Perioperative risk factors for acute kidney injury after off-pump coronary artery bypass grafting: a retrospective study

Effect of Dexmedetomidine on Postoperative Renal Function in Patients Undergoing Cardiac Valve Surgery Under Cardiopulmonary Bypass: A Randomized Clinical Trial

OBJECTIVE

The effect of dexmedetomidine on postoperative renal function was investigated in patients undergoing cardiac valve surgery under cardiopulmonary bypass (CPB).

DESIGN

A randomized controlled trial.

SETTING

University teaching, grade A tertiary hospital.

PARTICIPANTS

A total of 70 patients scheduled to undergo cardiac valve replacement or valvuloplasty under CPB were eligible and randomly divided into groups D (n = 35) and C (n = 35) between January 2020 and March 2021.

INTERVENTIONS

Patients in group D were administered 0.6 μg/kg/h of dexmedetomidine intravenously from 10 minutes before anesthesia induction to 6 hours after surgery; normal saline was used instead of dexmedetomidine in group C.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the incidence of acute kidney injury (AKI). Acute kidney injury was defined according to the Kidney Disease Improving Global Outcomes (2012). It was 22.86% and 48.57% in groups D and C, respectively (p = 0.025). The secondary outcomes were intraoperative hemodynamics and various indices in serum. Ten minutes before CPB (T₁), 10 minutes after CPB (T₂), and 30 minutes after CPB (T₃), mean arterial pressure in group D was lower than that in group C, with statistical significance (74.94 ± 8.52 v 81.89 ± 13.66 mmHg, p=0.013; 62.83 ± 11.27 v 71.86 ± 7.89 mmHg, p < 0.001; 72.26 ± 8.75 v 78.57 ± 8.83 mmHg, p = 0.004). At T₁, the heart rate in group D was significantly lower than in group C (80.89 ± 14.04 v 95.54 ± 12.53 bpm, p=0.022). The tumor necrosis factor α, interleukin-6, C-reactive protein, and cystatin C levels in group D were lower than those in group C after the surgery (T₄) and 24 hours after surgery (T₅), with statistical significance. The duration of mechanical ventilation, intensive-care-unit stay time, and hospital stay time in group D were significantly shorter than in group C. The incidences of tachycardia, hypertension, nausea, and vomiting in group D were similar to those in group C.

CONCLUSIONS

Dexmedetomidine may be considered as a way to reduce the incidence and severity of postoperative AKI in patients undergoing cardiac valve surgery under cardiopulmonary bypass.

Predictive role of arterial lactate in acute kidney injury associated with off-pump coronary artery bypass grafting

Objectives

This observational study aims to explore the predictive role of postoperative arterial lactate in off-pump coronary artery bypass grafting (CABG)-associated acute kidney injury (AKI).

Materials and methods

A total of 500 consecutive patients who underwent off-pump CABG from August 2020 to August 2021 at the Department of Cardiovascular Surgery, Qilu Hospital of Shandong University, were included. Logistic regression analysis was used to confirm the independent risk factors of off-pump CABG-associated AKI. Receiver operating characteristic (ROC) curve was performed to evaluate the discrimination ability and Hosmer–Lemeshow goodness of fit test was performed to evaluate the calibration ability.

Results

The incidence of off-pump CABG-associated AKI was 20.6%. Female gender, preoperative albumin, baseline serum creatinine, 12 h postoperative arterial lactate and duration of mechanical ventilation were independent risk factors. The area under the ROC curve (AUC) of 12 h postoperative arterial lactate for predicting off-pump CABG-associated AKI was 0.756 and the cutoff value was 1.85. The prediction model that incorporated independent risk factors showed reliable predictive ability (AUC = 0.846). Total hospital stay, intensive care unit stay, occurrence of other postoperative complications, and 28-day mortality were all significantly higher in AKI group compared to non-AKI group.

Conclusion

12 h postoperative arterial lactate was a validated predictive biomarker for off-pump CABG-associated AKI. We constructed a predictive model that facilitates the early recognition and management of off-pump CABG-associated AKI.

Preoperative use of furosemide may increase the incidence of acute kidney injury after coronary artery bypass grafting: a propensity score-matched study

Objectives

Furosemide is usually administered before the Coronary artery bypass grafting (CABG) to improve water–sodium retention. However, no final conclusions are available on the postoperative renal outcome of furosemide. We evaluated the effect of preoperative furosemide on acute kidney injury (AKI) after CABG.

Methods

We recorded the use of furosemide 14 days before surgery in all patients who underwent CABG from 2016 to 2017. Patients were divided into furosemide (F) group and non-furosemide (NF) group according to preoperative use of furosemide. A 1:1 propensity score matching was performed. Multivariate analyses were conducted to determine risk factors for AKI after CABG.

Results

Overall, 974 patients were included in the study, of which 82 cases were complicated with postoperative AKI. The incidence of AKI was significantly increased in F group than NF group (28.9% vs. 7.4%, p = 0.000). After adjusting for risk factors, the incidence of AKI in the F group was 5.34 times more than the NF group (95% confidence interval [CI] 2.45–11.64; p = 0.000). The incidence of AKI increased significantly when the cumulative dosage of furosemide exceeded 110 mg (odds ratio [OR] 6.23; 95% CI 2.07–18.74, p = 0.001) and 250 mg (OR 8.31; 95% CI 2.87–24.02, p = 0.000). After the propensity-matching group analysis, same results were obtained.

