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Mechanical ventilation exposes the lung to injurious stresses and strains that can negatively affect clinical outcomes in acute respiratory distress syndrome or cause pulmonary complications after general anesthesia. Excess global lung strain, estimated as increased respiratory system driving pressure, is associated with mortality related to mechanical ventilation. The role of small-dimension biomechanical factors underlying this association and their spatial heterogeneity within the lung are currently unknown. Using four-dimensional computed tomography with a voxel resolution of 2.4 cubic millimeters and a multiresolution convolutional neural network for whole-lung image segmentation, we dynamically measured voxel-wise lung inflation and tidal parenchymal strains. Healthy or injured ovine lungs were evaluated as the mechanical ventilation positive end-expiratory pressure (PEEP) was titrated from 20 to 2 centimeters of water. The PEEP of minimal driving pressure (PEEPDP) optimized local lung biomechanics. We observed a greater rate of change in nonaerated lung mass with respect to PEEP below PEEPDP compared with PEEP values above this threshold. PEEPDP similarly characterized a breaking point in the relationships between PEEP and SD of local tidal parenchymal strain, the 95th percentile of local strains, and the magnitude of tidal overdistension. These findings advance the understanding of lung collapse, tidal overdistension, and strain heterogeneity as local triggers of ventilator-induced lung injury in large-animal lungs similar to those of humans and could inform the clinical management of mechanical ventilation to improve local lung biomechanics.
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Pulmão , Respiração com Pressão Positiva , Respiração Artificial , Animais , Pulmão/fisiopatologia , Ovinos , Fenômenos Biomecânicos , Respiração Artificial/efeitos adversos , Pressão , Tomografia Computadorizada por Raios X , Volume de Ventilação PulmonarRESUMO
BACKGROUND: Cardiac injury caused by a sharp object is a medical and surgical therapeutic challenge. Mortality risk factors have been identified but there are major discrepancies in the literature. The aim of this study was to analyse the management of victims of penetrating cardiac injuries before and after admission to hospital and the anatomical characteristics of these injuries in order to facilitate diagnosis of the most critical patients. METHODS: To carry out this study, we conducted a retrospective analytical study with epidemiological data on victims of penetrating cardiac injuries. We included two types of patients, with those who underwent autopsy in our institution after death from sharp injury to the heart or great vessels and those who survived with treatment in the emergency department or intensive care unit between January 2015 and February 2022. RESULTS: We included 30 autopsied patients and 12 survivors aged between 18 and 73 years. Higher mortality was associated with prehospital or in-hospital cardiorespiratory arrest (OR = 4, CI [1.71-9.35]), preoperative mechanical ventilation (OR = 10, CI [1.53-65.41]), preoperative catecholamines (OR = 7, CI [1.12-6.29]), preoperative and perioperative adrenaline (OR = 13, CI [1.98-85.46] and [1.98-85.46]), penetrating cardiac injury (OR = 14, CI [2.10-93.22]), multiple cardiac injuries (OR = 1.5, CI [1.05-2.22]) and an Organ Injury Scaling of the American Association for the Surgery of Trauma (AAST-OIS) score of 5 (OR = 2.9, CI [1.04-8.54]; p = 0.0329) with an AUC-ROC curve value of 0.708 (CI [0.543-0.841]). CONCLUSIONS: This study identified risk mortality factors in penetrating cardiac injury patients. These findings can help improve the diagnosis and management of these patients. The AAST-OIS score may be a good tool to diagnose critical patients.
