SUSYGEN 2.2 - A Monte Carlo Event Generator for MSSM Sparticle Production at e+ e- Colliders

SUSYGEN is a Monte Carlo program designed for computing distributions and generating events for MSSM sparticle production in e+ e- collisions. The Supersymmetric (SUSY) mass spectrum may either be supplied by the user, or can alternatively be calculated in two different models of SUSY Breaking: gravity mediated supersymmetry breaking (SUGRA), and gauge mediated supersymmetry breaking (GMSB). The program incorporates the most important production processes and decay modes, including the full set of R-parity violating decays, and the decays to the gravitino in GMSB models. Initial state radiation corrections take into account pT/pL effects in the Structure Function formalism, and an optimised hadronisation interface to JETSET 7.4 including final state radiation is also provided.Comment: 68 pages, 8 figures. Submitted to Comp. Phys. Commu

Sonographic Lobe Localization of Alveolar-Interstitial Syndrome in the Critically Ill

Introduction. Fast and accurate diagnosis of alveolar-interstitial syndrome is of major importance in the critically ill. We evaluated the utility of lung ultrasound (US) in detecting and localizing alveolar-interstitial syndrome in respective pulmonary lobes as compared to computed tomography scans (CT). Methods. One hundred and seven critically ill patients participated in the study. The presence of diffuse comet-tail artifacts was considered a sign of alveolar-interstitial syndrome. We designated lobar reflections along intercostal spaces and surface lines by means of sonoanatomy in an effort to accurately localize lung pathology. Each sonographic finding was thereafter grouped into the respective lobe. Results. From 107 patients, 77 were finally included in the analysis (42 males with mean age = 61 ± 17 years, APACHE II score = 17.6 ± 6.4, and lung injury score = 1.0 ± 0.7). US exhibited high sensitivity and specificity values (ranging from over 80% for the lower lung fields up to over 90% for the upper lung fields) and considerable consistency in the diagnosis and localization of alveolar-interstitial syndrome. Conclusions. US is a reliable, bedside method for accurate detection and localization of alveolar-interstitial syndrome in the critically ill

Maximum inspiratory pressure, a surrogate parameter for the assessment of ICU-acquired weakness

<p>Abstract</p> <p>Background</p> <p>Physical examination has been advocated as a primary determinant of ICU-acquired weakness (ICU-AW). The purpose of the study is to investigate ICU-AW development by using Maximum Inspiratory Pressure (MIP) as a surrogate parameter of the standardized method to evaluate patients' peripheral muscle strength.</p> <p>Methods</p> <p>Seventy-four patients were recruited in the study and prospectively evaluated in a multidisciplinary university ICU towards the appearance of ICU-AW. APACHE II admission score was 16 ± 6 and ICU stay 26 ± 18 days. ICU-AW was diagnosed with the Medical Research Council (MRC) scale for the clinical evaluation of muscle strength. MIP was measured using the unidirectional valve method, independently of the patients' ability to cooperate.</p> <p>Results</p> <p>A significant correlation was found between MIP and MRC (r = 0.68, p < 0.001). Patients that developed ICU-AW (MRC<48) had a longer weaning period compared to non ICU-AW patients (12 ± 14 versus 2 ± 3 days, p < 0.01). A cut-off point of 36 cmH₂O for MIP was defined by ROC curve analysis for ICU-AW diagnosis (88% sensitivity,76% specificity). Patients with MIP below the cut-off point of 36 cmH₂O had a significant greater weaning period (10 ± 14 versus 3 ± 3 days, p = 0.004) also shown by Kaplan-Meier analysis (log-rank:8.2;p = 0.004).</p> <p>Conclusions</p> <p>MIP estimated using the unidirectional valve method may be a potential surrogate parameter for the assessment of muscle strength compromise, useful for the early detection of ICU-AW.</p

Echogenic Technology Improves Cannula Visibility during Ultrasound-Guided Internal Jugular Vein Catheterization via a Transverse Approach

Objective. Echogenic technology has recently enhanced the ability of cannulas to be visualized during ultrasound-guided vascular access. We studied whether the use of an EC could improve visualization if compared with a nonechogenic vascular cannula (NEC) during real-time ultrasound-guided internal jugular vein (IJV) cannulation in the intensive care unit (ICU). Material and Methods. We prospectively enrolled 80 mechanically ventilated patients who required central venous access in a randomized study that was conducted in two medical-surgical ICUs. Forty patients underwent EC and 40 patients were randomized to NEC. The procedure was ultrasound-guided IJV cannulation via a transverse approach. Results. The EC group exhibited increased visibility as compared to the NEC group (88%  ± 8% versus 20%  ± 15%, resp. P < 0.01). There was strong agreement between the procedure operators and independent observers (k = 0.9; 95% confidence intervals assessed by bootstrap analysis = 0.87–0.95; P < 0.01). Access time (5.2 s ± 2.5 versus 10.6 s ± 5.7) and mechanical complications were both decreased in the EC group compared to the NEC group (P < 0.05). Conclusion. Echogenic technology significantly improved cannula visibility and decreased access time and mechanical complications during real-time ultrasound-guided IJV cannulation via a transverse approach

Immediate post-operative effects of tracheotomy on respiratory function during mechanical ventilation

INTRODUCTION: Tracheotomy is widely performed in the intensive care unit after long-term oral intubation. The present study investigates the immediate influence of tracheotomy on respiratory mechanics and blood gases during mechanical ventilation. METHODS: Tracheotomy was performed in 32 orally intubated patients for 10.5 ± 4.66 days (all results are means ± standard deviations). Airway pressure, flow and arterial blood gases were recorded immediately before tracheotomy and half an hour afterwards. Respiratory system elastance (E(rs)), resistance (R(rs)) and end-expiratory pressure (EEP) were evaluated by multiple linear regression. Respiratory system reactance (X(rs)), impedance (Z(rs)) and phase angle (φ(rs)) were calculated from E(rs )and R(rs). Comparisons of the mechanical parameters, blood gases and pH were performed with the aid of the Wilcoxon signed-rank test (P = 0.05). RESULTS: E(rs )increased (7 ± 11.3%, P = 0.001), whereas R(rs )(-16 ± 18.4%, P = 0.0003), X(rs )(-6 ± 11.6%, P = 0.006) and φ (rs )(-14.3 ± 16.8%, P = <0.001) decreased immediately after tracheotomy. EEP, Z(rs), blood gases and pH did not change significantly. CONCLUSION: Lower R(rs )but also higher E(rs )were noted immediately after tracheotomy. The net effect is a non-significant change in the overall R(rs )(impedance) and the effectiveness of respiratory function. The extra dose of anaesthetics (beyond that used for sedation at the beginning of the procedure) or a higher FiO(2 )(fraction of inspired oxygen) during tracheotomy or aspiration could be related to the immediate elastance increase