Intensive Care Medicine Experimental最新文献

{"title":"Fugitive medical and patient-derived aerosol particle distribution following heparin nebulization in patients with COVID-19 acute hypoxemic respiratory failure: a secondary analysis of the CHARTER study.","authors":"Michael Walsh, Marc Mac Giolla Eain, Ronan MacLoughlin, John Laffey, Bairbre McNicholas","doi":"10.1186/s40635-024-00659-y","DOIUrl":"10.1186/s40635-024-00659-y","url":null,"abstract":"","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"73"},"PeriodicalIF":2.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11347535/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142055513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The physiological basis for individualized oxygenation targets in critically ill patients with circulatory shock.","authors":"Anne-Aylin Sigg, Vanja Zivkovic, Jan Bartussek, Reto A Schuepbach, Can Ince, Matthias P Hilty","doi":"10.1186/s40635-024-00651-6","DOIUrl":"10.1186/s40635-024-00651-6","url":null,"abstract":"<p><strong>Background: </strong>Circulatory shock, defined as decreased tissue perfusion, leading to inadequate oxygen delivery to meet cellular metabolic demands, remains a common condition with high morbidity and mortality. Rapid restitution and restoration of adequate tissue perfusion are the main treatment goals. To achieve this, current hemodynamic strategies focus on adjusting global physiological variables such as cardiac output (CO), hemoglobin (Hb) concentration, and arterial hemoglobin oxygen saturation (SaO₂). However, it remains a challenge to identify optimal targets for these global variables that best support microcirculatory function. Weighting up the risks and benefits is especially difficult for choosing the amount of oxygen supplementation in critically ill patients. This review assesses the physiological basis for oxygen delivery to the tissue and provides an overview of the relevant literature to emphasize the importance of considering risks and benefits and support decision making at the bedside.</p><p><strong>Physiological premises: </strong>Oxygen must reach the tissue to enable oxidative phosphorylation. The human body timely detects hypoxia via different mechanisms aiming to maintain adequate tissue oxygenation. In contrast to the pulmonary circulation, where the main response to hypoxia is arteriolar vasoconstriction, the regulatory mechanisms of the systemic circulation aim to optimize oxygen availability in the tissues. This is achieved by increasing the capillary density in the microcirculation and the capillary hematocrit thereby increasing the capacity of oxygen diffusion from the red blood cells to the tissue. Hyperoxia, on the other hand, is associated with oxygen radical production, promoting cell death.</p><p><strong>Current state of research: </strong>Clinical trials in critically ill patients have primarily focused on comparing macrocirculatory endpoints and outcomes based on stroke volume and oxygenation targets. Some earlier studies have indicated potential benefits of conservative oxygenation. Recent trials show contradictory results regarding mortality, organ dysfunction, and ventilatory-free days. Empirical studies comparing various targets for SaO_2, or partial pressure of oxygen indicate a U-shaped curve balancing positive and negative effects of oxygen supplementation.</p><p><strong>Conclusion and future directions: </strong>To optimize risk-benefit ratio of resuscitation measures in critically ill patients with circulatory shock in addition to individual targets for CO and Hb concentration, a primary aim should be to restore tissue perfusion and avoid hyperoxia. In the future, an individualized approach with microcirculatory targets will become increasingly relevant. Further studies are needed to define optimal targets.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"72"},"PeriodicalIF":2.8,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11341514/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A pilot feasibility study comparing large language models in extracting key information from ICU patient text records from an Irish population.","authors":"Emma Urquhart, John Ryan, Sean Hartigan, Ciprian Nita, Ciara Hanley, Peter Moran, John Bates, Rachel Jooste, Conor Judge, John G Laffey, Michael G Madden, Bairbre A McNicholas","doi":"10.1186/s40635-024-00656-1","DOIUrl":"10.1186/s40635-024-00656-1","url":null,"abstract":"<p><strong>Background: </strong>Artificial intelligence, through improved data management and automated summarisation, has the potential to enhance intensive care unit (ICU) care. Large language models (LLMs) can interrogate and summarise large volumes of medical notes to create succinct discharge summaries. In this study, we aim to investigate the potential of LLMs to accurately and concisely synthesise ICU discharge summaries.