Implementing evidence based medicine in general practice: audit and qualitative study of antithrombotic treatment for atrial fibrillation

OBJECTIVE

To determine the extent to which implementation of an evidence based treatment, antithrombotic treatment in atrial fibrillation, is possible in general practice.

DESIGN

Audit and qualitative study of patients with atrial fibrillation and an educational intervention for patients judged eligible for antithrombotic treatment.

SETTING

South east England.

SUBJECTS

56 patients with a history of atrial fibrillation.

INTERVENTIONS

Assessment and interview to ascertain patients' views on antithrombotic treatment.

MAIN OUTCOME MEASURES

Number of patients receiving antithrombotic treatment.

RESULTS

Out of 13 239 patients, 132 had a history of atrial fibrillation of which 100 were at risk of thromboembolism. After the study, 52 patients were taking warfarin. Of the remaining 48 patients (of whom 41 were taking aspirin), eight were too ill to participate, 16 were unable to consent, four refused the interview, and 20 declined warfarin. Patients declining warfarin were inclined to seek a higher level of benefit than those taking it, as measured by the minimal clinically important difference. Qualitative data obtained during the interviews suggested that patients' health beliefs were important factors in determining their choice of treatment.

CONCLUSION

Patients' unwillingness to take warfarin seemed to be a major factor in limiting the number who would eventually take it.

Fast single-cell biochemistry: theory, open source microscopy and applications

Fluorescence lifetime sensing enables researchers to probe the physicochemical environment of a fluorophore providing a window through which we can observe the complex molecular make-up of the cell. Fluorescence lifetime imaging microscopy (FLIM) quantifies and maps cell biochemistry, a complex ensemble of dynamic processes. Unfortunately, typical high-resolution FLIM systems exhibit rather limited acquisition speeds, often insufficient to capture the time evolution of biochemical processes in living cells. Here, we describe the theoretical background that justifies the developments of high-speed single photon counting systems. We show that systems with low dead-times not only result in faster acquisition throughputs but also improved dynamic range and spatial resolution. We also share the implementation of hardware and software as an open platform, show applications of fast FLIM biochemical imaging on living cells and discuss strategies to balance precision and accuracy in FLIM. The recent innovations and commercialisation of fast time-domain FLIM systems are likely to popularise FLIM within the biomedical community, to impact biomedical research positively and to foster the adoption of other FLIM techniques as well. While supporting and indeed pursuing these developments, with this work we also aim to warn the community about the possible shortcomings of fast single photon counting techniques and to highlight strategies to acquire data of high quality.

Exploiting Synthetic Lethality and Network Biology to Overcome EGFR Inhibitor Resistance in Lung Cancer

Despite the recent approval of third-generation therapies, overcoming resistance to epidermal growth factor receptor (EGFR) inhibitors remains a major challenge in non-small cell lung cancer. Conceptually, synthetic lethality holds the promise of identifying non-intuitive targets for tackling both acquired and intrinsic resistance in this setting. However, translating these laboratory findings into effective clinical strategies continues to be elusive. Here, we provide an overview of the synthetic lethal approaches that have been employed to study EGFR inhibitor resistance and review the oncogene and non-oncogene signalling mechanisms that have thus far been unveiled by synthetic lethality screens. We highlight the potential challenges associated with progressing these discoveries into the clinic including context dependency, signalling plasticity, and tumour heterogeneity, and we offer a perspective on emerging network biology and computational solutions to exploit these phenomena for cancer therapy and biomarker discovery. We conclude by presenting a number of tangible steps to bolster our understanding of fundamental synthetic lethality mechanisms and advance these findings beyond the confines of the laboratory.

