New Paper (Other): Acute Kidney Injury in Patients Hospitalized with COVID-19

[dziakj1]

Title: Acute Kidney Injury in Patients Hospitalized with COVID-19

General Information

Please paste a link to the paper or a citation here:

Link: https://www.kidney-international.org/article/S0085-2538(20)30532-9/fulltext

What is the paper's Manubot-style citation?

Citation: @doi:10.1016/j.kint.2020.05.006

Is this paper primarily relevant to Background or Pathogenesis?

• [ ] Background
• [x] Pathogenesis
• [ ] Methods

Please list some keywords (3-10) that help identify the relevance of this paper to COVID-19

• kidney injury
• respiratory failure
• risk factors

Please note the publication / review status

• [ ] Pre-print
• [x] New Peer-Reviewed Paper
• [ ] Peer-Reviewed Paper Pre-2020

Which areas of expertise are particularly relevant to the paper?

• [ ] virology
• [ ] epidemiology
• [x] biostatistics
• [ ] immunology
• [ ] pharmacology
• [x] other: internal medicine

[dziakj1]

Summary

Suggested questions to answer about each paper:

• What did they analyze?

They analyzed a retrospective sample of 5449 patients with PCR-confirmed COVID-19 in the medical records of a health system consisting of 13 hospitals in the New York area. In 1991 (36.6%) of them, acute kidney injury (AKI) developed.

• What methods did they use?

They used multiple logistic regression with stepwise variable selection for multivariate analyses, Fisher's exact test for categorical variable comparisons, and Kruskal-Wallis for continuous variable comparisons.

• Does this paper study COVID-19, SARS-CoV-2, or a related disease and/or virus?

Yes, it explicitly focuses on COVID-19.

• What is the main finding (or a few main takeaways)?

The authors concluded that among hospitalized patients with COVID-19, acute kidney injury is common. The 36.6% proportion of AKI which they observed was higher than previously reported in China or in Seattle. They suggested that their population may have had a higher rate of comorbidities such as diabetes.

Acute kidney injury is strongly associated with respiratory failure, with "89.7% of patients on mechanical ventilation developing AKI compared to 21.7% of non-ventilated patients." Of the patients requiring dialysis, most (86.9%) were also on mechanical ventilation. Among the patients who were both on dialysis and on a ventilator, most died (285 patients total in this category; 157 died, 9 discharged, 119 censored due to still being in hospital).

Outcomes were often poor: "Among patients with AKI, 694 died (35%), 519 (26%) were discharged and 780 (39%) were still hospitalized" as of the end of the study.

Based on a multivariate analysis of retrospective data, risk factors include "older age, diabetes mellitus, cardiovascular disease, black race, hypertension and need for ventilation and vasopressor medications." This is relevant to racial disparities and social determinants of health.

The authors note, "There has been interest in the role of blockers of the renin-angiotensin and aldosterone system and Covid-19 disease. We did not find that use of these drugs at hospital admission was related to greater AKI risk."

The authors say that they cannot come to a firm conclusion about why kidney injury occurs so frequently. It may be due to "ischemic acute tubular necrosis, which often happens concordant with systemic collapse," but there are other possibilities: "Since a cytokine storm often occurs in close temporal proximity to respiratory failure, it is possible that circulating substances or other related factors could contribute to AKI."

• What does this paper tell us about the background and/or diagnostics/therapeutics for COVID-19 / SARS-CoV-2?

It suggests to me the idea of COVID-19 as a disease that affects the whole body. It also suggests that different populations have not only different rates of infection but also different rates of consequences (here, acute kidney injury).

• Do you have any concerns about methodology or the interpretation of these results beyond this analysis?

The authors mention several limitations to the study: it is observational rather than causal, there may be unmeasured confounders, it is based only on records, and it considered only inpatients at that particular hospital system, not outpatients or patients at other hospitals. "In addition, the lack of baseline CKD status doesn’t allow us to specifically look at that factor as a risk factor."

I noticed that there were many significance tests, and I found no mention of multiple comparison adjustment. Also, the details of the multiple logistic regression were not well explained.