RESUMO
To assess the value of cord plasma arginine vasopressin [AVP] as an index of perinatal hypoxia, we studied 28 acutely asphxiated neonates with 5 minute Apgar score < 6 and/or umbilical arterial pH < 7.05 as well as 12 neonates whose mothers suffered from severe pre-eclampsia during pregnancy representing the chronic hypoxia group. AVP values in both groups were compared with cord blood control values obtained from 12 healthy neonates. AVP was correlated to cord arterial blood gases and pH as well as 5 minute Apgar score in the same group. In the acute asphyxia group, cord plasma AVP was significantly increased than the control group [P < 0.001]. Umbilical arterial PaO2 and pH were significantly decreased and PaCO2 was significantly increased [P < 0.001] in comparison to control group. Cord plasma AVP correlated significantly with umbilical arterial PaO2 [r = -0.38, P < 0.001], pH [r = -0.37, P < 0.001] and PaCO2 [r = 0.34, P < 0.05]. In the chronic hypoxia group AVP was insignificantly changed from the control value [P > 0.05]. Arterial PaO2, PaCO2 and pH were also insignificantly changed from control values [P > 0.05]. AVP did not correlate with core arterial blood gases or pH, AVP with Apgar score neither in the acute asphyxia nor chronic hypoxia group. Also pH did not correlate with Apgar score in either group. We concluded that cord plasma AVP is an index for acute asphyxia but not for chronic hypoxia. and recommend its evaluation as a predictor of neurologic outcome in severe acute as phyxia