</p><p><strong>Methods: </strong>Anonymised clinical notes from ICU admissions were used to train and validate a prompting structure in three separate LLMs (ChatGPT, GPT-4 API and Llama 2) to generate concise clinical summaries. Summaries were adjudicated by staff intensivists on ability to identify and appropriately order a pre-defined list of important clinical events as well as readability, organisation, succinctness, and overall rank.</p><p><strong>Results: </strong>In the development phase, text from five ICU episodes was used to develop a series of prompts to best capture clinical summaries. In the testing phase, a summary produced by each LLM from an additional six ICU episodes was utilised for evaluation. Overall ability to identify a pre-defined list of important clinical events in the summary was 41.5 ± 15.2% for GPT-4 API, 19.2 ± 20.9% for ChatGPT and 16.5 ± 14.1% for Llama2 (p = 0.002). GPT-4 API followed by ChatGPT had the highest score to appropriately order a pre-defined list of important clinical events in the summary as well as readability, organisation, succinctness, and overall rank, whilst Llama2 scored lowest for all. GPT-4 API produced minor hallucinations, which were not present in the other models.</p><p><strong>Conclusion: </strong>Differences exist in large language model performance in readability, organisation, succinctness, and sequencing of clinical events compared to others. All encountered issues with narrative coherence and omitted key clinical data and only moderately captured all clinically meaningful data in the correct order. However, these technologies suggest future potential for creating succinct discharge summaries.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"71"},"PeriodicalIF":2.8,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11327225/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141987903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Venous return physiology applied to post-cardiac arrest haemodynamic management: a post hoc analysis of the NEUROPROTECT trial.","authors":"Anders Aneman, Markus Benedikt Skrifvars, Koen Ameloot","doi":"10.1186/s40635-024-00657-0","DOIUrl":"10.1186/s40635-024-00657-0","url":null,"abstract":"<p><strong>Background: </strong>The European Resuscitation Council 2021 guidelines for haemodynamic monitoring and management during post-resuscitation care from cardiac arrest call for an individualised approach to therapeutic interventions. Combining the cardiac function and venous return curves with the inclusion of the mean systemic filling pressure enables a physiological illustration of intravascular volume, vasoconstriction and inotropy. An analogue mean systemic filling pressure (Pmsa) may be calculated once cardiac output, mean arterial and central venous pressure are known. The NEUROPROTECT trial compared targeting a mean arterial pressure of 65 mmHg (standard) versus an early goal directed haemodynamic optimisation targeting 85 mmHg (high) in ICU for 36 h after cardiac arrest. The trial data were used in this study to calculate post hoc Pmsa and its expanded variables to comprehensively describe venous return physiology during post-cardiac arrest management. A general estimating equation model was used to analyse continuous variables split by standard and high mean arterial pressure groups.</p><p><strong>Results: </strong>Data from 52 patients in each group were analysed. The driving pressure for venous return, and thus cardiac output, was higher in the high MAP group (p < 0.001) along with a numerically increased estimated stressed intravascular volume (mean difference 0.27 [- 0.014-0.55] L, p = 0.06). The heart efficiency was comparable (p = 0.43) in both the standard and high MAP target groups, suggesting that inotropy was similar despite increased arterial load in the high MAP group (p = 0.01). The efficiency of fluid boluses to increase cardiac output was increased in the higher MAP compared to standard MAP group (mean difference 0.26 [0.08-0.43] fraction units, p = 0.01).