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Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) is a major cause of complications and death. Here, we set out to identify high-performance predictive biomarkers of DCI and its underlying metabolic disruptions using metabolomics and lipidomics approaches. This single-center prospective observational study enrolled 61 consecutive patients with severe aSAH; among them, 22 experienced a DCI. Nine patients without aSAH were included as validation controls. Blood and cerebrospinal fluid (CSF) were sampled within the first 24 h after admission. We identified a panel of 20 metabolites that, together, showed high predictive performance for DCI. This panel of metabolites included lactate, cotinine, salicylate, 6 phosphatidylcholines, and 4 sphingomyelins. The interplay of the metabolome and the lipidome found between CSF and plasma in our patients underscores that aSAH and its associated DCI complications can extend beyond cerebral implications, with a peripheral dimension as well. As an illustration, early biological disruptions that might explain the subsequent DCI found systemic hypoxia driven mainly by higher blood lactate, arginine, and proline metabolism likely associated with vascular NO and disrupted ceramide/sphingolipid metabolism. We conclude that targeting early peripheral hypoxia preceding DCI could provide an interesting strategy for the prevention of vascular dysfunction.
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Isquemia Encefálica , Hemorragia Subaracnóidea , Humanos , Hemorragia Subaracnóidea/complicações , Isquemia Encefálica/etiologia , Biomarcadores , Ácido Láctico , HipóxiaRESUMO
BACKGROUND: Positive end-expiratory pressure (PEEP) individualized to a maximal respiratory system compliance directly implies minimal driving pressures with potential outcome benefits, yet, raises concerns on static and dynamic overinflation, strain and cyclic recruitment. Detailed accurate assessment and understanding of these has been hampered by methodological limitations. We aimed to investigate the effects of a maximal compliance-guided PEEP strategy on dynamic lung aeration, strain and tidal recruitment using current four-dimensional computed tomography (CT) techniques and analytical methods of tissue deformation in a surfactant depletion experimental model of acute respiratory distress syndrome (ARDS). METHODS: ARDS was induced by saline lung lavage in anesthetized and mechanically ventilated healthy sheep (n = 6). Animals were ventilated in a random sequence with: (1) ARDSNet low-stretch protocol; (2) maximal compliance PEEP strategy. Lung aeration, strain and tidal recruitment were acquired with whole-lung respiratory-gated high-resolution CT and quantified using registration-based techniques. RESULTS: Relative to the ARDSNet low-stretch protocol, the maximal compliance PEEP strategy resulted in: (1) improved dynamic whole-lung aeration at end-expiration (0.456 ± 0.064 vs. 0.377 ± 0.101, P = 0.019) and end-inspiration (0.514 ± 0.079 vs. 0.446 ± 0.083, P = 0.012) with reduced non-aerated and increased normally-aerated lung mass without associated hyperinflation; (2) decreased aeration heterogeneity at end-expiration (coefficient of variation: 0.498 ± 0.078 vs. 0.711 ± 0.207, P = 0.025) and end-inspiration (0.419 ± 0.135 vs. 0.580 ± 0.108, P = 0.014) with higher aeration in dorsal regions; (3) tidal aeration with larger inspiratory increases in normally-aerated and decreases in poorly-aerated areas, and negligible in hyperinflated lung (Aeration × Strategy: P = 0.026); (4) reduced tidal strains in lung regions with normal-aeration (Aeration × Strategy: P = 0.047) and improved regional distributions with lower tidal strains in middle and ventral lung (Region-of-interest [ROI] × Strategy: P < 0.001); and (5) less tidal recruitment in middle and dorsal lung (ROI × Strategy: P = 0.044) directly related to whole-lung tidal strain (r = 0.751, P = 0.007). CONCLUSIONS: In well-recruitable ARDS models, a maximal compliance PEEP strategy improved end-expiratory/inspiratory whole-lung aeration and its homogeneity without overinflation. It further reduced dynamic strain in middle-ventral regions and tidal recruitment in middle-dorsal areas. These findings suggest the maximal compliance strategy minimizing whole-lung dynamically quantified mechanisms of ventilator-induced lung injury with less cyclic recruitment and no additional overinflation in large heterogeneously expanded and recruitable lungs.
