摘要
To study the effect of hyperventilation on brain tissue oxygen pressure (P ti O 2) , brain tissue carbon dioxide pressure (P ti CO 2) , pH value and intracranial pressure (ICP) during intracranial hypertension in pigs. Methods: Autologous arterial blood ( 5.5 ml± 0.5 ml) was injected into the left frontal lobe by micropump to establish the model of intracerebral hematoma in pigs. After blood injection, the animals were hyperventilated for 15 minutes to decrease the pressure of carbon dioxide in arterial blood ( P aCO 2 ) to 27.35 mm*!Hg ± 11.97 mm*!Hg (1 mm*!Hg= 0.133 kPa). The mean arterial pressure (MAP), intracranial pressure (ICP), cerebral perfusion pressure (CPP), P ti O 2 , P ti CO 2 , pH value and [HCO 3 -] were continuously monitored and the blood gas was analyzed. Results: After hyperventilation, the ICP significantly decreased (P< 0.01 ), the CPP significantly increased (P< 0.05 ), while the P ti O 2 greatly decreased to the ischemic level ( 8.20 mm*!Hg± 2.50 mm*!Hg) (P< 0.01 ), the P ti CO 2 decreased (P< 0.01 ) and the pH value increased (P< 0.01 ). At the same time, blood gas analysis showed that the P aCO 2 greatly decreased and the pH value increased. Conclusions: Hyperventilation can decrease the ICP and the P ti O 2 significantly. Therefore, hyperventilation should be avoided early after brain injury. The P ti O 2 monitoring will be helpful for detecting cerebral ischemia early.
