Transpulmonary thermodilution: its role in assessment of lung water and pulmonary edema

Tissue edema, in particular pulmonary edema, increasingly is recognized as a perioperative complication affecting outcome. Management strategies directed at avoiding excessive fluid administration, reducing inflammatory response, and decreasing capillary permeability commonly are advocated in perioperative care protocols. In this review, transpulmonary thermodilution (TPTD) as a bedside tool to quantitatively monitor lung water accumulation and optimize fluid therapy is examined. Furthermore, the roles of TPTD as an early detector of fluid accumulation before the development of overt pulmonary edema and in risk stratification are explored. In addition, the ability of TPTD to provide insight into the etiology of pulmonary edema, specifically differentiating hydrostatic versus increased pulmonary capillary permeability, is emerging as an aid in therapeutic decision-making. The combination of hemodynamic and lung water data afforded by TPTD offers unique benefits for the care of high-risk perioperative patients

The right ventricle—structural and functional importance for anaesthesia and intensive care

No abstract available

Assessment of pulmonary edema: principles and practice

Pulmonary edema increasingly is recognized as a perioperative complication affecting outcome. Several risk factors have been identified, including those of cardiogenic origin, such as heart failure or excessive fluid administration, and those related to increased pulmonary capillary permeability secondary to inflammatory mediators. Effective treatment requires prompt diagnosis and early intervention. Consequently, over the past 2 centuries a concentrated effort to develop clinical tools to rapidly diagnose pulmonary edema and track response to treatment has occurred. The ideal properties of such a tool would include high sensitivity and specificity, easy availability, and the ability to diagnose early accumulation of lung water before the development of the full clinical presentation. In addition, clinicians highly value the ability to precisely quantify extravascular lung water accumulation and differentiate hydrostatic from high permeability etiologies of pulmonary edema. In this review, advances in understanding the physiology of extravascular lung water accumulation in health and in disease and the various mechanisms that protect against the development of pulmonary edema under physiologic conditions are discussed. In addition, the various bedside modalities available to diagnose early accumulation of extravascular lung water and pulmonary edema, including chest auscultation, chest roentgenography, lung ultrasonography, and transpulmonary thermodilution, are examined. Furthermore, advantages and limitations of these methods for the operating room and intensive care unit that are critical for proper modality selection in each individual case are explored

Acute lung injury associated with thoracic surgery

Lung cancer is the most common cause of cancer death in the UK. In suitable cases, the best chance of cure is surgical resection. Due to high levels of co-morbidity seen in this population, lung resection is associated with high cardio-respiratory complication rates. One such complication is the development of Acute Lung Injury / Acute Respiratory Distress Syndrome (ALI/ARDS). ALI/ARDS is reported to occur in four to 11% of patients undergoing lung resection and is the major cause of hospital mortality following lung resection. ALI/ARDS occurring following lung resection is widely interpreted to be a variant of ALI/ARDS and follows an identical clinical and pathophysiological course to that seen in the wider critical care environment. The pathophysiology of lung injury following lung resection is complex and can be broadly conceptualised as occurring secondary to insults specific to both the ipsilateral (surgical) lung, the contralateral (anaesthetic) lung in addition to those insults common to both lungs. Increased recognition of the role of ventilator induced lung injury, and peri-operative fluid prescribing in the pathogenesis of lung injury in this population has brought the prevention of lung injury to the attention of the thoracic anaesthetist. Though high quality evidence is lacking, expert opinion widely favours the adoption of lung protective ventilatory strategies and restriction of peri-operative fluids in patients undergoing lung resection. This thesis presents the rationale, methodology and results of four discrete studies concerning the development of lung injury in the thoracic surgical population undergoing resection of primary lung cancer. Investigation I is a survey of contemporary UK thoracic anaesthetic practice when anaesthetising for thoracic surgery and lung resection, with specific reference to strategies designed to prevent lung injury. Though implementation of the techniques described is far from universal, the survey results suggest that aspects of lung protective ventilation are widespread within UK thoracic anaesthetic practice. Investigation II seeks to examine the impact of increased adoption of such strategies over time. A random effects meta-analysis and meta-regression analysis was performed to examine the trends in the incidence of and mortality from ALI and/or ARDS over time. The main findings of this study are that whilst there is no evidence to suggest the incidence of ALI and/or ARDS post-lung resection is falling, mortality due to ARDS (but not ALI) does appear to be falling over time. Investigations III and IV examine the utility of two clinical monitoring methodologies which have potential to provide bedside clinical monitoring of lung injury development in the thoracic surgical population in order to guide clinical decision making, monitor patient progress and serve as a surrogate end point in future clinical studies. Investigation III examines the utility of a single lung injury biomarker (long chain Pentraxin 3 – PTX3) and a panel of multiple lung injury biomarkers in the early post-operative period following lung resection. The properties of the ‘ideal’ lung injury biomarker are defined, against which PTX3 and the multiple biomarker panel are compared. PTX3 compared favourably to properties of the ‘ideal’ lung injury biomarker and appeared to identify a population of patients with elevated post-operative Lung Injury Score with high sensitivity. Conversely there is no evidence from the results presented that a ‘risk of lung injury score’ derived from a panel of 7 candidate lung injury biomarkers (as previously defined in a cohort of critically ill patients with ALI/ARDS) has any utility in the lung resection population. Investigation IV tests the reproducibility and construct validity of transpulmonary thermodilution derived measurements of extravascular lung water and pulmonary vascular permeability index in patients undergoing lung resection. The study’s findings are largely supportive of the reproducibility and construct validity of extravascular lung water measurement and pulmonary vascular permeability measurements after lung resection. In combination, it is hoped that the studies presented provide greater insight into the syndrome of post lung resection lung injury. More accurate definition of standard anaesthetic practice and the incidence of and mortality from ALI/ARDS following lung resection should serve to inform future clinical studies seeking to prevent, treat, or better understand this important clinical syndrome. The biomarker PTX3 and transpulmonary thermodilution derived measurement of extravascular lung water and pulmonary vascular permeability index are presented as surrogate endpoints suitable for use in such studies

