Backgroud
COVID-19 coagulopathy linked to increased D-dimer levels has been associated with high mortality (Fei Z et al. in Clinical course and risk factors for mortality of adult inpatients with ...COVID-19 in Wuhan, China: a retrospective cohort study. Lancet (London, England) 395(10229):1054–62, 2020). While D-dimer is accepted as a disseminated intravascular coagulation marker, rotational thromboelastometry (ROTEM) also detects fibrinolysis (Wright FL et al. in Fibrinolysis shutdown correlates to thromboembolic events in severe COVID-19 infection. J Am Coll Surg (2020). Available from
https://pubmed.ncbi.nlm.nih.gov/32422349/
cited 14 Jun 2020; Schmitt FCF et al. in Acute fibrinolysis shutdown occurs early in septic shock and is associated with increased morbidity and mortality: results of an observational pilot study. Ann Intensive Care 9(1):19, 2019). We describe the ROTEM profile in severely ill COVID-19 patients and compare it with the standard laboratory coagulation test.
Methods
Adult patients diagnosed with COVID-19 admitted to the ICU were prospectively enrolled after Ethics Committee approval (HCB/2020/0371). All patients received venous thromboembolism prophylaxis; those on therapeutic anticoagulation were excluded. The standard laboratory coagulation test and ROTEM were performed simultaneously at 24–48 h after ICU admission. Sequential organ failure assessment (SOFA), disseminated intravascular coagulation (DIC) and sepsis-induced coagulopathy (SIC) scores were calculated at sample collection.
Results
Nineteen patients were included with median SOFA-score of 4 (2–6), DIC-score of 1 (0–3) and SIC-score of 1.8 (0.9). Median fibrinogen, D-dimer levels and platelet count were 6.2 (4.8–7.6 g/L), 1000 (600–4200 ng/ml) and 236 (136–364 10
9
/L), respectively. Clot firmness was above the normal range in the EXTEM and FIBTEM tests while clot lysis was decreased. There was no significant correlation between ROTEM or D-dimer parameters and the SOFA score.
Conclusion
In COVID-19 patients, the ROTEM pattern was characterized by a hypercoagulable state with decreased fibrinolytic capacity despite a paradoxical increase in D-dimer levels. We suggest that, in COVID-19 patients, the lungs could be the main source of D-dimer, while a systemic hypofibrinolytic state coexists. This hypothesis should be confirmed by future studies.
A frozen oceanic crystal mush Basch, V.; Ferrando, C.; Sanfilippo, A.
Terra nova,
August 2023, 2023-08-00, 20230801, Volume:
35, Issue:
4
Journal Article
Peer reviewed
Open access
The processes driving the evolution of crystal mushes are often documented in complex systems where crystallization, assimilation, magma replenishment and mixing occur concurrently and are generally ...overprinted by compaction and deformation. Documenting the characteristics of an undisturbed crystal mush is thus of upmost importance; it highlights the initial conditions with which complex crystal mush processes proceed. We here present the structure and composition of an oceanic crystal mush through detailed petro‐structural and chemical study of metre‐scale intrusions from the Mid‐Atlantic Ridge. Textures, bulk‐rock and mineral compositions indicate closed‐system crystallization of primitive melts, undisturbed by dissolution–precipitation reactions and subsequent deformation. These frozen crystal mushes record the simplest possible evolution of small‐scale intrusions and can be used as a baseline to pinpoint the impact of crystal mush processes on the evolution of complex systems. Any divergence from this reference results from processes occurring concomitantly to the progressive closure of the magmatic system.
