Acute respiratory illness, caused by novel coronavirus is not new now. Apart from the respiratory system, it can also attach to the nervous system, cardiovascular system, gastrointestinal (GI) tract, and urogenital system. Since the GI tract and kidneys regulate the fluid and electrolyte balance in the body, their involvement in the disease can lead to an imbalance of fluid and electrolytes, which could be potentially dangerous.

The virus interaction with the host cell can be explained as follows-

The virus binds to the angiotensin-converting enzyme 2 (ACE2) receptors of the host. These ACE2 receptors are present in the kidneys and gastrointestinal (GI) tract and thus can lead to acute conditions such as acute kidney injury (AKI) and digestive problems in the patient. 

Renal Impairment in COVID-19: 

The possible mechanisms involved in renal impairment in COVID-19 patients are rooted in fluid imbalance due to fever or reduction in fluid intake by patients. Reports of renal impairment in COVID-19 patients has been increasing by passing days.

GI Tract Impairment in COVID-19:

The SARS-CoV-2 can potentially damage the normal intestinal mucosa disrupting its normal function thus causing GI symptoms and difficulty absorbing nutrients. They may also impair the normal intestinal flora leading to various GI symptoms, especially diarrhoea. Ileum and colon involvement may cause diarrhoea, nausea, vomiting, and abdominal discomfort. Even these GI symptoms can precede respiratory symptoms which can further lead to fluid and electrolyte disturbance.

Complications following Fluid and Electrolyte Disturbance:

• Patients with hyponatremia are at increased risk of Acute cerebral edema, Rhabdomyolysis, seizures, mood swings, and even coma.
• Rapidly correcting hyponatremia or hypernatremia can further cause the demyelinating osmotic syndrome.
• Hypokalemia affects cardiovascular function, neurohormonal activation, and other vital organs.
• Hypocalcemia causes increased neuromuscular irritability, featuring muscle spasms, tingling in the limbs, and perioral numbness. Although rare it may even cause reversible cardiomyopathy.
• Change in chloride concentration can increase the risk of acute kidney injury, morbidity, and mortality.
• Hypovolemia may lead to ischemic injury of the vital organs and organ failure, and serve as a life-threatening factor (particularly in children).

Thus they concluded it to be the prime duty of the clinicians to monitor the fluid and electrolyte status of patients as Changes in their levels can serve as a reliable indicator of disease progression.

Source: Pourfridoni M, Abbasnia SM, Shafaei F, Razaviyan J, Heidari-Soureshjani R. "Fluid and Electrolyte Disturbances in COVID-19 and Their Complications", BioMed Research International, vol. 2021, Article ID 6667047, 5 pages, 2021. https://doi.org/10.1155/2021/6667047