Abstract
Background and Aims
With increasing global burden of cardiovascular diseases and advances in managing them, the number of cardiac surgeries performed in India has been increasing in the last couple of decades.A lot of western data from the last 5 to 10 years say that AKI episodes can cause significant renal damage and progress to chronic kidney disease (CKD) ,however the association between acute kidney injury (AKI) and chronic kidney disease (CKD) remains elusive in cardiac surgery. We investigated the association between postoperative AKI and CKD development, emphasizing the role of AKI in post cardiac surgery patients.
Method
We observed the incidence of cardiac surgery associated AKI (CSA-AKI), determinants of progressive kidney disease after CSA-AKI and followed the patients with CSA-AKI for three months to find out the incidence of CKD or progressive renal dysfunction.
Results
150 consecutive post cardiac surgery patients were included in the study. CSA-AKI incidence was 35.4%[Figure 1].Incidence of AKI was significant with prior AKI episodes(P<0.01) and with pre-existing CKD (P<0.01)[Figure 2].Among intraoperative risk factors for CSA-AKI, need for CPB(P-0.01), prolonged pump time(P-0.01), blood transfusion(P-0.04) and ultrafiltration(P-0.01) during surgery were found to be significant[Figure 3,4].Duration of ICU stay (P<0.01), hospital stay (P<0.01) and death rate (P-0.04) was higher in patients with AKI[Table 1]. Out of 53 patients who developed CSA-AKI, follow up for the progression of renal disease was done for 50 patients, as 3 patients with AKI died during hospital stay. Progressive renal dysfunction (new development of CKD or progressive CKD ) after 90 days was seen in 48% of patients with CSA-AKI. All the risk factors for the progression of renal disease after AKI like increased age, low serum albumin, presence of hypertension, diabetes mellitus, protein loss in urine, severe AKI(KDIGO stage>2) and multi factorial AKI was higher in patients who had progressive renal disease after AKI in the study group, however the relation was not statistically significant[Table 2].
Conclusion
AKI is not uncommon after cardiac surgery, progressive renal dysfunction was seen in 48% of patients after CSA-AKI and progressive renal dysfunction was common in those with increased age, low serum albumin, presence of hypertension, diabetes mellitus, protein loss in urine, severe AKI(KDIGO stage>2) and multi factorial AKI.
Mean age of patients with AKI in the study group was found to be 61±10 years and for NO AKI group mean age was found to be 58±12 years. This variation was not found to be statistically significant.
Among other pre-operative risk factors, though there was some difference in percentage for many risk factors, but the percentage variation was quite significant for subjects with prior AKI episodes and those with existing CKD. The increased incidence of AKI in patients with prior AKI episodes (P<0.01) and in those with pre-existing CKD (P<0.01) was found to be statistically significant.
Low socioeconomic status was found to be high in NO AKI group, however this was not found to be statistically significant (P-0.11).
When compared to both the groups, duration of stay in ICU (P<0.01), overall duration of hospital stay (P<0.01) and death rate (P-0.04) was higher in AKI group and this variation was found to be statistically significant.
All the risk factors for the progression of renal disease after AKI like increased age, low serum albumin, presence of hypertension, diabetes mellitus, protein loss in urine, severe AKI(KDIGO stage>2) and multifactorial AKI was higher in patients who had progressive renal disease after AKI in the study group, however the relation was not statistically significant.
Impact of Diabetes Mellitus on Cardiac Surgery Outcome
