In-person peer support for critical care survivors: The ICU REcovery Solutions cO-Led through surVivor Engagement (ICURESOLVE) pilot randomised controlled trial.

BACKGROUND: Peer support is a promising intervention to mitigate post-ICU disability, however there is a paucity of rigorously designed studies. OBJECTIVES: The objective of this study was to establish feasibility of an in-person, co-designed, peer-support model. METHODS: Prospective, randomised, adaptive, single-centre pilot trial with blinded outcome assessment, conducted at a university-affiliated hospital in Melbourne, Australia. Intensive care unit survivors (and their nominated caregiver, where survivor and caregiver are referred to as a dyad), >18 years of age, able to speak and understand English and participate in phone surveys, were eligible. Participants were randomised to the peer-support model (six sessions, fortnightly) or usual care (no follow-up or targeted information). Two sequential models were piloted: 1. Early (2-3 weeks post hospital discharge) 2. Later (4-6 weeks post hospital discharge). Primary outcome was feasibility of implementation measured by recruitment, intervention attendance, and outcome completion. Secondary outcomes included post-traumatic stress and social support. RESULTS: Of the 231 eligible patients, 80 participants were recruited. In the early model we recruited 38 participants (28 patients, 10 carers; 18 singles, 10 dyads), with an average (standard deviation) age of 60 (18) years; 55 % were female. Twenty-two participants (58 %) were randomised to intervention. Participants in the early intervention model attended a median (interquartile range) of 0 (0-1) sessions (total 24 sessions), with 53% (n = 20) completing the main secondary outcome of interest (Impact of Event Scale) at the baseline and 37 % (n = 14) at the follow-up. For the later model we recruited 42 participants (32 patients, 10 carers; 22 singles, 10 dyads), with an average (standard deviation) age of 60.4 (15.4) years; 50 % were female. Twenty-one participants (50 %) were randomised to intervention. The later intervention model attended a median (interquartile range) of 1 (0-5) sessions (total: 44 sessions), with the main secondary outcome impact of events scale (IES-R) completed by 41 (98 %) participants at baseline and 29 (69 %) at follow-up. CONCLUSIONS: In this pilot trial, a peer-support model that required in-person attendance delivered in a later posthospital phase of recovery appeared more feasible than an early model. Further research should investigate alternative modes of intervention delivery to improve feasibility (ACTRN12621000737831).

Highest terrestrial 3He/4He credibly from the core.

The observation that many lavas associated with mantle plumes have higher 3He/4He ratios than the upper convecting mantle underpins geophysical, geodynamic and geochemical models of Earth's deep interior. High 3He/4He ratios are thought to derive from the solar nebula or from solar-wind-irradiated material that became incorporated into Earth during early planetary accretion. Traditionally, this high-3He/4He component has been considered intrinsic to the mantle, having avoided outgassing caused by giant impacts and billions of years of mantle convection1-4. Here we report the highest magmatic 3He/4He ratio(67.2 ± 1.8 times the atmospheric ratio) yet measured in terrestrial igneous rocks, in olivines from Baffin Island lavas. We argue that the extremely high-3He/4He helium in these lavas might derive from Earth's core5-9. The viability of the core hypothesis relaxes the long-standing constraint-based on noble gases in lavas associated with mantle plumes globally-that volatile elements from the solar nebula have survived in the mantle since the early stages of accretion.

Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars.

The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding that the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Magnesium-iron carbonates along grain boundaries indicate reactions with carbon dioxide-rich water under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks have been stored aboard Perseverance for potential return to Earth.

An olivine cumulate outcrop on the floor of Jezero crater, Mars.

The geological units on the floor of Jezero crater, Mars, are part of a wider regional stratigraphy of olivine-rich rocks, which extends well beyond the crater. We investigated the petrology of olivine and carbonate-bearing rocks of the Séítah formation in the floor of Jezero. Using multispectral images and x-ray fluorescence data, acquired by the Perseverance rover, we performed a petrographic analysis of the Bastide and Brac outcrops within this unit. We found that these outcrops are composed of igneous rock, moderately altered by aqueous fluid. The igneous rocks are mainly made of coarse-grained olivine, similar to some martian meteorites. We interpret them as an olivine cumulate, formed by settling and enrichment of olivine through multistage cooling of a thick magma body.

In situ recording of Mars soundscape.

