COVID-19 and SIADH relations: impact of the positive pressure ventilation.

to the editor: With great interest we read the article by Yousaf et al. (5) recently published in your journal. This seems to be the first publication to raise the issue of association of COVID-19 and syndrome of inappropriate antidiuretic hormone secretion (SIADH). In fact, such an association should be quite expected, as according to one of the first reports on the COVID-19 outcomes, the majority (71%) of critically ill adult patients with SARS-CoV-2 pneumonia required mechanical ventilation. Critically ill patients of this center had a high mortality (61.5%) and those who did not survive were more likely to have received mechanical ventilation (94% vs. 35%) (4). Positive pressure ventilation (PPV) is a well-known reason of SIADH and hyponatremia development (1), probably due to nonosmotic stimulation of antidiuretic hormone (ADH) secretion, as pulmonary venous baroreceptors respond to a reduction in effective blood volume. Unfortunately, the authors of articles indicating an association between COVID-19 and plasma sodium depletion (2) or who provide advice on the level of PPV use in the treatment of severe acute respiratory distress syndrome from COVID-19 (3) do not mention the possibility of developing SIADH and methods of its treatment. Yousaf et al. (5) does not mention the possibility of developing SIADH in patients with COVID-19 in the case of treatment with PPV. Moreover, the authors propose a mechanism for SIADH in COVID-19 infection that not only does not mention PPV but contains some unusual statements. In particular, the authors claim that decreased intravascular osmolality leads to osmoreceptor activation and ADH secretion (see Fig. 1). It is known that the stimulus to ADH secretion is an increase in intravascular osmolality (1).

Thus, the development of SIADH may be one of the reasons for unsatisfactory treatment of COVID-19 with PPV, which should be considered during such treatment. In particular, this may include careful monitoring of sodium levels and fluid restriction in case of SIADH detection.

DISCLOSURES

No conflicts of interest, financial or otherwise, are declared by the author.

AUTHOR CONTRIBUTIONS

M.K. drafted manuscript; edited and revised manuscript; approved final version of manuscript.