Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Department of Neurology, St. Josefs-Krankenhaus, Potsdam, Germany.
Eur J Neurol. 2019 Jun;26(6):887-892. doi: 10.1111/ene.13903. Epub 2019 Feb 3.
Here, we studied the safety of apnea testing (AT) for the determination of brain death with regard to intracranial pressure (ICP), cerebral perfusion and arterial blood gas parameters. We hypothesized that ICP only increases when cerebral perfusion pressure (CPP) remains positive during AT.
A total of 34 patients who fulfilled brain death criteria were identified by chart review (2009-2017). We analysed ICP, CPP and mean arterial pressure (MAP) prior to AT, during AT and after AT, as well as arterial pH, paCO , paO and arterial O saturation at the start and end of AT.
Intracranial pressure was 87.9 ± 17.7 mmHg (mean ± SD) prior to AT, 89.9 ± 17.2 mmHg during AT and 86.4 ± 15.2 mmHg after AT (P = 0.9). CPP was -6.9 ± 12.8 mmHg prior to AT, -7.1 ± 13.7 mmHg during AT and -8.6 ± 13.0 mmHg after AT (P = 0.98), respectively. MAP was 82.9 ± 14.6 mmHg prior to AT, 84.7 ± 13.9 mmHg during AT and 79.7 ± 9.6 mmHg after AT (P = 0.57), respectively. A total of 10 patients had positive CPP (8.6 ± 4.3 mmHg), but ICP did not increase during AT. Arterial pH decreased from 7.43 ± 0.06 to 7.22 ± 0.06 (P < 0.05), paCO increased from 38.6 ± 4.2 to 69.6 ± 8.0 mmHg (P < 0.05), paO decreased from 416.3 ± 113.4 to 289.2 ± 146.5 mmHg (P < 0.05), and O saturation was stable at 99.8 ± 0.4% and 98.2 ± 3.2% (P = 0.39).
Apnea testing had no detrimental effect on ICP, CPP, MAP or oxygenation, regardless of the presence of an initially positive CPP. The lack of further ICP elevations is presumably explained by critical closing pressures above individual CPP levels during AT.
在这里，我们研究了颅内压（ICP）、脑灌注和动脉血气参数方面的呼吸暂停试验（AT）在确定脑死亡时的安全性。我们假设，只有在 AT 期间脑灌注压（CPP）保持正值时，ICP 才会升高。
通过图表回顾，确定了 34 名符合脑死亡标准的患者（2009-2017 年）。我们分析了 AT 前、AT 期间和 AT 后的 ICP、CPP 和平均动脉压（MAP），以及 AT 开始和结束时的动脉 pH、paCO 、paO 和动脉 O 饱和度。
AT 前的颅内压为 87.9 ± 17.7mmHg（平均值 ± 标准差），AT 期间为 89.9 ± 17.2mmHg，AT 后为 86.4 ± 15.2mmHg（P = 0.9）。CPP 在 AT 前为 -6.9 ± 12.8mmHg，在 AT 期间为 -7.1 ± 13.7mmHg，在 AT 后为 -8.6 ± 13.0mmHg（P = 0.98）。MAP 在 AT 前为 82.9 ± 14.6mmHg，在 AT 期间为 84.7 ± 13.9mmHg，在 AT 后为 79.7 ± 9.6mmHg（P = 0.57）。有 10 名患者的 CPP 为阳性（8.6 ± 4.3mmHg），但在 AT 期间 ICP 并未升高。动脉 pH 值从 7.43 ± 0.06 降至 7.22 ± 0.06（P < 0.05），paCO 从 38.6 ± 4.2mmHg 升至 69.6 ± 8.0mmHg（P < 0.05），paO 从 416.3 ± 113.4mmHg 降至 289.2 ± 146.5mmHg（P < 0.05），O 饱和度在 99.8 ± 0.4%和 98.2 ± 3.2%之间保持稳定（P = 0.39）。
无论初始 CPP 是否为阳性，呼吸暂停试验对 ICP、CPP、MAP 或氧合均无不良影响。在 AT 期间，个体 CPP 水平以上存在临界关闭压力，这可能解释了为什么 ICP 不再升高。
