Ability of the surgical Apgar score to predict acute kidney injury following radical cystectomy.

PURPOSE

Acute kidney injury (AKI) is a common complication after radical cystectomy (RC). Previous literature has shown that intraoperative hemodynamic instability measured via the surgical Apgar score is an independent predictor of major complications following RC. We sought to determine whether the surgical Apgar score is predictive of postoperative AKI.

METHODS

We performed a retrospective review of RC patients at our institution from 2010 to 2017. Intraoperative hemodynamic instability was captured via the Apgar score based on the lowest intraoperative mean arterial blood pressure, lowest heart rate, and estimated blood loss. Patients were divided into 3 groups: high-risk (HR; Apgar ≤4), intermediate-risk (IR; Apgar score 5-6), and low-risk (LR; Apgar score ≥7). AKIs were graded according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria. High grade AKIs were defined as KDIGO grade 2 or 3. Categorical variables were assessed using the Pearson Chi-Square test, quantitative with the Kruskal-Wallis test, and multivariable logistic regression to identify predictors of AKI and high grade AKIs within 30 days of RC.

RESULTS

Eight hundred and seventy-three patients were included with a median follow-up of 35 months. AKI within 30 days was observed in 28% of patients. Predictors of AKI within 30 days on adjusted analysis included IR (OR: 1.83, P = 0.002) and HR (OR: 3.53, P < 0.001) Apgar scores. IR (OR: 2.23, P = 0.007) and HR (OR: 4.87, P < 0.001) Apgar scores were also predictors of high-grade AKIs.

CONCLUSION

Intraoperative hemodynamic instability measured via the Apgar score can be predictive of AKI, which can guide individualized fluid management in the postoperative period.