Objectives: There are no studies in pediatrics evaluating the progression of acute kidney injury in septic shock. We investigated the evolution of sepsis-associated acute kidney injury and its association with systemic hemodynamics in children with fluid-refractory septic shock.
Design: Prospective cohort study.
Setting: PICU of a tertiary care hospital.
Patients: All patients with fluid-refractory septic shock (n = 61) between September 2010 and February 2014.
Interventions: Hemodynamic variables using noninvasive ultrasound cardiac output monitor were measured at admission and 6 hourly thereafter till 48 hours. We used the Kidney Disease: Improving Global Outcomes criteria to define and stage acute kidney injury. Associations between various hemodynamic variables and development of acute kidney injury were evaluated. Severe acute kidney injury was defined as stage 2 or 3 acute kidney injury and was compared with no acute kidney injury or stage 1 acute kidney injury.
Measurements and main results: Severe acute kidney injury developed in 29.5% (n = 18) of the 61 children with fluid-refractory septic shock, whereas 43 patients (70.49%) had either no or stage 1 acute kidney injury. Most patients who developed acute kidney injury did so within the first 48 hours of PICU admission. Severe acute kidney injury conferred a three-fold increased risk of death by day 28 (hazard ratio, 3.23; 95% CI, 1.52-6.67; p = 0.002), longer ICU stay, and increased duration of mechanical ventilation. Central venous pressure at presentation was higher in severe acute kidney injury by 5 cm H2O. Highest lactate in the first 24 hours of PICU admission, low diastolic blood pressure, low systemic vascular resistance index at admission were associated with severe acute kidney injury. This model reliably predicted stage 2/3 acute kidney injury by day 3 with area under the curve equals to 94%; 95% CI, 88.3-99.99. None of the other hemodynamic variables showed any association with severe acute kidney injury.
Conclusions: Manifestations of sepsis-associated acute kidney injury often occur early after PICU admission and is associated with increased morbidity and mortality. There is a need to develop a predictive model in septic shock which could facilitate early detection of acute kidney injury.