key: cord-0934879-9yx50c6j authors: Roper, Tayeba; Kumar, Nicola; Lewis-Morris, Timothy; Moxham, Vicki; Kassimatis, Theodoros; Game, David; Breen, Cormac; Moutzouris, Dimitrios-Anestis title: Delivering dialysis during the COVID-19 outbreak: Strategies and outcomes date: 2020-05-28 journal: Kidney Int Rep DOI: 10.1016/j.ekir.2020.05.018 sha: 72df180e37522245305eca5d52e40e8b7664aff0 doc_id: 934879 cord_uid: 9yx50c6j BACKGROUND: Haemodialysis (HD) patients are at increased risk of COVID-19 infection. Although all dialysis patients meet government criteria for shielding, only those on home treatment can comply. Patients attending incentre HD units represent a large and vulnerable group, who are unable to rigorously adhere to this advice. The need to adopt strategies to protect these patients is of great importance. We report our experience of delivering dialysis during the COVID-19 outbreak, describing the interventions taken to try to protect patients from virus transmission whilst maintaining optimal treatment. METHODS: We implemented measures, including use of; a system of active triage and isolation of suspected cases, separate transportation, a dedicated COVID-19 HD unit, personal protective equipment, active repatriation of patients back to base units. We collected data from all COVID-19 positive HD patients in our cohort, between 14/03/2020 - 20/04/2020. Data were compared to national reports of other units, and values obtained from a dialysis-specific Susceptible-Infectious-Removed model which predicted the impact of COVID-19 on our cohort. RESULTS: Results showed 76/670 (11.3%) tested positive for COVID-19. The majority were male (61.8%) and from a minority background (61.8%). 7/76 (9.2%) patients died following infection. The model projections overestimated the incidence of COVID-19, 221 vs 76 total number of infections by 20/4/20. Our incidence of COVID-19 and mortality are lower compared to other units across London. CONCLUSION: Implementation of measures to limit the spread of COVID-19, and optimise dialysis, could account for the low infection and mortality rates observed in our cohort of patients. COVID-19 is caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) and carries a fatality rate of 1-13.5% in confirmed cases [1, 2] . Infection is mainly through droplets reaching the eyes, mouth or nose of an individual and transmission can be mitigated by measures including hand washing, wearing masks and social distancing [3] . A further measure to protect those extremely vulnerable patients is shielding; a means of guarding individuals from coming into contact with others, achieved by minimising social interaction for a defined period. A large number of dialysis patients are of older age with coexisting health conditions including cardiovascular disease, hypertension, diabetes, and lung disease and are immunecompromised, which impacts on their ability to produce specific responses to infectious pathogens and to develop seroconversion [4] . They are therefore at increased risk of COVID-19 infection and its complications and met the United Kingdom (UK) government criteria for shielding. Logistically this cannot be rigorously adhered to by haemodialysis (HD) patients as they are required to attend dialysis units, to be in close proximity to other patients during HD, and often to use shared transport to their dialysis unit. Various preventative strategies which can be utilised in outpatient HD facilities have been proposed, which aim to minimize the spread of COVID-19, and dialysis providers have adopted these measures to varying degrees depending on resources [5, 6] . Guy's and St Thomas' NHS Foundation Trust provide incentre (IC)HD in 2 hospital-based dialysis units and 6 satellite units; 4 in inner London boroughs, 1 in outer London and 1 in a rural location. We serve a diverse population of patients, including a large proportion (52%) from Black, Asian and minority ethnic (BAME) backgrounds. We report our experience and reflect on the effectiveness of measures taken to reduce viral transmission whilst delivering optimal HD in our patient cohort during the initial phase of the COVID-19 pandemic in the UK. Between 14/03/2020 and 20/04/2020, of the 670 regular HD patients who dialyse at Guy's and St Thomas' NHS Foundation Trust, 76 (11.3%) tested positive for COVID-19 infection. Of these patients, all received ICHD, and 31 (40.1%) attend ICHD using hospital-organised patient transport. The first positive swab for COVID-19 from our HD cohort was on the 14/03/20. Amongst those patients who tested positive for COVID-19, the median age was 61.5 years (range 23-85), 47/76 (61.8%) were male and 29/76 (38.2%) were female (Table 2) . 72 (94.7%) infections were identified in patients attending the inner London units with only 4 (5.3%) in the outer London unit and none in the rural unit, reflecting the early community circulation of SARS-Cov-2 in these inner London boroughs. Ethnicities and cause of ESRD were representative of our HD population and are shown in Table 3 . 13/76 (17.1%) patients had previously received a renal transplant, 11/76 (14.5%) of these remain on immunosuppression. The overall median duration on dialysis was 28 months (range 4-384 months). Table 3 compares the demographics of the cohort of COVID-19 positive patients to our HD population as a whole. 31/76 (40.8%) patients required admission to hospital, the median length of hospital stay was 28.5 days (range 9-40). 