality in elderly patients with aspiration pneumonia, while focusing on the comparison between those with and without the syndrome of inappropriate antidiuresis (SIAD). DESIGN: Retrospective review of existing database and medical records. SETTING: A community teaching hospital in Japan. PATIENTS: Two hundred and twenty-one elderly patients hospitalized with aspiration pneumonia. MEASUREMENTS: Multivariate logistical regression models were used to compare 30-day and in-hospital mortality, in patients with hyponatremia of various severities and etiologies, with that in patients with normal serum sodium concentrations. RESULTS: Sixty-five (29%) of 221 patients had hyponatremia. Of these 62 (95%) had hypotonic hyponatremia, which were further assessed as having hypovolemic (39 [63%]), hypervolemic (3 [5%]), and euvolemic (20 [32%]) hyponatremia. Of the 20 euvolemic patients, 14 (70%) had SIAD. Both moderate and severe hypotonic hyponatremia were significantly associated with increased in-hospital mortality (odds ratio [OR] 6.05, 95% confidence interval [CI] 1.46-25.0, and OR 5.65, 95% CI 1.14-28.1, respectively). Hyponatremia due to SIAD was significantly associated with both increased 30-day mortality (OR 7.40, 95% CI 1.73-31.7) and increased in-hospital mortality (OR 22.3, 95% CI 4.26-117). In contrast, hypovolemic hyponatremia was not significantly associated with increased mortality. CONCLUSIONS: Hyponatremia due to SIAD was strongly associated with increased mortality in elderly patients with aspiration pneumonia, whereas hypovolemic hyponatremia was not associated with increased mortality.

Thoracic endometriosis unmasked by ovarian hyperstimulation for in vitro fertilization.

Thoracic endometriosis syndrome is a well-described, rare manifestation of endometriosis. We present a case of a 35-year old woman undergoing controlled ovarian stimulation prior to in vitro fertilization (IVF) who developed bilateral hemorrhagic pleural effusions. She was initially diagnosed with ovarian hyperstimulation syndrome, a complication of infertility therapy; however, she was later found to have occult thoracic endometriosis. We describe ovarian hyperstimulation syndrome and review the manifestations of thoracic endometriosis syndrome. Although endometriosis is a hormone-dependent disease, the rate of IVF complications related to endometriosis is low.

Least-squares estimation of imaging parameters for an ultrasonic array using known geometric image features.

Ultrasonic array images are adversely affected by errors in the assumed or measured imaging parameters. For non-destructive testing and evaluation, this can result in reduced defect detection and characterization performance. In this paper, an autofocus algorithm is presented for estimating and correcting imaging parameter errors using the collected echo data and a priori knowledge of the image geometry. Focusing is achieved by isolating a known geometric feature in the collected data and then performing a weighted leastsquares minimization of the errors between the data and a feature model, with respect to the unknown parameters. The autofocus algorithm is described for the estimation of element positions in a flexible array coupled to a specimen with an unknown surface profile. Experimental results are shown using a prototype flexible array and it is demonstrated that (for an isolated feature and a well-prescribed feature model) the algorithm is capable of generating autofocused images that are comparable in quality to benchmark images generated using accurately known imaging parameters.