Early-Cannulation Arteriovenous Grafts Are Safe and Effective in Avoiding Recurrent Tunneled Central Catheter Infection

OBJECTIVES

Tunneled central venous catheter infection (TCVCi) is a common complication that often necessitates removal of the TCVC and replacement by a further TCVC. Theoretically, insertion of an early - cannulation graft (ecAVG) early after TCVC infection is possible but not widely practiced with concerns over safety and infection in the ecAVG. With 8 years of ecAVG experience, the aim of this study was to compare the outcomes following TCVC infection, comparing replacement with TCVC (TCVCr) versus immediate ecAVG (ecAVGr).

DESIGN

Retrospective comparison of 2 cohorts, who underwent replacement of an infected TCVC either by an early cannulation graft (n = 18) or by a further central catheter (n = 39).

METHODS

Data were abstracted from a prospectively completed electronic patient record and collected on patient demographics, TCVC insertion, duration and infection, including culture proven bacteriaemia and subsequent access interventions.

RESULTS

Eighteen of 299 patients identified from 2012 to 2020 had an ecAVG implanted as treatment for a TCVCi. In a 1-year time-period (January 1, 2015-December 31, 2015) out of 222 TCVC inserted, 39 were as a replacement following a TCVCi. No patient with an ecAVGr developed an immediate infection, nor complication from the procedure. The rate of subsequent vascular access infection was significantly more frequent for those with a TCVCr than with an ecAVGr (0.6 vs. 0.1/patient/1000 HD days, P< 0.000). The number of further TCVC required was significantly higher in the TCVCr group (7.1 vs. 0.4/patient/1000 HD days, P= 0.000).

CONCLUSIONS

An ecAVG early following a TCVC infection is safe, reduces the incidence of subsequent infectious complications and reduces the number of TCVC required, with a better functional patency.

Clinical characteristics and outcome of critically ill COVID-19 patients with acute kidney injury: a single centre cohort study

BACKGROUND

Acute kidney injury (AKI) is a common manifestation among patients critically ill with SARS-CoV-2 infection (Coronavirus 2019) and is associated with significant morbidity and mortality. The pathophysiology of renal failure in this context is not fully understood, but likely to be multifactorial. The intensive care unit outcomes of patients following COVID-19 acute critical illness with associated AKI have not been fully explored. We conducted a cohort study to investigate the risk factors for acute kidney injury in patients admitted to and intensive care unit with COVID-19, its incidence and associated outcomes.

METHODS

We reviewed the medical records of all patients admitted to our adult intensive care unit suffering from SARS-CoV-2 infection from 14th March 2020 until 12th May 2020. Acute kidney injury was defined using the Kidney Disease Improving Global Outcome (KDIGO) criteria. The outcome analysis was assessed up to date as 3rd of September 2020.

RESULTS

A total of 81 patients admitted during this period. All patients had acute hypoxic respiratory failure and needed either noninvasive or invasive mechanical ventilatory support. Thirty-six patients (44%) had evidence of AKI (Stage I-33%, Stage II-22%, Renal Replacement Therapy (RRT)-44%). All patients with AKI stage III had RRT. Age, diabetes mellitus, immunosuppression, lymphopenia, high D-Dimer levels, increased APACHE II and SOFA scores, invasive mechanical ventilation and use of inotropic or vasopressor support were significantly associated with AKI. The peak AKI was at day 4 and mean duration of RRT was 12.5 days. The mortality was 25% for the AKI group compared to 6.7% in those without AKI. Among those received RRT and survived their illness, the renal function recovery is complete and back to baseline in all patients.

CONCLUSION

Acute kidney injury and renal replacement therapy is common in critically ill patients presenting with COVID-19. It is associated with increased severity of illness on admission to ICU, increased mortality and prolonged ICU and hospital length of stay. Recovery of renal function was complete in all survived patients.

Epidemiology of bloodstream infections in a Scottish haemodialysis population with focus on vascular access method

BACKGROUND

Infection is the second highest cause of mortality in end-stage renal disease, with a significant proportion relating to haemodialysis (HD) vascular access-related infection (VARI).

AIM

To report the rate and antimicrobial resistance (AMR) of all-source bloodstream infections (BSIs) by vascular access type in a Scottish HD cohort.

METHODS

Retrospective analysis was undertaken of data on adult patients attending seven HD units during 2017. Total HD days for each vascular access type were calculated. BSIs were analysed with rates expressed per 1000 HD days. AMR was verified using health board microbiology databases.

