23 research outputs found

    Economic assessment of flexibility offered by an optimally controlled hybrid heat pump generator: a case study for residential building

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    Abstract The ongoing decarbonisation process of the current energy system, driven by the EU directives, requires that more renewable energy sources are integrated in the global energy mix, as well as policies promoting investments in new low-carbon technologies, energy efficiency and grid infrastructure. The technical integration of renewable energy sources into the existing power system is not straightforward, due to the intrinsic aleatory characteristics of renewable production, which make the power grid balance harder. To handle this issue, beside the traditional supply-side management, grid flexibility can also be provided by enabling the active participation of the demand-side in power system operational procedures, by means of the so-called demand-side management (DSM). The present paper is aimed at assessing the ability of a cost-optimal control strategy, based on model predictive control, to activate demand-response (DR) actions in a residential building equipped with a hybrid heat pump generator coupled with a water thermal storage. Hourly electricity prices are considered as external signals from the grid driving the demand response actions. It is shown that the thermal energy storage turns out to be an effective way to improve the controller performances and make the system more flexible and able to provide services to the power grid. A daily cost-saving up to 35% and 15% have been highlighted with a 1 m3 0.5.m3 tanks, respectively. Finally, the achievable flexibility is shown to be strictly dependent on the storage capacity and operations, which in turn are affected by the generators sizing

    Relationship between low Ankle-Brachial Index and rapid renal function decline in patients with atrial fibrillation: A prospective multicentre cohort study

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    OBJECTIVE: To investigate the relationship between Ankle-Brachial Index (ABI) and renal function progression in patients with atrial fibrillation (AF). DESIGN: Observational prospective multicentre cohort study. SETTING:Atherothrombosis Center of I Clinica Medica of 'Sapienza' University of Rome; Department of Medical and Surgical Sciences of University Magna Græcia of Catanzaro; Atrial Fibrillation Registry for Ankle-Brachial Index Prevalence Assessment-Collaborative Italian Study. PARTICIPANTS: 897 AF patients on treatment with vitamin K antagonists. MAIN OUTCOME MEASURES: The relationship between basal ABI and renal function progression, assessed by the estimated Glomerular Filtration Rate (eGFR) calculated with the CKD-EPI formula at baseline and after 2 years of follow-up. The rapid decline in eGFR, defined as a decline in eGFR >5 mL/min/1.73 m(2)/year, and incident eGFR<60 mL/min/1.73 m(2) were primary and secondary end points, respectively. RESULTS: Mean age was 71.8±9.0 years and 41.8% were women. Low ABI (ie, ≤0.90) was present in 194 (21.6%) patients. Baseline median eGFR was 72.7 mL/min/1.73 m(2), and 28.7% patients had an eGFR60 mL/min/1.73 m(2), 153 (23.9%) had a reduction of the eGFR <60 mL/min/1.73 m(2). ABI ≤0.90 was also an independent predictor for incident eGFR<60 mL/min/1.73 m(2) (HR 1.851, 95% CI 1.205 to 2.845, p=0.005). CONCLUSIONS: In patients with AF, an ABI ≤0.90 is independently associated with a rapid decline in renal function and incident eGFR<60 mL/min/1.73 m(2). ABI measurement may help identify patients with AF at risk of renal function deterioration

    "Delirium Day": A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool

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    Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 \ub1 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys

    De Novo Malignancies Following Liver Transplantation: Results From a Multicentric Study in Central and Southern Italy, 1990e2008

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    The objective of this study was to quantify incidence rates (IR) and risks of de novo tumors (except nonmelanoma skin cancers) in patients who underwent orthotopic liver transplantation (OLT) in central and southern Ital

    The Role of Salvage Transplantation in Patients Initially Treated With Open Versus Minimally Invasive Liver Surgery: An Intention-to-Treat Analysis

