REN and acute kidney injury: Additionally, an increased ADH dependent free water retention induced by dehydration might have also contributed to Hyponatremia development.6 A probable third mechanism that might have played a role was Renin – Angiotensin – Aldosterone System (RAAS) dysfunction as seen in AKI.16 In the current study, half of the COVID-19 patients had AKI resulting from either a direct viral or an indirect ischemic / septic renal tubular damage.