Pyroxenites are diffuse in fertile mantle peridotites and considered an important component in the mantle source of oceanic basalts. They are rarely documented in abyssal and ophiolitic peridotites ...representing residual mantle after melt generation, and few studies defining their origin are to date available. We present a field-based microstructural and geochemical investigation of the pyroxenite layers associated with depleted peridotites from the Mt. Maggiore ophiolitic body (Corsica, France). Field and petrographic evidence indicate that pyroxenite formation preceded the melt–rock interaction history that affected this mantle sector during Jurassic exhumation, namely (1) spinel-facies reactive porous flow leading to partial dissolution of the pyroxenites, and (2) plagioclase-facies melt impregnation leading to plagioclase + orthopyroxene interstitial crystallization. Pyroxenes show major element compositions similar to abyssal pyroxenites from slow-spreading ridges, indicative of magmatic segregation at pressures higher than 7 kbar. Both the parental melts of pyroxenites and the melts involved in the subsequent percolation were characterized by Na
2
O-poor, LREE-depleted compositions, consistent with unaggregated melt increments. This implies that they represent the continuous evolution of similarly depleted melts leading to different processes (pyroxenite segregation and later melt–rock interaction) during their upward migration. To support the genetic relation and the continuity between the formation of pyroxenites and the subsequent melt–rock interaction history, we modeled all the documented processes in sequence, i.e.: (1) formation of single-melt increments after 6% mantle decompressional fractional melting; (2) high-pressure segregation of pyroxenites; (3) spinel-facies reactive porous flow, (4) plagioclase-facies melt impregnation. The early fractionation of pyroxenites leads to a decrease in pyroxene saturation that is necessary for the subsequent reactive porous flow process, without any significant change in the melt REE composition.
Abstract
The Doldrums Megatransform System (~7–8°N, Mid-Atlantic Ridge) shows a complex architecture including four intra-transform ridge segments bounded by five active transform faults. Lower ...crustal rocks are exposed along the Doldrums and Vernadsky transform walls that bound the northernmost intra-transform ridge segment. The recovered gabbros are characterized by variably evolved chemical compositions, ranging from olivine gabbros to gabbronorites and oxide gabbros, and lack the most primitive gabbroic endmembers (troctolites, dunites). Notably, the numerous recovered gabbronorites show up to 20 vol. % of coarse-grained orthopyroxene. Although covariations in mineral and bulk-rock chemical compositions of the olivine and oxide gabbros define trends of crystallization from a common parental melt, the gabbronorites show elevated light over heavy rare earth elements (LREE/HREE) ratios in both bulk-rock and mineral compositions. These features are not consistent with a petrological evolution driven solely by fractional crystallization, which cannot produce the preferential enrichments in highly incompatible elements documented in the orthopyroxene-bearing lithologies. We suggest that gabbronorites crystallized from evolved melts percolating and partly assimilating a pre-existing olivine gabbro matrix. Saturation in orthopyroxene and selective enrichments in LREE relative to M-HREE are both triggered by an increase in assimilated crystal mass, which ranges from negligible in the oxide-gabbros to abundant in the gabbronorites. This melt–rock reaction process has been related to lateral melt migration beneath ridge-transform intersections, where variably evolved melts injected from the peripheral parts of the melting region towards the transform zone may interact with a gabbroic crystal mush to form abundant oxide-bearing gabbronoritic associations.
The clinical course of COVID-19 critically ill patients, during their admission in the intensive care unit (UCI), including medical and infectious complications and support therapies, as well as ...their association with in-ICU mortality has not been fully reported.
This study aimed to describe clinical characteristics and clinical course of ICU COVID-19 patients, and to determine risk factors for ICU mortality of COVID-19 patients.
Prospective, multicentre, cohort study that enrolled critically ill COVID-19 patients admitted into 30 ICUs from Spain and Andorra. Consecutive patients from March 12
to May 26
, 2020 were enrolled if they had died or were discharged from ICU during the study period. Demographics, symptoms, vital signs, laboratory markers, supportive therapies, pharmacological treatments, medical and infectious complications were reported and compared between deceased and discharged patients.
