Dana Sajed

Axonal Regeneration through Regions of Chondroitin Sulfate Proteoglycan Deposition after Spinal Cord Injury: A Balance of Permissiveness and Inhibition

Increased expression of certain extracellular matrix (ECM) molecules after CNS injury is believed to restrict axonal regeneration. The chondroitin sulfate proteoglycans (CSPGs) are one such class of ECM molecules that inhibit neurite outgrowth in vitro and are upregulated after CNS injury. We examined growth responses of several classes of axons to this inhibitory environment in the presence of a cellular fibroblast bridge in a spinal cord lesion site and after a growth factor stimulus at the lesion site (fibroblasts genetically modified to secrete NGF). Immunohistochemical analysis showed dense labeling of the CSPGs NG2, brevican, neurocan, versican, and phosphacan at the host-lesion interface after spinal cord injury (SCI). Furthermore, robust expression of NG2, and to a lesser extent versican, was also observed throughout grafts of control and NGF-secreting fibroblasts. Despite this inhibitory milieu, several axonal classes penetrated control fibroblast grafts, including dorsal column sensory, rubrospinal, and nociceptive axons. Axon growth was amplified more in the presence of NGF-secreting grafts. Confocal microscopy demonstrated that axon growth was, paradoxically, preferentially associated with NG2-rich substrates in both graft types. NG2 expression also increased after sciatic nerve injury, wherein axons successfully regenerate. Cellular sources of NG2 in SCI and peripheral nerve lesion sites included Schwann cells and endothelial cells. Notably, these same cellular sources in lesion sites produced the cell adhesion molecules L1 and laminin, and these molecules all colocalized. Thus, axons grow along substrates coexpressing both inhibitory and permissive molecules, suggesting that regeneration is successful when local permissive signals balance and exceed inhibitory signals.

Bedside ultrasound maximizes patient satisfaction.

BACKGROUND Bedside ultrasound (US) is associated with improved patient satisfaction, perhaps as a consequence of improved time to diagnosis and decreased length of stay (LOS). OBJECTIVES Our study aimed to quantify the association between beside US and patient satisfaction and to assess patient attitudes toward US and perception of their interaction with the clinician performing the examination. METHODS We enrolled a convenience sample of adult patients who received a bedside US. The control group had similar LOS and presenting complaints but did not have a bedside US. Both groups answered survey questions during their emergency department (ED) visit and again by telephone 1 week later. The questionnaire assessed patient perceptions and satisfaction on a 5-point Likert scale. RESULTS Seventy patients were enrolled over 10 months. The intervention group had significantly higher scores on overall ED satisfaction (4.69 vs. 4.23; mean difference 0.46; 95% confidence interval [CI] 0.17-0.75), diagnostic testing (4.54 vs. 4.09; mean difference 0.46; 95% CI 0.16-0.76), and skills/abilities of the emergency physician (4.77 vs. 4.14; mean difference 0.63; 95% CI 0.29-0.96). A trend to higher scores for the intervention group persisted on follow-up survey. CONCLUSIONS Patients who had a bedside US had statistically significant higher satisfaction scores with overall ED care, diagnostic testing, and with their perception of the emergency physician. Bedside US has the potential not only to expedite care and diagnosis, but also to maximize satisfaction scores and improve the patient-physician relationship, which has increasing relevance to health care organizations and hospitals that rely on satisfaction surveys.

Impact of point-of-care ultrasound training on surgical residents' confidence.

OBJECTIVE Point-of-care ultrasound (POCUS) is a vital tool for diagnosis and management of critically ill patients, particularly in resource-limited settings where access to diagnostic imaging may be constrained. We aimed to develop a novel POCUS training curriculum for surgical practice in the United States and in resource-limited settings in low- and middle-income countries and to determine its effect on surgical resident self-assessments of efficacy and confidence. DESIGN We conducted an observational cohort study evaluating a POCUS training course that comprised 7 sessions of 2 hours each with didactics and proctored skills stations covering ultrasound applications for trauma (Focused Assessement with Sonography for Trauma (FAST) examination), obstetrics, vascular, soft tissue, regional anesthesia, focused echocardiography, and ultrasound guidance for procedures. Surveys on attitudes, prior experience, and confidence in point-of-care ultrasound applications were conducted before and after the course. SETTING General Surgery Training Program in Seattle, Washington. PARTICIPANTS A total of 16 residents participated in the course; 15 and 10 residents completed the precourse and postcourse surveys, respectively. RESULTS The mean composite confidence score from pretest compared with posttest improved from 23.3 (±10.2) to 37.8 (±6.7). Median confidence scores (1-6 scale) improved from 1.5 to 5.0 in performance of FAST (p < 0.001). Residents reported greater confidence in their ability to identify pericardial (2 to 4, p = 0.009) and peritoneal fluid (2 to 4.5, p < 0.001), to use ultrasound to guide procedures (3.5 to 4.0, p = 0.008), and to estimate ejection fraction (1 to 4, p = 0.004). Both before and after training, surgical residents overwhelmingly agreed with statements that ultrasound would improve their US-based practice, make them a better surgical resident, and improve their practice in resource-limited settings. CONCLUSIONS After a POCUS course designed specifically for surgeons, surgical residents had improved self-efficacy and confidence levels across a broad range of skills.

