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.

0338 Interactions Between Sleep, Stress Reactivity and Cognition in Early Childhood

Introduction

During early childhood, sleep impacts the development of the cognitive, behavioral and stress systems. Specifically, acute sleep restriction reduces the subsequent cortisol awakening response, predicts self-regulation strategies and moderates correlations between self-regulation strategies and response inhibition. However, little is known about the interaction between sleep, stress reactivity and cognition in early childhood. This preliminary cross over study aimed to determine how acute sleep restriction moderates the relationship between stress reactivity and cognition in 4-year-olds.

Methods

Healthy children (N=17; 57.4 months +/- 2.1; 10 female) participated in a sleep restriction protocol that included counterbalanced cognitive and behavioral assessments during baseline and sleep restriction conditions. An age appropriate inhibitory control task was administered and salivary cortisol samples (N=6) were collected during the task. Mean processing speed was measured, and stress reactivity was computed as area under the curve with respect to ground (AUCg).

Results

Two tailed correlation analyses were performed to examine the relationship between AUCg and mean processing speed. Under baseline conditions, AUCg and mean processing speed were positively associated (r=0.45; p=0.05). When children were sleep restricted, there was no association between AUCg and mean processing speed (r=0.05; p=0.83). Although not statistically significant, AUCg was predicted by an interaciton between sleep condition and mean processing speed B=-1.92; p=0.06).

Conclusion

These results suggest that healthy sleep may promote the coupling of stress and cognitive systems, which is likely adaptive when facing life’s challenges in early childhood. Examining the developmental trajectory of these interactions and incorporating individual difference factors will build upon this model that may eventually be applied in intervention approaches to sleep, stress and behavioral problems in preschool-aged children.

Support

NIH R01-MH086566 to Dr. Monique LeBourgeois

Introducing magnetic resonance imaging into the lung cancer radiotherapy workflow - An assessment of patient experience

INTRODUCTION

Magnetic resonance imaging (MRI) offers superior soft tissue contrast to computed tomography (CT), the current standard imaging modality for planning radiotherapy treatment. Improved soft tissue contrast could reduce uncertainties in identifying tumour and surrounding healthy tissues, potentially leading to improved outcomes in patients with lung cancer. This study explored patient experience of MR treatment planning scans in addition to a CT scan.

METHODS

Participants were recruited to the 'Magnetic Resonance Imaging for the Delineation of Organs At Risk and Target Volumes in Lung Cancer Patients (MR-Lung)' study at a UK specialist cancer centre. Participants completed their standard of care radiotherapy planning CT scan and two additional MRI scans. Baseline and post-scan questionnaires were completed assessing anxiety and claustrophobia. Motion artefact during MRI was assessed by a modified visual grading analysis. Sixteen participants completed semi-structured interviews; transcripts were analysed thematically.

RESULTS

29 people (66% female; aged 54-89 years) participated. Nineteen participants completed all imaging and 10 participants withdrew before completion. There was minimal adverse impact on state and scan-specific anxiety levels from completing the MRI scans. Completers experienced significantly less scan-specific anxiety during MRI 1 compared to non-completers (U = 33, z = -1.98, p < 0.05). 78% of those who withdrew during or post MRI 1 were positioned 'arms up'. Motion artefact negatively impacted image quality in 34% of scans. Participants commonly reported concerns during MRI; noise, claustrophobia and pain in upper limbs.

CONCLUSION

Two thirds of participants tolerated two additional MR scans with minimal adverse impact on anxiety levels.

IMPLICATIONS FOR PRACTICE

Patient arm positioning and comfort ought to be considered when introducing MR-Linac systems. A screening tool to identify those at high risk of non-completion should be developed.

Effect of atrial fibrillation on endovascular thrombectomy for acute ischemic stroke. A meta-analysis of individual patient data from six randomised trials: Results from the HERMES collaboration

Background

Atrial fibrillation is an important risk factor for ischemic stroke, and is associated with an increased risk of poor outcome after ischemic stroke. Endovascular thrombectomy is safe and effective in acute ischemic stroke patients with large vessel occlusion of the anterior circulation. This meta-analysis aims to investigate whether there is an interaction between atrial fibrillation and treatment effect of endovascular thrombectomy, and secondarily whether atrial fibrillation is associated with worse outcome in patients with ischemic stroke due to large vessel occlusion.

Methods

Individual patient data were from six of the recent randomised clinical trials (MR CLEAN, EXTEND-IA, REVASCAT, SWIFT PRIME, ESCAPE, PISTE) in which endovascular thrombectomy plus standard care was compared to standard care alone. Primary outcome measure was the shift on the modified Rankin scale (mRS) at 90 days. Secondary outcomes were functional independence (mRS 0–2) at 90 days, National Institutes of Health Stroke Scale score at 24 h, symptomatic intracranial hemorrhage and mortality at 90 days. The primary effect parameter was the adjusted common odds ratio, estimated with ordinal logistic regression (shift analysis); treatment effect modification of atrial fibrillation was assessed with a multiplicative interaction term.

