Investigation of the Effect of Pulsatile and Nonpulsatile Flow on Kidney in Coronary Surgery with NIRS

Background: Acute renal insufficiency is a significant cause of morbidity and mortality after coronary artery bypass grafting performed with cardiopulmonary bypass. Functional near-infrared spectroscopy (fNIRS) is an emerging brain-imaging technique that can be used to detect organ perfusions in adults. This study aims to determine the effects of pulsatile and nonpulsatile flow on renal circulation by using functional near-infrared spectroscopy and biochemical markers. Methods: Forty patients, who had undergone isolated CABG between March 2014 and July 2014 in the authors’ clinic, were included in the study. Patients were divided in the pulsatile and nonpulsatile groups by simple randomization. Results: Urine outputs statistically were higher in the pulsatile group, during CPB (P = .045). Renal perfusion measurements via fNIRS intra-operatively statistically were parallel between the groups. When we compared biochemical markers within the groups, in the nonpulsatile group, creatinin statistically is higher on the postoperative first day (P = .003), and BUN statistically is higher on the postoperative first (P = .015), second (P = .001), and fifth (P = .020) days, according to preoperative value. In the pulsatile group, only the postoperative second day BUN is higher (P = .007). Conclusion: fNIRS is being used to track cerebral functions. During operation, it also provides a correct observation for blood feeding of somatic organs, such as the kidneys, but it requires more clinical study to be accepted as routine.