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Surfactantes Pulmonares , Síndrome do Desconforto Respiratório , Lesão Pulmonar Induzida por Ventilação Mecânica , Animais , Tomografia Computadorizada Quadridimensional , Lipoproteínas , Pulmão , Respiração com Pressão Positiva/métodos , Síndrome do Desconforto Respiratório/terapia , Ovinos , Tensoativos , Volume de Ventilação Pulmonar , Lesão Pulmonar Induzida por Ventilação Mecânica/prevenção & controleRESUMO
BACKGROUND: The aims of this study were to describe pharmacokinetic/pharmacodynamic target attainment in intensive care unit (ICU) patients treated with continuously infused ß-lactam antibiotics, their associated covariates, and the impact of dosage adjustment. METHODS: This prospective, observational, cohort study was performed in three ICUs. Four ß-lactams were continuously infused, and therapeutic drug monitoring (TDM) was performed at days 1, 4, and 7. The primary pharmacokinetic/pharmacodynamic target was an unbound ß-lactam plasma concentration four times above the bacteria's minimal inhibitory concentration during the whole dosing interval. The demographic and clinical covariates associated with target attainment were evaluated. RESULTS: A total of 170 patients were included (426 blood samples). The percentages of empirical ß-lactam underdosing at D1 were 66% for cefepime, 43% for cefotaxime, 47% for ceftazidime, and 14% for meropenem. Indexed creatinine clearance was independently associated with treatment underdose if increased (adjusted odds ratio per unit, 1.01; 95% CI, 1.00 to 1.01; p = 0.014) or overdose if decreased (adjusted odds ratio per unit, 0.95; 95% CI, 0.94 to 0.97; p < 0.001). Pharmacokinetic/pharmacodynamic target attainment was significantly increased after ß-lactam dosage adjustment between day 1 and day 4 vs. no adjustment (53.1% vs. 26.2%; p = 0.018). CONCLUSIONS: This study increases our knowledge on the optimization of ß-lactam therapy in ICU patients. A large inter- and intra-patient variability in plasmatic concentrations was observed, leading to inadequate exposure. A combined indexed creatinine clearance and TDM approach enables adequate dosing for better pharmacokinetic/pharmacodynamic target attainment.
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OBJECTIVES: The occurrence of mediastinitis after cardiac surgery remains a rare and severe complication associated with poor outcomes. Whereas bacterial mediastinitis have been largely described, little is known about their fungal etiologies. We report incidence, characteristics and outcome of post-cardiac surgery fungal mediastinitis. METHODS: Multicenter retrospective study among 10 intensive care units (ICU) in France and Belgium of proven cases of fungal mediastinitis after cardiac surgery (2009-2019). RESULTS: Among 73,688 cardiac surgery procedures, 40 patients developed fungal mediastinitis. Five were supported with left ventricular assist device and five with veno-arterial extracorporeal membrane oxygenation before initial surgery. Twelve patients received prior heart transplantation. Interval between initial surgery and mediastinitis was 38 [17-61] days. Only half of the patients showed local signs of infection. Septic shock was uncommon at diagnosis (12.5%). Forty-three fungal strains were identified: Candida spp. (34 patients), Trichosporon spp. (5 patients) and Aspergillus spp. (4 patients). Hospital mortality was 58%. Survivors were younger (59 [43-65] vs. 65 [61-73] yo; p = 0.013), had lower body mass index (24 [20-26] vs. 30 [24-32] kg/m2; p = 0.028) and lower Simplified Acute Physiology Score II score at ICU admission (37 [28-40] vs. 54 [34-61]; p = 0.012). CONCLUSION: Fungal mediastinitis is a very rare complication after cardiac surgery, associated with a high mortality rate. This entity should be suspected in patients with a smoldering infectious postoperative course, especially those supported with short- or long-term invasive cardiac support devices, or following heart transplantation.