Implant-Based Reconstruction following Mastectomy in Patients Who Have Had a Previous Breast Augmentation:Lessons from the National Multicenter Implant Breast Reconstruction Evaluation Study

Background: Breast augmentation is the most commonly performed cosmetic procedure, and increasingly women in this group present with breast cancer or request risk-reducing surgery, but their optimal management is unclear. The authors explored the clinical and patient-reported outcomes of patients undergoing immediate implant-based breast reconstruction following previous augmentation and compared these with outcomes of patients who had not had cosmetic implants in the Implant Breast Reconstruction Evaluation (iBRA) Study.   Methods: Patients undergoing immediate implant-based breast reconstruction were prospectively recruited from breast and plastic surgical units across the United Kingdom. Demographic, operative, and oncologic data, and information regarding complications within 3 postoperative months were collected. Patient-reported outcomes at 18 months were assessed using the BREAST-Q. The clinical and patient-reported outcomes of patients undergoing immediate implant-based breast reconstruction with and without previous breast augmentation were compared.   Results: A total of 2108 women were included in the iBRA Study, of whom 49 had undergone a previous augmentation. Women in the augmentation group were younger (median age, 45 years versus 50 years; p = 0.01), had a lower body mass index (22.8 kg/m2 versus 24.9 kg/m2; p < 0.01), and had smaller tumors (15 mm versus 25 mm; p = 0.01) than patients without augmentation. No differences were seen in operative technique between the groups. Complications at 3 months were similar in both groups and there were no significant differences in patient-reported outcomes at 18 months.   Conclusions: The clinical and patient-reported outcomes of patients undergoing immediate implant-based breast reconstruction following previous augmentation are consistent with those observed in the wider iBRA Study cohort, supporting the safety of this approach

Cementitious Compositions

The invention provides a cementitious composition comprising a cement component comprising (i) an accelerant, (ii) a calcium sulphate source and (iii) an ettringite forming cement; an aggregate; and optionally water; wherein the cement has a minimum unconfined compressive strength of 1500 psi when tested in accordance with ASTM C1140 and/or C1604 at 15 minutes after placement; methods for its use and concrete formed from it

Can soluble urokinase plasminogen receptor predict outcomes after cardiac surgery?

Acknowledgements: We thank Lisa Jolly, from the Institute of Infection, Immunity and Inflammation at the University of Glasgow who performed all lab analysis. We thank Professor John Kinsella for his contributions to this research. Funding: This work was supported by the National Institute of Academic Anaesthesia through the Royal College of Anaesthetists Research, Education and Travel grant via the Ernest Leach Fund to Dr Philip McCall. The funding body had no role in design of the study, collection, analysis and interpretation of data or writing of the manuscript.Peer reviewedPostprintPostprintPostprin

Automated detection of rock glaciers using deep learning and object-based image analysis

