The severity of hypoxic-ischemic encephalopathy correlates with multiple organ dysfunction in the hypothermia era

Abstract

Objectives: The objectives are to 1) determine whether there is a positive correlation between the severity of hypoxic-ischemic encephalopathy and multiple organ dysfunction and 2) evaluate the organ dysfunction pattern in infants with hypoxic-ischemic encephalopathy in the hypothermia era. Design: Retrospective observational study of prospective data collected between April 2009 and December 2012. Setting: The study took place in the neonatal ICU of Hospital Sant Joan de Déu–Hospital Clínic of Barcelona. Patients: Prospective consecutive newborns with greater than or equal to 36 weeks of gestation, greater than or equal to 1,800 g of weight at birth, and a diagnosis of hypoxic-ischemic encephalopathy was included. Interventions: Severity of hypoxic-ischemic encephalopathy was established before starting controlled hypothermia. Six organ systems and 23 clinical and laboratory variables were studied by means of an asymmetrical grading scale. Data were recorded daily during the first 72 hours of life. Measurements and Main Results: Seventy-nine patients were studied. All presented with multiple organ dysfunction on day 1. There were differences in the number of affected organs on day 1 according to hypoxic-ischemic encephalopathy stage (p < 0.001). Scale scores correlated positively with the severity of hypoxic-ischemic encephalopathy (area under the curve ranged from 0.77 to 0.87 on every day studied). There were significant differences in the severity of dysfunction of each organ system among the three hypoxic-ischemic encephalopathy stages (p < 0.05). Although the most frequently involved were hepatic and pH and electrolyte imbalance, the most severely affected were the respiratory and cardiovascular systems. Conclusions: In the hypothermia era, multiple organ dysfunction continues to be almost universal in newborns with hypoxic-ischemic encephalopathy. There is a high correlation between the severity of hypoxic-ischemic encephalopathy and multiple organ dysfunction during the first 3 days of life. A high index of suspicion of relevant multiple organ dysfunction is required in infants admitted with a diagnosis of severe hypoxic-ischemic encephalopathy. Patients with moderate hypoxic-ischemic encephalopathy present wide variability in the severity of multiple organ dysfunction. In the absence of multiple organ dysfunction, a perinatal hypoxic-ischemic origin of acute severe neonatal encephalopathy should be carefully reconsidered.