MO849COVID-19 AT THE HEMODIALYSIS UNIT OF FELGUEIRAS, NORTH OF PORTUGAL
Authors: Homem Melo Marques Sofia , Balboa Martin , Tomé Manuel , Beco Ana , Faria Maria do Sameiro 
Published: May 2021

Abstract

Background and Aims
SARS-CoV-2 represents a challenge for hemodialysis (HD) patients due to their multiple comorbidities, disturbed immune defenses in the setting of kidney disease and increased age. Furthermore, sharing collective spaces during HD sessions increases the risk of contamination.
In March 2020, the first COVID-19 cases in Portugal occurred in Felgueiras, a municipality belonging to the district of Porto. The HD unit that serves this population has 69 in-center patients and, from March 2020 until January 2021, has had 14 COVID-19 cases. We describe our experience concerning patient management and their clinical characteristics.

Method
Clinical and laboratory data were collected. We aimed at assessing the impact of the infection in hemoglobin, alanine transaminase, several electrolytes - potassium, phosphorus, sodium and calcium - as well as the normalized protein catabolic rate (nPCR) comparing results from the month before infection with those of the month after cure. Statistical analysis used SPSS® and variables were compared using paired-samples t-test.

Results
We used a dedicated room and staff for COVID-19 patients, disinfection protocols and specific routes. Transportation was done with a maximum of 3 patients in a 9-seater vehicle, all patients used masks, practiced social distancing, were asked for symptoms and had their temperature measured on each HD session. SARS-CoV-2 infection was established by reverse transcription polymerase chain reaction on nasal and oropharyngeal swabs. Of the 14 cases, 3 occurred in March, 5 from October until Christmas and 6 from then onwards, accounting for approximately 20% of the unit’s patients. Of these, 2 were asymptomatic, 6 had predominantly respiratory symptoms, 1 had fever and 1 had gastrointestinal symptoms. Three were hospitalized, 2 died due to COVID-19 and 1 died 1 month after cure due to advanced cancer. Mean age of these patients was 70±13.2; 5 were females and 6 had diabetic nephropathy. Only 7 patients had post-COVID-19 results for comparison. The mean hemoglobin value before COVID-19 was 10.5±1.7g/dL and did not change significantly after COVID-19. Although phosphorous dropped from a mean 3.8±0.9mg/dL to 3.2±1.3mg/dL, this difference did not reach significance (p=0.43). All other electrolytes remained stable. nPCR dropped from 1.23±0.47 to 0.95±0.37 although not a significant difference (p=0.24). Five patients were tested for IgG/IgM antibodies against SARS-CoV-2 one month after cure using Elecsys® qualitative immunoassay and 4 tested positive.

Conclusion
COVID-19 is a problem for HD patients where the percent of cases is larger than in the general population. Our 3 first cases and the 4 last cases shared the same HD shift and occurred in the same period confirming that, despite all protective measures, sharing the facilities in close proximity is a risk factor. Respiratory symptoms predominated but were only severe requiring hospital admission in 3 patients. Mortality represented 14% and the 2 patients whose death was attributable to COVID-19 had an increased burden of comorbidities and were old. Seroconversion was high 1 month after the disease. The only patient who tested negative for antibodies had been asymptomatic raising doubts about whether there could have been false test results or an undetectable immune response.