Background: Renal dysfunction is one of the most common complications after cardiac surgery. The major concern is that despite advances in bypass techniques, intensive care and delivery of hemodialysis, mortality and morbidity associated with renal failure have not markedly changed in the last decade. The purpose of this work was to study the incidence of renal dysfunction after cardiac surgery, analyzing the possible causes, associated risk factors and treatment methods used.
Material and methods: In this prospective observational study we analyzed patients undergoing open-heart surgery between October 1, 2010 – December 15, 2010 at the Clinic of Cardiac Surgery Târgu Mureș. Blood urea nitrogen and creatinine level were recorded for all patients before and after surgery, patients age, sex, type of surgical intervention, length of cardiopulmonary bypass, and the degree of intraoperative hypothermia, hemodilution and postoperative hemodynamic function were noted.
Results: In this period 89 patients underwent cardiac surgery. Renal dysfunction developed in 20.2% of the patients and was more common in patients with complex surgery with prolonged cardiopulmonary bypass (p<0.0167), in patients with intraoperative hemodynamic instability. Other intraoperative factors, such as hemoglobin level lower than 8 g/dl (p=0.0103), postoperative hemodynamic dysfunction and use of vasoconstrictor agents also influenced the development of renal dysfunction.
Conclusions. Cardiac surgery is associated with a relative high incidence of renal dysfunction. Risk factors for this syndrome are varied and involve hemodynamic and inflammatory changes, but factors such as the body temperature and hemoglobin level during extracorporeal circulation could have a significant contribution.