15/37 (40.5%) of those admitted remain as current inpatients with a length of stay ranging from 3 to 98 days. Two of these patients however have been in hospital for 98 and 75 days, related to intra-abdominal collections and post endovascular treatment of an abdominal aortic aneurysm, respectively. Both of these patients acquired COVID-19 infections during their current inpatient stay. Excluding these two patients from analysis gives an median length of hospital stay for current inpatients of 12 days (range 3-29 days). Of the remaining 13 patients, only 3 have been in hospital for 20 or more days, but remain medically fit for discharge whilst awaiting social planning. 7/76 (9.2%) HD patients have died, all from respiratory failure secondary to COVID-19 pneumonitis. Of these 6/7 (85%) (p = 0.15) were male and 5/7 (71%) (p = 0.72) were from a BAME background. The median age of those who died was 79 (range 56-85 years old), and the median length of survival from time of first positive swab for COVID-19 was 28 days (range 6-38 days) ( Table 2) . Only 1 (14.3%) died from COVID-19 following a stay on the intensive care unit. All the patients who died had a number of additional comorbidities and high level of clinical frailty. None of the patients who died had previously received a renal transplant. The median dialysis duration of patients who died was 60 months (range 11-84). We compared our data to that of other dialysis unit cohorts in London, from UK renal registry (UKRR) weekly national reports of COVID-19 positivity, and associated mortality. Our unit appears to have had both fewer cases of COVID-19, as well as fewer deaths following infection [7] . Table 4 compares our data to that of other dialysis units across London. We used a dialysis-specific SIR prediction model designed by Imperial College London to help predict and plan for COVID-19 positivity in our HD patient population. The 'best guess' values calculated by this model, based on an R 0 of 2.0, predicted that there would be a total of 221 (33%) confirmed HD patients testing positive for COVID-19 by 20/4/20. This same model predicted that of these, 66 (9.9%) would be admitted to hospital. Figure 1 shows how the best guess predicted total number of COVID-19 positive HD patients and COVID-19 positive inpatients, compares to actual numbers recorded at our Trust between 30/3/20 -20/4/20. It is widely acknowledged that managing patients receiving ICHD in respect to control and prevention of infectious diseases differs from that in the general population due to their close proximity to each other whilst on treatment, in the waiting area, and on shared transport to and from dialysis facilities [8] . SARS-Cov-2 is a highly transmissible virus, and is associated with cluster outbreaks [9] .The majority of dialysis patients have other comorbidities, which in combination with the logistical considerations relating to dialysis facilities, have resulted in these patients being identified as a group that are at high risk for acquiring COVID-19 and it's complications. Emerging data from Wuhan and Italy reported death rates of 13.1% in dialysis patients with COVID-19 compared to 4% in the general population [1] . The demographics, prevention measures, treatments and outcomes of our ICHD patients infected with COVID-19 have been described. Facing the challenges of this world-wide pandemic we wish to share the strategies utilised to minimise transmission and to reflect on measures taken in managing patients, as well as consider those factors which may improve patient survival (summarised in Table 1 ). In respect to planning, in anticipation of the potential impact of COVID-19 on the healthcare system as a whole, we used dialysis-specific SIR modelling data to obtain best guess predictions of how many of our HD population may be affected. We hoped that this information would allow us to prepare for a potentially large influx of HD patients into hospital, adapt our outpatient HD service to optimise renal support for patients, and limit cross-contamination between COVID-19 positive and negative patients. Real-time modelling data has been shown to be of benefit in previous pandemics, particularly when it comes to planning of service provision in the early days of an pandemic [S1, S2]. The SIR model we used assumed an R 0 (i.e the expected number of cases generated by one case) of 2.0. The data presented herein highlights the low rate of COVID-19 positive HD patients identified at our hospital, compared to those predicted by the SIR model until the 20/04/2020; 221 (32.7%) predicted vs 76 (11.3%) confirmed cases. Similarly, the model predicted a large influx of patients into hospital compared to our actual data; 66 (9.9%) vs 37 (5.5%) being admitted to hospital. Our data would suggest that, with the measures we have put in place, we have reduced the R 0 to a value between 1.7 and 1.8. Further to this, we found that the death rate amongst COVID-19 positive patients is markedly lower than anticipated, with a total of only 7 (1.03%) deaths in this cohort. When compared to UKRR data from other units in London (Table 4) , the rate of COVID-19 positivity and death from COVID-19 in our Trust, appears to be lower at this early-stage [7] . The overestimation of affected patients predicted by the model is possibly related to the fact that so much remains unknown about SARS-CoV-2 and how it affects different populations. Much of the modelling data is based on analysis of how the virus has spread in other populations, however this does not necessarily mean this information is directly applicable to the population of patients we serve. Differences in not only population demographics, but also population behaviour, government interventions and local hospital responses will likely impact on the spread of disease, and therefore the accuracy of modelling data. Conversely, it could be that the modelling data predicting the total number of patients with COVID-19 was