Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

CREATE (Community deRivEd AutomaTEd insulin delivery) trial. Randomised parallel arm open label clinical trial comparing automated insulin delivery using a mobile controller (AnyDANA-loop) with an open-source algorithm with sensor augmented pump therapy in type 1 diabetes

Background

Commercialised automated insulin delivery (AID) systems have demonstrated improved outcomes in type 1 diabetes (T1D), however, they have limited capacity for algorithm individualisation, and can be prohibitively expensive if an individual is without access to health insurance or health funding subsidy. Freely available open-source algorithms, which have the ability to individualise algorithm parameters paired with commercial insulin pumps, and continuous glucose monitoring make up the so-called "do it yourself" (DIY) approach to AID. Limited data on the open-source approach have shown promising results, but data from a large randomised control trial are lacking.

Methods

The CREATE (Community deRivEd AutomaTEd insulin delivery) trial is an open-labelled, randomised, parallel 24-week, multi-site trial comparing sensor augmented pump therapy (SAPT) to our AnyDANA-loop. The three components of AnyDANA-loop are: 1) OpenAPS algorithm implemented in a smartphone (a version of AndroidAPS), 2) DANA-i™ insulin pump and, 3) Dexcom G6^R continuous glucose monitor (CGM). The primary outcome measure is the percentage of time in target sensor glucose range (3.9 -10mmol/L). Secondary outcomes include psycho-social factors and platform performance. Analysis of online collective learning, characteristic of the open-source approach, is planned. 100 participants with T1D aged 7 - 70 years (age stratified into children/adolescents 7-15 years and adults 16-70 years), will be recruited from four sites in New Zealand. A 24-week continuation phase follows, to assess long-term safety.

High order mode structure of intense light fields generated via a laser-driven relativistic plasma aperture

The spatio-temporal and polarisation properties of intense light is important in wide-ranging topics at the forefront of extreme light-matter interactions, including ultrafast laser-driven particle acceleration, attosecond pulse generation, plasma photonics, high-field physics and laboratory astrophysics. Here, we experimentally demonstrate modifications to the polarisation and temporal properties of intense light measured at the rear of an ultrathin target foil irradiated by a relativistically intense laser pulse. The changes are shown to result from a superposition of coherent radiation, generated by a directly accelerated bipolar electron distribution, and the light transmitted due to the onset of relativistic self-induced transparency. Simulations show that the generated light has a high-order transverse electromagnetic mode structure in both the first and second laser harmonics that can evolve on intra-pulse time-scales. The mode structure and polarisation state vary with the interaction parameters, opening up the possibility of developing this approach to achieve dynamic control of structured light fields at ultrahigh intensities.

Effects of short-term cannabidiol treatment on response to social stress in subjects at clinical high risk of developing psychosis

RATIONALE

Stress is a risk factor for psychosis and treatments which mitigate its harmful effects are needed. Cannabidiol (CBD) has antipsychotic and anxiolytic effects.

OBJECTIVES

We investigated whether CBD would normalise the neuroendocrine and anxiety responses to stress in clinical high risk for psychosis (CHR) patients.

METHODS

Thirty-two CHR patients and 26 healthy controls (HC) took part in the Trier Social Stress Test (TSST) and their serum cortisol, anxiety and stress associated with public speaking were estimated. Half of the CHR participants were on 600 mg/day of CBD (CHR-CBD) and half were on placebo (CHR-P) for 1 week.

RESULTS

One-way analysis of variance (ANOVA) revealed a significant effect of group (HC, CHR-P, CHR-CBD (p = .005) on cortisol reactivity as well as a significant (p = .003) linear decrease. The change in cortisol associated with experimental stress exposure was greatest in HC controls and least in CHR-P patients, with CHR-CBD patients exhibiting an intermediate response. Planned contrasts revealed that the cortisol reactivity was significantly different in HC compared with CHR-P (p = .003), and in HC compared with CHR-CBD (p = .014), but was not different between CHR-P and CHR-CBD (p = .70). Across the participant groups (CHR-P, CHR-CBD and HC), changes in anxiety and experience of public speaking stress (all p's < .02) were greatest in the CHR-P and least in the HC, with CHR-CBD participants demonstrating an intermediate level of change.

