Achenbach-Ng J, Siao T C, Mavroudakis N, Chiappa K H, Kiers L
Department of Neurology, Massachusetts General Hospital, Boston 02114.
J Clin Neurophysiol. 1994 Mar;11(2):220-5. doi: 10.1097/00004691-199403000-00007.
There are few data in the EEG literature describing the time course of hyperventilation-(HV) induced changes in blood gases, despite this being a routine activating procedure. We studied changes in blood gases and EEG in nine normal adult subjects before, during, and after HV. The mean PCO2 fell 18 mm Hg from the baseline during HV and recovered in 7 min. The mean PO2 rose 7 mmHg during HV and fell to 25 mm Hg below baseline 5 min after HV. The PCO2 recovery period is longer than is usually assumed in clinical EEG. The PO2 fall to a nadir at 5 min after the end of HV suggests that close attention should be paid to this period, as is confirmed by the re-buildup seen in moyamoya disease. Despite uniform changes in blood gases, the EEG median power frequency change showed marked variability; on average, it dropped by 1 Hz during HV and returned to baseline within 2 min of resumption of normal respiration. The EEG root-mean-square power showed a 200% increase during HV and also had returned to normal within 2 min.
尽管过度换气（HV）是一种常规的激活程序，但脑电图文献中很少有描述HV诱导的血气变化时间进程的数据。我们研究了9名正常成年受试者在HV之前、期间和之后的血气和脑电图变化。HV期间，平均二氧化碳分压（PCO₂）较基线下降了18毫米汞柱，并在7分钟内恢复。HV期间，平均氧分压（PO₂）上升了7毫米汞柱，并在HV后5分钟降至比基线低25毫米汞柱。PCO₂恢复期比临床脑电图中通常假设的要长。HV结束后5分钟时PO₂降至最低点，这表明应密切关注这一时期，烟雾病中见到的再蓄积现象证实了这一点。尽管血气有一致的变化，但脑电图中位功率频率变化显示出明显的变异性；平均而言，HV期间下降了1赫兹，并在恢复正常呼吸后2分钟内恢复到基线。脑电图均方根功率在HV期间增加了200%，也在2分钟内恢复正常。