Before the Perseverance rover landing, the acoustic environment of Mars was unknown. Models predicted that: (1) atmospheric turbulence changes at centimetre scales or smaller at the point where molecular viscosity converts kinetic energy into heat1, (2) the speed of sound varies at the surface with frequency2,3 and (3) high-frequency waves are strongly attenuated with distance in CO2 (refs. 2-4). However, theoretical models were uncertain because of a lack of experimental data at low pressure and the difficulty to characterize turbulence or attenuation in a closed environment. Here, using Perseverance microphone recordings, we present the first characterization of the acoustic environment on Mars and pressure fluctuations in the audible range and beyond, from 20 Hz to 50 kHz. We find that atmospheric sounds extend measurements of pressure variations down to 1,000 times smaller scales than ever observed before, showing a dissipative regime extending over five orders of magnitude in energy. Using point sources of sound (Ingenuity rotorcraft, laser-induced sparks), we highlight two distinct values for the speed of sound that are about 10 m s-1 apart below and above 240 Hz, a unique characteristic of low-pressure CO2-dominated atmosphere. We also provide the acoustic attenuation with distance above 2 kHz, allowing us to explain the large contribution of the CO2 vibrational relaxation in the audible range. These results establish a ground truth for the modelling of acoustic processes, which is critical for studies in atmospheres such as those of Mars and Venus.

Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars.

Observations from orbital spacecraft have shown that Jezero crater on Mars contains a prominent fan-shaped body of sedimentary rock deposited at its western margin. The Perseverance rover landed in Jezero crater in February 2021. We analyze images taken by the rover in the 3 months after landing. The fan has outcrop faces, which were invisible from orbit, that record the hydrological evolution of Jezero crater. We interpret the presence of inclined strata in these outcrops as evidence of deltas that advanced into a lake. In contrast, the uppermost fan strata are composed of boulder conglomerates, which imply deposition by episodic high-energy floods. This sedimentary succession indicates a transition from sustained hydrologic activity in a persistent lake environment to highly energetic short-duration fluvial flows.

Epidemiology of long-stay patients in a university teaching hospital.

BACKGROUND: Patients admitted to acute care hospitals may have multiple comorbidities, and a small proportion may stay for a protracted period. AIMS: To assess the proportion of hospital patients who are long stay (≥14 days) and evaluate associations with baseline variables and subsequent inpatient morbidity and mortality. METHODS: This is a retrospective observational study of patients aged ≥18 years staying in hospital for at least 24 h between 1 July 2013 and 30 June 2014. RESULTS: There were 22 094 admissions in 15 623 patients. The median (interquartile range (IQR)) length of stay (LOS) was 4 (2-8) days, and 10% had a LOS >16 days. Long-stay admissions comprised 13.1% of admissions but used 49.1% of bed days. Long-stay admissions were more likely to be associated with intensive care unit admission (21.2 vs 6.0%), medical emergency team review (20.5 vs 4.3%) and a longer duration of mechanical ventilation (P < 0.0001 all comparisons). Long-stay patients were more likely to develop in-hospital complications, were more likely to die in hospital (8.2 vs 3.1%) and were less likely to be discharged home (P < 0.001 all comparisons). Multiple variable analysis revealed several associations with prolonged stay, including multiple admissions in the study period, the nature of the admitting unit, the Charlson comorbidity index at admission, admission from another hospital and any history of smoking. CONCLUSIONS: Patients staying at least 14 days comprised one seventh of hospital admissions but used half of bed days and suffered increased in-hospital morbidity and mortality. Several pre-admission associations with prolonged stay were identified.

A feasibility study of functional status and follow-up clinic preferences of patients at high risk of post intensive care syndrome.

After prolonged mechanical ventilation patients may experience the 'post intensive care syndrome' (PICS) and may be candidates for post-discharge follow-up clinics. We aimed to ascertain the incidence and severity of PICS symptoms in patients surviving prolonged mechanical ventilation and to describe their views regarding follow-up clinics. In a teaching hospital, we conducted a cohort study of all adult patients discharged alive after ventilation in ICU for ≥7 days during 2013. We administered the EuroQol-5D (EQ-5D) and Hospital Anxiety and Depression Scale (HADS) via telephone interview and asked patients their views about the possible utility of a follow-up clinic. We studied 48 patients. At follow-up (average 19.5 months), seven (15%) patients had died and 14 (29%) did not participate (eight declined; two were non-English speakers; four were non-contactable). Among the 27 responders, 16 (59%) reported at least moderate problems in ≥1 EQ-5D dimension; 10 (37%) in ≥2 dimensions, and 8 (30%) in ≥3 dimensions. Moreover, 10 (37%) patients reported marked psychological symptoms; six (22%) scored borderline or abnormal on the HADS for both anxiety and depression; and four (15%) scored borderline or abnormal for one component. Finally, 21/26 (81%) patients stated that an ICU follow-up clinic would have been beneficial. At long-term follow-up, the majority of survivors of prolonged mechanical ventilation reported impaired quality of life and significant psychological symptoms. Most believed that a follow-up clinic would have been beneficial.