Results

Among 1351 patients, 447 patients had atrial fibrillation, 224 of whom were treated with endovascular thrombectomy. We found no interaction of atrial fibrillation with treatment effect of endovascular thrombectomy for both primary (p-value for interaction: 0.58) and secondary outcomes. Regardless of treatment allocation, we found no difference in primary outcome (mRS at 90 days: aOR 1.11 (95% CI 0.89–1.38) and secondary outcomes between patients with and without atrial fibrillation.

Conclusion

We found no interaction of atrial fibrillation on treatment effect of endovascular thrombectomy, and no difference in outcome between large vessel occlusion stroke patients with and without atrial fibrillation.

Comparing abundance distributions and range maps in spatial conservation planning for migratory species

Most spatial conservation planning for wide-ranging or migratory species is constrained by poor knowledge of species' spatiotemporal dynamics and is only based on static species' ranges. However, species have substantial variation in abundance across their range and migratory species have important spatiotemporal population dynamics. With growing ecological data and advancing analytics, both of these can be estimated and incorporated into spatial conservation planning. However, there is limited information on the degree to which including this information affects conservation planning. We compared the performance of systematic conservation prioritizations for different scenarios based on varying the input species' distributions by ecological metric (abundance distributions versus range maps) and temporal sampling resolution (weekly, monthly, or quarterly). We used the example of a community of 41 species of migratory shorebirds that breed in North America, and we used eBird data to produce weekly estimates of species' abundances and ranges. Abundance distributions at a monthly or weekly resolution led to prioritizations that most efficiently protected species throughout the full annual cycle. Conversely, spatial prioritizations based on species' ranges required more sites and left most species insufficiently protected for at least part of their annual cycle. Prioritizations with only quarterly species ranges were very inefficient as they needed to target 40% of species' ranges to include 10% of populations. We highlight the high value of abundance information for spatial conservation planning, which leads to more efficient and effective spatial prioritization for conservation. Overall, we provide evidence that spatial conservation planning for wide-ranging migratory species is most robust and efficient when informed by species' abundance information from the full annual cycle.

Death of a neonatal lamb due to Clostridium perfringens type B in New Zealand

Case history and clinical findings: A flock of 20 sheep was kept within three paddocks on a single property. None of the animals in the flock had been vaccinated against any disease for at least three years. Abdominal bloating and haemorrhagic diarrhoea were observed in Lamb 1 at 24 hours-of-age. The lamb subsequently died within an hour of the onset of clinical signs. Lamb 2 was 3-days-old when observed to be recumbent with opisthotonus. The lamb was treated with dextrose, vitamins B1 and B12, and penicillin G, but died 4 hours later.Pathological findings: Examination of Lamb 1 revealed markedly increased gas within the peritoneum and within dilated loops of intestine. The intestines were dark red and contained large quantities of haemorrhagic fluid. Histology of the intestines revealed peracute mucosal necrosis with minimal accompanying inflammation. The intestinal lumen contained cell debris, haemorrhage, and myriad large Gram-positive bacilli. The intestines of Lamb 2 did not appear bloated or reddened. However, multiple fibrin clots were visible within the pericardial sac. Histopathological examination revealed small foci of necrosis within the mucosa of the distal intestine. The necrotic foci were often associated with large numbers of large Gram-positive bacilli.Immunohistochemsitry and molecular biology: Intestinal samples from Lamb 1 were processed for Clostridium perfringens immunohistochemistry, which revealed large numbers of intralesional, positively immunostained rods. Fragments corresponding to the expected sizes for genes encoding alpha, beta, and epsilon C. perfringens typing toxins were amplified by PCR from DNA extracted from formalin-fixed sections of intestine.Diagnosis: Lamb dysentery due to C. perfringens type B.Clinical relevance: C. perfringens bacteria have a worldwide distribution, but disease due to C. perfringens type B has only been diagnosed in a small number of countries and has never been reported in New Zealand or Australia. C. perfringens type B produce both beta toxin and epsilon toxins, therefore both haemorrhagic enteritis and systemic vascular damage can develop. As many animals are exposed to C. perfringens without developing disease, there must be additional unknown factors that resulted in disease in these particular sheep. Vaccines that specifically protect against C. perfringens type B are available and may be recommended for use in smaller non-commercial flocks, as in the present case.

