Short-term risk prediction after major lower limb amputation: PERCEIVE study

BACKGROUND

The accuracy with which healthcare professionals (HCPs) and risk prediction tools predict outcomes after major lower limb amputation (MLLA) is uncertain. The aim of this study was to evaluate the accuracy of predicting short-term (30 days after MLLA) mortality, morbidity, and revisional surgery.

METHODS

The PERCEIVE (PrEdiction of Risk and Communication of outcomE following major lower limb amputation: a collaboratIVE) study was launched on 1 October 2020. It was an international multicentre study, including adults undergoing MLLA for complications of peripheral arterial disease and/or diabetes. Preoperative predictions of 30-day mortality, morbidity, and MLLA revision by surgeons and anaesthetists were recorded. Probabilities from relevant risk prediction tools were calculated. Evaluation of accuracy included measures of discrimination, calibration, and overall performance.

RESULTS

Some 537 patients were included. HCPs had acceptable discrimination in predicting mortality (931 predictions; C-statistic 0.758) and MLLA revision (565 predictions; C-statistic 0.756), but were poor at predicting morbidity (980 predictions; C-statistic 0.616). They overpredicted the risk of all outcomes. All except three risk prediction tools had worse discrimination than HCPs for predicting mortality (C-statistics 0.789, 0.774, and 0.773); two of these significantly overestimated the risk compared with HCPs. SORT version 2 (the only tool incorporating HCP predictions) demonstrated better calibration and overall performance (Brier score 0.082) than HCPs. Tools predicting morbidity and MLLA revision had poor discrimination (C-statistics 0.520 and 0.679).

CONCLUSION

Clinicians predicted mortality and MLLA revision well, but predicted morbidity poorly. They overestimated the risk of mortality, morbidity, and MLLA revision. Most short-term risk prediction tools had poorer discrimination or calibration than HCPs. The best method of predicting mortality was a statistical tool that incorporated HCP estimation.

P90 PERCEIVE: PrEdiction of Risk and Communication of outcome following major lower limb amputation - a collaboratIVE study

Introduction

Major Lower Limb Amputation (MLLA) is a life changing event with significant morbidity and mortality. Inaccurate risk prediction can lead to poor decision making, resulting in delay to definitive surgery, or undertaking amputation when not in the patient’s best interest. We aim to answer: In adult patients undergoing MLLA for chronic limb threatening ischaemia or diabetes, how accurately do health care professionals prospectively predict outcomes after MLLA, and how does this compare to existing prediction tools?

Methods

A multicentre prospective observational cohort study is being delivered through the Vascular and Endovascular Research Network. Dissemination was via an existing network of contacts and social media.

Consecutive data will be collected for seven months from site launch date, including demographic data and pre-operative outcome predictions from surgeons, anaesthetists, and allied healthcare professionals. Follow-up data will comprise 30-day (mortality, morbidity, MLLA revision, surgical site infection, and blood transfusion) and 1-year (mortality, MLLA revision and ambulation). The accuracy of surgeons’ predictions will be evaluated and compared to pre-existing risk prediction scoring tools.

Results

PERCEIVE launched on 01/10/2020 with 23 centres (16 UK, 7 international) registered to collect data. 50 other centres (27 UK, 23 international) have expressed interest/are pursuing local audit/ethical approval. We aim to collect data on clinicians estimate of outcomes for over 500 patients.

Discussion

This study will utilise a trainee research network to provide data on the accuracy of healthcare professionals’ predictions of outcomes following MLLA and compare this to the utility of existing prediction tools in this patient cohort.

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.

Systematic review and narrative synthesis of surgeons' perception of postoperative outcomes and risk

BACKGROUND

The accuracy with which surgeons can predict outcomes following surgery has not been explored in a systematic way. The aim of this review was to determine how accurately a surgeon's 'gut feeling' or perception of risk correlates with patient outcomes and available risk scoring systems.

METHODS

A systematic review was undertaken in accordance with PRISMA guidelines. A narrative synthesis was performed in accordance with the Guidance on the Conduct of Narrative Synthesis In Systematic Reviews. Studies comparing surgeons' preoperative or postoperative assessment of patient outcomes were included. Studies that made comparisons with risk scoring tools were also included. Outcomes evaluated were postoperative mortality, general and operation-specific morbidity and long-term outcomes.

RESULTS

Twenty-seven studies comprising 20 898 patients undergoing general, gastrointestinal, cardiothoracic, orthopaedic, vascular, urology, endocrine and neurosurgical operations were included. Surgeons consistently overpredicted mortality rates and were outperformed by existing risk scoring tools in six of seven studies comparing area under receiver operating characteristic (ROC) curves (AUC). Surgeons' prediction of general morbidity was good, and was equivalent to, or better than, pre-existing risk prediction models. Long-term outcomes were poorly predicted by surgeons, with AUC values ranging from 0·51 to 0·75. Four of five studies found postoperative risk estimates to be more accurate than those made before surgery.

CONCLUSION

Surgeons consistently overestimate mortality risk and are outperformed by pre-existing tools; prediction of longer-term outcomes is also poor. Surgeons should consider the use of risk prediction tools when available to inform clinical decision-making.

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.

Measuring implementation of evidence-based guidance on promoting workers' health

BACKGROUND

The National Health Service (NHS) employs 1.4 million people in England. In health care, improved workforce health has been associated with improved outcomes for patients. The UK's National Institute for Health and Clinical Excellence (NICE) has produced evidence-based guidance on improving workers' health. However, the extent of implementation of evidence-based guidance has not previously been measured.