CONCLUSIONS

Our findings show that it is worthwhile to design further well powered studies which investigate whether CBD may be used to affect cortisol response in clinical high risk for psychosis patients and any effect this may have on symptoms.

Coupled Modes of North Atlantic Ocean-Atmosphere Variability and the Onset of the Little Ice Age

Hydroclimate extremes in North America, Europe, and the Mediterranean are linked to ocean and atmospheric circulation anomalies in the Atlantic, but the limited length of the instrumental record prevents complete identification and characterization of these patterns of covariability especially at decadal to centennial timescales. Here we analyze the coupled patterns of drought variability on either side of the North Atlantic Ocean basin using independent climate field reconstructions spanning the last millennium in order to detect and attribute epochs of coherent basin-wide moisture anomalies to ocean and atmosphere processes. A leading mode of broad-scale moisture variability is characterized by distinct patterns of North Atlantic atmosphere circulation and sea surface temperatures. We infer a negative phase of the North Atlantic Oscillation and colder Atlantic sea surface temperatures in the middle of the 15th century, coincident with weaker solar irradiance and prior to strong volcanic forcing associated with the early Little Ice Age.

Strategies to improve maternal vaccination acceptance

BACKGROUND

In England, influenza and pertussis vaccination has been recommended for all pregnant women since 2010 and 2012 respectively. However, in some areas, vaccination uptake rates have been low. A qualitative study was conducted to gain a contextualised understanding of factors influencing vaccination acceptance during pregnancy in Hackney, a borough in north-east London, UK. This paper draws on in-depth insights gained from the above study, to provide recommendations for increasing long-term maternal vaccination acceptance.

METHODS

Hackney was chosen as the study site because it has one of the lowest vaccination coverage rates in pregnancy in the UK. A maximum variation sampling method was used to recruit 47 pregnant and recently pregnant women from a wide range of backgrounds, as well as ten healthcare professionals from three general practices; two community antenatal clinics; nine parent-toddler groups; and four community centres. In-depth interviews and a video-recording of a pregnant patient's consultation, explored experiences of care within the National Health Service during pregnancy, and women's views about maternal vaccination. In-depth interviews with healthcare professionals explored their views towards, and how they discuss and provide maternal vaccination. Study data were analysed both deductively, through drawing on insights from anthropological works that address diverse conceptualisations and practices around vaccination; and inductively, with a thematic analysis approach.

RESULTS

The findings of this study and the recommendations based on them were divided into five broad themes: access to maternal vaccination; healthcare institution rhetoric and its effect on maternal vaccination acceptance; community and family influences on maternal vaccination decisions; healthcare professionals' views towards maternal vaccination; and the influence of patient-healthcare professional relationships on maternal vaccination acceptance.

CONCLUSIONS

The strategies to improve maternal vaccination acceptance recommended in this paper would engender a more open and democratised healthcare system.

Healthcare workers' attitudes towards hand-hygiene monitoring technology

BACKGROUND

Automated radio-frequency identification (RFID)-based hand-hygiene monitoring technology was implemented in an infectious disease department to study healthcare workers' (HCWs') practices and to improve hand hygiene.

AIM

To assess HCWs' attitudes towards this innovative monitoring device in order to anticipate resistance to change and facilitate future implementation.

METHODS

In-depth interviews and an ethnographic approach.

FINDINGS

From the perspective of HCWs, while they recognize the usefulness of RFID technology to prevent the transmission of infections to patients, they expressed concerns about risks related to RFID electromagnetic waves, as well as control by their superiors. Overall, HCWs' opinions oscillated between positive feelings characterized by enthusiasm for the possibility of changing their practices using technologies and research, and negative feelings marked by strong criticisms of these technologies and research. These criticisms included blaming hand-hygiene monitoring technology for decontextualizing HCWs' practices. They perceived the technologies through the prism of the local and national contexts in which they are embedded. From their point of view, technologies are primarily in the best interests of the project team. Thus, they affirm and maintain the different interests and objectives between themselves and the project team, crystallizing a conflict of professional norms and values between these two groups. The forms of resistance taken by HCWs were practical as well as oral.

CONCLUSION

Innovative technologies should be developed to address HCWs' attitudes surrounding RFIDs. It is crucial to inform HCWs about the nature of these technologies, although some criticisms about monitoring systems are based on more structural causes.