B Robson was supported by the Meltzer foundation and a University of Bergen grant. S MacDonell was supported by CONICYT-Programa Regional (R16A10003) and the Coquimbo Regional Government via FIC-R(2016)BIP 40000343. D. Hölbling has been supported by the Austrian Science Fund through the project MORPH (Mapping, Monitoring and Modeling the Spatio-Temporal Dynamics of Land Surface Morphology; FWF-P29461-N29). N Schaffer was financed by CONICYT-FONDECYT (3180417) and P Rastner by the ESA Dragon 4 programme (4000121469/17/I-NB).Rock glaciers are an important component of the cryosphere and are one of the most visible manifestations of permafrost. While the significance of rock glacier contribution to streamflow remains uncertain, the contribution is likely to be important for certain parts of the world. High-resolution remote sensing data has permitted the creation of rock glacier inventories for large regions. However, due to the spectral similarity between rock glaciers and the surrounding material, the creation of such inventories is typically conducted based on manual interpretation, which is both time consuming and subjective. Here, we present a novel method that combines deep learning (convolutional neural networks or CNNs) and object-based image analysis (OBIA) into one workflow based on freely available Sentinel-2 optical imagery (10 m spatial resolution), Sentinel-1 interferometric coherence data, and a digital elevation model (DEM). CNNs identify recurring patterns and textures and produce a prediction raster, or heatmap where each pixel indicates the probability that it belongs to a certain class (i.e. rock glacier) or not. By using OBIA we can segment the datasets and classify objects based on their heatmap value as well as morphological and spatial characteristics. We analysed two distinct catchments, the La Laguna catchment in the Chilean semi-arid Andes and the Poiqu catchment in the central Himalaya. In total, our method mapped 108 of the 120 rock glaciers across both catchments with a mean overestimation of 28%. Individual rock glacier polygons howevercontained false positives that are texturally similar, such as debris-flows, avalanche deposits, or fluvial material causing the user's accuracy to be moderate (63.9–68.9%) even if the producer's accuracy was higher (75.0–75.4%). We repeated our method on very-high-resolution Pléiades satellite imagery and a corresponding DEM (at 2 m resolution) for a subset of the Poiqu catchment to ascertain what difference image resolution makes. We found that working at a higher spatial resolution has little influence on the producer's accuracy (an increase of 1.0%), however the rock glaciers delineated were mapped with a greater user's accuracy (increase by 9.1% to 72.0%). By running all the processing within an object-based environment it was possible to both generate the deep learning heatmap and perform post-processing through image segmentation and object reshaping. Given the difficulties in differentiating rock glaciers using image spectra, deep learning combined with OBIA offers a promising method for automating the process of mapping rock glaciers over regional scales and lead to a reduction in the workload required in creating inventories.Publisher PDFPeer reviewe

Glacier and rock glacier changes since the 1950s in the La Laguna catchment, Chile

Benjamin Aubrey Robson was supported by a University of Bergen mobility grant for this work. This work was also supported by ANID and Concurso de Fortalecimiento al Desarrollo Científico de Centros Regionales (grant no. 2020-R20F0008-CEAZA), and Álvaro Ayala was supported by ANID and FONDECYT (grant no. 3190732).Glaciers and rock glaciers play an important role in the hydrology of the semi-arid northern Chile. Several studies show that glaciers have rapidly lost mass in response to climate change during the last decades. The response of rock glaciers to climate change in this region is, however, less known. In this study we use a combination of historical aerial photography, stereo satellite imagery, airborne lidar, and the Shuttle Radar Topography Mission (SRTM) DEM to report glacier changes for the Tapado Glacier-rock glacier complex from the 1950s to 2020 and to report mass balances for the glacier component of the complex, Tapado Glacier. Furthermore, we examine high-resolution elevation changes and surface velocities between 2012 and 2020 for 35 rock glaciers in the La Laguna catchment. Our results show how Tapado Glacier has shrunk by -25.2 +/- 4.6 % between 1956 and 2020, while the mass balance of Tapado Glacier has become steadily more negative, from being approximately in balance between 1956 and 1978 (-0.04 +/- 0.08 m w.e. a(-1)) to showing increased losses between 2015 and 2020 (-0.32 +/- 0.08 m w.e. a(-1)). Climatological (re-)analyses reveal a general increase in air temperature, decrease in humidity, and variable precipitation since the 1980s in the region. In particular, the severe droughts starting in 2010 resulted in a negative mass balance of -0.54 +/- 0.10 m w.e. a(-1) between 2012 and 2015. The rock glaciers within the La Laguna catchment show heterogenous changes, with some sections of landforms exhibiting pronounced elevation changes and surface velocities exceeding that of Tapado Glacier. This could be indicative of high ice contents within the landforms and also highlights the importance of considering how landforms can transition from more glacial landforms to more periglacial features under permafrost conditions. As such, we believe high-resolution (sub-metre) elevation changes and surface velocities are a useful first step for identifying ice-rich landforms.Publisher PDFPeer reviewe