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Procedimentos Cirúrgicos Cardíacos , Mediastinite , Humanos , Estudos Retrospectivos , Mediastinite/epidemiologia , Mediastinite/microbiologia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/métodos , Candida , BélgicaRESUMO
Background: A novel multisystem inflammatory syndrome in children (MIS-C) temporally associated with the coronavirus disease 2019 (COVID-19) infection has been reported, arising weeks after the peak incidence of COVID-19 infection in adults. Patients with MIS-C have been reported to have cardiac involvement and clinical features overlapping with other acute inflammatory syndromes such as Kawasaki disease, toxic shock syndrome, and macrophage activation syndrome. Multisystem inflammatory syndrome in children may follow COVID-19 infection, most of the time after its asymptomatic form, even though it can lead to serious and life-threatening illness. Case summary: In this case series, we discuss two cases of young adults with no former medical history who fit with the criteria defined in MIS-C. They both developed a refractory cardiogenic shock and required intensive care treatment including mechanical circulatory support, specifically the use of venous-arterial extracorporeal membrane oxygenation. They were both treated early with intravenous immune globulin and adjunctive high-dose steroids. They recovered ad integrum in less than 2 weeks. Discussion: Multisystem inflammatory syndrome in children occurs 2-4 weeks after infection with severe acute respiratory syndrome coronavirus 2. Patients with MIS-C should ideally be managed in an intensive care environment since rapid clinical deterioration may occur. It would be preferable to have a multidisciplinary care to improve outcomes. Patients should be monitored for shock. Elucidating the mechanism of this new entity may have importance for understanding COVID-19 far beyond the patients who have had MIS-C to date. The pathogenesis seems to involve post-infectious immune dysregulation so early administration intravenous immune globulin associated with corticosteroids appears appropriate. It implies early recognition of the syndrome even in young adults.
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Pulmonary atelectasis is common in the perioperative period. Physiologically, it is produced when collapsing forces derived from positive pleural pressure and surface tension overcome expanding forces from alveolar pressure and parenchymal tethering. Atelectasis impairs blood oxygenation and reduces lung compliance. It is increasingly recognized that it can also induce local tissue biologic responses, such as inflammation, local immune dysfunction, and damage of the alveolar-capillary barrier, with potential loss of lung fluid clearance, increased lung protein permeability, and susceptibility to infection, factors that can initiate or exaggerate lung injury. Mechanical ventilation of a heterogeneously aerated lung (e.g., in the presence of atelectatic lung tissue) involves biomechanical processes that may precipitate further lung damage: concentration of mechanical forces, propagation of gas-liquid interfaces, and remote overdistension. Knowledge of such pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should guide optimal clinical management.
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Complicações Intraoperatórias/fisiopatologia , Pulmão/fisiopatologia , Assistência Perioperatória/métodos , Atelectasia Pulmonar/fisiopatologia , Atelectasia Pulmonar/terapia , Animais , Diafragma/diagnóstico por imagem , Diafragma/fisiopatologia , Humanos , Complicações Intraoperatórias/diagnóstico por imagem , Complicações Intraoperatórias/terapia , Pulmão/diagnóstico por imagem , Assistência Perioperatória/tendências , Atelectasia Pulmonar/diagnóstico por imagem , Respiração Artificial/efeitos adversos , Respiração Artificial/tendênciasRESUMO
The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.
