Measuring jugular bulb venous oxygen saturation (SjvO_(2) for cerebral oxygen balance is reported to be a effective monitoring. But it is questioned that reduction in SjvO_(2), can explain or predict brain injury. In this study, the author evaluated superior sagittal sinus oxygen saturation and the cortical somatosensory evoked potential(SSEP) in 21 cats with induced brain ischemia.
The cats were randomly divided into 3 groups in group Ⅰ (n=7), brain ischemia was induced for 5 minutes, in group Ⅱ (n=7) for 15 minutes and in group Ⅲ (n=7) for 30 minutes. Ischemia was induced by the intrathoracic occlusion of the innominate, the left subclavian and both mammarian arteries, and additionally the mean arterial blood pressure was maintained around 60 mmHg. Arterial blood pressure, heart rate, central venous pressure, arterial blood gases and superior sagittal sinus blood gases were evaluated before, during ischemia and 90 minutes after reperfusion. Cortical SSEP was recorded also before ischemia and 90 minutes after reperfusion.
The results were as follows :
1. Six of 7 cats in group Ⅰ , four of 7 cats in group Ⅱ and none in group Ⅲ showed return of SSEP after 90 minutes of reperfusion. The amplitude was 43.1±7.7% and 15.7±5.9% of preischemia level in group Ⅰ and Ⅱ, respectively and there was significant difference between two groups (p<0.05).
2. During ischemia, superior sagittal sinus PCO, was abruptly increased to 102.5±31.6, 121.8±26.4, 116.6±48.5 mmHg in group Ⅰ , Ⅱ and Ⅲ respectively(p(0.05). pH was decreased to 6.99±0.13, 6.8320.09, 6.83±0.14 in group Ⅰ, Ⅱ and Ⅲ respectively (p<0.05).
3. During ischemia, superior sagittal sinus oxygen saturation was decreased to 42. I±11.1, 21.8±12.5, 26.5±9.2 % in group Ⅰ, Ⅱ and Ⅲ respectively (p<0.05) and there was significant difference between group Ⅱ and group Ⅱ (p<0.05).
The above results suggest that measuring the superior sagittal sinus oxygen saturation can be a useful monitoring method for prediction of neural injury in cats with brain ischemia. But further study for cerebral venous blood sampling is needed.
더보기
|