</p><p><strong>Conclusions: </strong>Calculation of the analogue mean systemic filling pressure and expanded variables using haemodynamic data from the NEUROPROTECT trial demonstrated an increased venous return, and thus cardiac output, as well as increased volume responsiveness associated with targeting a higher MAP. Further studies of the analogue mean systemic filling pressure and its derived variables are warranted to individualise post-resuscitation care and evaluate any clinical benefit associated with this monitoring approach.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"70"},"PeriodicalIF":2.8,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11322455/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141975634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation and concordance of carotid Doppler ultrasound and echocardiography with invasive cardiac output measurement in critically ill patients.","authors":"María Camila Arango-Granados, Jaime Andrés Quintero-Ramírez, Felipe Mejía-Herrera, Lina Mayerly Henao-Cardona, Valentina Muñoz-Patiño, Luis Alfonso Bustamante-Cristancho","doi":"10.1186/s40635-024-00653-4","DOIUrl":"10.1186/s40635-024-00653-4","url":null,"abstract":"<p><strong>Background: </strong>Critical care management heavily relies on accurate cardiac output (CO) measurement. Echocardiography has been a mainstay in non-invasive cardiac monitoring; however, its comparability to invasive methods warrants further exploration. Recent studies have suggested the potential of carotid Doppler measurements as a promising approach to estimate CO. Despite this potential, the literature presents mixed outcomes regarding its reliability and accuracy. This study aims to evaluate the correlation and concordance between carotid Doppler ultrasonography and invasive hemodynamic monitoring in estimating CO in critically ill patients. Furthermore, it assesses the concordance and correlation between echocardiography CO and the standard invasive CO measurements.</p><p><strong>Methods: </strong>This concordance study involved critically ill adults requiring invasive CO measurement. Patients with arrhythmias, severe valvulopathy, pregnancy, and poor acoustic window were excluded. Statistical analyses comprised univariate analysis, Wilcoxon signed-rank test, Spearman correlation, and intraclass correlation coefficient. Ethical approval was granted by the institution's ethics committee.</p><p><strong>Results: </strong>A total of 49 critically ill patients were included, predominantly male (63.27%), with a median age of 57 years. Diagnoses included subarachnoid hemorrhage (53.06%) and heart failure (8.16%). Mean cardiac index was 3.36 ± 0.81 L/min/m² and mean cardiac output was 5.98 ± 1.47 L/min. Spearman correlation coefficient between echocardiography and invasive CO measurements was 0.58 (p-value = p < 0.001), with an ICC of 0.59 for CO and 0.52 for cardiac index. Carotid measurements displayed no significant correlation with invasive CO.</p><p><strong>Conclusion: </strong>There is a moderate correlation and concordance between echocardiography and invasive CO measurements. There is no significant correlation between carotid variables and invasive CO, underscoring the necessity for cautious interpretation and application, particularly in patients with distinctive cerebral blood flow dynamics.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"69"},"PeriodicalIF":2.8,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11319701/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141916618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Standard versus individualised positive end-expiratory pressure (PEEP) compared by electrical impedance tomography in neurocritical care: a pilot prospective single centre study.","authors":"Vera Spatenkova, Mikulas Mlcek, Alan Mejstrik, Lukas Cisar, Eduard Kuriscak","doi":"10.1186/s40635-024-00654-3","DOIUrl":"10.1186/s40635-024-00654-3","url":null,"abstract":"<p><strong>Background: </strong>Individualised bedside adjustment of mechanical ventilation is a standard strategy in acute coma neurocritical care patients. This involves customising positive end-expiratory pressure (PEEP), which could improve ventilation homogeneity and arterial oxygenation. This study aimed to determine whether PEEP titrated by electrical impedance tomography (EIT) results in different lung ventilation homogeneity when compared to standard PEEP of 5 cmH₂O in mechanically ventilated patients with healthy lungs.