Dr Sanjiv Jasuja, Nephrologist, Apollo Hospitals Delhi details how AKI is common among COVID-19 patients who are in the ICU and recommendations for in-hospital management issued by ASN
Novel Coronavirus Disease (COVID-19) is an acute respiratory illness that in some patients, especially vulnerable groups can be deadly. As per the reports, the elderly, the immunosuppressed and those patients with a history of chronic respiratory disease, asthma and diabetes have been at high-risk. The interview published on Medscape — a USA based Medical News portal,  suggests a spike in kidney injury, contradicting the earlier belief. In the initial reports, the burden of acute kidney injury (AKI) with COVID-19 was relatively low, ranging from 3-9 per cent.  But subsequent analyses demonstrated the incidence rates as high as 15 per cent. 
The AKI is a sudden episode of kidney failure or kidney damage that happens within a few hours to a few days, which causes a build-up of waste products in patient’s blood and makes it hard for the patient’s kidneys to keep the right balance of fluid in the body. This can also affect other organs such as the brain, heart, and lungs.
In observational data from Wuhan, AKI has been reported in 25-29 per cent of patients who were critically ill or deceased. [4, 5] The incidence of AKI among infected patients (including those with and without critical illness) is approximately 5 per cent. 
Italian data in more than 2000 patients published in Critical Care reinforces an AKI incidence of 27.8 per cent among hospitalised COVID-19 patients.  The AKI develops approximately nine days after admission and may be accompanied by cardiac complications and secondary infections. The risk factors for AKI include age, the severity of illness, and the presence of diabetes.
Not all coronavirus infections are associated with AKI; for example, the common cold virus like Rhinovirus. However, both the Middle-East Respiratory Syndrome Coronavirus (MERS-CoV) and the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) do appear to be associated with AKI, but through distinct pathways and with a different natural history. 
Challenges and management of COVID-19 borne AKI
From the above-mentioned reports, it comes out that AKI is common among COVID-19 patients in the intensive care unit (ICU) as it has been developing in 40-60 per cent of COVID-19 ICU patients, including 20-30 per cent who require dialysis. And it has been turning challenging to manage. In this regard, the American Society of Nephrology (ASN) has recently conducted a webinar and deliberated on certain recommendations for in-hospital management. 
As per American Society of Nephrology (ASN), for COVID-19 patients in the ICU, the preferred dialysis modalities are Continuous Renal Replacement Therapy (CRRT) and Prolonged Intermittent Renal Replacement Therapy (PIRRT). The CRRT is one of the forms of dialysis, which mimics the functions of the kidneys in regulating water, electrolytes, and toxic products
by the continuous slow removal of solutes and fluid. The CRRT is commonly used to provide renal support for critically ill patients with AKI, particularly patients who are haemodynamically unstable.
In cases of high demand and the shortage of machine and staffing, ASN has suggested using CRRT machines for prolonged intermittent treatments as PIRRT as it can potentially help minimise wastage of personal protective equipment and limit exposure among haemodialysis nurses.
Untreated severe AKI in critically ill patients is associated with a high mortality rate. The Renal Replacement Therapy (RRT) which includes different forms of dialysis represents the cornerstone of the management of severe AKI. Albeit expensive CRRT is considered the predominant form of RRT in the intensive care unit (ICU) due to its accurate volume control, steady acid-base, and electrolyte correction and achievement of haemodynamic stability. Also, if available, CRRT may be preferred in patients who require multi-organ support.
COVID-19 infection may affect other organs besides lungs
Many of the older patients who become severely ill have evidence of underlying illness such as cardiovascular disease, liver disease, kidney disease, or malignant tumours. These patients often die of their original comorbidities and not necessarily because of COVID-19; therefore, it is important to accurately evaluate all original comorbidities of individuals with COVID-19. Moreover in severe cases COVID-19 itself can damage other organs such as the heart, the liver, and the kidneys, as well as to organ systems such as the blood and the immune system. [10, 11]
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