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Complicações Intraoperatórias/fisiopatologia , Complicações Intraoperatórias/terapia , Assistência Perioperatória/métodos , Atelectasia Pulmonar/fisiopatologia , Atelectasia Pulmonar/terapia , Humanos , Complicações Intraoperatórias/diagnóstico por imagem , Complicações Intraoperatórias/epidemiologia , Pulmão/diagnóstico por imagem , Pulmão/fisiopatologia , Manometria/métodos , Manometria/tendências , Obesidade/diagnóstico por imagem , Obesidade/epidemiologia , Obesidade/fisiopatologia , Assistência Perioperatória/tendências , Respiração com Pressão Positiva/efeitos adversos , Respiração com Pressão Positiva/tendências , Atelectasia Pulmonar/diagnóstico por imagem , Atelectasia Pulmonar/epidemiologia , Respiração Artificial/efeitos adversos , Respiração Artificial/tendências , Fatores de Risco , Fumar/efeitos adversos , Fumar/epidemiologia , Fumar/fisiopatologiaRESUMO
OBJECTIVES: To describe clinical characteristics and management of intensive care units (ICU) patients with laboratory-confirmed COVID-19 and to determine 90-day mortality after ICU admission and associated risk factors. METHODS: This observational retrospective study was conducted in six intensive care units (ICUs) in three university hospitals in Marseille, France. Between 10 March and 10 May 2020, all adult patients admitted in ICU with laboratory-confirmed SARS-CoV-2 and respiratory failure were eligible for inclusion. The statistical analysis was focused on the mechanically ventilated patients. The primary outcome was the 90-day mortality after ICU admission. RESULTS: Included in the study were 172 patients with COVID-19 related respiratory failure, 117 of whom (67%) received invasive mechanical ventilation. 90-day mortality of the invasively ventilated patients was 27.4%. Median duration of ventilation and median length of stay in ICU for these patients were 20 (9-33) days and 29 (17-46) days. Mortality increased with the severity of ARDS at ICU admission. After multivariable analysis was carried out, risk factors associated with 90-day mortality were age, elevated Charlson comorbidity index, chronic statins intake and occurrence of an arterial thrombosis. CONCLUSION: In this cohort, age and number of comorbidities were the main predictors of mortality in invasively ventilated patients. The only modifiable factor associated with mortality in multivariate analysis was arterial thrombosis.
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ABSTRACT: This retrospective study aimed to describe the association between the "ß-lactam allergy" labeling (BLAL) and the outcomes of a cohort of intensive care unit (ICU) patients.Retrospective cohort study.Seven ICU of the Aix Marseille University Hospitals from Marseille in France.We collected the uses of the label "ß-lactam allergy" in the electronic medical files of patients aged 18âyears or more who required more than 48âhours in the ICU with mechanical ventilation and/or vasopressors admitted to 7 ICUs of a single institution.We retrospectively compared the patients with this labeling (BLAL group) with those without this labeling (control group).The primary outcome was the duration of ICU stay. Among the 7146 patients included in the analysis, 440 and 6706 patients were classified in the BLAL group and the control group, respectively. The prevalence of BLAL was 6.2%. In univariate and multivariate analyses, BLAL was weakly or not associated with the duration of ICU and hospital stays (respectively, 6 [3-14] vs 6 [3-14] days, standardized beta -0.09, Pâ=â.046; and 18 [10-29] vs 15 [8-28] days, standardized beta -0.09, Pâ=â.344). In multivariate analysis, the ICU and 28-day mortality rates were both lower in the BLAL group than in the control group (aOR 0.79 95% CI [0.64-0.98] Pâ=â.032 and 0.79 [0.63-0.99] Pâ=â.042). Antibiotic use differed between the 2 groups, but the outcomes were similar in the subgroups of septic patients in the BLAL group and the control group.In our cohort, the labeling of a ß-lactam allergy was not associated with prolonged ICU and hospital stays. An association was found between the labeling of a ß-lactam allergy and lower ICU and 28-day mortality rates.Trial registration: Retrospectively registered.
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Cuidados Críticos/métodos , Hipersensibilidade/etiologia , Unidades de Terapia Intensiva/estatística & dados numéricos , beta-Lactamas/efeitos adversos , Feminino , Seguimentos , França/epidemiologia , Mortalidade Hospitalar/tendências , Humanos , Hipersensibilidade/epidemiologia , Hipersensibilidade/terapia , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida/tendênciasRESUMO
A 35-year-old man, with a deep pectus excavatum due to a Marfan syndrome treated 9 years before for an acute type A dissection involving only the aortic arch, by a Bentall surgery, was admitted for acute chest pain. Computed tomography (CT) scan showed an acute type non-A non-B dissection extending to the iliac. After 5 days with strict arterial blood pressure management, the patient had recurrent refractory chest pain and a hybrid technique associating full supra-aortic vessels debranching and STABILISE technique during the same procedure was performed. The patient had an uneventful recovery with CT scan showing complete aortic arch aneurysm exclusion.