Mammalian lectin arrays for screening host-microbe interactions

Many members of the C-type lectin family of glycan-binding receptors have been ascribed roles in the recognition of microorganisms and serve as key receptors in the innate immune response to pathogens. Other mammalian receptors have become targets through which pathogens enter target cells. These receptor roles have often been documented with binding studies involving individual pairs of receptors and microorganisms. To provide a systematic overview of interactions between microbes and the large complement of C-type lectins, here we developed a lectin array and suitable protocols for labeling of microbes that could be used to probe this array. The array contains C-type lectins from cow, chosen as a model organism of agricultural interest for which the relevant pathogen–receptor interactions have not been previously investigated in detail. Screening with yeast cells and various strains of both Gram-positive and -negative bacteria revealed distinct binding patterns, which in some cases could be explained by binding to lipopolysaccharides or capsular polysaccharides, but in other cases they suggested the presence of novel glycan targets on many of the microorganisms. These results are consistent with interactions previously ascribed to the receptors, but they also highlight binding to additional sugar targets that have not previously been recognized. Our findings indicate that mammalian lectin arrays represent unique discovery tools for identifying both novel ligands and new receptor functions.

829 Perioperative Surgical Patients and The Availability and Utilisation Of ECGs Machines Pre- And Post-Pandemic

Introduction

ECGs are a NICE recommended pre-operative investigation and an integral part of post-operative monitoring. Delay in recognition of cardiac pathology can be catastrophic. Therefore, ECG machines should be readily available. Here, we report the results of an audit assessing the availability of ECG machines in surgical wards.

Method

In 2018 and then 2020, a bespoke, nine-item audit proforma was disseminated to all foundation doctors.

Results

In 2018, 17/32 wards had a ward based, readily available machine, 6/32 shared with another ward and 15/32 did not have a ward-based machine. The same was noted in 2020. In 2018 and 2020, the average time to obtain an ECG machine was 27 and 23 respectively. When no ECG was available, a doctor would obtain the machine 24% in 2018 compare to 52% in 2020. The diagnoses of the patients who had ECGs in 2018 were: normal sinus rhythm, atrial fibrillation, bradycardia, supraventricular tachycardia, sinus tachycardia and STEMI. In 2020 were: normal sinus rhythm, atrial fibrillation, supraventricular tachycardia, sinus tachycardia, atrial flutter, bradycardia, prolonged QTc, hyperkalaemia, STEMI and NSTEMI. The average time for NSTEMI patients to have an ECG was 35mins while for STEMI patients was 11.6mins.

Conclusions

Whilst our audit has highlighted the importance of ECG machine availability, the time to obtain one remained static between the two cycles. A study investigating the impact on patient outcomes may highlight the necessity for available ECG machines further.

911 Delayed Presentation of a Re-Bleed from A Traumatic Splenic Artery Rupture Following Endovascular Management in A Patient with Median Arcuate Ligament Syndrome

Endovascular management of splenic blunt trauma is widely accepted as a safe and effective alternative to open surgery in carefully selected patients. Following a radiologically successful intervention, patients are normally discharged with no follow up after 48-72 hours of haemodynamic stability and satisfactory serial haemoglobin levels.

We present a case of a fit and well 24-year-old male patient who presented with abdominal pain, syncope and haemodynamic instability 14 days post successful splenic artery coil-embolization for splenic artery aneurysm rupture secondary to blunt trauma. After initial resuscitation, computed tomography angiography was performed and demonstrated active bleeding from the splenic artery aneurysm which was deemed likely to be a consequence of retrograde filling. The patient underwent successful emergency re-embolization using a combination of embolization coils and Onyx via a trans-splenic approach to eliminate retrograde flow. On further review of the imaging, it was incidentally noted there was evidence suggesting a diagnosis of median arcuate ligament syndrome, which may have predisposed the patient to splanchnic artery aneurysm formation.

This case report highlights a potential limitation of endovascular management compared to open surgery and summarises the literature surrounding splenic artery anatomical variations and the implications of median arcuate ligament syndrome. A re-bleed following embolization is a hostile prospect with potentially catastrophic outcomes for patients if not recognised quickly. The authors propose that interval re-imaging should be considered following endovascular management of blunt splenic trauma.