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.