Kidney Disease Linked Increased Mortality Risk in Patients With COVID-19 in Intensive Care

October 17, 2020

Patients with coronavirus disease 2019 (COVID-19) who are admitted into the intensive care unit (ICU) and develop acute kidney injury (AKI) or have existing chronic kidney disease (CKD) have an increased mortality risk, according to a study published in the journal Anaesthesia.

Sanooj Soni, MD, Imperial College London, London, United Kingdom, and colleagues examined the association between AKI and CKD with clinical outcomes in 372 patients with COVID-19 admitted to 4 regional ICUs in the United Kingdom between March 10, 2020, and July 23, 2020. The average age of the patients was 60 years and 72% were male. The majority (76%) of patients were non-white.

Of the patients, 45% developed AKI during their ICU stay and 13% had pre-existing CKD. The patients who developed AKI had no history of serious kidney disease before their ICU admission, suggesting that the AKI was directly related to their COVID-19 infection.

Patients with no kidney injury or disease had a mortality rate of 21% (32/156 patients). Those with new onset AKI caused by the virus had a mortality rate of 48% (81/168), whilst for those with pre-existing CKD (stages 1-4), the mortality rate was 50% (11/22).

Among patients with end-stage renal failure, the mortality rate was 47% (9/19). Mortality was greatest in patients who had kidney transplants, with a mortality rate of 86% (6/7).

Out of the 216 patients with any form of kidney impairment, 121 (56%) required renal replacement therapy. Of the 48 survivors who needed dialysis for the first time during their ICU stay, 9 (19%) had to continue with dialysis after discharge from the ICU, suggesting COVID-19 may lead to chronic kidney problems.

“To the best of our knowledge, this is the first comprehensive analysis of outcomes in critically unwell COVID-19 patients in the United Kingdom with kidney failure, particularly in patients with pre-existing chronic kidney disease,” the authors wrote.

The authors noted their surprise that mortality in patients with end-stage renal failure and on dialysis, who normally have worse outcomes in many other diseases, was similar to that seen in patients with less severe kidney disease and COVID-19-associated AKI. This finding may suggest that such patients benefit equally from ICU admission and thus the threshold for admission should be calibrated accordingly in any future COVID-19 surge.

The authors noted that the study only included patients who were cared for in the ICU during the peak of the last surge, and other patients with end-stage renal failure, who may have been too unwell for admission to ICU, were not included. This may have contributed to these findings of similar mortality in patients with end-stage renal failure and those with less serious forms of CKD and AKI.

The reasons for the increased mortality in patients with kidney problems are not clearly understood. There are several theories, including that COVID-19 causes endotheliitis. Other reports have suggested that there could be direct kidney injury from the cytokine-induced immune system inflammatory response, and also death of kidney tissue related to multi-organ failure caused by COVID-19.

“Our data demonstrate that kidney disease and failure in critically ill patients with COVID-19 are common, and associated with high mortality,” the authors concluded. “However, important differences exist between stages of acute and chronic kidney disease in how they affect mortality in patients with COVID-19 and patients who have had a kidney transplant are an extremely vulnerable group. In view of this, attention needs to be paid to COVID-19 patients with any form of kidney disease or injury, and every effort made to prevent progression of this disease or injury to reduce mortality in this cohort of patients.”

Reference: https://doi.org/10.1111/anae.15293

SOURCE: Tony Kirby PR