The Effect of Dexmedetomidine on Prevention of Postoperative Acute Kidney Injury in Patients Undergoing Aortic Surgery

Acute kidney injury(AKI) is a common and severe complication after the cardiac surgery. Postoperative AKI increases the in-hospital stay, intensive care unit(ICU) stay and postoperative mortality. Aortic surgery is the most risky surgery that causes the postoperative AKI, and the incidence of AKI after aortic surgery is about 50%.

The α1- and α2-adrenergic receptors in the kidney modulate vasoconstrictor and vasodilatory effects, respectively. Agents that attenuate renal vasoconstriction may have potential as renoprotective drugs because vasoconstriction most likely contributes to the pathophysiology of AKI. Clonidine, an α2-agonist, has been shown experimentally to inhibit renin release and cause a diuresis, and it has been evaluated in an experimental AKI model, confirming its potential as a renoprotective agent. Furthermore, it has been already reported that dexmedetomidine, α2-agonist, reduce the impairment of renal function after cardiac operation.

The aim of this study is to examine the association between preoperative dexmedetomidine infusion and the incidence of postoperative acute kidney injury(AKI) in patients undergoing aortic surgery.

Inclusion Criteria:

1. the patients undergoing ascending, arch and/or proximal descending aorta surgery with cardiopulmonary bypass
2. 20 - 100 yrs old

Exclusion Criteria:

1. having preoperative severe renal dysfunction (eGFR < 15 ml/min per 1.73m2)
2. Left ventricular-ejection fraction < 30%
3. Preexisting congestive heart failure
4. Severe coronary artery disease
5. Hemodynamically unstable arrhythmia
6. Cardiogenic shock during perioperative period
7. Ventricular assist device use
8. cannot communication because of a language barrier or illiteracy