Sex-Dimorphic Interactions of MAOA Genotype and Child Maltreatment Predispose College Students to Polysubstance Use

Polysubstance use (PSU) is highly prevalent among college students. Recent evidence indicates that PSU is based on gene x environment (G×E) interactions, yet the specific biosocial factors underlying this problem remain elusive. We recently reported that lifetime use of tobacco and cannabis in college students is influenced by the interaction of the X-linked MAOA (monoamine oxidase A) gene and child maltreatment. Building on these premises, here we evaluated whether the same G×E interaction may also predict PSU in this population. Students of a large Midwestern university (n = 470; 50.9% females) took part in a computer survey for substance use, as well as childhood trauma exposure, using the Child Trauma Questionnaire (CTQ). DNA was extracted from their saliva samples and genotyped for MAOA variable-number of tandem repeat (VNTR) variants. Findings indicated that the highest number of substances were used by male students harboring low-activity MAOA alleles with a history of childhood emotional abuse. In contrast, female homozygous high-activity MAOA carriers with a history of emotional and physical abuse reported consumption of the greatest number of substances. Our results indicate that PSU among college students is influenced by the interaction of MAOA and child maltreatment in a sex-specific fashion. Further studies are warranted to understand the mechanisms of sex differences in the biosocial interplays underlying PSU in this at-risk group.

Clinicopathological factors associated with death from thin (≤ 1·00 mm) melanoma

BACKGROUND

Thin cutaneous melanomas (≤ 1·00 mm) are increasing worldwide, causing around a quarter of all melanoma deaths in the U.S.A. and Australia. Identification of predictive factors for potentially fatal thin melanomas could allow better use of resources for follow-up.

OBJECTIVES

To identify the clinicopathological factors associated with fatal thin melanomas.

METHODS

This large, nested case-case study extracted data from the population-based Queensland Cancer Registry, Australia. Our cohort consisted of Queensland residents aged 0-89 years who were diagnosed with a single, locally invasive thin melanoma (≤ 1·00 mm) between 1995 and 2014. Fatal cases (eligible patients who died from melanoma) were individually matched to three nonfatal cases (eligible patients who were not known to have died from melanoma) according to sex, age, year of diagnosis and follow-up interval. Using conditional logistic regression, we calculated odds ratios (ORs) for melanoma-specific death, adjusting for all collected clinicopathological variables.

RESULTS

In the cohort, 27 660 eligible patients were diagnosed with a single, thin melanoma. The final case-case series included 424 fatal cases and 1189 nonfatal cases. Fatal cases were sixfold as likely to arise on the scalp as on the back [OR 6·39, 95% confidence interval (CI) 2·57-15·92] and six times as likely to be of thickness 0·80-1·00 mm as of < 0·30 mm (OR 6·00, 95% CI 3·55-10·17).

CONCLUSIONS

Scalp location is a strong prognostic factor of death from thin melanoma. Further, this study provides support that melanomas with a thickness of 0·80-1·00 mm are the more hazardous thin lesions. Patients with these tumour characteristics require specific attention during follow-up. What's already known about this topic? Thin invasive melanomas (≤ 1·00 mm) contribute a substantial proportion of melanoma fatalities, owing to the high volume of disease. There is a need to find prognostic factors that will better identify fatal thin melanomas at the time of diagnosis. What does this study add? In this large population-based study, fatal thin tumours were sixfold as likely to be located on the scalp as on the back. Thin melanomas of 0·80-1·00 mm thickness were six times as likely to be associated with death as tumours < 0·30 mm. Scalp location and increasing thickness are strong predictive factors of fatal thin melanomas, indicating that patients with these tumour characteristics require close follow-up.

Relationship Between Body Habitus and Aggression Subtypes Among Healthy Young Adults from the American Midwest

This study examined associations between body habitus and functions of aggression, in a sample of 474 college students from the Midwestern region of the United States (age range = 18-25y; 73% Caucasian). Two instruments of aggression, the Reactive-Proactive Aggression Questionnaire from Dodge & Coie 1987 (DC) and Raine et al. 2006 (RPQ) were given as self-assessments. Body habitus measures standardized by age and gender specific weight and height were collected. Subjects considered to have a large body habitus in our study had both weight and height measures above the 75th percentile. Large body habitus was positively correlated with both proactive and reactive functions of aggression among adult males but not females; however, regression analyses indicated that body habitus was most strongly and robustly associated with proactive aggression. Findings suggest that even in a healthy homogeneous population, large body size in males is associated with aggression, particularly proactive aggression including bullying rather than retaliatory aggression. The presence of a large body physique may reinforce aggressive behavioral traits acquired through life experiences and activities evoking physical dominance. Alternatively, the relationship may reflect neurological processes related to size influenced by genetic factors and hormones leading to antisocial behaviors requiring future research on the role of genes for aggression.

P4743Inappropriate dosing of non-vitamin K oral anticoagulants (NOACs) in atrial fibrillation patients in Europe

Background

Prescription of Non-vitamin K oral anticoagulants (NOACs) has increased since the first therapies were launched in Europe in 2011, and they are becoming the standard of care in prevention of stroke in patients with non-valvular atrial fibrillation (NVAF). There are concerns about inappropriate NOAC dosing in clinical practice.

