Near-infrared spectroscopy cerebral XXXX saturation thresholds for @entity519 -ischemia in piglets.

@entity32749 @entity871 @entity26 @entity7853 @entity519 @entity880 @entity432 @entity855
Detection of @entity7853 remains problematic in neonates. Near-infrared spectroscopy, a noninvasive bedside technology has potential, although thresholds for @entity7853 have not been defined. This study determined @entity519 -ischemic thresholds for cerebral @entity26 saturation ( @entity32749 ) in terms of EEG, brain @entity855 , and @entity880 concentrations, and compared these values with CBF and sagittal sinus @entity26 saturation (SVO2). Sixty anesthetized piglets were equipped with near-infrared spectroscopy, EEG, laser-Doppler flowmetry, and a sagittal sinus catheter. After baseline, @entity32749 levels of less than 20%, 20% to 29%, 30% to 39%, 40% to 49%, 50% to 59%, 60% to 79%, or 80% or greater were recorded for 30 minutes of normoxic normocapnia, hypercapnic @entity871 , or bilateral @entity432 with or without arterial @entity519 . Brain @entity855 and @entity880 concentrations were measured biochemically. Logistic and linear regression determined the @entity32749 , CBF, and SVO2 thresholds for abnormal EEG, @entity855 , and @entity880 findings. Baseline @entity32749 was 68 + 5%. The @entity32749 thresholds for increased @entity880 , minor and major EEG change, and decreased @entity855 were 44 +/- 1%, 42 +/- 5%, 37 +/- 1%, and 33 +/- 1%. The @entity32749 correlated linearly with SVO2 (r = 0.98) and CBF (r = 0.89), with corresponding SVO2 thresholds of 23%, 20%, 13%, and 8%, and CBF thresholds (% baseline) of 56%, 52%, 42%, and 36%. Thus, @entity7853 near-infrared spectroscopy thresholds for functional impairment are @entity32749 33% to 44%, a range that is well below baseline @entity32749 of 68%, suggesting a buffer between normal and dysfunction that also exists for CBF and SVO2.
