Variability of Cerebral Hemoglobin Concentration in Very Preterm Infants During the First 6 Hours of Life
Part of the
Advances in Experimental Medicine and Biology
book series (AEMB, volume 566)
Cerebral hemoglobin concentration (cHbc), a major determinant of oxygen transport capacity in the brain, shows a considerable variability due to physiological and methodological factors. In order to determine the (relative) contribution of these factors, the cHbc variability within the first 6 hours of life was studied in 28 very preterm infants using near infrared spectrophotometry (NIRS). Mean cHbc values were 46.4 ± 14.1 µmol/1 (2.75 ± 0.84 ml/100 g). Is the variability in cHbc related to the methodology of cHbc measurements or to physiological variables? A statistical model of stepwise regression (backward selection) with 13 independent variables and with cHbc as a dependent variable showed that, from the total variability of ± 14.1 µmol/1, only 3.7 µmol/1 (26%) were of methodological origin, while the major portion, 9.3 µmol/1 (66%) were related to four physiological variables: birth weight, gestational age, blood glucose and transcutaneous carbon dioxide tension. The remaining 1.1 µmol/1 (7.8%) were unexplained.
We conclude that NIRS, which allows continuous monitoring of cerebral oxygenation and metabolism even in the first hours of postnatal life, is a valid technique to measure cHbc in very preterm infants. The major portion of the large variability of early cHbc registrations can be attributed to physiological factors.
KeywordsBirth Weight Preterm Infant Physiological Variable Cerebral Blood Volume Cerebral Oxygenation
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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