Dings J, Meixensberger J, Jäger A, Roosen K
Department of Neurosurgery, University of Würzburg, Germany.
Neurosurgery. 1998 Nov;43(5):1082-95. doi: 10.1097/00006123-199811000-00045.
We assessed the technical and diagnostic reliability of partial pressure of oxygen (PO2) of brain tissue (P(ti)O2) monitoring. The monitoring system and the catheter probes were tested in vitro, and clinical experiences obtained with 118 brain P(ti)O2 catheter probes, used in 101 patients, are reported.
The polarographic (LICOX; Medical Systems Corp., Greenvale, NY) P(ti)O2 catheter probe lies 22 to 27 mm below the dura level; its PO2-sensitive surface is 7.1 mm2. For 10 patients, the adaptation time (with initially unreliable signals after insertion) was determined. For 27 patients, the probe was removed in a stepwise fashion (three increments of 5 mm) and the heterogeneity of brain P(ti)O2 levels was investigated. After removal of the catheter probes, their PO2 and zero display error values were determined and compared with probe performance data obtained in vitro with unused PO2 catheter probes.
Small iatrogenic hematomas were observed for two patients (1.7%). No infection occurred after 6.7 +/- 3.9 days (mean +/- standard deviation) of monitoring. The technical complication (dislocation or defect) rate was 13.6%. The mean adaptation time was 79.0 +/- 51.7 min. A flow chart is presented, which helps to rule out artifacts. The mean P(ti)O2 measured at 22 to 27 mm below the dura was 23.8 +/- 8.1 mm Hg, at 17 to 22 mm was 25.7 +/- 8.3 mm Hg, at 12 to 17 mm was 33.0 +/- 13.3 mm Hg (P < 0.01, compared with the initial value), and at 7 to 12 mm was 33.3 +/- 13.3 mm Hg (P < 0.01). Recent catheter probe versions exhibited a PO2 display error of -1.2 +/- 5.1% (mean +/- standard deviation, n = 38) and a mean zero display error of 1.1 +/- 0.9 mm Hg (n = 34). The greatest PO2 display errors were measured during the first 4 days of continuous monitoring. In the in vitro test (of 12 unused catheter probes), the maximal probe display error was 1.07 +/- 2.14%, tested at temperatures between 22 degrees C and 37 degrees C and tested at oxygen pressures of 0, 44, and 150 mm Hg. In vitro, the zero display error was -0.21 +/- 0.25 mm Hg.
Brain P(ti)O2 monitoring, reflecting an area 17 to 27 mm below the dura, is a safe and reliable technique for monitoring cerebral oxygenation. Excluding the first 1 hour after insertion, data are reliable, with almost 100% good data quality.
我们评估了脑组织氧分压（P(ti)O2）监测的技术可靠性和诊断可靠性。对监测系统和导管探头进行了体外测试，并报告了在101例患者中使用118个脑P(ti)O2导管探头所获得的临床经验。
极谱法（LICOX；Medical Systems Corp.，纽约州格林维尔）P(ti)O2导管探头位于硬脑膜水平以下22至27毫米处；其对PO2敏感的表面面积为7.1平方毫米。对10例患者确定了适应时间（插入后最初信号不可靠）。对27例患者逐步取出探头（每次增加5毫米，分三步），并研究脑P(ti)O2水平的异质性。取出导管探头后，确定其PO2和零显示误差值，并与未使用的PO2导管探头在体外获得的探头性能数据进行比较。
观察到2例患者（1.7%）出现小的医源性血肿。监测6.7±3.9天（平均±标准差）后未发生感染。技术并发症（移位或缺陷）发生率为13.6%。平均适应时间为79.0±51.7分钟。给出了一个流程图，有助于排除伪影。在硬脑膜以下22至27毫米处测得的平均P(ti)O2为23.8±8.1毫米汞柱，在17至22毫米处为25.7±8.3毫米汞柱，在12至17毫米处为33.0±13.3毫米汞柱（与初始值相比，P<0.01），在7至12毫米处为33.3±13.3毫米汞柱（P<0.01）。最近的导管探头版本显示PO2显示误差为-1.2±5.1%（平均±标准差，n = 38），平均零显示误差为1.1±0.9毫米汞柱（n = 34）。最大的PO2显示误差是在连续监测的前4天测得的。在体外测试（12个未使用的导管探头）中，在22℃至37℃的温度下以及在0、44和150毫米汞柱的氧压下测试，最大探头显示误差为1.07±2.14%。在体外，零显示误差为-0.21±0.25毫米汞柱。
反映硬脑膜以下17至27毫米区域的脑P(ti)O2监测是一种安全可靠的脑氧合监测技术。排除插入后最初1小时的数据，数据可靠，数据质量几乎100%良好。
