Factors influencing delayed discharge after day-surgery laparoscopic cholecystectomy: the DeDiLaCo study protocol

OBJECTIVE: Laparoscopic cholecystectomy (LC) is the gold standard for most benign gallbladder diseases. Early discharge (<24 hours) has the same outcomes as longer (>24 hours) hospital stay. Nevertheless, the rate of delayed discharge >24 hours range from 4.6% to 37%. The primary endpoint of this Italian nationwide study is to analyze the prevalence of patients undergoing elective LC who experienced a delayed discharge >24 hours and identify potential limiting factors of early discharge. Results from these analyses will be used to select patients who can be safely discharged on the same day after surgery. Secondary endpoints will be to evaluate the patient’s quality of life (QoL), assess the direct health costs associated with late discharge, and quantify the patient’s involvement in the treatment process. PATIENTS AND METHODS: This prospective, observational study was conducted following a resident-led model and the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines. All patients were treated according to the local hospital protocol and received routine care as standard therapy. RESULTS: We expected to obtain the enrollment of at least 500 patients based on an assumed difference in discharge delay between the reference and the recruitable population of 6% and the identification of factors related to discharge failure within 24 h. Early discharge after LC leads to advantages both in terms of clinical outcomes and quality of life of the patient, and it is highly effective in terms of health costs and shortening the waiting list. However, clinical reality differs from the results of randomized studies by a complex series of non-objectionable real-world data influencing treatment plans. Therefore, we expected to identify independent predictors and factors of failure of early discharge. CONCLUSIONS: Clinical reality often differs from randomized trial results. In Italy, the vast majority of delayed discharges after LC may not be related to surgery and can be prevented both with logistical reorganization and with a readjustment of the trust reimbursement policies

Factors influencing delayed discharge after day-surgery laparoscopic cholecystectomy: the DeDiLaCo study protocol

Objective: Laparoscopic cholecystectomy (LC) is the gold standard for most benign gallbladder diseases. Early discharge (<24 hours) has the same outcomes as longer (>24 hours) hospital stay. Nevertheless, the rate of delayed discharge >24 hours range from 4.6% to 37%. The primary endpoint of this Italian nationwide study is to analyze the prevalence of patients undergoing elective LC who experienced a delayed discharge >24 hours and identify potential limiting factors of early discharge. Results from these analyses will be used to select patients who can be safely discharged on the same day after surgery. Secondary endpoints will be to evaluate the patient's quality of life (QoL), assess the direct health costs associated with late discharge, and quantify the patient's involvement in the treatment process. Patients and methods: This prospective, observational study was conducted following a resident-led model and the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines. All patients were treated according to the local hospital protocol and received routine care as standard therapy. Results: We expected to obtain the enrollment of at least 500 patients based on an assumed difference in discharge delay between the reference and the recruitable population of 6% and the identification of factors related to discharge failure within 24 h. Early discharge after LC leads to advantages both in terms of clinical outcomes and quality of life of the patient, and it is highly effective in terms of health costs and shortening the waiting list. However, clinical reality differs from the results of randomized studies by a complex series of non-objectionable real-world data influencing treatment plans. Therefore, we expected to identify independent predictors and factors of failure of early discharge. Conclusions: Clinical reality often differs from randomized trial results. In Italy, the vast majority of delayed discharges after LC may not be related to surgery and can be prevented both with logistical reorganization and with a readjustment of the trust reimbursement policies

Latest results from NA60

The NA60 experiment has measured the production of muon pairs and of charged particles in In+In collisions at a beam energy of 158 AGeV. For invariant dimuon masses below the phi the space-time averaged rho spectral function was isolated by a novel procedure. It shows a strong broadening but essentially no shift in mass. The production of J/psi was measured as a function of the collision centrality. As in previous experiments studying Pb+Pb collisions an anomalous supression is observed, setting in at approximately 90 participant nucleons. Using the charged particles the reaction plane was reconstructed. The elliptic flow of charged particles increases with pt showing a saturation for pt > 2GeV/c. For the first time azimuthal distributions for J/psi are shown.Comment: 9 pages, 11 figures, talk given at the conference "Strangeness in Quark Matter 2006 (SQM2006)", March 2006, Los Angeles, USA, accepted for publication in Journal of Physics

A simulation tool for MRPC telescopes of the EEE project

The Extreme Energy Events (EEE) Project is mainly devoted to the study of the secondary cosmic ray radiation by using muon tracker telescopes made of three Multigap Resistive Plate Chambers (MRPC) each. The experiment consists of a telescope network mainly distributed across Italy, hosted in different building structures pertaining to high schools, universities and research centers. Therefore, the possibility to take into account the effects of these structures on collected data is important for the large physics programme of the project. A simulation tool, based on GEANT4 and using GEMC framework, has been implemented to take into account the muon interaction with EEE telescopes and to estimate the effects on data of the structures surrounding the experimental apparata.A dedicated event generator producing realistic muon distributions, detailed geometry and microscopic behavior of MRPCs have been included to produce experimental-like data. The comparison between simulated and experimental data, and the estimation of detector resolutions is here presented and discussed

