Lot Sizing Heuristics Performance

Each productive system manager knows that finding the optimal trade‐off between reducing inventory and decreasing the frequency of production/ replenishment orders allows a great cut‐back in operations costs. Several authors have focused their contributions, trying to demonstrate that among the various dynamic lot sizing rules there are big differences in terms of performance, and that these differences are not negligible. In this work, eight of the best known lot sizing algorithms have been described with a unique modelling approach and have then been exhaustively tested on several different scenarios, benchmarking versus Wagner and Whitin’s optimal solution. As distinct from the contributions in the literature, the operational behaviour has been evaluated in order to determine which one is more suitable to the characteristics of each scenario

Lung Ultrasound in COVID-19 Pneumonia: Correlations with Chest CT on Hospital admission

Background: Lung ultrasound (LUS) is an accurate, safe, and cheap tool assisting in the diagnosis of several acute respiratory diseases. The diagnostic value of LUS in the workup of coronavirus disease-19 (COVID-19) in the hospital setting is still uncertain. Objectives: The aim of this observational study was to explore correlations of the LUS appearance of COVID-19-related pneumonia with CT findings. Methods: Twenty-six patients (14 males, age 64 ± 16 years) urgently hospitalized for COVID-19 pneumonia, who underwent chest CT and bedside LUS on the day of admission, were enrolled in this observational study. CT images were reviewed by expert chest radiologists, who calculated a visual CT score based on extension and distribution of ground-glass opacities and consolidations. LUS was performed by clinicians with certified competency in thoracic ultrasonography, blind to CT findings, following a systematic approach recommended by ultrasound guidelines. LUS score was calculated according to presence, distribution, and severity of abnormalities. Results: All participants had CT findings suggestive of bilateral COVID-19 pneumonia, with an average visual scoring of 43 ± 24%. LUS identified 4 different possible -abnormalities, with bilateral distribution (average LUS score 15 ± 5): focal areas of nonconfluent B lines, diffuse confluent B lines, small subpleural microconsolidations with pleural line irregularities, and large parenchymal consolidations with air bronchograms. LUS score was significantly correlated with CT visual scoring (r = 0.65, p < 0.001) and oxygen saturation in room air (r = -0.66, p < 0.001). Conclusion: When integrated with clinical data, LUS could represent a valid diagnostic aid in patients with suspect COVID-19 pneumonia, which reflects CT findings

COVID-19 respiratory support outside the ICU's doors. An observational study for a new operative strategy

During the first wave of the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) pandemic, we faced a massive clinical and organizational challenge having to manage critically ill patients outside the Intensive Care Unit (ICU). This was due to the significant imbalance between ICU bed availability and the number of patients presenting Acute Hypoxemic Respiratory Failure caused by SARS-CoV-2-related interstitial pneumonia. We therefore needed to perform Non-Invasive Ventilation (NIV) in non-intensive wards to assist these patients and relieve pressure on the ICUs and subsequently implemented a new organizational and clinical model. This study was aimed at evaluating its effectiveness and feasibility

Association between respiratory distress time and invasive mechanical ventilation in COVID-19 patients: a multicentre regional cohort study.

Aim: to determine whether the duration of respiratory distress symptoms in severe COVID-19 pneumonia affects the need for invasive mechanical ventilation and clinical outcomes. Materials and methods: an observational multicentre cohort study of patients hospitalised in five COVID-19–designated ICUs of the University Hospitals of Emilia-Romagna Region. Patients included were adults with pneumonia due to SARS-CoV-2 with PaO₂/FiO₂ ratio <300 mmHg, respiratory distress symptoms, and need for mechanical ventilation (invasive or non-invasive). Exclusion criteria were an uncertain time of respiratory distress, end-of-life decision, and mechanical respiratory support before hospital admission. Measurements and main results: we analysed 171 patients stratified into tertiles according to respiratory distress duration (distress time, DT) before application of mechanical ventilation support. The rate of patients requiring invasive mechanical ventilation was significantly different (p<0.001) among the tertiles: 17/57 patients in the shortest duration, 29/57 in the intermediate duration, and 40/57 in the longest duration. The respiratory distress time significantly increased the risk of invasive ventilation in the univariate analysis (OR 5.5 [CI 2.48–12.35], p = 0.003). Multivariable regression analysis confirmed this association (OR 10.7 [CI 2.89–39.41], p <0.001). Clinical outcomes (mortality and hospital stay) did not show significant differences between DT tertiles. Discussion: albeit preliminary and retrospective, our data raised the hypothesis that the duration of respiratory distress symptoms may play a role in COVID-19 patients’ need for invasive mechanical ventilation. Furthermore, our observations suggested that specific strategies may be directed towards identifying and managing early symptoms of respiratory distress, regardless of the levels of hypoxemia and the severity of the dyspnoea itself

Management of Germ Cell Tumors During the Outbreak of the Novel Coronavirus Disease-19 Pandemic:A Survey of International Expertise Centers

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has become a public health emergency affecting frail populations, including patients with cancer. This poses the question of whether cancer treatments can be postponed or modified without compromising their efficacy, especially for highly curable cancers such as germ cell tumors (GCTs). MATERIALS AND METHODS: To depict the state-of-the-art management of GCTs during the COVID-19 pandemic, a survey including 26 questions was circulated by e-mail among the physicians belonging to three cooperative groups: (a) Italian Germ Cell Cancer Group; (b) European Reference Network-Rare Adult Solid Cancers, Domain G3 (rare male genitourinary cancers); and (c) Genitourinary Medical Oncologists of Canada. Percentages of agreement between Italian respondents (I) versus Canadian respondents (C), I versus European respondents (E), and E versus C were compared by using Fisher's exact tests for dichotomous answers and chi square test for trends for the questions with three or more options. RESULTS: Fifty-three GCT experts responded to the survey: 20 Italian, 6 in other European countries, and 27 from Canada. Telemedicine was broadly used; there was high consensus to interrupt chemotherapy in COVID-19-positive patients (I = 75%, C = 55%, and E = 83.3%) and for use of granulocyte colony-stimulating factor primary prophylaxis for neutropenia (I = 65%, C = 62.9%, and E = 50%). The main differences emerged regarding the management of stage I and stage IIA disease, likely because of cultural and geographical differences. CONCLUSION: Our study highlights the common efforts of GCT experts in Europe and Canada to maintain high standards of treatment for patients with GCT with few changes in their management during the COVID-19 pandemic. IMPLICATIONS FOR PRACTICE: Despite the chaos, disruptions, and fears fomented by the COVID-19 illness, oncology care teams in Italy, other European countries, and Canada are delivering the enormous promise of curative management strategies for patients with testicular cancer and other germ cell tumors. At the same time, these teams are applying safe and innovative solutions and sharing best practices to minimize frequency and intensity of patient contacts with thinly stretched health care capacity

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223