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Aneurisma da Aorta Torácica/cirurgia , Dissecção Aórtica/cirurgia , Implante de Prótese Vascular , Procedimentos Endovasculares , Síndrome de Marfan/complicações , Adulto , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/etiologia , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/etiologia , Prótese Vascular , Implante de Prótese Vascular/instrumentação , Procedimentos Endovasculares/instrumentação , Humanos , Masculino , Síndrome de Marfan/diagnóstico , Stents , Resultado do TratamentoRESUMO
We report a fatal case of coxsackievirus B4 chronic infection in a 30-year-old woman with a diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disorder controlled by rituximab monotherapy for 3 years. Initially presenting as self-limited meningitis, the infection remained silent for 8 months before the sudden onset of fulminant myocarditis. Analysis of the complete genome showed that the same virus was responsible for both episodes.
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Infecções por Enterovirus , Enterovirus , Neuromielite Óptica , Adulto , Autoanticorpos , Sistema Nervoso Central , Infecções por Enterovirus/tratamento farmacológico , Feminino , Humanos , Glicoproteína Mielina-OligodendrócitoRESUMO
BACKGROUND: In the Protective Ventilation in Cardiac Surgery (PROVECS) randomized, controlled trial, an open-lung ventilation strategy did not improve postoperative respiratory outcomes after on-pump cardiac surgery. In this prespecified subanalysis, the authors aimed to assess the regional distribution of ventilation and plasma biomarkers of lung epithelial and endothelial injury produced by that strategy. METHODS: Perioperative open-lung ventilation consisted of recruitment maneuvers, positive end-expiratory pressure (PEEP) = 8 cm H2O, and low-tidal volume ventilation including during cardiopulmonary bypass. Control ventilation strategy was a low-PEEP (2 cm H2O) low-tidal volume approach. Electrical impedance tomography was used serially throughout the perioperative period (n = 56) to compute the dorsal fraction of ventilation (defined as the ratio of dorsal tidal impedance variation to global tidal impedance variation). Lung injury was assessed serially using biomarkers of epithelial (soluble form of the receptor for advanced glycation end-products, sRAGE) and endothelial (angiopoietin-2) lung injury (n = 30). RESULTS: Eighty-six patients (age = 64 ± 12 yr; EuroSCORE II = 1.65 ± 1.57%) undergoing elective on-pump cardiac surgery were studied. Induction of general anesthesia was associated with ventral redistribution of tidal volumes and higher dorsal fraction of ventilation in the open-lung than the control strategy (0.38 ± 0.07 vs. 0.30 ± 0.10; P = 0.004). No effect of the open-lung strategy on the dorsal fraction of ventilation was noted at the end of surgery after median sternotomy closure (open-lung = 0.37 ± 0.09 vs. control = 0.34 ± 0.11; P = 0.743) or in extubated patients at postoperative day 2 (open-lung = 0.63 ± 0.18 vs. control = 0.59 ± 0.11; P > 0.999). Open-lung ventilation was associated with increased intraoperative plasma sRAGE (7,677 ± 3,097 pg/ml vs. 6,125 ± 1,400 pg/ml; P = 0.037) and had no effect on angiopoietin-2 (P > 0.999). CONCLUSIONS: In cardiac surgery patients, open-lung ventilation provided larger dorsal lung ventilation early during surgery without a maintained benefit as compared with controls at the end of surgery and postoperative day 2 and was associated with higher intraoperative plasma concentration of sRAGE suggesting lung overdistension.
