Energy Injection for Fast Ignition

In the fast ignition concept, assembled fuel is ignited through a separate high intensity laser pulse. Fast Ignition targets facilitate this ignition using a reentrant cone. It provides clear access through the overlaying coronal plasma, and controls the laser plasma interaction to optimize hot-electron production and transport into the compressed plasma. Recent results suggest that the cone does not play any role in guiding light or electrons to its tip, and coupling to electrons can be reduced by a small amount of preplasma. This puts stringent requirements on the ignition laser focusing, pointing, and prepulse

Predictors of Unattempted Central Venous Catheterization in Septic Patients Eligible for Early Goal-directed Therapy

Introduction: Central venous catheterization (CVC) can be an important component of the management of patients with severe sepsis and septic shock. CVC, however, is a time- and resource-intensive procedure associated with serious complications. The effects of the absence of shock or the presence of relative contraindications on undertaking central line placement in septic emergency department (ED) patients eligible for early goal-directed therapy (EGDT) have not been well described. We sought to determine the association of relative normotension (sustained systolic blood pressure >90 mmHg independent of or in response to an initial crystalloid resuscitation of 20 mL/kg), obesity (body mass index [BMI] ≥30), moderate thrombocytopenia (platelet count <50,000 per μL), and coagulopathy (international normalized ratio ≥2.0) with unattempted CVC in EGDT-eligible patients. Methods: This was a retrospective cohort study of 421 adults who met EGDT criteria in 5 community EDs over a period of 13 months. We compared patients with attempted thoracic (internal jugular or subclavian) CVC with those who did not undergo an attempted thoracic line. We also compared patients with any attempted CVC (either thoracic or femoral) with those who did not undergo any attempted central line. We used multivariate logistic regression analysis to calculate adjusted odd ratios (AORs). Results: In our study, 364 (86.5%) patients underwent attempted thoracic CVC and 57 (13.5%) did not. Relative normotension was significantly associated with unattempted thoracic CVC (AOR 2.6 95% confidence interval [CI], 1.6-4.3), as were moderate thrombocytopenia (AOR 3.9; 95% CI, 1.5-10.1) and coagulopathy (AOR 2.7; 95% CI, 1.3-5.6). When assessing for attempted catheterization of any central venous site (thoracic or femoral), 382 (90.7%) patients underwent attempted catheterization and 39 (9.3%) patients did not. Relative normotension (AOR 2.3; 95% CI, 1.2-4.5) and moderate thrombocytopenia (AOR 3.9; 95% CI, 1.5-10.3) were significantly associated with unattempted CVC, whereas coagulopathy was not (AOR 0.6; 95% CI, 0.2-1.8). Obesity was not significantly associated with unattempted CVC, either thoracic in location or at any site. Conclusion: Septic patients eligible for EGDT with relative normotension and those with moderate thrombocytopenia were less likely to undergo attempted CVC at any site. Those with coagulopathy were also less likely to undergo attempted thoracic central line placement. Knowledge of the decision-making calculus at play for physicians considering central venous catheterization in this population can help inform physician education and performance improvement programs. [West J Emerg Med. 2014;15(1):67–75.

Use of an Electronic Medical Record “Dotphrase” Data Template for a Prospective Head Injury Study

Introduction: The adoption of electronic medical records (EMRs) in emergency departments (EDs) has changed the way that healthcare information is collected, charted, and stored. A challenge for researchers is to determine how EMRs may be leveraged to facilitate study data collection efforts. Our objective is to describe the use of a unique data collection system leveraging EMR technology and to compare data entry error rates to traditional paper data collection. Methods: This was a retrospective review of data collection methods during a multicenter study of ED, anti-coagulated, head injury patients. On-shift physicians at 4 centers enrolled patients and prospectively completed data forms. These physicians had the option of completing a paper data form or an electronic “dotphrase” (DP) data form. A feature of our Epic®-based EMR is the ability to use DPs to assist in medical information entry. A DP is a preset template that may be inserted into the EMR when the physician types a period followed by a code phrase (in this case “.ichstudy”). Once the study DP was inserted at the bottom of the electronic ED note, it prompted enrolling physicians to answer study questions. Investigators then extracted data directly from the EMR. Results: From July 2009 through December 2010, we enrolled 883 patients. DP data forms were used in 288 (32.6%; 95% confidence interval [CI] 29.5, 35.7%) cases and paper data forms in 595 (67.4%; 95% CI 64.3, 70.5%). Sixty-six (43.7%; 95% CI 35.8, 51.6%) of 151 physicians enrolling patients used DP data entry at least once. Using multivariate analysis, we found no association between physician age, gender, or tenure and DP use. Data entry errors were more likely on paper forms (234/595, 39.3%; 95% CI 35.4, 43.3%) than DP forms (19/288, 6.6%; 95% CI 3.7, 9.5%), difference in error rates 32.7% (95% CI 27.9, 37.6%, P &lt; 0.001). Conclusion: DP data collection is a feasible means of data collection. DP data forms maintain all study data within the secure EMR environment, obviating the need to maintain and collect paper data forms. This innovation was embraced by many of our emergency physicians and resulted in lower data entry error rates. [West J Emerg Med 2013;14(2):109-113.

Density measurement of shock compressed foam using two-dimensional x-ray radiography

We have used spherically bent quartz crystal to image a laser-generated shock in a foam medium. The foam targets had a density of 0.16 g/cm(3) and thickness of 150 mu m, an aluminum/copper pusher drove the shock. The experiment was performed at the Titan facility at Lawrence Livermore National Laboratory using a 2 ns, 250 J laser pulse to compress the foam target, and a short pulse (10 ps, 350 J) to generate a bright Ti K alpha x-ray source at 4.5 keV to radiograph the shocked target. The crystal used gives a high resolution (similar to 20 mu m) monochromatic image of the shock compressed foam