The effects of induced apneic episodes on cerebral cortical oxygenation in newborn piglets

Outi K T Tammela, Nasser Lajevardi, Chao Ching Huang, David F. Wilson, Maria Delivoria-Papadopoulos, Anna Pastuszko

研究成果: 雜誌貢獻文章同行評審

10 引文 斯高帕斯(Scopus)


The effect of different inspiratory oxygen levels (FiO2) on cortical oxygenation (pO2) during and after recovery from apnea, was investigated in 18 anesthetized, paralyzed, and mechanically ventilated newborn piglets. Heart rate (HR) and mean arterial blood pressure (MABP) were continuously monitored as the piglets were subjected to repeated episodes of apnea initiated by disconnecting the ventilator and terminated when HR decreased to less than 80 beats/min by reconnecting the ventilator. A closed cranial window was placed over the parietal cortex of the animals and cortical pO2 was measured optically by phosphorescence quenching. Apneic episodes induced in animals ventilated with 15%, 22% and 40% oxygen had mean duration's of apnea (time before HR decreased to less than 80 beats/min) of 80, 128 and 134 s, respectively. By the end of the apnea the MABP decreased to 82%, 64%, and 54% of control, respectively. The cortical pO2 decreased from control values of 24.1, 32.3 and 38.3 Torr at 15%, 22% and 40% oxygen, respectively, to 1.7 to 3.2 Torr at the end of the apneic episode. The duration of apnea necessary for the cortical pO2 to drop below 20.3 Torr was 18, 44 and 81 s at 15%, 22% and 40% oxygen, respectively. There was an inverse correlation between the rate of decline of cortical pO2 and baseline FiO2 levels. With reventilation, the cortical pO2 reached maximal values of 42.8, 51.9 and 57.2 Torr at 15%, 22%, and 40% oxygen, respectively, before returning to the pre-apnea values. The present results show that apnea of less than 30 s duration at an FiO2 of 22% do not result in significant cortical hypoxia in hemodynamically stable piglets. Increasing the FiO2 to above 22% may possibly increase the rate of recovery of tissue oxygenation but it also may facilitate post-hypoxic cortical hyperoxia, a factor that may predispose the immature brain to free radical injury.

頁(從 - 到)160-165
期刊Brain Research
出版狀態已發佈 - 11月 25 1996

ASJC Scopus subject areas

  • 神經科學 (全部)


深入研究「The effects of induced apneic episodes on cerebral cortical oxygenation in newborn piglets」主題。共同形成了獨特的指紋。