Are the unreamed nails indicated in diaphyseal fractures of the lower extremity? A biomechanical study.

INTRODUCTION: Intramedullary nailing is generally accepted as the first choice for the treatment of diaphyseal fractures of femur and tibia, with a gradual incease in the use of unreamed nails. Different studies during last years show controversial outcomes. Some authors strongly favor unreamed nailing, but most of the authors conclude that reamed nailing have proved to be more successful. MATERIAL AND METHODS: This study simulates unreamed intramedullary nailing of four femoral and three tibial fracture types by means of Finite Element (FE) models, at early postoperative stages with a fraction of physiological loads, in order to determine whether sufficient stability is achieved, and if the extent of movements and strains at the fracture site may preclude proper consolidation. RESULTS: The behavior observed in the different fracture models is very diverse. In the new biomechanical situation, loads are only transmitted through the intramedullary nail. Mean relative displacement values of fractures in the femoral bone range from 0.30 mm to 0.82 mm, depending on the fracture type. Mean relative displacement values of the tibial fractures lie between 0.18 and 0.62 mm, depending on the type of fracture. Concerning mean strains, for femoral fractures the maximum strains ranged between 12.7% and 42.3%. For tibial fractures the maximum strains ranged between 10.9% and 40.8%. CONCLUSIONS: The results showed that unreamed nailing provides a very limited mechanical stability, taking into account that analyzed fracture patterns correspond to simple fracture without comminution. Therefore, unreamed nailing is not a correct indication in femoral fractures and should be an exceptional indication in open tibial fractures produced by high-energy mechanism.

Ultrahigh molecular weight polyethylene/graphene oxide nanocomposites: Wear characterization and biological response to wear particles.

In the field of total joint replacements, polymer nanocomposites are being investigated as alternatives to ultrahigh molecular weight polyethylene (UHMWPE) for acetabular cup bearings. The objective of this study was to investigate the wear performance and biocompatibility of UHMWPE/graphene oxide (GO) nanocomposites. This study revealed that low concentrations of GO nanoparticles (0.5 wt %) do not significantly alter the wear performance of UHMWPE. In contrast, the addition of higher concentrations (2 wt %) led to a significant reduction in wear. In terms of biocompatibility, UHMWPE/GO wear particles did not show any adverse effects on L929 fibroblast and PBMNC viability at any of the concentrations tested over time. Moreover, the addition of GO to a UHMWPE matrix did not significantly affect the inflammatory response to wear particles. Further work is required to optimize the manufacturing processes to improve the mechanical properties of the nanocomposites and additional biocompatibility testing should be performed to understand the potential clinical application of these materials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 183-190, 2018.

A national survey of Turkish emergency physicians perspectives regarding family witnessed cardiopulmonary resuscitation.

We investigated Turkish emergency physicians' views regarding family witnessed resuscitation (FWR) and to determine the current practice in Turkish academic emergency departments with regard to family members during resuscitation. A national cross-sectional, anonymous survey of emergency physicians working in academic emergency departments was conducted. Nineteen of the 23 university-based emergency medicine programs participated in the study. Two hundred and thirty-nine physicians completed the survey. Of the respondents, 83% did not endorse FWR. The most common reasons for not endorsing FWR was reported as higher stress levels of the resuscitation team and fear of causing physiological trauma to family members. Previous experience, previous knowledge in FWR, higher level of training and the acceptance of FWR in the institution where the participant works were associated with higher rates of FWR endorsement for this practice among emergency physicians.

Simulation based teamwork training for emergency department staff: does it improve clinical team performance when added to an existing didactic teamwork curriculum?

OBJECTIVE: To determine if high fidelity simulation based team training can improve clinical team performance when added to an existing didactic teamwork curriculum. SETTING: Level 1 trauma center and academic emergency medicine training program. PARTICIPANTS: Emergency department (ED) staff including nurses, technicians, emergency medicine residents, and attending physicians. INTERVENTION: ED staff who had recently received didactic training in the Emergency Team Coordination Course (ETCC) also received an 8 hour intensive experience in an ED simulator in which three scenarios of graduated difficulty were encountered. A comparison group, also ETCC trained, was assigned to work together in the ED for one 8 hour shift. Experimental and comparison teams were observed in the ED before and after the intervention. DESIGN: Single, crossover, prospective, blinded and controlled observational study. Teamwork ratings using previously validated behaviorally anchored rating scales (BARS) were completed by outside trained observers in the ED. Observers were blinded to the identification of the teams. RESULTS: There were no significant differences between experimental and comparison groups at baseline. The experimental team showed a trend towards improvement in the quality of team behavior (p = 0.07); the comparison group showed no change in team behavior during the two observation periods (p = 0.55). Members of the experimental team rated simulation based training as a useful educational method. CONCLUSION: High fidelity medical simulation appears to be a promising method for enhancing didactic teamwork training. This approach, using a number of patients, is more representative of clinical care and is therefore the proper paradigm in which to perform teamwork training. It is, however, unclear how much simulator based training must augment didactic teamwork training for clinically meaningful differences to become apparent.

