The value of inferior vena cava ultrasonography administration for hypovolemia detection in patients with acute kidney injury hospitalized in intensive care unit

The hypo‑perfusion of the kidneys can lead to impairment in renal function and induce renal injury in case of delayed diagnosis and treatment. To date, laboratory markers are routinely used to determine the fluid volume status of the patients. The current study aims to evaluate the values of inferior vena cava (IVC) collapsibility index in hypovolemia diagnosis among critical patients admitted at the intensive care unit (ICU).

This is a cross‑sectional study performed on 67 patients admitted to the ICU due to acute kidney injury from May 2018 to October 2019. Hypovolemia was assessed assessing IVC collapsibility using ultrasonography. Laboratory data, including urine osmolality, urine‑plasma creatinine ratio, sodium excretion fraction and urinary sodium level were checked. Afterward, IVC collapsibility index was measured for each patient using ultrasonography and the values of this index in accordance with the mentioned criteria was evaluated. Accordingly, reciever operating curve was depicted.

There was no significant asosociation between IVC collapsibility index with fractional excretion of sodium (P = 0.69), urine Na (P = 0.93) and urine osmolality ([P = 0.09]), while urine: Plasma creatinie ration revealed a significant association with IVC collapsibility index at cut point of 40.5% with sensitivity and specificity of 96% and 44% (P = 0.017, area under the curve: 0.67, 95% confidence interval: 0.551–0.804), respectively.

According to the findings of this study, IVC collapsibility detected via ultrasonography was not an appropriate index to figure out hypovolemia in ICU patients. Furthermore, detailed studies are recommended.