FINDINGS

Excluding contaminant organisms, there was an overall BSI rate of 0.57 per 1000 HD days. The highest all-source and vascular access-related infection (VARI) BSI rates per 1000 HD days were in the non-tunnelled central venous catheter (CVC) group (3.11 and 2.07 respectively), followed by tunnelled CVC (1.10 and 0.67), arteriovenous graft (0.51 and 0.31), and finally arteriovenous fistula (0.29 and 0.02). The non-VARI BSI rates were lowest in the arteriovenous graft group. Staphylococci comprised the majority of events, with Staphylococcus aureus implicated in 29%. Gram-negative BSIs were prevalent, particularly in CVC groups, and associated with higher mortality. Multidrug-resistant (MDR) S. aureus and carbapenem resistance were relatively low. MDR Gram-negatives were high compared with the Scottish population.

CONCLUSION

Arteriovenous fistula access is confirmed as having lowest all-source and VARI BSI rates, and arteriovenous graft access the lowest non-VARI BSI rates. Staphylococci remain the prevailing genus; however, the contributions of Gram-negative BSIs, the higher mortality, and proportion of MDR organisms in this group are notable.

Communication from the cerebellum to the neocortex during sleep spindles

Surprisingly little is known about neural activity in the sleeping cerebellum. Using long-term wireless recording, we characterised dynamic cerebro-thalamo-cerebellar interactions during natural sleep in monkeys. Similar sleep cycles were evident in both M1 and cerebellum as cyclical fluctuations in firing rates as well as a reciprocal pattern of slow waves and sleep spindles. Directed connectivity from motor cortex to the cerebellum suggested a neocortical origin of slow waves. Surprisingly however, spindles were associated with a directional influence from the cerebellum to motor cortex, conducted via the thalamus. Furthermore, the relative phase of spindle-band oscillations in the neocortex and cerebellum varied systematically with their changing amplitudes. We used linear dynamical systems analysis to show that this behaviour could only be explained by a system of two coupled oscillators. These observations appear inconsistent with a single spindle generator within the thalamo-cortical system, and suggest instead a cerebellar contribution to neocortical sleep spindles. Since spindles are implicated in the off-line consolidation of procedural learning, we speculate that this may involve communication via cerebello-thalamo-neocortical pathways in sleep.

National Guidelines on the Provision of Outpatient Parenteral Antimicrobial Therapy (OPAT)

Aim Outpatient parenteral antimicrobial therapy (OPAT) is an option in patients who require parenteral antimicrobial administration and are clinically well enough for hospital discharge. This is an update of the Irish National OPAT guidelines which were last reviewed in 2011. Methods The guideline was devised through a collaborative process with the national OPAT Working Group and a review of the literature. It is intended for clinicians who prescribe any intravenous (IV) antimicrobials outside of the inpatient setting in the Republic of Ireland. Results Patient care while on OPAT should be provided by a designated OPAT service, with clear managerial and clinical governance lines of responsibility. It should be conducted using a team approach with a clinical lead on each site either as an infection specialist, or a general medical physician with infection specialist input and an OPAT nurse. An antimicrobial pharmacist is also desirable. Several factors must be considered when assessing patient's suitability for OPAT including exclusion criteria, infection-specific factors, and patient specific factors such as physical, social and logistic criteria. Conclusion This updated guideline advocates a more individualised OPAT approach, with the recognition that specific antimicrobials and/or specific delivery models may be more appropriate for certain patient groups. Full guidelines are available through www.opat.ie.

AB0402 DISEASE ACTIVITY AND OBSESSIVE-COMPULSIVE DISORDER IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Obsessive-compulsive disorder (OCD) is more prevalent in systemic autoimmune diseases when compared to healthy controls. This is in part due to inflammatory mechanisms, common across both conditions. Neuroinflammation and specifically problems within the basal ganglia are associated with OCD.

Objectives:

The primary objective of this analysis was to investigate the effects of disease activity in systemic lupus erythematosus (SLE) on OCD. Other variables investigated included psychiatric aspects, inflammatory biomarkers and structural brain abnormalities.

Methods:

SLE patients who met ACR or SLICC criteria were recruited. Demographic and clinical data were collected and data measuring disease activity (BILAG and SLEDAI-2K), disease damage (SLICC-DI), depression (MADRS, BDI-II, HADS), anxiety (HADS, STAI), fatigue (FSMC), quality of life (LupusQoL and EQ5D), inflammatory and endothelial activation (EA) biomarkers (IL-6, ESR, TNF-α, MCP-1, hsCRP, BLyS, VCAM-1, VEGF, EMVs) and OCD (OCI-R). MRI FLAIR structural scans were also used to examine signal hyperintensities in the brain. Participants with active disease (SLE-F) also had a 2ndvisit approx. 4 months later. Non-parametric correlations with the OCI-R were undertaken for all SLE participants and for the change over time scores for the SLE-F participants (n=11).