Incremental clinical effectiveness and cost effectiveness of providing supervised physiotherapy in addition to usual medical care in patients with osteoarthritis of the hip or knee: 2-year results of the MOA randomised controlled trial

OBJECTIVE

To investigate the clinical- and cost-effectiveness at 2-year follow-up of providing individual, supervised exercise physiotherapy and/or manual physiotherapy in addition to usual medical care.

METHOD

People with hip or knee osteoarthritis meeting the American College of Rheumatology clinical diagnostic criteria were randomised (1:1, concealed, assessor-blinded) to four groups: usual medical care; supervised exercise physiotherapy; manual physiotherapy; or combined exercise and manual physiotherapy. Physiotherapy group participants were provided 10 50-min treatment sessions including booster sessions at 4 and 13 months, in addition to usual care. The primary outcome at 2-year follow-up was incremental cost-utility ratio (ICUR) of each physiotherapy intervention in addition to usual care, compared with usual care alone, from the health system and societal perspectives. To allow interpretation of negative ICURs, we report incremental net benefit (INB). The primary clinical outcome was the Western Ontario and McMaster Osteoarthritis Index (WOMAC).

RESULTS

Of 206 patients, 186 (90·3%) were retained at 2-year follow-up. Exercise physiotherapy and manual physiotherapy dominated usual care, demonstrating cost savings; combined therapy did not. Exercise therapy had the highest incremental net benefits (INBs), statistically significant at all willingness-to-pay (base-case: societal New Zealand (NZ)$6,312, 95%CI 334 to 12,279; health system NZ$8,065, 95%CI 136 to 15,994). Clinical improvements were superior to usual care only in the exercise physiotherapy group (-28.2 WOMAC points, 95%CI -49.2 to -7.1). No serious adverse events were recorded.

CONCLUSION

Individually supervised exercise therapy is cost-effective and clinically effective in addition to usual medical care at 2-year follow-up, and leads to cost savings for the health system and society.

TRIAL REGISTRATION

Prospectively registered with the Australian NZ Clinical Trials Registry, reference ACTRN12608000130369.

Long-term relationships between screening rates, breast cancer characteristics, and overdiagnosis in US counties, 1975-2009

Effects of mammography screening in the general population are disputed. Screening rates differ greatly between US counties, providing a natural opportunity to investigate effects of screening. We compared mammography screening rates with the types and outcomes of breast cancers diagnosed in US counties. The county screening rate was defined as the proportion of women age ≥40 with ≥1 mammogram in the past 2 years (range, 34-91%). Two periods were analyzed: 1975-2009 (612,941 breast cancer cases, 195 counties) and 1996-2009 (645,057 cases, 211-547 counties). Multiple signs of overdiagnosis were observed: First, breast cancer incidence increased as screening became common. Second, incidence stopped increasing once screening rates stabilized. Third, the increases in incidence were limited to age groups receiving screening. Fourth, the increases were larger in counties where screening became more common. Fifth, the increases were limited to small and early-stage breast cancers (which are consistent with overdiagnosis). Sixth, compensatory reductions in large and advanced-stage breast cancers were much smaller than the increases. Difference-in-differences regression analysis suggested 31% (95% CI: 28-34%) of breast cancers diagnosed in 1996-2009 were overdiagnosed. Screening rates correlated with increased incidence for all hormone receptor statuses, HER2 statuses, and grades. Reductions in breast cancer mortality during 1975-2009 were similar in screened and unscreened age groups. Overall, we found repeated signs that breast cancer overdiagnosis is widespread in the US, but the biological nature of overdiagnosed tumors remains unclear. Mortality benefits of screening, though they may be present and substantial, could not be detected at the population level.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Multi-lumen capillary based trypsin micro-reactor for the rapid digestion of proteins

