The Incidence of Acute Kidney Injury after Coronary Artery Bypass Surgery with or without Cardiopulmonary Bypass

The incidence of acute kidney injury commonly follows cardiac surgery. Some studies have demonstrated better outcomes following off-pump cardiac surgery.
This study was conducted to compare the incidence of acute kidney injury and laboratory findings in patients undergoing cardiac surgery with or without cardiopulmonary bypass.
In a retrospective study, 167 patients who underwent coronary artery bypass grafts (CABG) with or without cardiopulmonary bypass were selected by systematic randomized sampling method from the list of Jamaran heart hospital (Tehran) patients and the incidence of acute kidney injury and laboratory findings were compared.
There was no significant difference in the demographics (age, sex, drug history, and chronic disease) between the groups (P > 0.05). The acute kidney injury (AKI) was observed in 19.3 and 33.7% of the off-pump and on-pump patients, respectively. A total number of16 (19.3%) in the off-pump and 44 (52.9%) in on-pump group needed blood transfusion. The mean hospital stay was 6.74 ± 1.86 days for OPCAB and 7.2 ± 1.72 for on-pump patients. Haemoglobin and haematocrit level, also, were higher in OPCAB.
This study showed that off-pump coronary artery bypass (OPCAB) is superior in acute kidney injury, blood transfusion, blood glucose management, and hospital stay. Considering these complications and those adverse effects, it seems that off-pump technique is better in selected patients, but it is proposed that more prospective multi-disciplinary studies with larger sample sizes should be done.