Results:

39 participants were included in the analysis and were typical for a SLE population. 6 (23%) patients had scores above the threshold for OCD. OCI-R significantly correlated with disease activity, quality of life, fatigue, depression and anxiety measures for all the SLE participants. Change in monocyte chemoattractant protein-1 (MCP-1) correlated with the OCI-R for the within SLE-F group analysis (Table 1). No significant correlations were found with the full SLE group for inflammatory or EA biomarkers or with either group for the structural brain analysis.

Table 1.

Significant correlations with the OCI-R for: a) all SLE participants; b) the SLE-F group only (visit 1 minus visit 2).

Variablersp-valuea)All SLE participants, n=39Disease activity: BILAG global score0.4080.01Quality of life: LupusQoL – Physical-0.4950.001  – Pain-0.535<0.001  – Planning-0.586<0.001  – Intimate-0.3420.03  – Burden-0.5040.001  – Emotion-0.3970.01  – Fatigue-0.4710.002 EQ5D: VAS-0.4180.01  total-0.3590.03Fatigue measures (FSMC): Cognitive0.5210.001 Motor0.4480.004Depression measures: MADRS0.4670.003 HADS – D0.545<0.001Anxiety measure: HADS-A0.3750.02b)SLE-F group (v1-v2), n=11Inflammatory marker: MCP-10.7710.006

BILAG The British Isles Lupus Assessment Group index, LupusQoL Lupus quality of life, EQ5D European quality of life, VAS visual analogue scale, FSMC Fatigue scale for motor and cognitive function, MADRS Montgomery Asberg depression rating scale, HADS Hospital anxiety and depression scale, D-depression, A-anxiety score, MCP-1 monocyte chemoattractant protein-1

Conclusion:

OCD in lupus is strongly related to other psychological co-morbidities, fatigue and quality of life. Our results also support a role for inflammatory pathways in mediating some of these changes and so obsessive-compulsive features should be assessed in SLE patients who flare. A larger study is underway to better understand the mechanisms underlying these associations.

Acknowledgments:

This study was partially funded by an unrestricted grant from Sanofi Genzyme and supported by the NIHR Manchester Biomedical Research Centre.

Disclosure of Interests: :

Michelle Barraclough Grant/research support from: This study was partially funded by an unrestricted grant from Sanofi Genzyme., Ben Parker Grant/research support from: GSK and Sanofi Genzyme, Consultant of: GSK, AstraZenaca, UCV, Abbvie, Pfizer, BMS, Celltrion, Shane McKie: None declared, Philip Pemberton: None declared, Alan Jackson: None declared, Rebecca Elliott: None declared, Ian N. Bruce Grant/research support from: Genzyme Sanofi, GSK, and UCB, Consultant of: Eli Lilly, AstraZeneca, UCB, Iltoo, and Merck Serono, Speakers bureau: UCB

A trio of simple optimized axisymmetric kinematic dynamos in a sphere

Planetary magnetic fields are generated by the motion of conductive fluid in the planet's interior. Complex flows are not required for dynamo action; simple flows have been shown to act as efficient kinematic dynamos, whose physical characteristics are more straightforward to study. Recently, Chen et al. (2018, J. Fluid Mech. 839, 1-32. (doi:10.1017/jfm.2017.924)) found the optimal, unconstrained kinematic dynamo in a sphere, which, despite being of theoretical importance, is of limited practical use. We extend their work by restricting the optimization to three simple two-mode axisymmetric flows based on the kinematic dynamos of Dudley & James (1989, Proc. R. Soc. Lond. A 425, 407-429. (doi:10.1098/rspa.1989.0112)). Using a Lagrangian optimization, we find the smallest critical magnetic Reynolds number for each flow type, measured using an enstrophy-based norm. A Galerkin method is used, in which the spectral coefficients of the fluid flow and magnetic field are updated in order to maximize the final magnetic energy. We consider the t ⁰ ₁ s ⁰ ₁, t ⁰ ₁ s ⁰ ₂ and t ⁰ ₂ s ⁰ ₂ flows and find enstrophy-based critical magnetic Reynolds numbers of 107.7, 142.4 and 125.5 (13.7, 19.6 and 16.4, respectively, with the energy-based definition). These are up to four times smaller than the original flows. These simple and efficient flows may be used as benchmarks in future studies.

