Non-invasive assessment of cerebral oxygen metabolism following surgery of congenital heart disease

OBJECTIVES Cerebral protection is a major issue in the treatment of infants with complex congenital heart disease. We tested a new device combining tissue spectrometry and laser Doppler flowmetry for non-invasive determination of cerebral oxygen metabolism following cardiac surgery in infants. METHODS We prospectively measured regional cerebral oxygen saturation cSO 2 and microperfusion (rcFlow) in 43 infants 12-24 h following corrective ( n = 30) or palliative surgery ( n = 13) of congenital heart defects. For comparison, cerebral blood flow (CBF) was determined by colour duplex sonography of the extracranial cerebral arteries. Cerebral fractional tissue oxygen extraction, approximated cerebral metabolic rate of oxygen (aCMRO 2 ) and cerebral metabolic rate of oxygen (CMRO 2 ) were calculated. RESULTS cSO 2 was lower [54.6% (35.7-64.0) vs 59.7% (44.5-81.7); P