**5. Renal system involvement and electrolyte imbalance in COVID-19 infection**

COVID-19 infection and kidney injury has been well observed and reported. In one study by Chen et al., in 710 patients, 15.5% had raised creatinine on admission and 44% had hematuria and proteinuria [19–24]. It implies that kidney involvement



#### *COVID-19 and Multiorgan Dysfunction Syndrome DOI: http://dx.doi.org/10.5772/intechopen.99676*


**Table 2.** *Manifestations and markers of organ involvement*

#### *COVID-19 and Multiorgan Dysfunction Syndrome DOI: http://dx.doi.org/10.5772/intechopen.99676*

can be direct; perhaps in the form of glomerulonephritis that can be immune complex mediated or secondary to hypotension and multi organ dysfunction. The mechanism of injury can be multi-factorial. The presence of co-morbidities also play role in pathogenesis, as underlying renal injury in patients with diabetic nephropathy can get exacerbated due to decreased renal perfusion owing to shock. It has been found that this virus can have direct cytopathic effect on renal cells, as ACE2 is highly expressed in kidneys as well [20]. As cytokine storm can affect other organs due to increased pro-inflammatory markers like IL10, IL7, TNF alpha etc., which can result in injury to kidneys [21].

The electrolyte imbalances have also been found in form of hyponatremia and hypokalemia. In patients requiring ICU care, the strong association of electrolyte imbalance with severity of illness has been found [22]. In one multicenter casecontrol study in adult patients presenting in emergency department conducted in France, they found that 20.4% patients with infection had hyponatremia whereas it was found only in 12.3% controls [23]. Again, the possible role of ACE2, which is an important enzyme of RAS system can be postulated. As many patients have co-morbid conditions like hypertension and heart failure and are on diuretics, their water excretion is already disturbed and above that the severe COVID-19 infection with severe acute respiratory illness requiring ventilatory support renders these patients more dehydrated with fluid and electrolyte imbalance. In above mentioned French study, they found that hyponatremia was associated with most severe presentation of the disease and that it can be linked to increased ADH secretion in response to dehydration and volume depletion. Also, the syndrome of inappropriate ADH secretion occurs secondary to ARDS in such patients. The urinary loss of potassium was the primary cause of hypokalemia in these patients [24].
