Age-related cerebrovascular carbon dioxide reactivity in children with ventricular septal defect younger than 3years.

Abstract

Impaired cerebrovascular reactivity to carbon dioxide was proposed to contribute to neurological morbidity in children undergoing cardiac surgery. The objective of this study was to assess carbon dioxide reactivity and regional cerebral oxygen saturation in children younger than 3years. This study enrolled children younger than 3years undergoing ventricular septal defect repair. The cohort was divided into three age groups: younger than 6months, 6-12months, and 12-36months. Under steady-state anesthesia, carbon dioxide reactivity was calculated by measuring changes in middle cerebral artery blood flow velocity using transcranial Doppler sonography. Regional cerebral oxygen saturation changes were measured by near-infrared spectroscopy while endtidal carbon dioxide pressure was adjusted from 30 to 45mmHg. Carbon dioxide reactivity showed a statistically significant increasing relationship with age (younger than 6months group: 4.42%±2.73%, 6-12months group: 5.86%±1.91%, 12-36months group: 7.58%±1.49%; P<.001). Regional cerebral oxygen saturation showed a statistically significant increasing relationship with age (younger than 6months group: 65%±6%, 6-12months group: 68%±5%, 12-36months group: 70%±5%; P=.027). Regional cerebral oxygen saturation showed a statistically significant increasing relationship with endtidal carbon dioxide pressure in all children (P<.001). Abnormal carbon dioxide reactivity is prevalent in children younger than 3years and the degree varies according to age.