AIMS

To measure progress with implementation of NICE guidance on workplace health and identify opportunities to improve this.

METHODS

All NHS organizations in England were invited to participate in an audit of implementation of NICE guidance. A web-based tool was developed to collect information on the extent to which each organization had implemented NICE guidance addressing health promotion in the workplace.

RESULTS

The number of organizations that participated was 282. These employed a total of 868 979 workers. Organizations were more likely to involve staff in planning and designing an organizational approach to each topic where health and well-being was a regular board agenda item. Those with an overarching strategy were more likely to have staff health and well-being as a regular board agenda item (P < 0.05) and more likely to have specific policies for obesity, physical activity and promoting mental well-being (all P <0.01).

CONCLUSIONS

Implementation of NICE guidance on health at work is incomplete across the NHS in England. Implementation was more complete where boards were leading health and well-being plans and the workforce were actively involved. There is scope to improve the implementation of evidence-based guidance to improve workers' health.

Who contributes to the occupational health evidence base?

BACKGROUND

Whilst there has been recognition of the need to strengthen the evidence base for occupational health in the UK, it is not clear how much different groups contribute to the emerging research.

AIMS

To establish the research contribution from different types of organization and how this has changed.

METHODS

All original research papers published in Occupational Medicine in the 5-year periods July 1996 to June 2001 and July 2006 to June 2011 were reviewed. The lead authors' affiliations were classified in the most relevant sector.

RESULTS

The number of research papers published by authors affiliated to UK organizations was greater in the past 5 years than in a similar period a decade ago. The increase is wholly explained by a large increase in papers from universities. About one-fifth of all papers published in Occupational Medicine from UK sources had a principal affiliation with the National Health Service (NHS). The number of papers affiliated to large private sector companies reduced from 14 to 2. No papers arose from the work of established specialists employed by the large commercial providers of occupational health services.

CONCLUSIONS

Services provided in the NHS and other public sector organizations are important contributors of new evidence in occupational health. Commissioners of public sector services should take account of the importance of this to the research and innovation in occupational health.

Limits on the spin-dependent WIMP-nucleon cross sections from the first science run of the ZEPLIN-III experiment

We present new experimental constraints on the WIMP-nucleon spin-dependent elastic cross sections using data from the first science run of ZEPLIN-III, a two-phase xenon experiment searching for galactic dark matter weakly interacting massive particles based at the Boulby mine. Analysis of approximately 450 kg x days fiducial exposure allow us to place a 90%-confidence upper limit on the pure WIMP-neutron cross section of sigma(n)=1.9x10(-2) pb at 55 GeV/c(2) WIMP mass. Recent calculations of the nuclear spin structure based on the Bonn charge-dependent nucleon-nucleon potential were used for the odd-neutron isotopes 129Xe and 131Xe. These indicate that the sensitivity of xenon targets to the spin-dependent WIMP-proton interaction could be much lower than implied by previous calculations, whereas the WIMP-neutron sensitivity is impaired only by a factor of approximately 2.

Prevention of laboratory animal allergy

BACKGROUND

Laboratory animal allergy (or LAA) is an important threat to the occupational health of those who work with rats, mice and other species.

AIM

This review examines the risk factors for LAA and the effectiveness of control measures.

METHODS

A literature review was performed.

RESULTS

An extensive literature was identified regarding LAA and the use of control measures. The contribution that these measures can make to the overall effectiveness of an occupational health and safety programme is discussed in the context of the literature currently available.

CONCLUSION

The incidence of this disease can be reduced by effective, integrated health risk management, with the conscientious use of engineering, procedural and personal control measures.

New and future diabetes therapies: are they safe during pregnancy?

Diabetes in pregnancy, whether the woman had diabetes prior to becoming pregnant or developed gestational diabetes, is associated with many complications and risks. In the first trimester, organogenesis can be disrupted by complications due to poor control of the mother's diabetes, leading to fetal malformations or perinatal mortality. Problems with glucose control in the remainder of the pregnancy can also have consequences for the child. These include macrosomia, shoulder dystocia, pre-eclampsia, hypoglycemia and an increased risk for obesity and diabetes in the future. Therefore, aggressive and prompt treatment of the high blood sugar levels, which cause these complications, is necessary. This review looks at the current treatments for pregnancies complicated by diabetes and evaluates the place of new and possible future treatments including diet, exercise, insulin, insulin analogs and oral and inhaled agents.

The effect of rehabilitation at different stages of development of rats marginally malnourished for ten to twelve generations

1. Rats which have been maintained for ten to twelve generations on diets of low protein value were rehabilitated in utero (group P), from birth (group F) and from 4 weeks of age (group W). 2. Group W showed little change in physique, behaviour or learning, indicating that for recovery to be effective refeeding must begin earlier. 3. Group F just failed to attain full physical recovery (90%) whereas group P overgrew by 18.6% in weight and 8.5% in length. 4. In a test designed to evaluate learning ability rehabilitated rats of groups P and F were significantly less successful than normal rats, but more successful than rats of group W or rats of the original undernourished colony. 5. Rehabilitation for a further two generations in groups F and P corrected any residual physical and behavioural defects but produced no further improvement on the Lashley (1938) jumping platform.