The nontraumatic, acute scrotum.

Regardless of age, any presentation of an acute scrotum requires prompt triage and immediate evaluation. The potential for significant reduction in morbidity and mortality exists if timely diagnosis and treatment are provided. Often overlooked, an early scrotal examination in the emergency department may produce the most accurate information into the underlying pathologic process, be it systemic or localized to the scrotum. Although the immediately lethal conditions presenting as acute scrotal pain should be considered, the combined incidence and morbidity associated with testicular torsion make its exclusion paramount in acute scrotal presentations. Similarly, a painless scrotal mass must be assumed to be a testicular neoplasm until proven otherwise, with appropriate work-up and rapid urologic follow-up assured.

Genitourinary trauma.

Injuries to the GU system commonly occur in patients with high-energy lower abdominal or pelvic trauma. The emergency physician should be well versed in the diagnosis and management of GU trauma, although these injuries are not usually life threatening because of the potential for loss of urinary or sexual function. In the setting of hemodynamic instability, diagnosis and treatment of GU injuries is often accomplished in the operative setting. In the stable patient, diagnostic testing is directed by the type of suspected injury and must proceed in a reverse manner, i.e., external injury then urethral injury then bladder, and finally urethral and renal damage. Treatment focuses on a team approach between the emergency physician, general, orthopedic, and urologic surgeon. The decision for operative repair is often dictated more by other associated injuries than urologic injuries, and the urologic surgeon often provides temporizing measures with definitive repair at a later time. Prompt diagnosis and treatment of injuries to the external genitals results in excellent long-term outcome, minimizing the devastating consequences of impotence, urinary incontinence, and sexual disfiguration.

A porcine model for instruction of lateral canthotomy.

OBJECTIVES: Retrobulbar hemorrhage is a rare condition often necessitating immediate lateral canthotomy for preservation of vision. It is performed infrequently in emergency departments (EDs); therefore, a laboratory-based curriculum using a swine model was developed to teach emergency medicine (EM) residents and pediatric emergency medicine (PEM) fellows the proper technique of lateral canthotomy and to provide them with hands-on training. METHODS: Anesthetized adult swine are used due to similarity with human anatomy and availability from other concurrent procedure laboratories. Fifteen to twenty milliliters of saline is injected behind the orbit to produce proptosis and mimic retrobulbar hemorrhage. A dissection is performed on one orbit to demonstrate the technique and to illustrate the lateral canthal ligaments. The resident then performs a rapid lateral canthotomy on the contralateral orbit under faculty supervision. RESULTS: Over one year, 19 EM residents and 3 PEM fellows were trained using this model. During the same period no lateral canthotomies were performed in the EDs. A post-laboratory survey demonstrated a high subjective level of comfort with this procedure. Video-based demonstration of this laboratory is publicly available on the World Wide Web. CONCLUSION: Adult swine can effectively serve as a model for resident training in lateral canthotomy, a rarely performed sight-saving procedure.

Development of an equipment and supply list for emergency medical services delivery at an annual air show.

INTRODUCTION: Reports of medical care at mass gatherings reflect variability in mission and delivery models. Equipment recommendations are similarly varied. Thoughtful pre-planning and experience-based analysis are the best mechanisms for defining general and specific equipment recommendations. OBJECTIVE: This report presents a suggested supply and equipment list developed over a six-year period of medical coverage at an air show, with an emphasis on the usage and cost of expendable supplies. METHODS: The authors were involved in the planning for and execution of emergency medical care for a large, local, military air show on an annual basis, including provision of expendable medical supplies. A list of such supplies was developed over the initial two to three years, formalized and refined over the subsequent two years, and analyzed in the final, highest patient volume year of coverage. Detailed usage and cost was tracked over the final year for expendable supplies. RESULTS: The results of this analysis indicate that comprehensive emergency medical care from first aid to mass casualty care can be offered at reasonable equipment and supply costs, if existing equipment resources can be supplemented by expendable supplies from a pre-determined list. Given the need for large quantities of supplies for a mass casualty contingency and the low likelihood of occurrence, a loan arrangement with a supplier, with return of unused supplies, is particularly convenient and economical. The approach used in this study should be appreciable in other similar settings. In concurrent scheduled events, the iterative process described can lead to greater specificity of needs for expendable supplies.

Pediatric gamma hydroxybutyrate intoxication.

