Case Management Reduces Length of Stay, Charges, and Testing in Emergency Department Frequent Users

Introduction: Case management is an effective, short-term means to reduce emergency department (ED) visits in frequent users of the ED. This study sought to determine the effectiveness of case management on frequent ED users, in terms of reducing ED and hospital length of stay (LOS), accrued costs, and utilization of diagnostic tests. Methods: The study consisted of a retrospective chart review of ED and inpatient visits in our hospital’s ED case management program, comparing patient visits made in the one year prior to enrollment in the program, to the visits made in the one year after enrollment in the program. We examined the LOS, use of diagnostic testing, and monetary charges incurred by these patients one year prior and one year after enrollment into case management.  Results: The study consisted of 158 patients in case management. Comparing the one year prior to enrollment to the one year after enrollment, ED visits decreased by 49%, inpatient admissions decreased by 39%, the use of computed tomography imaging decreased 41%, the use of ultrasound imaging decreased 52%, and the use of radiographs decreased 38%. LOS in the ED and for inpatient admissions decreased by 39%, reducing total LOS for these patients by 178 days. ED and hospital charges incurred by these patients decreased by 5.8 million dollars, a 41% reduction. All differences were statistically significant.Conclusion: Case management for frequent users of the ED is an effective method to reduce patient visits, the use of diagnostic testing, length of stay, and cost within our institution

Case Management Reduces Length of Stay, Charges, and Testing in Emergency Department Frequent Users

Introduction: Case management is an effective, short-term means to reduce emergency department (ED) visits in frequent users of the ED. This study sought to determine the effectiveness of case management on frequent ED users, in terms of reducing ED and hospital length of stay (LOS), accrued costs, and utilization of diagnostic tests. Methods: The study consisted of a retrospective chart review of ED and inpatient visits in our hospital’s ED case management program, comparing patient visits made in the one year prior to enrollment in the program, to the visits made in the one year after enrollment in the program. We examined the LOS, use of diagnostic testing, and monetary charges incurred by these patients one year prior and one year after enrollment into case management. Results: The study consisted of 158 patients in case management. Comparing the one year prior to enrollment to the one year after enrollment, ED visits decreased by 49%, inpatient admissions decreased by 39%, the use of computed tomography imaging decreased 41%, the use of ultrasound imaging decreased 52%, and the use of radiographs decreased 38%. LOS in the ED and for inpatient admissions decreased by 39%, reducing total LOS for these patients by 178 days. ED and hospital charges incurred by these patients decreased by 5.8 million dollars, a 41% reduction. All differences were statistically significant. Conclusion: Case management for frequent users of the ED is an effective method to reduce patient visits, the use of diagnostic testing, length of stay, and cost within our institution

Case Management Reduces Length of Stay, Charges, and Testing in Emergency Department Frequent Users

Introduction: Case management is an effective, short-term means to reduce emergency department (ED) visits in frequent users of the ED. This study sought to determine the effectiveness of case management on frequent ED users, in terms of reducing ED and hospital length of stay (LOS), accrued costs, and utilization of diagnostic tests. Methods: The study consisted of a retrospective chart review of ED and inpatient visits in our hospital’s ED case management program, comparing patient visits made in the one year prior to enrollment in the program, to the visits made in the one year after enrollment in the program. We examined the LOS, use of diagnostic testing, and monetary charges incurred by these patients one year prior and one year after enrollment into case management. Results: The study consisted of 158 patients in case management. Comparing the one year prior to enrollment to the one year after enrollment, ED visits decreased by 49%, inpatient admissions decreased by 39%, the use of computed tomography imaging decreased 41%, the use of ultrasound imaging decreased 52%, and the use of radiographs decreased 38%. LOS in the ED and for inpatient admissions decreased by 39%, reducing total LOS for these patients by 178 days. ED and hospital charges incurred by these patients decreased by 5.8 million dollars, a 41% reduction. All differences were statistically significant. Conclusion: Case management for frequent users of the ED is an effective method to reduce patient visits, the use of diagnostic testing, length of stay, and cost within our institution