First Measurement of the rho Spectral Function in High-Energy Nuclear Collisions

We report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions at the CERN SPS. A significant excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of 360 000 dimuons and the good mass resolution of about 2% allow us to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from pi+pi-->rho-->mu+mu- annihilation. The associated space-time averaged rho spectral function shows a strong broadening, but essentially no shift in mass. This may rule out theoretical models linking hadron masse

Evidence for radial flow of thermal dileptons in high-energy nuclear collisions

The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158 AGeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present precision results on the associated transverse momentum spectra. The slope parameter Teff extracted from the spectra rises with dimuon mass up to the rho, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline signals a transition to an emission source with much smaller flow. This may well represent the first direct evidence for thermal radiation of partonic origin in nuclear collisions.Comment: Accepted for publication in Physical Review Letter

Measurements of the reaction pˉp→ϕη\bar{p}p \to \phi \eta of antiproton annihilation at rest at three hydrogen target densities

The proton-antiproton annihilation at rest into the $\phi\eta$ final state was measured for three different target densities: liquid hydrogen, gaseous hydrogen at NTP and at a low pressure of 5 mbar. The yield of this reaction in the liquid hydrogen target is smaller than in the low-pressure gas target. The branching ratios of the $\phi\eta$ channel were calculated on the basis of simultaneous analysis of the three data samples. The branching ratio for annihilation into $\phi\eta$ from the $^3S_1$ protonium state turns out to be about ten times smaller as compared to the one from the $^1P_1$ state.Comment: 10 pages, 3 Postscript figures. Accepted by Physics Letters

First results from NA60 on low mass muon pair production in In-In collisions at 158 GeV/nucleon

The NA60 experiment at the CERN SPS studies dimuon production in proton-nucleus and nucleus-nucleus collisions. The combined information from a novel vertex telescope made of radiation-tolerant silicon pixel detectors and from the muon spectrometer previously used in NA50 allows for a precise measurement of the muon vertex and a much improved dimuon mass resolution. We report on first results from the data taken for Indium-Indium collisions at 158 AGeV/nucleon in 2003, concentrating on a subsample of about 370 000 muon pairs in the mass range $<1.2$ GeV/$c^{2}$. The light vector mesons $\omega$ and $\phi$ are completely resolved, with a mass resolution of about 23 MeV/$c^{2}$ at the $\phi$. The transverse momentum spectra of the $\phi$ are measured over the continuous range $0<p_{\rm T}<2.5$ GeV/c; the inverse slope parameter of the spectra is found to increase with centrality, with an average value of $T=252\pm3$ MeV.Comment: 9 pages, 6 figures. Plenary talk, SQM2004 conference, Cape Town, South Africa 15-20 September, 2004. To be published in Journal of Physics G: Nuclear and Particle Physic

J/psi azimuthal anisotropy relative to the reaction plane in Pb-Pb collisions at 158 GeV per nucleon

The J/$\psi$ azimuthal distribution relative to the reaction plane has been measured by the NA50 experiment in Pb-Pb collisions at 158 GeV/nucleon. Various physical mechanisms related to charmonium dissociation in the medium created in the heavy ion collision are expected to introduce an anisotropy in the azimuthal distribution of the observed J/$\psi$ mesons at SPS energies. Hence, the measurement of J/$\psi$ elliptic anisotropy, quantified by the Fourier coefficient v$_2$ of the J/$\psi$ azimuthal distribution relative to the reaction plane, is an important tool to constrain theoretical models aimed at explaining the anomalous J/$\psi$ suppression observed in Pb-Pb collisions. We present the measured J/$\psi$ yields in different bins of azimuthal angle relative to the reaction plane, as well as the resulting values of the Fourier coefficient v$_{2}$ as a function of the collision centrality and of the J/$\psi$ transverse momentum. The reaction plane has been estimated from the azimuthal distribution of the neutral transverse energy detected in an electromagnetic calorimeter. The analysis has been performed on a data sample of about 100 000 events, distributed in five centrality or p$_{\rm T}$ sub-samples. The extracted v$_{2}$ values are significantly larger than zero for non-central collisions and are seen to increase with p$_{\rm T}$.Comment: proceedings of HP08 conference corrected a typo in one equatio

NA60 results on pTp_T spectra and the ρ\rho spectral function in In-In collisions

The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of close to 400K events and the good mass resolution of about 2% have made it possible to isolate the excess by subtraction of the decay sources (keeping the $\rho$). The shape of the resulting mass spectrum exhibits considerable broadening, but essentially no shift in mass. The acceptance-corrected transverse-momentum spectra have a shape atypical for radial flow and show a significant mass dependence, pointing to different sources in different mass regions.Comment: 4 pages, 4 figures, Quark Matter 2006 conference proceeding