A total of 663 patients were included. Overall ICU mortality was 31% (203 patients). At ICU admission non-survivors were more hypoxemic SpO
with non-rebreather mask, 90 (IQR 83 to 93) vs. 91 (IQR 87 to 94); P<.001 and with higher sequential organ failure assessment score SOFA, 7 (IQR 5 to 9) vs. 4 (IQR 3 to 7); P<.001. Complications were more frequent in non-survivors: acute respiratory distress syndrome (ARDS) (95% vs. 89%; P=.009), acute kidney injury (AKI) (58% vs. 24%; P<10
), shock (42% vs. 14%; P<10
), and arrhythmias (24% vs. 11%; P<10
). Respiratory super-infection, bloodstream infection and septic shock were higher in non-survivors (33% vs. 25%; P=.03, 33% vs. 23%; P=.01 and 15% vs. 3%, P=10
), respectively. The multivariable regression model showed that age was associated with mortality, with every year increasing risk-of-death by 1% (95%CI: 1 to 10, P=.014). Each 5-point increase in APACHE II independently predicted mortality OR: 1.508 (1.081, 2.104), P=.015. Patients with AKI OR: 2.468 (1.628, 3.741), P<10
), cardiac arrest OR: 11.099 (3.389, 36.353), P=.0001, and septic shock OR: 3.224 (1.486, 6.994), P=.002 had an increased risk-of-death.
Older COVID-19 patients with higher APACHE II scores on admission, those who developed AKI grades ii or iii and/or septic shock during ICU stay had an increased risk-of-death. ICU mortality was 31%.
Pneumonia caused by coronavirus, which originated in Wuhan, China, in late 2019, has been spread around the world already becoming a pandemic. Unfortunately, there is not yet a specific vaccine or ...effective antiviral drug for treating COVID-19. Many of these patients deteriorate rapidly and require intubation and are mechanically ventilated, which is causing the collapse of the health system in many countries due to lack of ventilators and intensive care beds. In this document we review two simple adjuvant therapies to administer, without side effects, and low cost that could be useful for the treatment of acute severe coronavirus infection associated with acute respiratory syndrome (SARS-CoV-2). VitaminC, a potent antioxidant, has emerged as a relevant therapy due to its potential benefits when administered intravenous. The potential effect of vitaminC in reducing inflammation in the lungs could play a key role in lung injury caused by coronavirus infection. Another potential effective therapy is ozone: it has been extensively studied and used for many years and its effectiveness has been demonstrated so far in multiples studies. Nevertheless, our goal is not to make an exhaustive review of these therapies but spread the beneficial effects themselves. Obviously clinical trials are necessaries, but due to the potential benefit of these two therapies we highly recommended to add to the therapeutic arsenal.
Beneath slow‐spreading ridges, melt bodies are generally considered to represent ephemeral magma reservoirs filled with crystal mushes. Formation of the oceanic crust requires at least partial ...extraction of melts from these crystal mushes. However, melts collection and extraction are processes yet to be fully constrained. We investigate olivine gabbros from the plutonic section recovered at the IODP Hole U1473A, in the Atlantis Bank Oceanic Core Complex (Southwest Indian Ridge), to unravel (i) the process of melt migration through lower crustal crystal mushes, and (ii) the collection and segregation of melts forming discrete microgabbro intervals. Throughout the Hole, fine‐ to coarse‐grained intervals are widespread in olivine gabbros. Along the contacts, coarse‐grained minerals display resorbed grain boundaries against the fine‐grained minerals, suggesting partial dissolution by the melt crystallizing the fine‐grained material. Coarse‐grained plagioclase and clinopyroxene are zoned, showing progressive chemical evolution from more primitive crystal cores to more evolved crystal rims. Fine‐grained minerals are unzoned and chemically similar to rims of coarse‐grained minerals, indicating a genetic relationship. We attribute significant enrichments in the most incompatible elements of plagioclase and clinopyroxene to a magma evolution process associated with reactive melt migration. As temperature decreased, melts residual from the reactive processes were segregated in magma pockets that ultimately crystallize the fine‐grained intervals (microgabbros). We document, for the first time, that these microgabbros are crystallization products of melts modified by reactive melt migration; the melts were extracted from the crystal mush and accumulated into discrete melt‐rich zones. This process could have promoted partial extraction of those melts that in turn potentially contribute to Mid Ocean Ridge Basalts erupted at the seafloor.