Conclusions

The incidence of AKI after CABG was related to the use of preoperative furosemide, and it increased exponentially with the increase of cumulative dose of furosemide. This provides guidance for the dose of preoperative furosemide.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11748-021-01599-0.

Predictors of acute kidney injury in patients undergoing adult cardiac surgery

Background

Acute kidney injury (AKI) after cardiac surgery (CS) is not uncommon and has serious effects on mortality and morbidity. A majority of patients suffer mild forms of AKI. There is a paucity of Indian data regarding this important complication after CS.

Aims and Objectives

The primary objective was to study the incidence of AKI associated with CS in an Indian study population. Secondary objectives were to describe the risk factors associated with AKI-CS in our population and to generate outcome data in patients who suffer this complication.

Methods

Serial patients (n = 400) presenting for adult CS (emergency/elective) at a tertiary referral care hospital in South India from August 2016 to November 2017 were included as the study individuals. The incidence of AKI-CS AKI network (AKIN criteria), risk factors associated with this condition and the outcomes following AKI-CS are described.

Results

Out of 400, 37 (9.25%) patients developed AKI after CS. AKI associated with CS was associated with a mortality of 13.5% (no AKI group mortality 2.8%, P = 0.001 [P < 0.05]). When AKI was severe enough to need renal replacement therapy, the mortality increased to 75%. Patients with AKI had a mean hospital stay 16.92 ± 12.75 days which was comparatively longer than patients without AKI (14 ± 7.98 days). Recent acute coronary syndrome, postoperative atrial fibrillation, and systemic hypertension significantly predicted the onset of AKI-CS in our population.

Conclusions

The overall incidence of AKI-CS was 9.25%. The incidence of AKI-CS requiring dialysis (Stage 3 AKIN) AKI-CS was lower (2%). However, mortality risks were disproportionately high in patients with AKIN Stage 3 AKI-CS (75%). There is a need for quality improvement in the care of patients with AKI-CS in its most severe forms since mortality risks posed by the development of Stage 3 AKIN AKI is higher than reported in other index populations from high resource settings.

Acute Kidney Injury after Cardiac Surgery in Patients Without Chronic Kidney Disease

Introduction

Among patients undergoing cardiac surgery, the occurrence of acute renal injury appears to be associated with worse prognosis and increased mortality. The objective of this study was to evaluate risk factors and the impact this complication on mortality and survival after cardiac surgery among patients without chronic kidney disease.

Methods

In this retrospective study, we reviewed the medical records of 142 patients who underwent elective coronary artery bypass grafting, valve replacement (single or multiple), or both (simultaneously) at a tertiary care hospital.

Results

Among the 142 patients evaluated, the mean age was 58.28±13.87 years and 80 (56.33%) were female. The postoperative incidence of acute renal injury was 43.66%. Univariate analysis between the groups with and without acute renal injury revealed no significant differences, whereas multivariate analysis showed that risk factors for acute renal injury included valve replacement (OR=4.7, P=0.002, 95% CI=1.76-12.62, age (OR=1.044, P=0.012, 95% CI=1.01-1.07), previous cardiac surgery (OR=36.1, P=0.015, 95% CI=1.99-653.85), postoperative use of the vasoactive drug norepinephrine (OR=3.32, P=0.013, 95% CI=1.29-8.58) and dobutamine (OR=5.3, P=0.019, 95% CI=1.32-21.64). In our sample, there were 30 deaths, of which 25 had acute kidney injury. Survival was also lower among the patients with this complication, especially those who had required hemodialysis (OR=2.60, P<0.001, 95% CI=1.01-6.70) or had previously undergone cardiac surgery (OR=3.68, P<0.001, 95% CI=1.09-12.37).

Conclusion

Our findings underscore the importance of identifying risk factors for developing acute renal injury after cardiac surgery, which can further the development of effective renoprotective strategies.

Fluids and Organ Dysfunction: A Narrative Review of the Literature and Discussion of 5 Controversial Topics

Evidence-based clinical decision making is at the forefront of modern cardiothoracic anesthesia practice. Therefore, as a field, cardiac anesthesiologist should strive to ensure that the available evidence is of the highest possible quality. In this narrative review, 5 important topics that the authors believe require additional investigation in cardiothoracic anesthesia and critical care related to fluid therapy and organ dysfunction are outlined briefly. In particular, the authors believe that the areas of pulmonary artery catheter use, restrictive versus liberal transfusion strategies, cardiopulmonary bypass prime composition, colloid use in resuscitation and its effects on acute kidney injury, and management of acute kidney injury after cardiac surgery hold many unanswered questions and opportunities for continued improvement in the specialty of cardiac anesthesia. This article accompanies a presentation at the 46th Association of Cardiac Anesthesiologists Annual Meeting on October 22, 2017.