The History of Point-of-Care Ultrasound Use in Disaster and Mass Casualty Incidents.

During disasters and mass casualties, point-of-care ultrasound makes it possible to diagnose thoraco-abdominal injuries rapidly and accurately, offers a tool for procedure guidance, and has streamlined patient triage. Virtual Mentor is a monthly bioethics journal published by the American Medical Association.

Delayed pneumothorax after stab wound to thorax and upper abdomen: Truth or myth?

BACKGROUND Stab wounds to the thorax and upper abdomen have the potential to cause pneumothorax (PTX). When a CXR (CXR) obtained during initial resuscitation is negative, a second CXR (CXR-2) is commonly performed with the goal of identifying delayed PTX. OBJECTIVES To assess the diagnostic yield of the CXR-2 in identifying delayed PTX. METHODS Prospective observational study of patients (age >or=13 years) with stab wounds to the thorax (chest/back) and upper abdomen with suspected PTX, in a level 1 trauma centre. Patients were included if they had a negative initial CXR followed by a repeat CXR 3-6h after the initial one. EXCLUSION CRITERIA patients who died, were transferred out of the ED, or received chest tubes before the second CXR. The outcome of interest was delayed PTX. All CXR were read by an attending radiologist. To test the inter-observer agreement, another blinded radiologist reviewed 20% of CXR. Continuous data is presented as mean+/-standard deviation and categorical data as percentages with 95% confidence interval (CI). Kappa statistics were used to measure the inter-observer agreement between radiologists. RESULTS Between January 2003 and December 2006 a total of 185 patients qualified for the enrollment (mean age: 28+/-10 years, age range: 13-65, 94% male). Only 2 patients (1.1%, 95% CI, 0.4- 4.1%) had PTX on the CXR-2. Both patients received chest tubes. The inter-observer agreement for radiology reports was high (kappa: 0.79). CONCLUSION Occurrence of delayed PTX in patients with stab wounds to the thorax and upper abdomen and negative triage CXR is rare.

BE-SAFE: Bedside sonography for assessment of the fetus in emergencies: educational intervention for late-pregnancy obstetric ultrasound.

Introduction Late obstetric emergencies are time critical presentations in the emergency department. Evaluation to ensure the safety of mother and child includes rapid assessment of fetal viability, fetal heart rate (FHR), fetal lie, and estimated gestational age (EGA). Point-of-care (POC) obstetric ultrasound (OBUS) offers the advantage of being able to provide all these measurements. We studied the impact of POC OBUS training on emergency physician (EP) confidence, knowledge, and OBUS skill performance on a live model. Methods This is a prospective observational study evaluating an educational intervention we designed, called the BE-SAFE curriculum (BEdside Sonography for the Assessment of the Fetus in Emergencies). Subjects were a convenience sample of EP attendings (N=17) and residents (N=14). Prior to the educational intervention, participants completed a self-assessment survey on their confidence regarding OBUS, and took a pre-test to assess their baseline knowledge of OBUS. They then completed a 3-hour training session consisting of didactic and hands-on education in OBUS. After training, each subject’s time and accuracy of performance of FHR, EGA, and fetal lie was recorded. Post-intervention knowledge tests and confidence surveys were administered. Results were compared with non-parametric t-tests. Results Pre- and post-test knowledge assessment scores for previously untrained EPs improved from 65.7% [SD=20.8] to 90% [SD=8.2] (p<0.0007). Self-confidence on a scale of 1–6 improved significantly for identification of FHR, fetal lie, and EGA. After training, the average times for completion of OBUS critical skills were as follows: cardiac activity (9s), FHR (68.6s), fetal lie (28.1s), and EGA (158.1 sec). EGA estimates averaged 28w0d (25w0d-30w6d) for the model’s true gestational age of 27w0d. Conclusion After a focused POC OBUS training intervention, the BE-SAFE educational intervention, EPs can accurately and rapidly use ultrasound to determine FHR, fetal lie, and estimate gestational age in mid-late pregnancy.

DIAGNOSIS OF MEGAURETER BY POINT-OF-CARE ULTRASOUND

BACKGROUND Presentation of congenital megaureter in adult life is rare; patients usually become symptomatic in childhood. CASE REPORT A 32-year-old man presented to the Emergency Department (ED) with dyspnea, tongue swelling, and a rash, which he attributed to amoxicillin he had taken shortly prior to onset of symptoms. He was hypotensive on arrival to the ED. To further evaluate the hypotension, point-of-care ultrasound of the heart, lungs, and abdomen were performed while treatment for anaphylaxis was initiated. Ultrasound examination did not identify a cause for hypotension, but the treating physician noted an anechoic structural abnormality posterior to the bladder, suggestive of megaureter. The patient responded well to treatment of anaphylaxis; further history and diagnostic imaging subsequently confirmed a diagnosis of congenital megaureter. CONCLUSION We report an unusual case of congenital megaureter, identified by point-of-care ultrasound performed to evaluate hypotension. Clinicians performing limited ultrasound examinations must be attentive to incidental findings that will require follow-up.