accurate, but our testing of only symptomatic patients, and not asymptomatic, patients resulted in lower numbers being recorded. We implemented a strict protocol for retesting of confirmed COVID-19 cases at our COVID-19 positive HD unit. By using this approach, we have previously shown that by day 15 following the initial positive swab, 41% of patients have not cleared the virus and could not be repatriated back to their original HD unit [S3] . Although it is unclear if detection of viral RNA represents ability to transmit virus, this may have prevented the cross-contamination in this population. In addition, 35% of our patients could be repatriated in their base unit at day 12, which is crucial for the capacity of the dedicated COVID-19 positive dialysis unit. Following data from Wuhan province reporting the major cause of death in HD patients with COVID-19 infection to be related to cardiovascular events and hyperkalaemia, we protected our patients by maintaining their regular three times a week HD schedules [S4]. We did however counsel patients starting dialysis for the first time during the COVID-19 pandemic that we should adopt incremental twice weekly dialysis in order to limit their time in the dialysis units and away from home [S5]. In addition to the measures taken to limit patient exposure to the virus, we took steps to ensure that our cohort of COVID-19 positive HD patients were monitored closely by renal physicians in order to limit the impact of the pandemic on their regular care. By maintaining a cohort of COVID-19 positive patients in a single unit and actively monitoring them for both deterioration or clearance of infection, we ensured timely referral to inpatient care or repatriation to their base HD unit, respectively. This further allowed us to ensure that there were an adequate number of HD slots available to allow all COVID-19 positive patients to continue on 3 times a week HD treatment [S3]. The data presented should be interpreted with a degree of caution in view of some inherent limitations. Firstly, the number of COVID-19 positive cases we report is likely to be an underestimate, as only symptomatic patients were screened for the virus. A number of patients are likely to have remained asymptomatic in spite of infection, and therefore not included in our testing. The true accuracy of the SIR model is therefore difficult to determine. Second, when comparing data to other units it is important to bear in mind that they may have had different protocols for testing (e.g. testing of asymptomatic patients), and that they may have had different starting points for testing of ICHD patients. This makes the validity of comparison between different units less reliable. Lastly, the total number of reported patients on dialysis at different hospitals is based on UKRR data from the end of 2018 (Table 4 ). We have assumed that current populations have not changed meaningfully and so actual percentages of patients with COVID-19 is not vastly different. Therefore, the comparison of our infection rates to those in other units can only be viewed as an approximation to how our measures are impacting on infection rates compared to other units. We have shown that the measures we have taken have had a positive impact, slowing the spread of COVID-19 infection, and protecting our HD patients whilst maintaining optimal dialysis treatment. This package of interventions (Table 1 ) required rigorous implementation by staff, and the commitment from our HD patient cohort, in order to make a difference and ultimately help protect this vulnerable group of patients. Whilst these interventions are shown to have been effective in the initial phase of this pandemic, it will be important to maintain them in subsequent phases of increased SARS-Cov-2 transmission, such as may occur when social distancing strategies for the general population are relaxed. -Kieron Clarkdata manager in Renal for collecting the data -Dr Damian Ashby -Renal Consultant at Imperial College London for providing the prediction model. Not applicable TR data analysis and writing the main body of text. DM data analysis, review and amendments to main text, and approval of final draft. TLM data analysis. NK writing of introduction, review and amendments of drafts, and approval of final draft. VM, TK, DG, CB review and amendment of drafts and approval of final draft. Table 1 -Summary of strategies to optimise care and limit spread of SARS-CoV-2 amongst haemodialysis (HD) patients. Table 4 -UK Renal registry data comparing number of COVID-19 positive cases and deaths amongst incentre haemodialysis (ICHD) at our unit (Guy's) and different London Renal units (adapted from [7] ). Estimates of the severity of coronavirus disease 2019: a model-based analysis. The Lancet Infectious Diseases Retrieved from Coronavirus disease (COVID-19) technical guidance: Infection prevention and control:. WHO Mortality caused by sepsis in patients with end-stage renal disease compared with the general population Interim Additional Guidance for Infection Prevention and Control Recommendations for Patients with Suspected or Confirmed COVID-19 in Outpatient Hemodialysis Facilities Nephrologists Transforming Dialysis Safety (NTDS), Coronavirus Disease 2019. ASN Weekly COVID-19 surveillance report for renal centres in the UK; London -up to 22 Infection control guidelines in hemodialysis facilities Investigation of three clusters of COVID-19 in Singapore: implications for surveillance and response measures. The Lancet The authors would like to acknowledge the following individuals for their contributions; Methods and supplementary references. Supplementary information is available at KI Report's website (pdf).