Management of severe blunt hepatic injury in the era of computed tomography and transarterial embolization: A systematic review and critical appraisal of the literature.

BACKGROUND: During the last decade, the management of blunt hepatic injury has considerably changed. Three options are available as follows: nonoperative management (NOM), transarterial embolization (TAE), and surgery. We aimed to evaluate in a systematic review the current practice and outcomes in the management of Grade III to V blunt hepatic injury. METHOD: The MEDLINE database was searched using PubMed to identify English-language citations published after 2000 using the key words blunt, hepatic injury, severe, and grade III to V in different combinations. Liver injury was graded according to the American Association for the Surgery of Trauma classification on computed tomography (CT). Primary outcome analyzed was success rate in intention to treat. Critical appraisal of the literature was performed using the validated National Institute for Health and Care Excellence "Quality Assessment for Case Series" system. RESULTS: Twelve articles were selected for critical appraisal (n = 4,946 patients). The median quality score of articles was 4 of 8 (range, 2-6). Overall, the median Injury Severity Score (ISS) at admission was 26 (range, 0.6-75). A median of 66% (range, 0-100%) of patients was managed with NOM, with a success rate of 94% (range, 86-100%). TAE was used in only 3% of cases (range, 0-72%) owing to contrast extravasation on CT with a success rate of 93% (range, 81-100%); however, 9% to 30% of patients required a laparotomy. Thirty-one percent (range, 17-100%) of patients were managed with surgery owing to hemodynamic instability in most cases, with 12% to 28% requiring secondary TAE to control recurrent hepatic bleeding. Mortality was 5% (range, 0-8%) after NOM and 51% (range, 30-68%) after surgery. CONCLUSION: NOM of Grade III to V blunt hepatic injury is the first treatment option to manage hemodynamically stable patients. TAE and surgery are considered in a highly selective group of patients with contrast extravasation on CT or shock at admission, respectively. Additional standardization of the reports is necessary to allow accurate comparisons of the various management strategies. LEVEL OF EVIDENCE: Systematic review, level IV

Performance measurement of a mini thermoacoustic refrigerator and associated drivers

A miniature Thermoacoustic refrigerator is being developed to cool integrated circuits - which must sometimes operate at high temperatures nearing the upper threshold of their tolerance - to temperature spans more within the circuits' tolerable limits, without the need of the chemicals of a traditional refrigerating system. The development of an electrically powered acoustic driver that powers the thermoacoustic refrigerator is described, as well as different schemes to improve its delivered acoustic power. The driver utilizes a flexural tri-laminar piezoelectric disk to generate one to two Watts of acoustic power at 4 kHz in 15 bar of He-Kr gas mixture. Two different drivers are tested on a pressurized test resonator, and their quantitative performance is analyzed. The analysis of the drivers' performance indicates one power-improvement scheme may be faulty, while data taken before the second broke indicates its design may be beneficial to power-improvement. Tests are also conducted using a refrigerating resonator; these first attempts to meet design criteria of temperature span and cooling power are unsuccessful, but the results obtained - including a thermodynamic coefficient of performance (COP) 13.1% below the modeled ideal value for the given data set - with less-than-ideal acoustic power delivered to the resonator signal suggest continued research is worthwhile.http://archive.org/details/performancemeasu109455858Ensign, United States NavyApproved for public release; distribution is unlimited

Wigner phase space distribution as a wave function

We demonstrate that the Wigner function of a pure quantum state is a wave function in a specially tuned Dirac bra-ket formalism and argue that the Wigner function is in fact a probability amplitude for the quantum particle to be at a certain point of the classical phase space. Additionally, we establish that in the classical limit, the Wigner function transforms into a classical Koopman-von Neumann wave function rather than into a classical probability distribution. Since probability amplitude need not be positive, our findings provide an alternative outlook on the Wigner function's negativity.Comment: 6 pages and 2 figure

Out-of-surface vortices in spherical shells

The interplay of topological defects with curvature is studied for out-of-surface magnetic vortices in thin spherical nanoshells. In the case of easy-surface Heisenberg magnet it is shown that the curvature of the underlying surface leads to a coupling between the localized out-of-surface component of the vortex with its delocalized in-surface structure, i.e. polarity-chirality coupling.Comment: 6 pages, 4 figure

Percutaneous Drainage versus Emergency Cholecystectomy for the Treatment of Acute Cholecystitis in Critically Ill Patients: Does it Matter?

Background: The aim if this study was to compare percutaneous drainage (PD) of the gallbladder to emergency cholecystectomy (EC) in a well-defined patient group with sepsis related to acute calculous/acalculous cholecystitis (ACC/AAC). Methods: Between 2001 and 2007, all consecutive patients of our ICU treated by either PD or EC were retrospectively analyzed. Cases were collected from a prospective database. Percutaneous drainage was performed by a transhepatic route and EC by open or laparoscopic approach. Patients' general condition and organ dysfunction were assessed by two validated scoring systems (SAPS II and SOFA, respectively). Morbidity, mortality, and long-term outcome were systematically reviewed and analyzed in both groups. Results: Forty-two patients [median age=65.5years (range=32-94)] were included; 45% underwent EC (ten laparoscopic, nine open) and 55% PD (n=23). Both patient groups had similar preoperative characteristics. Percutaneous drainage and EC were successful in 91 and 100% of patients, respectively. Organ dysfunctions were similarly improved by the third postoperative/postdrainage days. Despite undergoing PD, two patients required EC due to gangrenous cholecystitis. The conversion rate after laparoscopy was 20%. Overall morbidity was 8.7% after PD and 47% after EC (P=0.011). Major morbidity was 0% after PD and 21% after EC (P=0.034). The mortality rate was not different (13% after PD and 16% after EC, P=1.0) and the deaths were all related to the patients' preexisting disease. Hospital and ICU stays were not different. Recurrent symptoms (17%) occurred only after ACC in the PD group. Conclusions: In high-risk patients, PD and EC are both efficient in the resolution of acute cholecystitis sepsis. However, EC is associated with a higher procedure-related morbidity and the laparoscopic approach is not always possible. Percutaneous drainage represents a valuable intervention, but secondary cholecystectomy is mandatory in cases of acute calculous cholecystiti

Conceptual inconsistencies in finite-dimensional quantum and classical mechanics

Utilizing operational dynamic modeling [Phys. Rev. Lett. 109, 190403 (2012); arXiv:1105.4014], we demonstrate that any finite-dimensional representation of quantum and classical dynamics violates the Ehrenfest theorems. Other peculiarities are also revealed, including the nonexistence of the free particle and ambiguity in defining potential forces. Non-Hermitian mechanics is shown to have the same problems. This work compromises a popular belief that finite-dimensional mechanics is a straightforward discretization of the corresponding infinite-dimensional formulation.Comment: 5 pages, 2 figure