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    Despite gaining wide consensus in the management of hepatocellular carcinoma (HCC), minimally invasive liver surgery (MILS) has been poorly investigated for its role in the setting of salvage liver transplantation (SLT). A multicenter retrospective analysis was carried out in 6 Italian centers on 211 patients with HCC who were initially resected with open (n&nbsp;=&nbsp;167) versus MILS (n&nbsp;=&nbsp;44) and eventually wait-listed for SLT. The secondary endpoint was identification of risk factors for posttransplant death and tumor recurrence. The enrolled patients included 211 HCC patients resected with open surgery (n&nbsp;=&nbsp;167) versus MILS (n&nbsp;=&nbsp;44) and wait-listed for SLT between January 2007 and December 2017. We analyzed the intention-to-treat survival of these patients. MILS was the most important protective factor for the composite risk of delisting, posttransplant patient death, and HCC recurrence (OR, 0.26; 95% confidence interval [CI], 0.11-0.63; P&nbsp;=&nbsp;0.003). MILS was also the only independent protective factor for the risk of post-SLT patient death (OR, 0.29; 95% CI, 0.09-0.93; P&nbsp;=&nbsp;0.04). After propensity score matching, MILS was the only independent protective factor against the risk of delisting, posttransplant death, and HCC recurrence (OR, 0.22; 95% CI, 0.07-0.75; P&nbsp;=&nbsp;0.02). On the basis of the current analysis, MILS seems protective over open surgery for the risk of delisting, posttransplant patient death, and tumor recurrence. Larger prospective studies balancing liver function and tumor stage are strongly favored to better clarify the beneficial effect of MILS for HCC patients eventually referred to SLT

    Liver resection for perihilar cholangiocarcinoma: Impact of biliary drainage failure on postoperative outcome. Results of an Italian multicenter study

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    Background: Preoperative biliary drainage may be essential to reduce the risk of postoperative liver failure after hepatectomy for perihilar cholangiocarcinoma. However, infectious complications related to preoperative biliary drainage may increase the risk of postoperative mortality. The strategy and optimal drainage method continues to be controversial. Methods: This is a retrospective multicenter study including patients who underwent hepatectomy for perihilar cholangiocarcinoma between 2000 and 2016 at 14 Italian referral hepatobiliary centers. The primary end point was to evaluate independent predictors for postoperative outcome in patients undergoing liver resection for perihilar cholangiocarcinoma after preoperative biliary drainage. Results: Of the 639 enrolled patients, 441 (69.0%) underwent preoperative biliary drainage. Postoperative mortality was 8.9% (12.5% after right-side hepatectomy versus 5.7% after left-side hepatectomy; P = .003). Of the patients, 40.5% underwent preoperative biliary drainage at the first admitting hospital, before evaluation at referral centers. Use of percutaneous preoperative biliary drainage was significantly more frequent at referral centers than at community hospitals where endoscopic preoperative biliary drainage was the most frequent type. The overall failure rate after preoperative biliary drainage was 43.3%, significantly higher at community hospitals than that at referral centers (52.7% v 36.9%; P = .002). Failure of the first preoperative biliary drainage was one of the strongest predictors for postoperative compli-cations after right-side and left-side hepatectomies and for mortality after right-side hepatectomy. Type of preoperative biliary drainage (percutaneous versus endoscopic) was not associated with significantly different risk of mortality. Conclusion: Failure of preoperative biliary drainage was significantly more frequent at community hospitals and it was an independent predictor for postoperative outcome. Centers' experience in pre-operative biliary drainage management is crucial to reduce the risk of failure that is closely associated with postoperative morbidity and mortality. (c) 2021 Elsevier Inc. All rights reserved