Novel phase I trial design to evaluate the addition of cediranib or selumetinib to preoperative chemoradiotherapy for locally advanced rectal cancer: the DREAMtherapy trial

BACKGROUND

The DREAMtherapy (Dual REctal Angiogenesis MEK inhibition radiotherapy) trial is a novel intertwined design whereby two tyrosine kinase inhibitors (cediranib and selumetinib) were independently evaluated with rectal chemoradiotherapy (CRT) in an efficient manner to limit the extended follow-up period often required for radiotherapy studies.

PATIENTS AND METHODS

Cediranib or selumetinib was commenced 10 days before and then continued with RT (45 Gy/25#/5 wks) and capecitabine (825 mg/m2 twice a day (BID)). When three patients in the cediranib 15-mg once daily (OD) cohort were in the surveillance period, recruitment to the selumetinib cohort commenced. This alternating schedule was followed throughout. Three cediranib (15, 20 and 30 mg OD) and two selumetinib cohorts (50 and 75 mg BID) were planned. Circulating and imaging biomarkers of inflammation/angiogenesis were evaluated.

RESULTS

In case of cediranib, dose-limiting diarrhoea, fatigue and skin reactions were seen in the 30-mg OD cohort, and therefore, 20 mg OD was defined as the maximum tolerated dose. Forty-one percent patients achieved a clinical or pathological complete response (7/17), and 53% (9/17) had an excellent clinical or pathological response (ECPR). Significantly lower level of pre-treatment plasma tumour necrosis factor alpha (TNFα) was found in patients who had an ECPR. In case of selumetinib, the 50-mg BID cohort was poorly tolerated (fatigue and diarrhoea); a reduced dose cohort of 75-mg OD was opened which was also poorly tolerated, and further recruitment was abandoned. Of the 12 patients treated, two attained an ECPR (17%).

CONCLUSIONS

This novel intertwined trial design is an effective way to independently investigate multiple agents with radiotherapy. The combination of cediranib with CRT was well tolerated with encouraging efficacy. TNFα emerged as a potential predictive biomarker of response and warrants further evaluation.

Microbiological evaluation of UV disinfection effectiveness in a specialist cystic fibrosis clinic

The aim of the study was to evaluate the impact of manual cleaning and manual cleaning followed by Ultraviolet-C disinfection on the colony forming units of bacteria retrievable from equipment and surfaces within clinic rooms following a CF outpatient encounter. While UV disinfection has proven to be effective within general healthcare settings, it has not been evaluated in a CF centre. Microbiological sampling was performed following outpatient encounters involving 11 adult patients with CF and chronic infection with P.aeruginosa, MRSA or E. coli ESBL. The results of this study suggest that manual cleaning followed by UV-C disinfection is more effective than manual cleaning alone at reducing environmental contamination within a CF clinic and that UV-C isinfection is likely to reduce the risk of fomite transmission in the CF outpatient setting.

Toward personalized dose-prescription in locally advanced non-small cell lung cancer: Validation of published normal tissue complication probability models

PURPOSE

To identify published normal tissue complication probability (NTCP) models suitable for patient-specific dose-prescription in locally advanced non-small cell lung cancer (LA-NSCLC) through in-house validation.

MATERIAL AND METHODS

From eight previously published candidate NTCP models (≥grade 2 acute esophagitis and radiation pneumonitis; AE2, RP2), patient-specific dose-responses were calculated using model variables and fractionation-corrected doses for 241 LA-NSCLC patients treated with chemo-IMRT to 50-80 Gy@1.8-2.0 Gy between 2004 and 2014 (AE2/RP2 rate: 50%/12%). A model was judged final if it significantly predicted AE2 or RP2 (p ≤ 0.05), was discriminative and well calibrated (AUC > 0.60; Hosmer-Lemeshow test p_HL > 0.05), which were assessed as the median over 1000 bootstrap samples.

RESULTS

Models for AE2 had superior discrimination to RP2 models (AUC = 0.63-0.65 vs. 0.51-0.65). The final AE2 model included mean esophageal dose and concurrent chemotherapy (AUC = 0.65; p < 0.0001). The final RP2 model was a slightly adjusted version of the RP2 model with the best discrimination, and included age, mean lung dose, and pulmonary comorbidity (AUC = 0.73; p < 0.0001).

CONCLUSION

Of the eight investigated and published NTCP models, one model successfully described AE2 and one slightly adjusted model successfully described RP2 in the independent cohort. Estimates from these two NTCP models will, therefore, be considered internally when prescribing patient-specific doses in LA-NSCLC patients.