Non-invasive hemodynamic monitoring techniques for detecting Preload responsiveness in critically ill patients

Volume expansion is the first-line treatment for acute circulatory failure in almost all cases. However, its inconsistent effectiveness and its side effects make it necessary to predict the effects before undertaking it. Several tests have been developed to detect this state of preload dependence, and we are interested in refining some of them and improve their use. The end expiratory occlusion (EEXPO) test consists in transiently stopping mechanical ventilation at end expiration to increase venous return and, thus, cardiac preload. In preload responder patients it is expected to increase cardiac output. We have gathered an amount of information from the existing literature, showing that its ability of detecting fluid responsiveness is very high, through a systematic review and meta-analysis. The effects of this test must be assessed on cardiac output, and several methods have already been described for this. Bioreactance is a completely non invasive technique to measure cardiac output, which has been demonstrated to be reliable in detecting preload responsiveness through a passive leg raising (PLR) maneuver. Nevertheless, its role in detecting a positive EEXPO test was never investigated. In the main study of this PhD project, we show that the current available commercial version of the bioreactance device is not suitable for this purpose, due to its very long averaging and refreshing times (24 and 4 seconds, respectively). However, when we used a research version of the device, which allowed us to reduce both intervals (8 and 1 second for averaging and refreshing times, respectively), bioreactance proved to be a reliable method to detect preload responsiveness through the EEXPO test. We have also described an original and reliable method for measuring the effects of both PLR and EEXPO tests, which consists of measuring the perfusion index (PI), the ratio between the pulsatile and the non-pulsatile portion of the pulse oxygen saturation signal. Although the signal could not be collected stably in all patients, changes in this index during passive leg raising were able to measure the effects of the PLR test and predict the response to volume expansion. Similarly, Pl measurements could identify a positive EEXPO test, even though their changes were of lower amplitude compared to those of a PLR test. Our results open up the possibility of measuring the effects of these tests of preload responsiveness using non-invasive tools. This could prompt their use outside the intensive care unit, such as in the emergency department, where tracking changes of cardiac output during the first hours of the management of acute circulatory failure could lead to a more rational use of fluid administration

Bleeding Pseudocyst of the Pancreatic Head. The role of Omentoplasty and Local Hemostasis

Treatment of bleeding psedoaneurysms and pseudocysts of the pancreas is controversial. Surgical treatment with pancreatic resection or trancystic arterial ligation is not always satisfactory since postoperative mortality rate is high, especially for lesions located in the pancreatic head and rebleeding is not unusual. Two patients with bleeding pseudoaneurysms (one post traumatic, one spontaneous) and one with a hemorrhagic pseudocyst of the pancreatic head were treated surgically with arterial suture and omentoplasty. Bleeding was controlled in all, without any postoperative mortality or morbidity. No rebleeding occurred with a follow up of 33, 26 and 12 months. Trancystic ligation of bleeding vessels with omentoplasty may be a useful approach, which should be compared to arterial embolization in the future

Fatality rate and predictors of mortality in an Italian cohort of hospitalized COVID-19 patients

Clinical features and natural history of coronavirus disease 2019 (COVID-19) differ widely among different countries and during different phases of the pandemia. Here, we aimed to evaluate the case fatality rate (CFR) and to identify predictors of mortality in a cohort of COVID-19 patients admitted to three hospitals of Northern Italy between March 1 and April 28, 2020. All these patients had a confirmed diagnosis of SARS-CoV-2 infection by molecular methods. During the study period 504/1697 patients died; thus, overall CFR was 29.7%. We looked for predictors of mortality in a subgroup of 486 patients (239 males, 59%; median age 71 years) for whom sufficient clinical data were available at data cut-off. Among the demographic and clinical variables considered, age, a diagnosis of cancer, obesity and current smoking independently predicted mortality. When laboratory data were added to the model in a further subgroup of patients, age, the diagnosis of cancer, and the baseline PaO2/FiO2 ratio were identified as independent predictors of mortality. In conclusion, the CFR of hospitalized patients in Northern Italy during the ascending phase of the COVID-19 pandemic approached 30%. The identification of mortality predictors might contribute to better stratification of individual patient risk

Electrokinetic effects across Nafion 120 membranes

The electroosmotic coefficient, and the streaming potential across Nafion 120 membrane separating two uni-univalent electrolyte solutions of the same concentration have been studied. Different electrolytes have been considered, namely NaCl, LiOH, NaOH, KOH and CsOH. According to the non-equilibrium thermodynamic theories the ratio (Δφ/ΔP)/(Jv/I), with (Δφ)(electrical potential)/(gDP)(pressure difference) the streaming potential and Jv(volume flow)/I(electrical current flow) the electroosmotic quantity, approaches the unity

Growth Arrest-Specific Gene 6 Administration Ameliorates Sepsis-Induced Organ Damage in Mice and Reduces ROS Formation In Vitro

Sepsis is a widespread life-threatening disease, with a high mortality rate due to inflammation-induced multiorgan failure (MOF). Thus, new effective modulators of the immune response are urgently needed to ameliorate the outcome of septic patients. As growth arrest-specific gene 6 (Gas6)/Tyro3, Axl, MerTK (TAM) receptors signaling has shown immunomodulatory activity in sepsis, here we sought to determine whether Gas6 protein injection could mitigate MOF in a cecal slurry mouse model of sepsis. Mice, divided into different groups according to treatment-i.e., placebo (B), ampicillin (BA), Gas6 alone (BG), and ampicillin plus Gas6 (BAG)-were assessed for vitality, histopathology and cytokine expression profile as well as inducible nitric oxide synthase (iNOS), ALT and LDH levels. BAG-treated mice displayed milder kidney and lung damage and reduced levels of cytokine expression and iNOS in the lungs compared to BA-treated mice. Notably, BAG-treated mice showed lower LDH levels compared to controls. Lastly, BAG-treated cells of dendritic, endothelial or monocytic origin displayed reduced ROS formation and increased cell viability, with a marked upregulation of mitochondrial activity. Altogether, our findings indicate that combined treatment with Gas6 and antibiotics ameliorates sepsis-induced organ damage and reduces systemic LDH levels in mice, suggesting that Gas6 intravenous injection may be a viable therapeutic option in sepsis