Acute kidney injury following first-stage palliation in hypoplastic left heart syndrome: hybrid versus Norwood palliation

Objective: The aim of this study was to evaluate the prevalence of acute kidney injury after first-stage surgical palliation in patients with a single ventricle and to explore associated risk factors and outcomes. Design and patients: This single-centre retrospective study included neonates who underwent either Norwood or Hybrid procedure from 2008 to 2015 for a single ventricle. Postoperative acute kidney injury was defined using the paediatric risk, injury, failure, loss, end-stage renal disease (pRIFLE), criteria within 72 hours of the procedure. Main results: Our cohort (n = 48) underwent surgical palliation at a mean (SD) age of 12 (11) days. Postoperative acute kidney injury was diagnosed in 14 (29%) patients. The prevalence of acute kidney injury in the Hybrid group was 16% and 53% in the Norwood group. Infants who developed acute kidney injury underwent surgery at younger ages [6 (5-10) versus 10 (8-16) days, p = 0.016], and had a higher peak lactate level in the initial 24 hours [5.9 (4.2-9.1) versus 3.4 (2.4-6.7), p = 0.007]. Norwood procedure was significantly associated with acute kidney injury [odds ratio 11.7 (95% confidence interval 1.3-101.9), p = 0.03]. ICU stay [38 (21-84) versus 16 (6-45) days, p = 0.038] and time to extubation [204 (120-606) versus 72 (26-234) hours, p = 0.014] were longer in those with acute kidney injury. The two patients who developed early postoperative renal failure as per pRIFLE died before discharge from associated comorbidities. Conclusions: Acute kidney injury occurs in a third of the patients with single ventricle after surgical palliation but is mostly transient. Norwood, compared with Hybrid procedure, is a risk factor for postoperative acute kidney injury, which, in turn, is associated with longer ICU stay and time to extubation.