Key Points
Geochemical zoning in coarse crystals record crystallization of primitive crystal mush and subsequent reactive melt migration thereof
Fine‐grained olivine gabbros testify collection of residual melts from the crystal mush; their crystallization is dominated by nucleation
Accumulation of migrating melts could have promoted extraction of those melts that potentially contribute to Mid Ocean Ridge Basalt erupted at the seafloor
809 deep IODP Hole U1473A at Atlantis Bank, SWIR, is 2.2 km from 1,508‐m Hole 735B and 1.4 from 158‐m Hole 1105A. With mapping, it provides the first 3‐D view of the upper levels of a 660‐km2 lower ...crustal batholith. It is laterally and vertically zoned, representing a complex interplay of cyclic intrusion, and ongoing deformation, with kilometer‐scale upward and lateral migration of interstial melt. Transform wall dives over the gabbro‐peridotite contact found only evolved gabbro intruded directly into the mantle near the transform. There was no high‐level melt lens, rather the gabbros crystallized at depth, and then emplaced into the zone of diking by diapiric rise of a crystal mush followed by crystal‐plastic deformation and faulting. The residues to mass balance the crust to a parent melt composition lie at depth below the center of the massif—likely near the crust‐mantle boundary. Thus, basalts erupted to the seafloor from >1,550 mbsf. By contrast, the Mid‐Atlantic Ridge lower crust drilled at 23°N and at Atlantis Massif experienced little high‐temperature deformation and limited late‐stage melt transport. They contain primitive cumulates and represent direct intrusion, storage, and crystallization of parental MORB in thinner crust below the dike‐gabbro transition. The strong asymmetric spreading of the SWIR to the south was due to fault capture, with the northern rift valley wall faults cutoff by a detachment fault that extended across most of the zone of intrusion. This caused rapid migration of the plate boundary to the north, while the large majority of the lower crust to spread south unroofing Atlantis Bank and uplifting it into the rift mountains.
Key Points
No evidence of a high‐level melt lens with gabbros intruded at depth, then emplaced to high levels by crystal mush diapirism, plastic deformation, and faulting
Diving over the crust‐mantle boundary on the transform wall found no primitive cumulates, and evolved gabbro was intruded directly into the mantle at the transform
Primitive cumulates needed to mass balance MORB must lie at depth near the crust‐mantle boundary, while the few diabase dikes encountered intrude the gabbro
The susceptibility to infection probably increases in COVID-19 patients due to a combination of virusand drug-induced immunosuppression. The reported rate of secondary infections was quite low in ...previous studies. The objectives of our study were to investigate the rate of secondary infections, risk factors for secondary infections and risk factors for mortality in COVID-19 critically ill patients.
We performed a single-center retrospective study in mechanically ventilated critically ill COVID-19 patients admitted to our Critical Care Unit (CCU). We recorded the patients' demographic data; clinical data; microbiology data and incidence of secondary infection during CCU stay, including ventilator-associated pneumonia (VAP) and nosocomial bacteremia (primary and secondary).
A total of 107 patients with a mean age 62.2 ± 10.6 years were included. Incidence of secondary infection during CCU stay was 43.0% (46 patients), including nosocomial bacteremia (34 patients) and VAP (35 patients). Age was related to development of secondary infection (65.2 ± 7.3 vs. 59.9 ± 12.2 years, p=0.007). Age ≥ 65 years and secondary infection were independent predictors of mortality (OR=2.692, 95% CI 1.068-6.782, p<0.036; and OR=3.658, 95% CI 1.385- 9.660, p=0.009, respectively). The hazard ratio for death within 90 days in the ≥ 65 years group and in patients infected by antimicrobial resistant pathogens was 1.901 (95% CI 1.198- 3.018; p= 0.005 by log-rank test) and 1.787 (95% CI 1.023-3.122; p= 0.036 by log-rank test), respectively.
Our data suggest that the incidence of secondary infection and infection by antimicrobial resistant pathogens is very high in critically ill patients with COVID-19 with a significant impact on prognosis.
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