Using Deep Dive Methodology to Investigate an Increased Incidence of Hospital-Acquired Avoidable Category 2 and 3 Pressure Ulcers.

Background: Between October 2017 and March 2018, the Trust experienced significant winter pressures and an increase in category 2 and 3 hospital-acquired avoidable pressure ulcers. This review aimed to investigate the causal factors of this increase. Methods: A 'Deep Dive' review of 37 cases was undertaken in three stages: (i) assurance; ensure the increase was not due to insufficient equipment; (ii) collation of relevant data, including age, length of time in A&E, bed surface, number of internal moves; (iii) analysis identifying factors that might account for the observed increase. Findings: Age combined with prolonged length of time in A&E, being nursed on a trolley followed by three or four internal moves were observed in patients who developed pressure ulcers. Patient age was observed as a key factor, with those over 80 years experiencing pressure ulcers more frequently. Conclusion: The small size of this data suggests a need for the greater awareness of frailty issues in older people, timely assessment and intervention to prevent a chain of detrimental factors might be key to reduce and prevent hospital-acquired avoidable pressure ulcers. Recommendations for immediate action, education and future research have been made to the Trust Quality and Safety Committee.

Internal noise in contrast discrimination propagates forwards from early visual cortex.

Human contrast discrimination performance is limited by transduction nonlinearities and variability of the neural representation (noise). Whereas the nonlinearities have been well-characterised, there is less agreement about the specifics of internal noise. Psychophysical models assume that it impacts late in sensory processing, whereas neuroimaging and intracranial electrophysiology studies suggest that the noise is much earlier. We investigated whether perceptually-relevant internal noise arises in early visual areas or later decision making areas. We recorded EEG and MEG during a two-interval-forced-choice contrast discrimination task and used multivariate pattern analysis to decode target/non-target and selected/non-selected intervals from evoked responses. We found that perceptual decisions could be decoded from both EEG and MEG signals, even when the stimuli in both intervals were physically identical. Above-chance decision classification started <100 ms after stimulus onset, suggesting that neural noise affects sensory signals early in the visual pathway. Classification accuracy increased over time, peaking at >500 ms. Applying multivariate analysis to separate anatomically-defined brain regions in MEG source space, we found that occipital regions were informative early on but then information spreads forwards across parietal and frontal regions. This is consistent with neural noise affecting sensory processing at multiple stages of perceptual decision making. We suggest how early sensory noise might be resolved with Birdsall's linearisation, in which a dominant noise source obscures subsequent nonlinearities, to allow the visual system to preserve the wide dynamic range of early areas whilst still benefitting from contrast-invariance at later stages. A preprint of this work is available at: https://doi.org/10.1101/364612.

Clinical Evaluation of the Cook Advance Enforcer 35 Focal-Force PTA Balloon Catheter for Treatment of Hemodialysis Fistula Stenoses: A Feasibility Study.

PURPOSE: A prospective, single-center, single-arm feasibility study evaluated procedural and short-term performance of the Advance Enforcer 35 focal-force percutaneous transluminal angioplasty (PTA) balloon catheter in treating stenoses of mature native arteriovenous (AV) hemodialysis access circuits. MATERIALS AND METHODS: Twenty-eight patients undergoing treatment for stenosis of a mature native AV hemodialysis access circuit were enrolled at a single institution. Angiographic assessments of the study lesion were required at baseline and after the procedure. Adjunctive procedures for significant residual stenosis were permitted, and patients had clinical and imaging follow-up for as long as 6 months. RESULTS: Treatment with the study balloon was effective in reducing the average percent diameter stenosis of the treated lesion from 66.3% (range, 43.8%-93.3%) before the procedure to 23.7% (range, -6.7% to 51.4%) after the procedure. The average inflation pressure required was 12.3 atm. Only 1 patient required an adjunctive procedure, and all patients could resume normal dialysis following the study procedure. At 3 months, 62.0% of study lesions remained patent, and the 6-month patency rate was 25.1%. Two adverse events associated with the study procedure were reported: access-site hematoma and forearm pain (3.6% each). CONCLUSIONS: The results demonstrate safety of the study balloon in treating AV access stenosis. Nominal-diameter angioplasty was achieved at relatively low pressure in most study patients without the use of adjunctive procedures, and resumption of normal dialysis was achieved for all patients.

Intravenous magnesium sulphate as an adjuvant therapy in acute exacerbations of chronic obstructive pulmonary disease: a single centre, randomised, double-blinded, parallel group, placebo-controlled trial: a pilot study.

AIM: To investigate the effects on lung function of IV magnesium in acute exacerbations of COPD (AECOPD), when given in conjunction with standard bronchodilator therapy. METHODS: This was a pilot study to a randomised, double-blinded, placebo-controlled trial. 30 patients presenting to ED with AECOPD were included. In addition to standard bronchodilator therapy, 17 patients were given saline, and 13 received 2 g of magnesium sulphate intravenously. Spirometry was carried out at presentation (TA), after initial standard bronchodilator therapy (TB) and immediately (T0), at 60 minutes (T60) and 120 minutes (T120) after trial drug infusion. Primary outcomes were percentage change in FEV1 and FVC at T0, T60 and T120. Secondary outcomes were admission rates, length of stay and requirement for NIV or mechanical ventilation. Trial registration (ANZCTR), ACTRN12613000837729. RESULTS: Greater improvements were seen in FEV1 at T0, T60 and T120 compared to TB in magnesium group (at T120, mean percentage change in FEV1 was 27.07% with magnesium versus 11.39% in the placebo group, 95%CI 3.7 to 27.7, p=0.01). Similar significantly greater improvements were noted with FVC in the magnesium group, compared to TB. CONCLUSIONS: IV magnesium sulphate used as an adjunct therapy to standard bronchodilators in AECOPD presenting to ED may improve lung function in the short term.

Use of an implantable needle guide to access difficult or impossible to cannulate arteriovenous fistulae using the buttonhole technique.

PURPOSE: The aim of this work was to assess the safety and efficacy of the VWING Vascular Needle Guide to assist in cannulation of difficult or impossible to access fistulae using the buttonhole cannulation technique. METHODS: VWING devices were surgically implanted into patients with difficult to access fistulae. A nondevice site and a device site were used to access the fistula and perform dialysis over a six month period. The device site utilized the buttonhole cannulation technique. The performance of each access site was recorded. RESULTS: VWING devices were implanted in nine patients. A total of 387 cannulations took place over 1367 study days. The device site was successfully used 94% of the time compared to 77% for the nondevice site. Cannulation success was comparable between the device and nondevice sites. Ease of insertion, pain during insertion and complication rates were also comparable. No interventions were required at the device site to maintain access compared with four interventions for the nondevice access site. CONCLUSIONS: The VWING performed as intended by facilitating required repeated access to the vascular system and access for hemodialysis treatment. The study has demonstrated that the VWING is a potential solution for access to difficult to cannulate fistulae.