    Italian experience in minimally invasive liver surgery: a national survey

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    This survey provides an overview about current spread of Minimally Invasive Liver Resection (MILR) in Italy. Primary endpoint was to assess evolution of MILR in recent years and its degree of application among centres with different experience in laparoscopic and hepatic surgery. A questionnaire with items describing activity MILR was sent to Italian surgical centers. Diagnosis, technical approaches, resection extent, devices and vascular control, reasons for conversion, morbidity and mortality were recorded. Level of expertise per centre was analysed in terms of learning curve acquisition and relationship with hepatobiliary background. 1497 MILRs from 39 centers (median 27 patients/center, range 1–145, period 1995–2012) were collected. Conversion rate was 10.7&nbsp;% (180 patients out of 1677, excluded from subsequent analysis), with bleeding representing most frequent cause of conversion (34.4&nbsp;%). Eleven centers completed learning curve, performing &gt;60 MILR. Benign lesions were 27.5&nbsp;% and malignant 72.5&nbsp;%, with hepatocellular carcinoma being the most frequent indication. 92.6&nbsp;% of cases were performed with a totally laparoscopic technique (1.3&nbsp;% were hand-assisted, 1.9&nbsp;% single-port and 4.2&nbsp;% robotic). Minor resections accounted for 92.9&nbsp;% (left lateral sectionectomy resulted the most frequent procedure; 23.8&nbsp;%), while major resections represented 7.1&nbsp;%. Overall mortality was 0.2&nbsp;% (3 of 1497 patients) and morbidity 22.8&nbsp;%. Mean length of stay was 5&nbsp;days. Correlation between MILR activity and a hepatobiliary background was not clear comparing MILR cases and liver resection volumes per center. MILR has been significantly widespread in Italy in recent years, with several centers having definitely completed the learning curve as attested by clinical results consistent with major series from the Western and Eastern countries. MILR programs in Italy seem to arise from both centers with specific hepatobiliary expertise and centers performing advanced general laparoscopic surgery

    Perioperative outcomes of laparoscopic and robot-assisted major hepatectomies: an Italian multi-institutional comparative study

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    Background: Laparoscopic major hepatectomy (LMH), although safely feasible in experienced hands and in selected patients, is a formidable challenge because of the technical demands of controlling hemorrhage, sealing bile ducts, avoiding gas embolism, and maintaining oncologic surgical principles. The enhanced surgical dexterity offered by robotic assistance could improve feasibility and/or safety of minimally invasive major hepatectomy. The aim of this study was to compare perioperative outcomes of LMH and robotic-assisted major hepatectomy (RMH).SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Model to predict major complications following liver resection for HCC in patients with metabolic syndrome

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    Background: Metabolic syndrome (MS) is rapidly growing as risk factor for HCC. Liver resection for HCC in patients with MS is associated with increased postoperative risks. There are no data on factors associated with postoperative complications. Aims: The aim was to identify risk factors and develop and validate a model for postoperative major morbidity after liver resection for HCC in patients with MS, using a large multicentric Western cohort. Materials and methods: The univariable logistic regression analysis was applied to select predictive factors for 90 days major morbidity. The model was built on the multivariable regression and presented as a nomogram. Performance was evaluated by internal validation through the bootstrap method. The predictive discrimination was assessed through the concordance index. Results: A total of 1087 patients were gathered from 24 centers between 2001 and 2021. Four hundred and eighty-four patients (45.2%) were obese. Most liver resections were performed using an open approach (59.1%), and 743 (68.3%) underwent minor hepatectomies. Three hundred and seventy-six patients (34.6%) developed postoperative complications, with 13.8% major morbidity and 2.9% mortality rates. Seven hundred and thirteen patients had complete data and were included in the prediction model. The model identified obesity, diabetes, ischemic heart disease, portal hypertension, open approach, major hepatectomy, and changes in the nontumoral parenchyma as risk factors for major morbidity. The model demonstrated an AUC of 72.8% (95% CI: 67.2%-78.2%) (https://childb.shinyapps.io/NomogramMajorMorbidity90days/). Conclusions: Patients undergoing liver resection for HCC and MS are at high risk of postoperative major complications and death. Careful patient selection, considering baseline characteristics, liver function, and type of surgery, is key to achieving optimal outcomes
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