Risk factors for acute kidney injury after pediatric cardiac surgery: a meta-analysis

Background Cardiac surgery-associated acute kidney injury (AKI) is associated with increased morbidity and mortality in both adults and children. Objectives This study aimed to identify clinical risk factors for AKI following cardiac surgery in the pediatric population. Data sources PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for studies published by August 2020. Study eligibility criteria Studies were included if (1) the population consisted of pediatric patients (< 18 years old), (2) patients underwent cardiac surgery, (3) risk factors were compared between patients who developed AKI and those who did not, and (4) studies were prospective or retrospective observational studies or randomized controlled trials. Participants and interventions Children undergoing pediatric cardiac surgery. Study appraisal and synthesis methods Random-effects meta-analysis was performed, comparing potential risk factors between pediatric patients who developed CS-AKI and those who did not. Results Sixty-one publications including a total of 19,680 participants (AKI: 7257 participants; no AKI: 12,423 participants) were included from studies published between 2008 and 2020. The pooled estimated incidence of AKI was 34.3% (95% confidence interval 30.0–38.8%, I 2 = 96.8%). Binary risk factors that were significantly and consistently associated with AKI were the presence of pulmonary hypertension, cyanotic heart disease, univentricular heart, risk adjustment for congenital heart surgery 1 (RACHS-1) score ≥ 3, vasopressor use, cardiopulmonary bypass use, reoperation, and sepsis. Significant continuous risk factors included younger age, lower body weight, lower preoperative creatinine, higher preoperative estimated glomerular filtration rate (eGFR), higher RACHS-1 score, longer surgery time, longer cardiopulmonary bypass time, longer aortic cross-clamp time, and higher red blood cell transfusion volume. Limitations Results are limited by heterogeneity and potential residual confounding. Conclusions and implications of key findings Our meta-analysis identified clinical risk factors that are associated with AKI in children undergoing cardiac surgery. This might help clinicians anticipate and manage more carefully this population and implement standardized preventive strategies. Systematic review registration number CRD42021262699. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information.