Evolution of the Cañadas edifice and its implications for the origin of the Cañadas Caldera (Tenerife, Canary Islands)

The volcano-stratigraphic and geochronologic data presented in this work show that the Tenerife central zone has been occupied during the last 3 Ma by shield or central composite volcanoes which reached more than 3000 m in height. The last volcanic system, the presently active Teide-Pico Viejo Complex began to form approximately 150 ka ago. The first Cañadas Edifice CE. volcanic activity took place between about 3.5 Ma and 2.7 Ma. The CE-I is formed mainly by basalts, trachybasalts and trachytes. The remains of this phase outcrop in the Cañadas Wall CW. sectors of La Angostura 3.5–3.0 Ma and 3.0–2.7 Ma., Boca de Tauce 3.0 Ma., and in the bottom of some external radial ravines 3.5 Ma.. The position of its main emission center was located in the central part of the CC. The volcano could have reached 3000 m in height. This edifice underwent a partial destruction by failure and flank collapse, forming debris-avalanches during the 2.6–2.3 Ma period. The debris-avalanche deposits can be seen in the most distal zones in the N flank of the CE-I Tigaiga Breccia.. A new volcanic phase, whose deposits overlie the remains of CE-I and the former debris-avalanche deposits, constituted a new volcanic edifice, the CE-II. The dyke directions analysis and the morphological reconstruction suggest that the CE-II center was situated somewhat westward of the CE-I, reaching some 3200 m in height. The CE-II formations are well exposed on the CW, especially at the El Cedro 2.3–2.00 Ma. sector. They are also frequent in the S flank of the edifice 2.25–1.89 Ma. in Tejina 2.5–1.87 Ma. as well as in the Tigaiga massif to the N 2.23 Ma.. During the last periods of activity of CE-II, important explosive eruptions took place forming ignimbrites, pyroclastic flows, and fall deposits of trachytic composition. Their ages vary between 1.5 and 1.6 Ma Adeje ignimbrites, to the W.. In the CW, the Upper Ucanca phonolitic Unit 1.4 Ma. could be the last main episode of the CE-II. Afterwards, the Can˜adas III phase began. It is well represented in the CW sectors of Tigaiga 1.1 Ma–0.27 Ma., Las Pilas 1.03 Ma–0.78 Ma., Diego Hernández 0.54 Ma–0.17 Ma. and Guajara 1.1 Ma–0.7 Ma.. The materials of this edifice are also found in the SE flank. These materials are trachybasaltic lava-flows and abundant phonolitic lava and pyroclastic flows 0.6 Ma–0.5 Ma. associated with abundant plinian falls. The CE-III was essentially built between 0.9 and 0.2 Ma, a period when the volcanic activity was also intense in the ‘Dorsal Edifice’ situated in the easterly wing of Tenerife. The so called ‘valleys’ of La Orotava and Gu¨imar, transversals to the ridge axis, also formed during this period. In the central part of Tenerife, the CE-III completed its evolution with an explosive deposit resting on the top of the CE, for which ages from 0.173 to 0.13 Ma have been obtained. The CC age must be younger due to the fact that the present caldera scarp cuts these deposits. On the controversial origin of the CC central vertical collapse vs. repeated flank failure and lateral collapse of mature volcanic edifices., the data discussed in this paper favor the second hypothesis. Clearly several debris-avalanche type events exist in the history of the volcano but most of the deposits are now under the sea. The caldera wall should represent the proximal scarps of the large slides whose intermediate scarps are covered by the more recent Teide-Pico Viejo volcanoes

Geochemical insights into the internal dynamics of debris avalanches. A case study: The Socompa avalanche, Chile