Micromotion at the tibial plateau in primary and revision total knee arthroplasty: fixed versus rotating platform designs.

OBJECTIVES: Initial stability of tibial trays is crucial for long-term success of total knee arthroplasty (TKA) in both primary and revision settings. Rotating platform (RP) designs reduce torque transfer at the tibiofemoral interface. We asked if this reduced torque transfer in RP designs resulted in subsequently reduced micromotion at the cemented fixation interface between the prosthesis component and the adjacent bone. METHODS: Composite tibias were implanted with fixed and RP primary and revision tibial trays and biomechanically tested under up to 2.5 kN of axial compression and 10° of external femoral component rotation. Relative micromotion between the implanted tibial tray and the neighbouring bone was quantified using high-precision digital image correlation techniques. RESULTS: Rotational malalignment between femoral and tibial components generated 40% less overall tibial tray micromotion in RP designs than in standard fixed bearing tibial trays. RP trays reduced micromotion by up to 172 µm in axial compression and 84 µm in rotational malalignment models. CONCLUSIONS: Reduced torque transfer at the tibiofemoral interface in RP tibial trays reduces relative component micromotion and may aid long-term stability in cases of revision TKA or poor bone quality.Cite this article: Mr S. R. Small. Micromotion at the tibial plateau in primary and revision total knee arthroplasty: fixed versus rotating platform designs. Bone Joint Res 2016;5:122-129. DOI: 10.1302/2046-3758.54.2000481.

How to improve communication quality with patients and relatives in the ICU.

The experience of intensive care for patients and their families is known to be very stressful and may result in both acute and chronic psychological problems that include sleep disturbance, depression, anxiety and post-traumatic stress disorder. While some non-modifiable risk factors for psychological harm are known, there are also a several modifiable risk factors that may be addressed using strategically planned interventions such as optimal communication techniques. Effective communication is increasingly being recognized as an essential non-technical skills for all intensive care clinicians. One situation which is central to communication in the ICU is the family meeting. Similar to other procedures in the ICU, training, practice, preparation and reflective review may improve performance when conducting family meetings and lead to better outcomes for patients and families.

Enhanced East Pacific Rise hydrothermal activity during the last two glacial terminations.

Mid-ocean ridge magmatism is driven by seafloor spreading and decompression melting of the upper mantle. Melt production is apparently modulated by glacial-interglacial changes in sea level, raising the possibility that magmatic flux acts as a negative feedback on ice-sheet size. The timing of melt variability is poorly constrained, however, precluding a clear link between ridge magmatism and Pleistocene climate transitions. Here we present well-dated sedimentary records from the East Pacific Rise that show evidence of enhanced hydrothermal activity during the last two glacial terminations. We suggest that glacial maxima and lowering of sea level caused anomalous melting in the upper mantle and that the subsequent magmatic anomalies promoted deglaciation through the release of mantle heat and carbon at mid-ocean ridges.

Neutrophil elastase-deficient mice form neutrophil extracellular traps in an experimental model of deep vein thrombosis.

