Kathrine Parker

INTRODUCTION: COVID-19 has spread globally to now be considered a pandemic by the World Health Organisation. Initially patients appeared to have a respiratory limited disease but there are now increasing reports of multiple organ involvement including renal disease in association with COVID-19. We studied the development and outcomes of acute kidney injury (AKI) in patients with COVID-19, in a large multicultural city hospital trust in the UK, to better understand the role renal disease has in the disease process. METHODS: This was a retrospective review using electronic records and laboratory data of adult patients admitted to the four Manchester University Foundation Trust Hospitals between March 10 and April 30 2020 with a diagnosis of COVID-19. Records were reviewed for baseline characteristics, medications, comorbidities, social deprivation index, observations, biochemistry and outcomes including mortality, admission to critical care, mechanical ventilation and the need for renal replacement therapy. RESULTS: There were 1032 patients included in the study of whom 210 (20.3%) had AKI in association with the diagnosis of COVID-19. The overall mortality with AKI was considerably higher at 52.4% compared to 26.3% without AKI (p-value <0.001). More patients with AKI required escalation to critical care (34.8% vs 11.2%, p-value <0.001). Following admission to critical care those with AKI were more likely to die (54.8% vs 25.0%, p-value <0.001) and more likely to require mechanical ventilation (86.3% vs 66.3%, p-value 0.006). DISCUSSION: We have shown that the development of AKI is associated with dramatically worse outcomes for patients, in both mortality and the requirement for critical care. Patients with COVID-19 presenting with, or at risk of AKI should be closely monitored and appropriately managed to prevent any decline in renal function, given the significant risk of deterioration and death.

BACKGROUND: Patients with chronic kidney disease (CKD) have an increased risk of venous thromboembolism (VTE) and atrial fibrillation (AF). Anticoagulants have not been studied in randomised controlled trials with CrCl < 30 ml/min. The objective of this review was to identify the impact of different anticoagulant strategies in patients with advanced CKD including dialysis. METHODS: We conducted a systematic review of randomized controlled trials and cohort studies, searching electronic databases from 1946 to 2022. Studies that evaluated both thrombotic and bleeding outcomes with anticoagulant use in CrCl < 50 ml/min were included. RESULTS: Our initial search yielded 14,503 papers with 53 suitable for inclusion. RCTs comparing direct oral anticoagulants (DOACs) versus warfarin for patients with VTE and CrCl 30-50 ml/min found no difference in recurrent VTE events (RR 0.68(95% CI 0.42-1.11)) with reduced bleeding (RR 0.65 (95% CI 0.45-0.94)). Observational data in haemodialysis suggest lower risk of recurrent VTE and major bleeding with apixaban versus warfarin. Very few studies examining outcomes were available for therapeutic and prophylactic dose low molecular weight heparin for CrCl < 30 ml/min. Findings for patients with AF on dialysis were that warfarin or DOACs had a similar or higher risk of stroke compared to no anticoagulation. For patients with AF and CrCl < 30 ml/min not on dialysis, anticoagulation should be considered on an individual basis, with limited studies suggesting DOACs may have a preferable safety profile. CONCLUSION: Further studies are still required, some ongoing, in patients with advanced CKD (CrCl < 30 ml/min) to identify the safest and most effective treatment options for VTE and AF.

Increasing use of direct oral anticoagulants (DOACs) has made management of non-valvular atrial fibrillation and venous thromboembolism easier in most patients. But the presence of co-existing renal impairment could render the use of DOACs problematic because all of these drugs have varying degrees of renal excretion. In this paper we address misconceptions about the safety and efficacy of DOACs in moderate-severe renal impairment by presenting a summary of the literature from phase III trials and real-world studies. It also addresses the important consideration of correct estimate of renal function for DOAC dosing. It is hoped that the review will serve as a valuable resource for clinicians involved in anticoagulation decision-making in patients with renal impairment to guide the choice of most suitable agent. Accurate dosing is of particular relevance as registry data suggests it is done inconsistently and may be resulting in avoidable thromboembolic and bleeding events.

Thromboembolism is one of the most serious complications of nephrotic syndrome, including both arterial and venous thromboembolic events. Rates of thromboembolism depend on a multitude of factors, including the severity and cause of nephrotic syndrome, with primary membranous nephropathy having the highest reported rates. In relation to arterial thromboembolism, the risk can be as high as 8 times that of an age- and sex-matched population. However, extrapolating risks is challenging, with published studies not being homogeneous, several being single center and retrospective, and including different causes of primary nephrotic syndrome. Determining thromboembolic risk in nephrotic syndrome is essential to enable decision making on preventive strategies. However, lack of proven strategies to help estimate risk-benefit aspects underpins variations in clinical practice. Although the use of anticoagulation following a thrombotic event is clear, this still leaves us with a clinical dilemma as to if, and who, should receive prophylactic anticoagulation, with what agent, and for how long. In the absence of clear evidence to answer these questions, prophylactic anticoagulation strategies for nephrotic syndrome currently rely on expert consensus opinion, such as in the recently published 2021 Kidney Disease Improving Global Outcomes glomerular disease guidelines. In the mainstay, these recommendations relate to patients with membranous nephropathy. Here, we detail the current controversies still faced by clinicians around the risk of thromboembolism in nephrotic syndrome, use of prophylactic anticoagulation in nephrotic syndrome and propose ways of advancing existing knowledge and practice in this field to unravel the conundrum.

BACKGROUND: Medication adherence is thought to be around 50% in the general and dialysis population. Reducing the pill burden (PB) reduces regime complexity and can improve adherence. Increased adherence should lead to improvement in treatment outcomes and patient quality of life. There is currently little published data on PB in CKD-5D across dialysis modalities. METHODS: This is a retrospective, single renal network study. All in-centre HD (MHD), peritoneal dialysis (PD) and home HD (HHD) patients were identified in the Greater Manchester East sector renal network. Information collected included age, sex, comorbidities, daily PB, dialysis vintage and adequacy. Data were retrieved from a customized renal database, clinic and discharge letters with cross validation from the general practitioner when needed. RESULTS: Two hundred and thirty-six prevalent dialysis patients were studied. HHD patients had a significantly lower PB (11 ± 7 pills/day) compared with PD and MHD (16 ± 7 pills/day). The HHD patients required fewer BP medications to meet the recommended target. HD setting was the only significant factor for reducing PB. For home therapies (HHD versus PD), weekly Kt/v and serum phosphate were significant factors influencing PB. When comparing all modalities, OR of PB ≥ 15/day for MHD versus HHD was 3.9 and PD versus HHD was 4.9. The influence of HHD is dominant above factors such as comorbidities or clinical variables in reducing PB for MHD. Higher clearances achieved by HHD could explain differences in PB with PD. CONCLUSION: This is the first comparative study of PB across all dialysis modalities and factors that influence it. The PB advantage in HHD may result in greater adherence and might contribute to the outcome benefit often seen with this modality. Higher clearances achieved by HHD could explain differences in PB with PD but the precise reasons for lower PB remain speculative and deserve further research in larger settings.