In this work we evaluated a novel microreactor prepared using a surface modified, high surface-to-volume ratio multi-lumen fused silica capillary (MLC). The MLC investigated contained 126 parallel channels, each of 4 μm internal diameter. The MLC, along with conventional fused silica capillaries of 25 μm and 50 μm internal diameter, were treated by (3-aminopropyl)triethoxysilane (APTES) and then modified with gold nanoparticles, of ∼20 nm in diameter, to ultimately provide immobilisation sites for the proteolytic enzyme, trypsin. The modified capillaries and MLCs were characterised and profiled using non-invasive scanning capacitively coupled contactless conductivity detection (sC4D). The sC4D profiles confirmed a significantly higher amount of enzyme was immobilised to the MLC when compared to the fused silica capillaries, attributable to the increased surface to volume ratio. The MLC was used for dynamic protein digestion, where peptide fragments were collected and subjected to off-line chromatographic evaluation. The digestion was achieved with the MLC reactor, using a residence time of just 1.26 min, following which the HPLC peak associated with the intact protein decreased by >70%. The MLC reactors behaved similarly to the classical in vitro or in-solution approach, but provided a reduction in digestion time, and fewer peaks associated with trypsin auto-digestion, which is common using in-solution digestion. The digestion of cytochrome C using both the MLC-IMER and the in-solution approach, resulted in a sequence coverage of ∼80%. The preparation of the MLC microreactor was reproducible with <2.5% RSD between reactors (n = 3) as determined by sC4D.

Transcriptional subtyping and CD8 immunohistochemistry identifies poor prognosis stage II/III colorectal cancer patients who benefit from adjuvant chemotherapy

Purpose

Transcriptomic profiling of colorectal cancer (CRC) has led to the identification of four consensus molecular subtypes (CMS1 to 4) that have prognostic value in stage II and III disease. More recently, the Colorectal Cancer Intrinsic Subtypes (CRIS) classification system has helped to define the biology specific to the epithelial component of colorectal tumors; however, the clinical value of these classification systems in the prediction of response to standard-of-care adjuvant chemotherapy remains unknown.

Patients and Methods

Using samples from four European sites, we assembled a novel cohort of patients with stage II and III CRC (n = 156 samples) and performed transcriptomic profiling and targeted sequencing and generated a tissue microarray to enable integrated multiomics analyses. We also accessed data from two published cohorts of patients with stage II and III CRC: GSE39582 and GSE14333 (n = 479 and n = 185 samples, respectively).

Results

The epithelial-rich CMS2 subtype of CRC benefitted significantly from treatment with adjuvant chemotherapy in both stage II and III disease (P = .02 and P < .001, respectively), whereas the CMS3 subtype significantly benefitted in stage III only (P = .001). After CRIS substratification of CMS2, we observed that only the CRIS-C subtype significantly benefitted from treatment with adjuvant chemotherapy in stage II and III disease (P = .0081 and P < .001, respectively), whereas the CRIS-D subtype significantly benefitted in stage III only (P = .0034). We also observed that CRIS-C patients with low levels of CD8⁺ tumor-infiltrating lymphocytes were most at risk for relapse in both stage II and III disease (log-rank P = .0031; hazard ratio, 12.18 [95% CI, 1.51 to 98.58]).

Conclusion

Patient stratification using a combination of transcriptional subtyping and CD8 immunohistochemistry analyses is capable of identifying patients with poor prognostic stage II and III disease who benefit from adjuvant standard-of-care chemotherapy. These findings are particularly relevant for patients with stage II disease, where the overall benefit of adjuvant chemotherapy is marginal.

Tree rings reveal globally coherent signature of cosmogenic radiocarbon events in 774 and 993 CE

Though tree-ring chronologies are annually resolved, their dating has never been independently validated at the global scale. Moreover, it is unknown if atmospheric radiocarbon enrichment events of cosmogenic origin leave spatiotemporally consistent fingerprints. Here we measure the ¹⁴C content in 484 individual tree rings formed in the periods 770–780 and 990–1000 CE. Distinct ¹⁴C excursions starting in the boreal summer of 774 and the boreal spring of 993 ensure the precise dating of 44 tree-ring records from five continents. We also identify a meridional decline of 11-year mean atmospheric radiocarbon concentrations across both hemispheres. Corroborated by historical eye-witness accounts of red auroras, our results suggest a global exposure to strong solar proton radiation. To improve understanding of the return frequency and intensity of past cosmic events, which is particularly important for assessing the potential threat of space weather on our society, further annually resolved ¹⁴C measurements are needed.

Despite their extensive use, the absolute dating of tree-ring chronologies has not hitherto been independently validated at the global scale. Here, the identification of distinct ¹⁴C excursions in 484 individual tree rings, enable the authors to confirm the dating of 44 dendrochronologies from five continents.