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Acute kidney injury (AKI) as a result of COVID-19 is more deadly in patients in intensive care even when compared with those who have preexisting renal dysfunction, and dialysis only moderately influences survival, new research indicates.
“Our study shows that deterioration of renal function parameters could be an early marker for severe progression of COVID-19,” Katharina Oberneder, MD, Sigmund-Freud-Private University, Vienna, Austria, told Medscape Medical News in an email.
“It is therefore important to focus on renal function even in patients without preexisting renal disease,” Oberneder stressed.
Preventive measures such as optimization of renal perfusion through monitoring mean arterial pressure as well as blood pressure should be measured in patients who are found to have a reduction in renal function, or who are at risk of acute kidney injury (AKI), she recommended.
The study was presented virtually at Euroanaesthesia, the annual meeting of the European Society of Anaesthesiology and Intensive Care (ESAIC).
Study of 129 Patients in Two ICUs
A total of 129 patients from two intensive care units (ICUs) serving as COVID-19 centers in Vienna, Austria were included in the analysis. All patients admitted to the ICUs had confirmed COVID-19 and were followed up until the end of their ICU stay.
The patients were divided into 3 groups: group 1 consisted of 33 patients who had a history of previous renal disease; group 2 included 26 patients with healthy kidney function initially but who acquired AKI on day 5 of their ICU stay; and group 3 included 70 patients with normal kidney function both prior to being admitted to the ICU and at day 5 of their ICU stay.
In total, 32 patients required renal replacement therapy (dialysis). In group 1, 55% of patients survived compared with only 46% of patients in group 2 who acquired AKI because of COVID-19. In contrast, 83% of group 3 whose kidney function remained healthy prior to and during their ICU stay survived.
“In both renal injured groups (1 and 2), survival probability was significantly below average…indicating a higher mortality compared to [patients] with normal kidney function,” the investigators note.
They also point out that neither earlier initiation of dialysis nor the number of days spent on dialysis made much difference in patient survival, although survivors did spend more days on dialysis — at a median of 11.5 days — than patients who died, at a median of 5 days.
“The median number of days on dialysis was slightly higher in survivors compared to those who died, but this was only observed descriptively,” Oberneder affirmed. “But these values were not found to be statistically significant,” she emphasized.
The longer the duration of dialysis, the longer the length of ICU stay among survivors as well, the investigators add.
Kidney Dysfunction Key Risk Factor
“Our findings confirm that kidney dysfunction is a key risk factor for COVID-19 related death in intensive care patients,” Oberneder said in a statement.
More importantly, she added, their research suggests that patients with COVID-19 who develop AKI face a higher risk of death in the ICU than those with preexisting chronic kidney disease (CKD).
“Ultimately, what is most important is focusing on the early diagnosis of acute kidney dysfunction and how we can use these results to improve the care of critically ill COVID-19 patients,” she said.
Oberneder has disclosed no relevant financial relationships.
Euroanaesthesia. Abstract 7091. Presented December 17, 2021.