The adverse impact of pre-operative anaemia on survival following major lower limb amputation.

INTRODUCTION: Approximately 5000 major lower-limb amputations (MLLA) for PAD occur per-annum in the UK with clinical outcomes being poor for this high-risk cohort of patients. Existing evidence suggests that anaemic surgical patients have an increased 30-day mortality, but this has not been explored in the context of MLLA. Recent prioritization processes suggested that MLLAs are a target area for research into outcome improvement. This cohort study evaluates the impact of anaemia on the outcome of MLLA to understand if optimization might improve outcomes. METHODS: All PAD patients undergoing MLLA during 2015-2018 at a tertiary vascular centre were reviewed. Patients were stratified into groups; non-anaemia (>12 g/dL), mild-anaemia (12-10 g/dL) and severe-anaemia (<10 g/dL) by pre-operative haemoglobin (Hb). Primary outcome was overall survival by Kaplan-Meier. Secondary outcomes included length of stay (LOS), post-operative blood-transfusion, surgical-site infection (SSI) and myocardial infarction (MI). Cox-proportional-hazard and receiver-operator characteristics (ROC) analyses were conducted. RESULTS: 345 patients were followed up over (mean) 23 months. 105 were non-anaemic, 111 mildly anaemic and 129 severely anaemic. Patients with severe-anaemia had a higher incidence of heart and renal failure (p = 0.003) than those with non- or mild-anaemia. Overall survival worsened significantly with increasing anaemia (p = 0.001). LOS was significantly longer in mild-anaemia which is 26 (16-43) days, (p = 0.006) and severe-anaemia of 28 days (17-40), (p < 0.001) compared to non-anaemia of 18 (10-30) days. Post-operative blood-transfusion (RBC) was required more frequently in 70.5% of severely anaemic patients (p < 0.001), compared to mildly anaemic (24.3%) and non-anaemic (7.6%) patients, with those receiving RBCs having a significantly worse survival. There was no difference in MI, SSI or wound dehiscence. Anaemia was significantly associated with mortality; (HR 1.7 (1.04-2.78), p = 0.03). A minimum-Hb of 10.4 g/L (by ROC) was identified as a cutoff Hb for an increased risk of mortality. CONCLUSION: Pre-operative anaemia is associated with worse outcome following MLLA, with increasing severity of anaemia associated with increasing mortality and RBC transfusion being potentially detrimental. More work is required to prospectively evaluate this relationship in this complex and multi-morbid cohort of patients.

Social Deprivation and the Association With Survival Following Fenestrated Endovascular Aneurysm Repair.

BACKGROUND: Social deprivation is associated with poor clinical outcomes. It is known to have an impact on length of stay and post-operative mortality across a number of other surgical specialties. This study evaluates the impact of social deprivation on outcomes following fenestrated endovascular aneurysm repair (FEVAR). METHODS: All elective FEVARs performed between 2010 and 2018 at a tertiary vascular center were analyzed. Deprivation (index of multiple deprivation [IMD]) data was sourced from the English indices of deprivation 2019, by postcode. Primary outcome was overall survival by Kaplan-Meier. Secondary outcomes included length of hospital stay (LOS) and complications. Cox-proportional hazard analyses were conducted. RESULTS: Some 132 FEVAR patients were followed-up for 3.7 (SD 2.2) years. Fifty-seven patients lived in areas with high levels of deprivation (IMD 1-3), 34 in areas with moderate deprivation (IMD 4-6) and 41 in areas with the lowest level (IMD 7-10) of deprivation. Groups were comparable for Age, BMI, AAA diameter and co-morbidity. A higher proportion of patients from deprived areas had renal failure (15% [26.3%] vs. 9% [11.8%] P = 0.019) but no overall difference in procedure time was observed (200 min [155-250] vs. 180 min [145-240] P = 0.412). Kaplan-Meier analysis demonstrated significantly poorer survival for patients living in areas with high levels of deprivation (IMD 1-3) (P = 0.03). Mortality was comparable for IMD 4-6 and 7-10 groups. Patients from the most deprived areas had longer hospital stay (6 days [4-9] vs. 5 [3-7] P = 0.005) and higher all-cause complication rates (21 [36.8%] vs. 14 [18.4%] P = 0.02). Decreasing IMD was associated with worse survival (HR -0.85 [0.75-0.97] [P = 0.02]). CONCLUSIONS: Social deprivation was associated with increased mortality, length of stay and all-cause complication rates in patients undergoing FEVAR for complex abdominal aortic aneurysm (AAA). These results may help direct preoptimization measures to improve outcomes in higher risk sub-groups.