Purpose

This paper examines the extent of inappropriate dose prescription among NOAC patients in Germany, Italy, Spain and United Kingdom. Inappropriate dosing refers to patients who do not meet the criteria for dose reduction (under-dose) or patients who should be on the reduced dose as they meet the criteria for dose reduction (overdose).

Methods

Ipsos' Stroke Prevention in Atrial Fibrillation Therapy Monitor was fielded for 6 weeks between January 2017 to February 2017 and 6 weeks between January 2018 to March 2018, with 450 treating doctors in 2017 and 509 in 2018 providing data from 5,692 (2017: n=2,497, 2018: n=3,195) patients with non-valvular atrial fibrillation in Europe. We analysed the results for the 3,477 patients with a NOAC prescription that had sufficient data to decide on the appropriate dose.

Results

Overall, 23.4% of patients (n=813) were receiving an inappropriate dose of dabigatran, rivaroxaban, apixaban or edoxaban. Receiving an under-dose was more common than an overdose (19.2% vs 4.2%).

Ipsos data indicate 32.8% of NOAC patients in EU4 (n=1,139) were prescribed a reduced dose, and Italy had a higher proportion of patients who received a reduced dosed; Italy: 41.0% (n=345), Germany: 30.2% (n=402), Spain: 30.6% (n=216) and UK: 29.4% (n=176). Among these patients, a considerable proportion did not meet the criteria for dose reduction in EU4 (58.6%). This suggests that reduced dose is frequently prescribed to patients when not indicated.

Conclusion

Overall, the majority of patients were prescribed a correct dose according to the product label. However, we see evidence that nearly half of patients receiving a reduced dose were not indicated for a dose reduction. Further research is needed to identify reasons prompting the over-use of reduced dose.

P3792The impact of elective cardioversion for atrial fibrillation in heart failure patients

Introduction

Severe left ventricular systolic dysfunction (LVSD) is associated with worse outcomes in heart failure (HF) patients. Persistent atrial fibrillation (AF) is common in this patient group. As part of a nurse-led cardioversion service at a district general hospital we assessed the impact of elective cardioversion (DCCV) for AF in patients with LVSD on their ejection fraction (EF), and compared outcomes in patients selectively pre-treated with amiodarone for their DCCV.

Methods

A retrospective analysis was undertaken of DCCV for AF over 5 years, recording demographic, medication, serial echocardiogram (TTE), and outcome data. Significant LVSD was classified as moderate (ejection fraction [EF] 35–45%) or severe (EF<35%). All patients treated with amiodarone had baseline and serial thyroid, liver, renal function monitored, were counselled on side effects and followed up.

Results

103 patients with significant LVSD and follow-up TTE underwent DCCV, with a median age of 66 (IQR 58–73) and mean CHA2DS2-VASc 2.5. Overall mean baseline EF was 30% (SD ±11), overall follow-up EF (regardless of repeat TTE rhythm) was 42% (SD ±12), and the mean delta EF +12% improvement (SD ±11). At follow-up TTE, 66% (68/103) of patients were in sinus rhythm (SR) and 34% (35/103) in AF. 62/68 (91%) patients in SR at follow-up TTE were also treated with HF medications, vs 33/35 (94%) of those in AF. 61/68 (90%) of patients in SR at follow-up TTE had any improvement in EF vs 21/35 (60%) patients in AF (p=0.0007). For patients in SR the mean baseline EF was 31% (SD ±10) and mean follow-up EF 47% (SD ±9), vs the AF at repeat TTE patients' mean baseline EF 27% (SD ±12) and mean follow-up EF 35% (SD ±13). The mean delta EF of patients still in SR at follow-up scan was 15% (SD ±10) vs 8% (SD ±11) for patients who had reverted to AF (p=0.0004). Prior analysis of our data-set including patients awaiting repeat TTE demonstrated a significant improvement in 6 month AF recurrence rate.

Table 1. Comparing outcomes with amiodarone pre-treatment for patient with follow-up EF data Acute DCCV Success Mean Baseline EF Mean Repeat EF Mean Delta EF AF Recurrence to 6 months Amiodarone 17/17 (100%) 29% (SD 11) 45% (SD 11) 15% (SD 13) 6/17 (35%) No Amiodarone 80/86 (93%) 30% (SD 11) 42% (SD 12) 12% (SD 10) 50/86 (58%) P value 0.59 0.22 0.11

Conclusion

Restoration of SR in a cohort of patients with AF, severe LVSD, on good medical therapy significantly improves left ventricular EF. This reinforces the importance of maintaining SR for HF patients. There was also a trend towards improved medium term outcomes in patients pre-treated with amiodarone. Further study into long-term rhythm control and ablation outcomes is needed.