UNLABELLED: ESSENTIALS: Neutrophil elastase (NE) plays a role in extracellular trap formation (NETosis) triggered by microbes. The contribution of NE was evaluated in mouse NETosis models of sterile inflammation and thrombosis. NE is not required for mouse neutrophil NET production in vitro with non-infectious stimuli. NE deficiency had no significant effect on thrombosis in the inferior vena cava stenosis model. BACKGROUND: Neutrophil serine proteases have been implicated in coagulation and neutrophil extracellular trap (NET) formation. In human neutrophils, neutrophil elastase (NE) translocates to the nucleus during NETosis and cleaves histones, thus aiding in chromatin decondensation. NE(-/-) mice were shown not to release NETs in response to microbes. However, mouse studies evaluating the role of NE in NET formation in sterile inflammation and thrombosis are lacking. OBJECTIVE: We wished to establish if neutrophils from NE(-/-) mice have a defect in NETosis, similar to peptidylarginine deiminase 4 (PAD4(-/-)) mice, and how this might have an impact on venous thrombosis, a model where NETs are produced and are crucial to thrombus development. METHODS: We performed in vitro NET assays using neutrophils from wild-type (WT), NE(-/-), SerpinB1 (SB1)(-/-) and NE(-/-) SB1(-/-) mice. We compared WT and NE(-/-) animals using the inferior vena cava stenosis model of deep vein thrombosis (DVT). RESULTS: Neutrophil elastase deficiency resulted in a small reduction in ionomycin-induced NET formation in vitro without affecting histone citrullination. However, NET production in response to phorbol 12-myristate 13-acetate or platelet activating factor was normal in neutrophils from two independent NE-deficient mouse lines, and in NE(-/-) SB1(-/-) as compared with SB1(-/-) neutrophils. NE deficiency or inhibition did not prevent NETosis in vivo or DVT outcome. CONCLUSIONS: Neutrophil elastase is not required for NET formation in mice. NE(-/-) mice, which form pathological venous thrombi containing NETs, do not phenocopy PAD4(-/-) mice in in vitro NETosis assays or experimental venous thrombosis. Our study suggests that NET-targeted therapies need to be highly effective to have an impact on DVT.

A practical approach to end-of-life care rapid response team calls.

ICU registrars frequency encounter RRT calls associated with EOLC during their training. Interventions involving EOLC appear to be some of the commonest interventions performed during RRT review. Therefore, training about the assessment an management of such calls should be provided to registrars who participate in RRT calls. The approach outlined here provides a framework for such training.

Helium and lead isotopes reveal the geochemical geometry of the Samoan plume.

Hotspot lavas erupted at ocean islands exhibit tremendous isotopic variability, indicating that there are numerous mantle components hosted in upwelling mantle plumes that generate volcanism at hotspots like Hawaii and Samoa. However, it is not known how the surface expression of the various geochemical components observed in hotspot volcanoes relates to their spatial distribution within the plume. Here we present a relationship between He and Pb isotopes in Samoan lavas that places severe constraints on the distribution of geochemical species within the plume. The Pb-isotopic compositions of the Samoan lavas reveal several distinct geochemical groups, each corresponding to a different geographic lineament of volcanoes. Each group has a signature associated with one of four mantle endmembers with low (3)He/(4)He: EMII (enriched mantle 2), EMI (enriched mantle 1), HIMU (high µ = (238)U/(204)Pb) and DM (depleted mantle). Critically, these four geochemical groups trend towards a common region of Pb-isotopic space with high (3)He/(4)He. This observation is consistent with several low-(3)He/(4)He components in the plume mixing with a common high-(3)He/(4)He component, but not mixing much with each other. The mixing relationships inferred from the new He and Pb isotopic data provide the clearest picture yet of the geochemical geometry of a mantle plume, and are best explained by a high-(3)He/(4)He plume matrix that hosts, and mixes with, several distinct low-(3)He/(4)He components.

In situ radiometric and exposure age dating of the martian surface.

We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 ± 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray-produced (3)He, (21)Ne, and (36)Ar yield concordant surface exposure ages of 78 ± 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.

Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale crater, Mars.

H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.

Inappropriate continuation of stress ulcer prophylaxis beyond the intensive care setting.

OBJECTIVE: To determine how frequently stress ulcer prophylaxis (SUP) medications prescribed in the intensive care unit are inappropriately continued on the ward and on hospital discharge. DESIGN: Retrospective cohort study; chart review. SETTING: Two Australian ICUs: one tertiary centre and one metropolitan centre. PARTICIPANTS: We included 387 adult, non-pregnant patients who were admitted to the ICU between 1 February 2011 and 31 March 2011 and who survived to hospital discharge. MAIN OUTCOME MEASURES: Rate of unnecessary continuation of ICU-prescribed SUP medications on the ward and on discharge from hospital. RESULTS: While in the ICU, 329 of the 387 patients (85%) were prescribed SUP medications. Of the 233 patients who had not been taking acid-suppressive medications before admission to the ICU, 190 were prescribed SUP medications in the ICU. Of these 190 patients, most (63%) had their SUP continued in the ward without any obvious indication, and many (39%) had their SUP medications inappropriately continued on discharge from hospital. CONCLUSIONS: SUP medications commenced in ICU are frequently continued unnecessarily, both in the wards and hospital discharge.