Acute kidney injury after Fontan completion: Risk factors and outcomes

Abstract

Objective: Acute kidney injury (AKI) is a predictor of outcomes in heterogeneous populations of children undergoing cardiac surgery. We investigated its causes and consequences in a cohort undergoing Fontan completion, hypothesizing that central venous pressure is independently associated with development of AKI.Methods: In this retrospective cohort study of patients undergoing Fontan (n ¼ 211), univariable and multivariable analyses identified factors associated with AKI within 3 days of surgery. Secondary analyses identified factors associated with hospital length of stay, and examined effects of perioperative kidney injury on follow-up renal function.Results: Acute kidney injury occurred in 42% of cases (n ¼ 89), with the following independent risk factors: mean renal perfusion (mean arterial minus central venous) pressure on postoperative day zero (per mm Hg; adjusted odds ratio [AOR] 0.83; P < .001); preoperative atrioventricular valve regurgitation > mild (AOR 6.78; P ¼ .02); bypass time (per 10 minutes, AOR 1.08; P ¼ .04); peak inotrope score on postoperative day zero (per point, AOR 1.17; P < .001); and preoperative pulmonary vascular resistance (per Wood unit, AOR 1.69; P ¼ .04). Central venous pressure was not independently associated with AKI. Moderate and severe (but not mild) AKI were independently associated with prolonged hospital length of stay (adjusted hazard ratios, 0.56; P ¼ .004, and .41; P ¼ .006, respectively). Perioperative injury was not associated with longer-term renal dysfunction.Conclusions: Acute kidney injury is common after Fontan completion and has several potentially modifiable risk factors. Moderate-to-severe injury is associated with longer hospital length of stay but not with renal dysfunction at follow-up. (J Thorac Cardiovasc Surg 2015;150:190-7) Effect of acute kidney injury on length of stay after Fontan completion. Central MessageAcute kidney injury is common after Fontan completion, and moderate-to-severe AKI predicts longer hospital length of stay. Injury seems to be mediated more by systemic hypotension than by central venous hypertension. Maintaining postoperative renal perfusion pressure while moderating inotrope use might reduce risk of injury and thus length of stay. PerspectiveAcute kidney injury in adults undergoing cardiac surgery is strongly associated with adverse outcomes. The importance of cardiac surgery-associated AKI in children is less clear. Patients undergoing Fontan completion face an acute rise in renal venous pressure and thus comprise an appealing model population. Acute kidney injury is common after the Fontan procedure, and moderate-to-severe AKI predicts longer hospital length of stay. Lower renal perfusion pressure and higher peak inotrope score are independent risk factors for AKI, whereas higher central venous pressure is not. This study provides important insight on the pathophysiology of AKI, and suggests strategies to mitigate AKI in this population.

Comparison of creatinine and cystatin C for estimation of glomerular filtration rate in pediatric patients after Fontan operation

“…The Fontan operation is a palliative procedure that creates a circulatory system characterized by elevated central venous pressures and results in a host of comorbidities. Central venous hypertension and low cardiac output have been shown to decrease renal perfusion in this cohort . Cardiopulmonary bypass itself is a risk factor for acute kidney injury.…”

“…Cardiopulmonary bypass itself is a risk factor for acute kidney injury. As a result, acute kidney injury following the Fontan operation is a common occurrence, ranging from 42% to 52% of patients . The presence of acute kidney injury following the Fontan procedure is associated with greatly increased morbidity, including prolonged mechanical ventilation and increased length of hospital stay .…”

“…KIRELIK Et aL. in this cohort. 1 Cardiopulmonary bypass itself is a risk factor for acute kidney injury. As a result, acute kidney injury following the Fontan operation is a common occurrence, ranging from 42% to 52% of patients.…”

“…As a result, acute kidney injury following the Fontan operation is a common occurrence, ranging from 42% to 52% of patients. 1,2 The presence of acute kidney injury following the Fontan procedure is associated with greatly increased morbidity, including prolonged mechanical ventilation and increased length of hospital stay. 2 Fontan survivors are also at increased risk for developing chronic kidney disease later on in life with a prevalence of up to 50% after 10 years.…”

Acute kidney injury after Fontan completion: Risk factors and outcomes “The good, the bad, and the ugly”

“…Why is this study 1 interesting and what is the relevance to a surgical audience? Most (96%) of the patients had only mild or moderate AKI that resolved without identifiable sequelae at 1 year.…”