Effect of Aortic Cross Clamp Time on Renal Function in Patients Undergoing Coronary Artery Bypass Grafting

Abstract

Objective: The aim of the study is to see the effect of aortic cross clamp time on renal function
post operatively.
Material and Methods: In a prospective study 90 patients were selected for CABG first time
with normal renal function. A questionnaire was made to see the effect of aortic cross clamp time
on post operative renal function. Demographic factors, pre operative, intra operative and post
operative variables were evaluated. The patient were divided into two groups according to aortic
cross clamp time, patient with aortic cross clamp time 50 minutes and patients with aortic cross
clamp time > 50 minutes ultimately they were evaluated to see the occurrence of acute kidney
injury (AKI).
Results: AKI was observed in 6 patients with aortic cross clamp time ≤ 50 minutes and 36
patients with aortic cross clamp time > 50 minutes. The aortic cross clamp time was highly
associated with blood urea post operatively at day 1 (p value 0.002), day 2 (p-value 0.000) and
day 3 (p-value 0.000). It had significant effects on serum creatinine postoperatively day 1 (p-value
0.000), day 2 (p-value 0.005) and day 3 (p-value 0.001). It also had significant effect on reduction
of GFR post operatively day 1 (p-value 0.011), day 2 (p-value 0.003) and day 3 (p-value 0.001).
Conclusion: The greatest likelihood of developing acute kidney injury (AKI) after CABG was
observed with prolonged aortic cross clamp time. The levels of blood urea and serum creatinine
was increased in patients with aortic cross clamp time > 50 minutes. Glomerular filtration rate
(GFR) was reduced with aortic cross clamp time > 50 minutes