Cerebral edema as a manifestation of dilution hyponatremia on the background of hemorrhagic fever with renal syndrome

The article defines hemorrhagic fever with renal syndrome (HFRS), provides literature data on the prevalence and features of the clinical course depending on the virulence of hantavirus serotypes. More than 90 % of the total number of HFRS cases reported annually is in the European part and 3 % in the Asian part of Russia. The most active foci of the disease are the regions between the Volga and the Urals (Bashkiria, Tataria, Udmurtia, Samara and Ulyanovsk regions). The annual incidence of HFRS in the Russian Far East averages 2 per 100,000 population and is registered mainly among residents of Primorsky and Khabarovsk Territories, Jewish Autonomous and Amur Regions. The disease is characterized by a cyclical course and a variety of clinical variants from abortive febrile forms to severe forms with massive hemorrhagic syndrome and persistent renal failure. Severe forms are of particular importance in the problem of HFRS, causing possible complications and an unfavorable outcome of the disease. The severity of clinical manifestations of HFRS is associated with the virulence of hantavirus serotypes (Puumala, Hantaan, Seul, Dobrava), the genetic characteristics of the macroorganism, the presence of concomitant chronic renal pathology, environmental problems, the infecting dose, epidemiological features of infection, and other factors. Severe forms of HFRS from the first days of the disease demonstrate the entire symptom complex of multiple organ failure in the form of various combinations of hemodynamic disorders with dysfunctions of the kidneys, liver, heart, lungs, and nervous system. The article presents a clinical case of a patient with the diagnosis: “Hemorrhagic fever with renal syndrome (ELISA: IgM positive to hantavirus (1:6400), IgG positive to hantavirus (1:400)), severe severity. The complication is dilutional hyponatremia with transient CNS damage.” According to the literature, mortality rates in hospitalized patients with severe hyponatremia, with a sodium level of less than 125 mmol/l, are significantly higher than those in patients without hyponatremia (28 % versus 9 %), while the increase in mortality is exponential as the sodium level decreases. As a result, it is important to have a deep understanding of the pathophysiology and ways of influencing dilution hyponatremia syndrome. Proper correction of the developed hyponatremia is crucial for the prognosis and outcome of the disease. Thus, the manifestations of hyponatremia can be diverse, up to cerebral edema and hemodynamic instability of patients.

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