International audienceOne way to infer the internal dynamics of debris avalanches is to characterize the heterogeneity of their deposits. Here we present high-precision Sr-Nd isotope compositions, plus major and trace element concentrations, of matrix samples and rock fragments from the Socompa debris-avalanche deposit (Chile). The Socompa blocks are easily identifiable in the field, but distinguishing substrate debris from disaggregated material formed at the volcano is difficult to do with only field criteria. Combining isotope data with field observations can help with this. Measured Sr and Nd isotope ratios show significant variations, defining a binary mixing array where matrix and rock deposits overlap. This testifies to the mixing of crushed rocks during collapse and/or movement. Assimilation of Socompa basement appears to be variable; overall, it is far lower than was previously proposed. Comparison between matrix and block samples in contact, over the whole surface area of the deposit, shows that the isotopic heterogeneity increases from source to front. Close to the Socompa, matrices are resulting from simple crushing of adjacent rocks. At the front, rock samples with distinct compositions are found in a close relationship with matrices that result either from mixing of these (or some of these) rocks or from crushing of basement material. Between the source and the front, the efficient mixing of Socompa rocks (and basement rocks) generates matrices with isotopic compositions distinct from those of the blocks they are in contact with. We interpret these results as being due to more efficient vertical mixing during the avalanche emplacement

Analogue models of the effect of long-term basement fault movement on volcanic edifices

Long-term fault movement under volcanoes can control the edifice structure and can generate collapse events. To study faulting effects, we explore a wide range of fault geometries and motions, from normal, through vertical to reverse and dip-slip to strike-slip, using simple analogue models. We explore the effect of cumulative sub-volcanic fault motions and find that there is a strong influence on the structural evolution and potential instability of volcanoes. The variety of fault types and geometries are tested with realistically scaled displacements, demonstrating a general tendency to produce regions of instability parallel to fault strike, whatever the fault motion. Where there is oblique-slip faulting, the instability is always on the downthrown side and usually in the volcano flank sector facing the strike-slip sense of motion. Different positions of the fault beneath the volcano change the location, type and magnitude of the instability produced. For example, the further the fault is from the central axis, the larger the destabilised sector. Also, with greater fault offset from the central axis larger unstable volumes are generated. Such failures are normal to fault strike. Using simple geometric dimensionless numbers, such as the fault dip, degree of oblique motion (angle of obliquity), and the fault position, we graphically display the geometry of structures produced. The models are applied to volcanoes with known underlying faults, and we demonstrate the importance of these faults in determining volcanic structures and slope instability. Using the knowledge of fault patterns gained from these experiments, geological mapping on volcanoes can locate fault influence and unstable zones, and hence monitoring of unstable flanks could be carried out to determine the actual response to faulting in specific cases

On the use of Saint-Venant equations to simulate the spreading of a granular mass

Cliff collapse is an active geomorphological process acting at the surface of the Earth and telluric planets. Recent laboratory studies have investigated the collapse of an initially cylindrical granular mass along a rough horizontal plane for different initial aspect ratios a = Hi/Ri, where Hi and Ri are the initial height and radius, respectively. A numerical simulation of these experiments is performed using a minimal depth-integrated model based on a long-wave approximation. A dimensional analysis of the equations shows that such a model exhibits the scaling laws observed experimentally. Generic solutions are independent of gravity and depend only on the initial aspect ratio a and an effective friction angle. In terms of dynamics, the numerical simulations are consistent with the experiments for a ≤ 1. The experimentally observed saturation of the final height of the deposit, when normalized with respect to the initial radius of the cylinder, is accurately reproduced numerically. Analysis of the results sheds light on the correlation between the area overrun by the granular mass and its initial potential energy. The extent of the deposit, the final height, and the arrest time of the front can be directly estimated from the ‘‘generic solution'' of the model for terrestrial and extraterrestrial avalanches. The effective friction, a parameter classically used to describe the mobility of gravitational flows, is shown to depend on the initial aspect ratio a. This dependence should be taken into account when interpreting the high mobility of large volume events