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Procedimentos Cirúrgicos Cardíacos/métodos , Lesão Pulmonar/prevenção & controle , Assistência Perioperatória/métodos , Respiração com Pressão Positiva/métodos , Volume de Ventilação Pulmonar/fisiologia , Idoso , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Feminino , Humanos , Lesão Pulmonar/etiologia , Lesão Pulmonar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Assistência Perioperatória/efeitos adversos , Respiração com Pressão Positiva/efeitos adversos , Respiração Artificial/efeitos adversos , Respiração Artificial/métodos , Volume de Ventilação Pulmonar/efeitos dos fármacosRESUMO
Strategies to split ventilators to support multiple patients requiring ventilatory support have been proposed and used in emergency cases in which shortages of ventilators cannot otherwise be remedied by production or procurement strategies. However, the current approaches to ventilator sharing lack the ability to individualize ventilation to each patient, measure pulmonary mechanics, and accommodate rebalancing of the airflow when one patient improves or deteriorates, posing safety concerns to patients. Potential cross-contamination, lack of alarms, insufficient monitoring, and inability to adapt to sudden changes in patient status have prevented widespread acceptance of ventilator sharing. We have developed an individualized system for augmenting ventilator efficacy (iSAVE) as a rapidly deployable platform that uses a single ventilator to simultaneously and more safely support two individuals. The iSAVE enables individual-specific volume and pressure control and the rebalancing of ventilation in response to improvement or deterioration in an individual's respiratory status. The iSAVE incorporates mechanisms to measure pulmonary mechanics, mitigate cross-contamination and backflow, and accommodate sudden flow changes due to individual interdependencies within the respiratory circuit. We demonstrate these capacities through validation using closed- and open-circuit ventilators on linear test lungs. We show that the iSAVE can temporarily ventilate two pigs on one ventilator as efficaciously as each pig on its own ventilator. By leveraging off-the-shelf medical components, the iSAVE could rapidly expand the ventilation capacity of health care facilities during emergency situations such as pandemics.
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Pandemias , Ventiladores Mecânicos , Animais , Humanos , Pulmão , SuínosRESUMO
BACKGROUND: The natural history of type B intramural hematomas is little-known. Aneurysmal progression or an aortic dissection occurs in 15 to 20% of the cases. The study of the natural anatomical evolution could help identify the patients at risk of unfavorable evolution. METHODS: All the patients monitored for a type B intramural hematoma between 2009 and 2018 were included in this monocentric retrospective study. Computed tomography angiography centerline measurement of diameters was obtained in various points of aortic segmentation on day (D) 0 and at one month (M1). Aortic volumes (lumen, intramural hematoma, and total volume) were calculated. The circulating volume was calculated using the volume rendering method. The volume of the intramural hematoma was measured using a manual section-by-section segmentation tool, and the total volume was obtained by summing up the two preceding volumes. Two groups of patients were compared: group 1 (favorable anatomical evolution) and group 2 (unfavorable anatomical evolution). RESULTS: Between January 2008 and August 2018, 25 patients were managed for a type B intramural hematoma in our center. After an average follow-up of 15.5 months (1-52), 13 patients (52%) presented a favorable evolution and 12 (48%) an unfavorable evolution. At M1, a significant increase of the luminal diameters (37 mm vs. 32 mm; P < 0.01) and a significant reduction in the longitudinal extension (19 mm vs. 26 mm; P < 0.01) were observed. The maximum aortic diameter evolved significantly between D0 and M1 in the unfavorable evolution group (49 mm vs. 44 mm, respectively; P = 0.038). Such a difference was not found in the favorable evolution group (37.4 vs. 37.1, respectively; P = 0.552). An overall significant reduction in the total aortic volume (166 cm3 vs. 219 cm3; P < 0.01), the circulating volume (124 cm3 vs. 145 cm3; P = 0,026), and the volume of the hematoma (42 cm3 vs. 39 cm3; P < 0.01) was observed. The circulating volume decreased significantly between D0 and M1 in the favorable evolution group (110 cm3 vs. 135 cm3; P = 0.05), whereas no difference was noted in the unfavorable group (142 cm3 vs, 157 cm3; P = 0.24). CONCLUSIONS: The progression of the maximum aortic diameter and of the circulating volume after one month of follow-up could be predictive factors of the poor long-term evolution of type B intramural hematomas.