Stewart Campbell, Haitsma Iain, Zador Zsolt, Hemphill J Claude, Morabito Diane, Manley Geoffrey, Rosenthal Guy
Department of Surgery, San Francisco General Hospital, University of California, San Francisco, San Francisco, California 94110, USA.
Neurosurgery. 2008 Dec;63(6):1159-64; discussion 1164-5. doi: 10.1227/01.NEU.0000333265.19131.7C.
Monitoring of brain tissue oxygen tension is increasingly being used to monitor patients after severe traumatic brain injury and to guide therapies aimed at maintaining brain tissue oxygen tension above threshold levels. The new Licox PMO combined oxygen and temperature catheter (Integra LifeSciences, Plainsboro, NJ) combines measurements of oxygen tension and temperature in a single probe inserted through a bolt mechanism. In this study, we sought to evaluate the accuracy of the new Licox PMO probe under controlled laboratory conditions and to assess the accuracy of oxygen tension and temperature measurements and the new automated card calibration system. We also describe our clinical experience with the Licox PMO probe.
Oxygen tension was measured in a 2-chambered apparatus at different oxygen tensions and temperatures. The new card calibration system was compared with a manually calibrated system. Rates of hematoma, infection, and dislodgement in our clinical experience were recorded.
The new Licox PMO probe accurately measures oxygen tension over a wide range of oxygen concentrations and physiological temperatures, but it does have a small tendency to underestimate oxygen tension (mean error, -3.8 +/- 3.5%) that is more pronounced between the temperatures of 33 and 39 degrees C. The thermistor of the PMO probe also has a tendency to underestimate temperature when compared with a resistance thermometer (mean error, -0.67 +/- 0.22 degrees C). The card calibration system was also found to introduce some variability in measurements of oxygen tension when compared with a manually calibrated system. Clinical experience with the new probe indicates good placement within the white matter using the improved bolt system and low rates of hematoma (2.9%), infection (0%), and dislodgement (5.9%).
The new Licox PMO probe is accurate but has a small, consistent tendency to under-read oxygen tension that is more pronounced at higher temperatures. The probe tends to under-read temperature by 0.5 to 0.8 degrees C across temperatures, suggesting that caution should be used when brain temperature is measured with the Licox PMO probe and used to guide temperature-directed treatment strategies. The Licox PMO probe improves upon previous models in allowing consistent and accurate placement in the white matter and obviating the need for placement of 2 separate probes to measure oxygen tension and temperature.
脑组织氧分压监测越来越多地用于重度创伤性脑损伤患者的监测，并指导旨在将脑组织氧分压维持在阈值水平以上的治疗。新型Licox PMO联合氧和温度导管（英特格拉生命科学公司，新泽西州普林斯顿）通过一个螺栓装置插入的单个探头结合了氧分压和温度的测量。在本研究中，我们试图在受控实验室条件下评估新型Licox PMO探头的准确性，并评估氧分压和温度测量以及新型自动卡片校准系统的准确性。我们还描述了我们使用Licox PMO探头的临床经验。
在一个双腔装置中于不同的氧分压和温度下测量氧分压。将新型卡片校准系统与手动校准系统进行比较。记录我们临床经验中的血肿、感染和移位发生率。
新型Licox PMO探头在广泛的氧浓度和生理温度范围内能准确测量氧分压，但确实有轻微低估氧分压的倾向（平均误差为-3.8±3.5%），在33至39摄氏度之间更为明显。与电阻温度计相比，PMO探头的热敏电阻也有低估温度的倾向（平均误差为-0.67±0.22摄氏度）。与手动校准系统相比，还发现卡片校准系统在氧分压测量中引入了一些变异性。使用新型探头的临床经验表明，使用改进的螺栓系统在白质内放置良好，血肿发生率低（2.9%）、感染率低（0%）和移位率低（5.9%）。
新型Licox PMO探头准确，但有轻微且一致的低估氧分压的倾向，在较高温度下更为明显。该探头在不同温度下倾向于低估温度0.5至0.8摄氏度，这表明在使用Licox PMO探头测量脑温并用于指导温度导向治疗策略时应谨慎。Licox PMO探头在允许在白质中一致且准确地放置以及无需放置两个单独探头来测量氧分压和温度方面比以前的型号有所改进。
