Prevalence of Acute Kidney Injury following Cardiac Surgery and Related Risk Factors in Chinese Patients

Abstract

Background/Aims: Acute kidney injury (AKI) following surgery is a major complication, but the prevalence and risk factors in the Asian population are unclear. Recently, a consensus definition of AKI (AKIN) was proposed. We studied a cohort of cardiac surgery patients and identified AKI by AKIN and associated risk factors. Methods: We retrospectively evaluated 1,056 consecutive patients undergoing cardiac surgery in Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China from January 1, 2004 to June 30, 2007. We recorded AKIN stage, clinical characteristics, perioperative variables and complications, as well as clinical outcomes. Univariate and multivariate regression as well as survival analysis was performed. Results: AKI occurred in 328 (31.1%) patients, stage 1 in 21.1%, stage 2 in 6.3% and stage 3 in 3.7%. Patients with AKI were older (65.8 vs. 53.5 years, p < 0.001), more often male (66.8 vs. 54.1%, p < 0.001), and had higher Charlson Comorbidity Index (CCI) (CCI >2: 22.6 vs. 7.8%, p < 0.001). In logistic regression, advanced age (OR 1.48 per decade, 95% CI 1.32–1.67), CCI >2 (OR 2.82, 95% CI 1.80–4.41), hypertension (OR 2.13, 95% CI 1.47–3.09), left ventricular ejection fraction (LVEF) <45% (OR 1.97, 95% CI 1.14–3.40), postoperative central venous pressure (CVP) <6 cm H₂O (OR 13.28, 95% CI 8.72–20.14) and postoperative use of ACEI/ARB (OR 1.90, 95% CI 1.27–2.85) were risk factors of AKI. Mortality rose progressively with increased AKIN stage (non-AKI 0.7%, stage 1 4.9%, stage 2 12.1% and stage 3 48.7%). In ROC analysis, AKIN classification was identified to be associated with in-hospital mortality with an AUC of 0.865 (95% CI 0.801–0.929, sensitivity 0.884, specificity 0.714, p < 0.001). Finally, in a Cox proportional hazards model, AKIN stage (HR 2.40, p < 0.001), re-exploration (HR 6.30, p = 0.002) and multiple organ dysfunction syndrome (MODS) (HR 4.42, p = 0.001) were associated risk factors for in-hospital mortality. Conclusion: We evaluated AKIN as a marker of AKI and mortality risk in a large, unselected Chinese cohort of incident patients undergoing cardiac surgery. AKI following cardiac surgery was diagnosed by AKIN criteria in around one third of the patients, and AKI may be associated with outcome. The value of preventative strategies to reduce AKI and their effect on in-hospital mortality should be studied.

The Impact of Integrating Nephrologists into the Postoperative Cardiac Intensive Care Unit: A Cohort Study

“…We found a significant reduction in AKI with Nephrology On-Site and a baseline AKI incidence with Nephrology On-Demand of 31.9%, similar to previous studies [3,4]. As expected, a higher positive impact was achieved in patients with intermediate risk.…”

“…With Nephrology On-Site, there was a trend towards a higher proportion of patients receiving RST, together with some parameters of earlier dialysis, even though the proportion of severe AKI was lower than previously reported [4]. Although no specific criterion was used to determine when RST should be started, in our center patients with RIFLE-I/AKIN-2 plus an unfavorable state (mechanical ventilation, hemodynamic instability, inputs higher than urine output or sepsis) are usually considered for RST, and with Nephrology On-Site this recognition process might be accelerated.…”

“…The incidence of acute kidney injury (AKI) after cardiac surgery defined using the internationally accepted RIFLE [1] and AKIN [2] criteria has been reported to be around 30%, contributing to a mortality rate of 30-50% as the AKI stage increases [3,4,5,6,7]. …”

Risk factors of acute kidney injury after acute myocardial infarction

“…), multiple organ failure and other factors. [16][17][18][19][20] Therefore, it is necessary to strictly monitor patient's hemodynamics to reduce volatility of renal perfusion. In addition, for high-risk patients with insufficient effective circulating blood volume, these drugs should be used with caution at early stage of post-operation in addition to closely monitoring changes in renal function.…”

Effect of Cardiac Surgery-Associated Acute Kidney Injury on Long-Term Outcomes of Chinese Patients: A Historical Cohort Study

“…Although some studies have reported the short-term outcomes of cardiac surgery in China [6], few have investigated the long-term outcomes of CSA-AKI [7], which is important to plan follow-up strategies and to formulate and adjust healthcare policies in China. Here, a historical cohort study of patients who underwent cardiac surgery in a tertiary general hospital in southeast China was conducted to investigate the long-term survival rate and the incidence of stages 3-5 CKD and to analyze the impact of CSA-AKI on these outcomes.…”