Reported are 2 uncommon cases of childhood gamma hydroxybutyrate (GHB) toxicity and the surreptitious manner in which GHB was made. Two children unintentionally ingested a soft drink containing GHB and were found comatose. Both had been well 1 hour earlier. The parent had made GHB by combining gamma butyrolactone with caustic soda (sodium hydroxide). Symptoms were early in onset and resolved in 24 hours. The ECG changes in one case are unique to GHB toxicity and are unexplained. GHB-toxic children appear similar to adults who have this poisoning. Supportive management remains the mainstay of therapy. Health care providers should be aware of GHB's clandestine production and its increasing presence on the streets and in the home. This agent is not detected with common drug screens.

Fatal spontaneous rupture of a gravid uterus: case report and literature review of uterine rupture.

Spontaneous uterine rupture is a life-threatening obstetrical emergency encountered infrequently in the emergency department. The diagnosis of spontaneous uterine rupture is often missed or delayed, leading to maternal and fetal mortality. Emergency physicians must consider this diagnosis when presented with a pregnant patient in shock with abdominal pain. We present the case of a 38-year-old gravid female who presented to the emergency department in cardiac arrest 24 hours after an initial complaint of abdominal pain. We review the uterine rupture literature with specific focus on risk factors, signs and symptoms, diagnosis, treatment, and outcome.

Child with idiopathic ventricular tachycardia of prolonged duration.

Ventricular tachycardia is a dangerous dysrhythmia most commonly encountered in adult patients with heart disease. It is uncommon for a previously healthy child to present to the emergency department with hemodynamically stable ventricular tachycardia. The diagnosis and management of this dysrhythmia may pose a significant challenge to the emergency physician. We present the case of a previously healthy child with a structurally normal heart who had ventricular tachycardia for a prolonged period. Common causes of childhood tachycardia and options for treatment of stable and unstable patients are discussed.

Dynamic organization of primary motor cortex output to target muscles in adult rats. II. Rapid reorganization following motor nerve lesions.

In the accompanying paper (Sanes et al. 1989), we demonstrated that the map of motor cortex (MI) output was reorganized when examined 1 week to 4 months after a motor nerve lesion in adult rats. The present experiments measured the extent of functional reorganization that occurs within the first hours after this lesion. Shifts in MI output were examined by testing the effect of stimulation at a site in MI vibrissa area before and up to 10 h after nerve section of the branches of the facial nerve that innervate the vibrissa. Immediately following nerve transection, no movement or forelimb EMG activity was evoked by intracortical electrical stimulation within the vibrissa area. Within hours of the nerve transection, however, stimulation elicited forelimb EMG responses that were comparable to those obtained by stimulating within the pre-transection forelimb area. Remapping of MI after nerve transection indicated that the forelimb boundary had shifted about 1 mm medially from its original location into the former vibrissa territory. Forelimb EMG could be evoked for up to 10 h within this reorganized cortex. These results indicated that the output circuits of MI can be quickly reorganized by nerve lesions in adult mammals.

Dynamic organization of primary motor cortex output to target muscles in adult rats. I. Long-term patterns of reorganization following motor or mixed peripheral nerve lesions.

These experiments examined the ability of the adult motor cortex to reorganize its relationship with somatic musculature following nerve lesions. Cortical motor output organization was assessed by mapping the areal extent of movements evoked by intracortical electrical stimulation in anesthetized rats. Output patterns of the motor cortex of normal rats were compared with those of adult rats that had received either a forelimb amputation or a facial motor nerve transection 1 week to 4 months earlier. In both experimental conditions the extent of some representations increased. Stimulation thresholds required to elicit movements in expanded representations were at or below normal levels. After forelimb amputation, the area from which shoulder movements could be evoked at low thresholds enlarged. Sectioning of the branches of the facial nerve that innervate the vibrissa musculature enlarged the motor cortex forelimb and eye/eyelid output areas; these enlargements appeared to occupy the former vibrissa area. These results indicate that the amount of cortex controlling a group of muscles and the strength of the relationship between a cortical locus with its target muscles is modified by nerve lesions in adult mammals. They also show that motor nerve lesions are sufficient to produce this change and that the changes can appear as early as 7 days following a peripheral nerve injury.

Rapid reorganization of adult rat motor cortex somatic representation patterns after motor nerve injury.

The potential for peripheral nerve injury to reorganize motor cortical representations was investigated in adult rats. Maps reflecting functional connections between the motor cortex and somatic musculature were generated with intracortical electrical stimulation techniques. Comparison of cortical somatotopic maps obtained in normal rats with maps generated from rats with a facial nerve lesion indicated that the forelimb and eye/eyelid representations expanded into the normal vibrissa area. Repeated testing from an electrode placed chronically in the motor cortex showed a shift from vibrissa to forelimb within hours after facial nerve transection. These comparatively quick changes in motor cortex representation pattern suggest that synaptic relations between motor cortex and somatic musculature are continually reshaped in adult mammals.