Asynchronous Unsupervised Video-Enhanced Feedback As Effective As Direct Expert Feedback in the Long-Term Retention of Practical Clinical Skills: Randomised Trial Comparing 2 Feedback Methods in a Cohort of Novice Medical Students.

OBJECTIVES: To determine the degree of practical clinical skills' retention over a 7-week period after receiving either video-enhanced direct expert feedback (DEF) or asynchronous unsupervised video-enhanced feedback (UVF). DESIGN: A prospective single-blinded randomized trial was conducted over a 7-week period with novice medical students. Following a generic introduction, PowerPoint presentation and live demonstration of intravenous cannulation was given by an expert, and candidates performed the same task in isolation while being recorded and were randomized to receive either DEF or UVF. Further, 20 students were randomized to receive UVF and 22 to receive DEF. Candidates returned to repeat the video-recorded task at week 1, 4, and 7, with no further feedback provision on these occasions. Performances were fully anonymized and independently marked by 2 expert assessors. SETTING: Newcastle University, Medical School, England, United Kingdom. PARTICIPANTS: A total of 42 novice medical students from the preclinical years were selected, with no prior experience of intravenous cannulation. RESULTS: No significant difference existed between demographics of either cohort. Good between-assessor score correlation was noted, with an intraclass correlation coefficient (ICC) of 0.89. The DEF arm significantly improved from their prefeedback performance at Day 1 on repeating the skill a week later (p < 0.0001); this improved score was maintained throughout the duration of the study. The UVF arm showed a nonsignificant improvement; however, there was no significant difference in the scores between the UVF and the DEF groups at any point in the trial. CONCLUSIONS: Video-technology may play a significant role in the provision of feedback for practical skills. The ability for experts to provide remotely delivered but individualized feedback can be an efficient use of valuable resources, while students being able to self-assess their own performance alongside an expert video have the potential to provide students with an excellent opportunity to learn clinical skills without requiring intensive educator involvement.

Management options in the treatment of femoral pseudoaneurysms secondary to intravenous drug abuse: A case series.

INTRODUCTION: Infected femoral pseudoaneurysms are a common presentation in intravenous drug users with little consensus as to the optimum management of these patients. Whilst emergency revascularisation options are available, excision and ligation of the femoral artery remains the most common operative intervention but risks leaving the patient with critical ischaemia or intermittent claudication. This case series reviewed the outcomes of 4 patients who underwent excision-ligation without revascularisation of an infected femoral pseudoaneurysm at a district general hospital. PRESENTATION: Four patients (2 male, 2 female) with infected femoral pseudoaneurysms presented via the emergency room with diagnosis confirmed with contrast cross-sectional imaging. All patients underwent emergency excision and ligation of the pseudoaneurysm without revascularisation. One patient returned to theatre with critical ischaemia necessitating a hindquarter amputation. The remaining 3 patients were discharged without claudication symptoms. CONCLUSION: With the identification of suitable patients and pre-operative optimisation, revascularisation can be performed in the emergency setting with an extra-anatomical bypass appearing to confer the best results. Currently endovascular approaches appear to be used only as a bridge to a future definitive revascularisation procedure, however, there are several case reports documenting successful outcomes when using a stent graft alongside a prolonged course of antibiotics. For the majority of patients, excision-ligation without revascularisation is both safe and effective as few are left with symptoms of limb ischaemia.

Cholinergic neuromodulation controls directed temporal communication in neocortex in vitro.

Acetylcholine is the primary neuromodulator involved in cortical arousal in mammals. Cholinergic modulation is involved in conscious awareness, memory formation and attention - processes that involve intercommunication between different cortical regions. Such communication is achieved in part through temporal structuring of neuronal activity by population rhythms, particularly in the beta and gamma frequency ranges (12-80 Hz). Here we demonstrate, using in vitro and in silico models, that spectrally identical patterns of beta2 and gamma rhythms are generated in primary sensory areas and polymodal association areas by fundamentally different local circuit mechanisms: Glutamatergic excitation induced beta2 frequency population rhythms only in layer 5 association cortex whereas cholinergic neuromodulation induced this rhythm only in layer 5 primary sensory cortex. This region-specific sensitivity of local circuits to cholinergic modulation allowed for control of the extent of cortical temporal interactions. Furthermore, the contrasting mechanisms underlying these beta2 rhythms produced a high degree of directionality, favouring an influence of association cortex over primary auditory cortex.