It has been observed that Covid-19 leaves long-lasting adverse effects on the body’s organs, thereby damaging the heart, lungs, brain and kidneys. Studies have shown that kidneys are especially affected and in severe cases of Covid-19, acute kidney injury (AKI) has been seen, which can lead to renal failure. Approximately 10% of patients hospitalized due to Covid-19 showed signs of kidney failure.
What is the function of kidneys?
- Help in making oxygen-rich red blood cells;
- Maintain the fluid balance: the nephrons in the kidneys help to filter the waste out of the blood through urine; and
- Maintain the body’s blood pressure.
How does Covid-19 affect kidneys?
When the Sars-CoV-2 virus infects the body, it attaches itself to ACE-2 receptors (enzymes which are present in the cells lining the lungs, kidneys, arteries, etc. and help to moderate the body’s blood pressure by controlling angiotensin, the protein responsible for raising blood pressure). The virus rapidly replicates itself, leading to inflammation, cell damage and poor function of kidneys in filtering the blood of its waste. As a result, the waste continues to build up in the blood and impairs the fluid balance of the body. This can lead to infection in the kidneys, where in septic shock can set in, along with an increase in blood-clotting, resulting in kidney failure, which can be life-threatening.
If a person is already suffering from kidney disease and gets Covid-19, he/she is likely to suffer severe damage to the kidneys, which can be fatal.
- Water retention;
- Swelling in legs, ankles, feet and around eyes;
- Shortness of breath;
- Weakness and fatigue;
- Nausea and dizziness;
- Mental confusion;
Kidney function evaluation tests
- KFT (kidney function test): A renal panel comprises an evaluation of kidney function by screening the following:
- Electrolytes: Sodium, Potassium, Chloride, Bicarbonate: Electrolyte blood levels can be affected by kidney disease in different ways depending on the cause, with some levels decreasing while others increase. This leads to fluid balance and/or pH of the blood, resulting in metabolic acidosis.
- Phosphorus: High levels indicate kidney disease.
- Calcium: Low levels are seen in kidney failure.
- Albumin: Low levels in indicate that kidneys are unable to prevent the albumin from leaking into the urine.
- Urea/BUN: High level suggests impaired kidney function caused by acute or chronic kidney disease, damage, or failure, or due to another condition causing decreased blood flow to the kidneys, such as CHF or dehydration, or causing obstruction of urine flow, such as prostate disease or kidney stones.
- Creatinine: High blood level suggests impaired kidney function due to conditions listed above for urea.
- Glucose: High blood level indicates diabetes, a common cause of kidney disease.
- Urea (Blood urea nitrogen or BUN)/Creatinine ratio: High ratio could indicate decreased blood flow to the kidneys while low ratio may be due to other conditions such as liver disease.
- Estimated Glomerular Filtration Rate (eGFR): Calculated from the blood creatinine test result, an eGFR below 60 mL/min suggests that some kidney damage has occurred; an eGFR below 15 indicates kidney failure.
- Anion Gap: A high result can indicate excess acid (acidosis) in the blood that may be related to kidney disease, but the acidosis can also be caused by many other conditions.
- Urinalysis test: A urinalysis, urine protein or creatinine clearance is done to assess kidney function, especially for those who have a pre-existing morbidities like diabetes and hypertension.
- Urine albumin (microalbumin) test: This test measures small amounts of albumin leakage from the blood into the urine, indicating kidney damage, along with an albumin/creatinine ratio (ACR) calculation.
Look after your kidneys post-Covid-19
- Wear a mask.
- Wash hands frequently.
- Practice social distancing.
- Get vaccinated for Covid-19.
If already suffering from kidney dysfunction, damage or failure, diligently follow the treatment plan advised by the doctor.