Correlación del índice resistivo renal y presión de perfusión renal con la severidad de la lesión renal aguda

Background

Acute kidney injury is a frequent complication in the intensive care unit (ICU) leading to prolonged stay and increased mortality; severity staging requires markers such as creatinine which is late and with multiple factors that bias its measurement and interpretation. Renal ultrasound has increased its use, mainly the resistive index, in addition, the evaluation of renal perfusion in post-surgical patients has been described, however, its relationship with severity in acute kidney injury has not been demonstrated.

Objective

To establish the correlation of the resistive index and renal perfusion pressure with the severity of acute kidney injury in the Intensive Care Unit.

Material and methods

Cross-sectional study in the Intensive Care Unit; patients with acute kidney injury were included and severity was staged according to KDIGO criteria, and renal vascular ultrasonographic measurements were obtained. Statistical analysis was with Kendal's Tau-b test and linear regression analysis.

Results

Final population of 81 patients, the variable that correlated with severity was renal perfusion pressure (r = 0.62, p ≤ 0.001) and diastolic velocity (r = 0.30, p = 0.007), however, the resistive index had no correlation (r = 0.135, p = 0.314). Similarly, renal perfusion pressure correlated with changes in creatinine (r = −0.554), BUN (r = −0.480) and bicarbonate (r = 0.331).

Conclusion

No statistically significant results were found in relation to the resistive index, however, we found that the decrease in renal perfusion pressure correlates with greater severity of acute kidney injury in the intensive care unit.