COVID-Related AKI Chronically Hard on Kidneys

Critically ill, mechanically ventilated patients with COVID-related acute kidney injury (AKI) were at high risk for lasting kidney issues, according to a retrospective case-control study.

Among intubated patients with COVID-19 pneumonia, those who developed incident AKI while hospitalized had a 148% higher risk for subsequently developing chronic kidney disease (CKD) within 90 days compared with those who had bacterial pneumonia (HR 2.48, 95% CI 1.06-5.78, P=0.036), reported Sherida Edding, MD, of Lincoln Medical and Mental Health Center in the Bronx, New York, during the National Kidney Foundation Spring Clinical Meetings.

Likewise, after adjusting for comorbidities, mechanical ventilation days, and highest AKI stage, COVID patients had a higher likelihood of developing CKD by day 90 after AKI versus bacterial pneumonia patients (OR 2.62, 95% CI 1.06-6.45, P =0.037), she noted.

"We already had an idea that patients with pneumonia who are critically ill requiring mechanical intubation are at risk of developing AKI," Edding told MedPage Today. "But it was still surprising to note that those who were put on a ventilator because of COVID had worse prognosis and higher risk of progression to CKD regardless of comorbidities, mechanical ventilation days, or highest AKI stage during admission."

"This goes to show that there might be additional pathophysiology of the COVID virus to the kidneys that makes them sicker," she added. "As clinicians, this translates to also closely monitoring our patients' renal function when we see them as outpatients, on top of evaluating them for other long COVID symptoms."

"Of the patients who survived and were eventually discharged alive, we were curious if this incident AKI will put them at risk of progression to CKD," she explained.

AKI was a common occurrence among hospitalized patients with pneumonia, affecting 45% and 55% of those with COVID-19 pneumonia and bacterial pneumonia, respectively. However, fewer patients with COVID pneumonia experienced renal recovery:

• COVID-19 pneumonia with AKI: 68% had renal recovery; 30% progressed to CKD
• Bacterial pneumonia with AKI: 84% had renal recovery; 16% progressed to CKD

When comparing the highest serum creatinine levels during admission, COVID-19 pneumonia patients hit higher average peaks than bacterial pneumonia patients -- 2.16 mg/dL versus 2.03 mg/dL. However, both groups had average levels of 0.90 mg/dL after 90 days.

Significantly more COVID-19 patients newly required in-patient hemodialysis (20% vs 7%, P<0.043), and more COVID patients continued to need dialysis after hospital discharge compared with bacterial pneumonia patients (18% vs 3%, P<0.005).

"New York City was one of the hardest hit during the early stage of the COVID pandemic," Edding noted. "At that time, we already realized that the virus not only affects the lungs but also the kidneys. A lot of our patients, especially those who were mechanically intubated, developed AKI -- either needing dialysis or not, and this has portended a graver prognosis."

This study compared 125 intubated patients in 2020: 56 with COVID-19 pneumonia and 69 with bacterial pneumonia. All patients developed AKI during admission, had similar baseline characteristics, and were discharged alive from Lincoln Medical and Mental Health Center. AKI was defined according to Kidney Disease: Improving Global Outcomes criteria.

Edding said that her research team is continuing to follow these patients.

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