Hypoxanthine as a Test of Perinatal Hypoxia as Compared to Lactate, Base Deficit, and pH

Abstract

SummaryThe possibility of detecting past hypoxia during the first 2 h after birth by means of blood analyses of hypoxanthine, lactate, base deficit, and pH was investigated in six infants with a 1 min Apgar score of 4 . Reference values for the four biochemical variables were obtained in 16 healthy infants with a normal 1 min Apgar score of 28. In the asphyxiated infants, elevated values for hypoxanthine were found in 48%, for lactate in 54%, and for base deficit in 46% while 21% of the pH values were lower than the reference. In the group of asphyxiated infants, significantly elevated hypoxanthine values were found during the first 20 min after birth, base deficit during 30 min, and lactate values during 120 min while lower pH values than the reference were found during the first 30 min. Significant correlations were found between hypoxanthine and lactate concentrations and also between hypoxanthine and base deficit but not between hypoxanthine and pH. It is concluded that the optimal time for detecting past intrauterine hypoxia in the newborn using the hypoxanthine test is between 10 and 20 rnin after birth, but in individual cases, significantly increased hypoxanthine concentrations may be found at any time in the 10-120 min period. We propose an equation that can be used to calculate an upper normal limit for hypoxanthine concentration in any sampling time during this period.

The relationship of hypoxia to hypoxanthine concentration during pregnancy and delivery

“…Whether an extremely high hypoxanthine concentration can be considered to indicate a risk of hypoxic brain damage [4,15] cannot be answered from the results of this study. Because the births were well-managed, the hypoxanthine concentrations in umbilical cord blood did not reach high levels.…”

“…The literature suggests that the hypoxanthine concentration relates more to postnatal than intranatal hypoxia [1,13,15].…”

“…Les distributions de frequence cumulative des naissances normales et compliquees (figure 2) ne varient pas assez pour garantir Putilisation des concentrations d'hypoxanthine dans les vaisseaux ombilicaux comme parametre de distinction entre les nouveaux-nes hypoxiques et non hypoxiques. La litterature suggere que les concentrations d'hypoxanthine depistent plus les hypoxies post-natales qu'intranatales [1,13,15].…”

Plasma hypoxanthine levels in newbom infants: A specific indicator of hypoxia

“…Since we introduced hypoxanthine measurements in plasma for evaluating hypoxia [18], several other investigators have documented that plasma hypoxanthine levels in humans reflect hypoxia [4,6,11,29,30]. It has further been established in a series of animal experiments that the hypoxanthine concentration of plasma sensitively reflects the degree and duration of hypoxia [21, 22, Hypoxanthine is the breakdown product of energy rieh nucleotides such äs ATP.…”

Measurement of purine release with microelectrode biosensors

“…A sizeable literature supports the notion that hypoxanthine is a marker of foetal hypoxia and asphyxia [82][83][84][85][86][87][88][89][90]. Continual measurement of the unborn child's heart rate during labour is currently the main tool in judging its wellbeing in utero.…”