Cortey A, Monin P, Hascoet J M, Hamon I, Vert P
INSERM, Unité 272 et Maternité Universitaire, Université de Nancy, France.
Biol Neonate. 1994;65(6):396-405. doi: 10.1159/000244069.
Phenobarbital (PB), at anticonvulsant dosages, has been used in an attempt to reduce hypoxic brain injury in asphyxiated newborn infants. The effects of PB pretreatment on the cerebral blood flow (CBF) response in hypoxia were studied in 15 curarized and mechanically ventilated piglets: 7 animals were pretreated with 20 mg/kg of PB (group 1) and 8 served as untreated controls (group 2). Successive aliquots (25 ml) of carbon monoxide were introduced into a closed ventilator circuit and CBF (measured with radiolabelled microspheres), arterial blood pressure, blood gases, arterial pH and PaO2 were subsequently determined at different levels of hypoxia. The amount of hemoglobin available for oxygen transport (i.e. total Hb-HbCO) was used to express hypoxic aggression and decreased from grade I (> 2 mmol/l) to grade II (1-2 mmol/l) to grade III (< 1 mmol/l). In the control group, CBF increased during grade-I hypoxia and continuously remained above baseline values during grade-II and grade-III hypoxia. In pretreated animals, however, only grade-II hypoxia was associated with a significant increase in CBF above baseline. In addition during grade-III hypoxia, CBF decreased to the prehypoxic values despite a fall in cerebral oxygen delivery and cardiac index. These data suggest that PB should be used with caution to prevent brain damage in the asphyxiated newborn infants.
苯巴比妥（PB）在抗惊厥剂量下，已被用于尝试减少窒息新生儿的缺氧性脑损伤。在15只箭毒化并机械通气的仔猪中研究了PB预处理对缺氧时脑血流量（CBF）反应的影响：7只动物用20mg/kg的PB进行预处理（第1组），8只作为未处理的对照（第2组）。将连续等分的一氧化碳（25ml）引入封闭的通气回路，随后在不同程度的缺氧情况下测定CBF（用放射性标记微球测量）、动脉血压、血气、动脉pH值和动脉血氧分压。可用于氧运输的血红蛋白量（即总Hb-HbCO）用于表示缺氧程度，从I级（>2mmol/l）降至II级（1-2mmol/l）再降至III级（<1mmol/l）。在对照组中，CBF在I级缺氧时增加，在II级和III级缺氧时持续保持高于基线值。然而，在预处理的动物中，只有II级缺氧与CBF显著高于基线值相关。此外，在III级缺氧期间，尽管脑氧输送和心脏指数下降，但CBF降至缺氧前的值。这些数据表明，在预防窒息新生儿脑损伤时应谨慎使用PB。