</p><p><strong>Methods: </strong>In this prospective single-centre study, we evaluated 55 acute adult neurocritical care patients starting controlled ventilation with PEEPs close to 5 cmH₂O. Next, the optimal PEEP was identified by EIT-guided decremental PEEP titration, probing PEEP levels between 9 and 2 cmH₂O and finding the minimal amount of collapse and overdistension. EIT-derived parameters of ventilation homogeneity were evaluated before and after the PEEP titration and after the adjustment of PEEP to its optimal value. Non-EIT-based parameters, such as peripheral capillary Hb saturation (SpO₂) and end-tidal pressure of CO₂, were recorded hourly and analysed before PEEP titration and after PEEP adjustment.</p><p><strong>Results: </strong>The mean PEEP value before titration was 4.75 ± 0.94 cmH₂O (ranging from 3 to max 8 cmH₂O), 4.29 ± 1.24 cmH₂O after titration and before PEEP adjustment, and 4.26 ± 1.5 cmH₂O after PEEP adjustment. No statistically significant differences in ventilation homogeneity were observed due to the adjustment of PEEP found by PEEP titration. We also found non-significant changes in non-EIT-based parameters following the PEEP titration and subsequent PEEP adjustment, except for the mean arterial pressure, which dropped statistically significantly (with a mean difference of 3.2 mmHg, 95% CI 0.45 to 6.0 cmH₂O, p < 0.001).</p><p><strong>Conclusion: </strong>Adjusting PEEP to values derived from PEEP titration guided by EIT does not provide any significant changes in ventilation homogeneity as assessed by EIT to ventilated patients with healthy lungs, provided the change in PEEP does not exceed three cmH₂O. Thus, a reduction in PEEP determined through PEEP titration that is not greater than 3 cmH₂O from an initial value of 5 cmH₂O is unlikely to affect ventilation homogeneity significantly, which could benefit mechanically ventilated neurocritical care patients.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"67"},"PeriodicalIF":2.8,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11300775/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141893402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Apelin-13 administration allows for norepinephrine sparing in a rat model of cecal ligation and puncture-induced septic shock.","authors":"William Salvail, Dany Salvail, Frédéric Chagnon, Olivier Lesur","doi":"10.1186/s40635-024-00650-7","DOIUrl":"10.1186/s40635-024-00650-7","url":null,"abstract":"<p><strong>Background: </strong>Infusion of exogenous catecholamines (i.e., norepinephrine [NE] and dobutamine) is a recommended treatment for septic shock with myocardial dysfunction. However, sustained catecholamine infusion is linked to cardiac toxicity and impaired responsiveness. Several pre-clinical and clinical studies have investigated the use of alternative vasopressors in the treatment of septic shock, with limited benefits and generally no effect on mortality. Apelin-13 (APL-13) is an endogenous positive inotrope and vasoactive peptide and has been demonstrated cardioprotective with vasomodulator and sparing life effects in animal models of septic shock. A primary objective of this study was to evaluate the NE-sparing effect of APL-13 infusion in an experimental sepsis-induced hypotension.</p><p><strong>Methods: </strong>For this goal, sepsis was induced by cecal ligation and puncture (CLP) in male rats and the arterial blood pressure (BP) monitored continuously via a carotid catheter. Monitoring, fluid resuscitation and experimental treatments were performed on conscious animals. Based on pilot assays, normal saline fluid resuscitation (2.5 mL/Kg/h) was initiated 3 h post-CLP and maintained up to the endpoint. Thus, titrated doses of NE, with or without fixed-doses of APL-13 or the apelin receptor antagonist F13A co-infusion were started when 20% decrease of systolic BP (SBP) from baseline was achieved, to restore SBP values ≥ 115 ± 1.5 mmHg (baseline average ± SEM).</p><p><strong>Results: </strong>A reduction in mean NE dose was observed with APL-13 but not F13A co-infusion at pre-determined treatment time of 4.5 ± 0.5 h (17.37 ± 1.74 µg/Kg/h [APL-13] vs. 25.64 ± 2.61 µg/Kg/h [Control NE] vs. 28.60 ± 4.79 µg/Kg/min [F13A], P = 0.0491). A 60% decrease in NE infusion rate over time was observed with APL-13 co-infusion, (p = 0.008 vs NE alone), while F13A co-infusion increased the NE infusion rate over time by 218% (p = 0.003 vs NE + APL-13). Associated improvements in cardiac function are likely mediated by (i) enhanced left ventricular end-diastolic volume (0.18 ± 0.02 mL [Control NE] vs. 0.30 ± 0.03 mL [APL-13], P = 0.0051), stroke volume (0.11 ± 0.01 mL [Control NE] vs. 0.21 ± 0.01 mL [APL-13], P < 0.001) and cardiac output (67.57 ± 8.63 mL/min [Control NE] vs. 112.20 ± 8.53 mL/min [APL-13], P = 0.0036), and (ii) a reduced effective arterial elastance (920.6 ± 81.4 mmHg/mL/min [Control NE] vs. 497.633.44 mmHg/mL/min. [APL-13], P = 0.0002). APL-13 administration was also associated with a decrease in lactate levels compared to animals only receiving NE (7.08 ± 0.40 [Control NE] vs. 4.78 ± 0.60 [APL-13], P < 0.01).</p><p><strong>Conclusion: </strong>APL-13 exhibits NE-sparing benefits in the treatment of sepsis-induced shock, potentially reducing deleterious effects of prolonged exogenous catecholamine administration.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"68"},"PeriodicalIF":2.8,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11300420/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141893401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The ADVanced Organ Support (ADVOS) hemodialysis system removes IL-6: an in vitro proof-of-concept study.","authors":"Susanne Himmelein, Aritz Perez Ruiz de Garibay, Veronika Brandel, Frank Zierfuß, Tobias Michael Bingold","doi":"10.1186/s40635-024-00652-5","DOIUrl":"10.1186/s40635-024-00652-5","url":null,"abstract":"<p><strong>Background: </strong>IL-6 is a pleiotropic cytokine modulating inflammation and metabolic pathways. Its proinflammatory effect plays a significant role in organ failure pathogenesis, commonly elevated in systemic inflammatory conditions. Extracorporeal blood purification devices, such as the Advanced Organ Support (ADVOS) multi hemodialysis system, might offer potential in mitigating IL-6's detrimental effects, yet its efficacy remains unreported.</p><p><strong>Methods: </strong>We conducted a proof-of-concept in vitro study to assess the ADVOS multi system's efficacy in eliminating IL-6. Varying concentrations of IL-6 were introduced into a swine blood model and treated with ADVOS multi for up to 12 h, employing different blood and concentrate flow rates. IL-6 reduction rate, clearance, and dynamics in blood and dialysate were analyzed.</p><p><strong>Results: </strong>IL-6 clearance rates of 0.70 L/h and 0.42 L/h were observed in 4 and 12-h experiments, respectively. No significant differences were noted across different initial concentrations. Reduction rates ranged between 40 and 46% within the first 4 h, increasing up to 72% over 12 h, with minimal impact from flow rate variations. Our findings suggest that an IL-6-albumin interaction and convective filtration are implicated in in vitro IL-6 elimination with ADVOS multi.</p><p><strong>Conclusions: </strong>This study demonstrates for the first time an efficient and continuous in vitro removal of IL-6 by ADVOS multi at low blood flow rates. Initial concentration-dependent removal transitions to more consistent elimination over time. Further clinical investigations are imperative for comprehensive data acquisition.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"66"},"PeriodicalIF":2.8,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11291793/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141855396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical power ratio threshold for ventilator-induced lung injury.","authors":"Rosanna D'Albo, Tommaso Pozzi, Rosmery V Nicolardi, Mauro Galizia, Giulia Catozzi, Valentina Ghidoni, Beatrice Donati, Federica Romitti, Peter Herrmann, Mattia Busana, Simone Gattarello, Francesca Collino, Aurelio Sonzogni, Luigi Camporota, John J Marini, Onnen Moerer, Konrad Meissner, Luciano Gattinoni","doi":"10.1186/s40635-024-00649-0","DOIUrl":"10.1186/s40635-024-00649-0","url":null,"abstract":"<p><strong>Rationale: </strong>Mechanical power (MP) is a summary variable incorporating all causes of ventilator-induced-lung-injury (VILI). We expressed MP as the ratio between observed and normal expected values (MP_ratio).</p><p><strong>Objective: </strong>To define a threshold value of MP_ratio leading to the development of VILI.</p><p><strong>Methods: </strong>In a population of 82 healthy pigs, a threshold of MP_ratio for VILI, as assessed by histological variables and confirmed by using unsupervised cluster analysis was 4.5. The population was divided into two groups with MP_ratio above or below the threshold.</p><p><strong>Measurements and main results: </strong>We measured physiological variables every six hours. At the end of the experiment, we measured lung weight and wet-to-dry ratio to quantify edema. Histological samples were analyzed for alveolar ruptures, inflammation, alveolar edema, atelectasis. An MP_ratio threshold of 4.5 was associated with worse injury, lung weight, wet-to-dry ratio and fluid balance (all p < 0.001). After 48 h, in the two MP_ratio clusters (above or below 4.5), respiratory system elastance, mean pulmonary artery pressure and physiological dead space differed by 32%, 36% and 22%, respectively (all p < 0.001), being worse in the high MP_ratio group. Also, the changes in driving pressure, lung elastance, pulmonary artery occlusion pressure, central venous pressure differed by 17%, 64%, 8%, 25%, respectively (all p < 0.001).</p><p><strong>Limitations: </strong>The main limitation of this study is its retrospective design. In addition, the computation for the expected MP in pigs is based on arbitrary criteria. Different values of expected MP may change the absolute value of MP ratio but will not change the concept of the existence of an injury threshold.</p><p><strong>Conclusions: </strong>The concept of MP_ratio is a physiological and intuitive way to quantify the risk of ventilator-induced lung injury. Our results suggest that a mechanical power ratio > 4.5 MP_ratio in healthy lungs subjected to 48 h of mechanical ventilation appears to be a threshold for the development of ventilator-induced lung injury, as indicated by the convergence of histological, physiological, and anatomical alterations. In humans and in lungs that are already injured, this threshold is likely to be different.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"65"},"PeriodicalIF":2.8,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11289208/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141855395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ventriculo-arterial (VA) coupling and fQRS as new selection criteria for primary prevention ICD placement.","authors":"Nathan Engstrom, Hayley L Letson, Kevin Ng, Geoffrey P Dobson","doi":"10.1186/s40635-024-00642-7","DOIUrl":"10.1186/s40635-024-00642-7","url":null,"abstract":"<p><p>For decades, left ventricular ejection fraction (LVEF < 35%) has been a mainstay for identifying heart failure (HF) patients most likely to benefit from an implantable cardioverter defibrillator (ICD). However, LVEF is a poor predictor of sudden cardiac death (SCD) and ignores 50% of HF patients with mildly reduced and preserved LVEF. The current international guidelines for primary prophylaxis ICD therapy are inadequate. Instead of LVEF, which is not a good measure of LV contractility or hemodynamic characterization, we hypothesize ventriculo-arterial (VA) coupling combined with fragmented QRS (fQRS) will improve risk stratification and patient suitability for an ICD. Quantifying cardiac and aortic mechanics, and predicting active arrhythmogenic substrate, from varying fQRS morphologies, may help to stratify ischemic and non-ischemic patients with different functional capacities and predisposition for lethal arrhythmias. We propose HF patients with a low physiological reserve may not benefit from ICD therapy, whereas those patients with higher reserves and extensive arrhythmogenic substrate may benefit. Our hypothesis combining VA coupling with fQRS changes has the potential to widen HF patient participation (low and high LVEF) and advance personalized medicine for HF patients at high risk of SCD.</p>","PeriodicalId":13750,"journal":{"name":"Intensive Care Medicine Experimental","volume":"12 1","pages":"62"},"PeriodicalIF":2.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11231105/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141554774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}