title: Brain tissue pO2-monitoring: catheterstability and complications.
abstract: The authors report on the stability and complications of 73 LICOX brain ti-pO2-microcatheters in 70 patients. Mean monitoring time was 7.5 +/- 4.0 days. Patients prone to cerebral hypoxia (after severe head injury (GCS < 9) or a subarachnoid hemorrhage) had a ti-pO2-microcatheter inserted next to the ICP-probe in the typical frontal position. After the first 15 insertions, instead of the 3-way-screw (needing a 6 mm burrhole), a 1-way-screw (needing a 2.7 mm burrhole) was used for fixation in the bone; by doing so, the procedure can be performed in the ICU and takes only 15 min. Whenever possible a calibration at room air (to determine the sensitivity-drift) and in oxygen free solution (to determine the zero-drift) was performed after removal of the catheters. Ideally the expected pO2 at room air was around 154 mmHg (temperature dependent) and at zero calibration 0 mmHg. Mean sensitivity-drift for 54 catheters was -8.5 +/- 15.4%. Dividing the catheters into groups, depending on the duration of monitoring (1-4, 5-8 and 9-16 days), revealed that the greatest part of the (negative) sensitivity-drift occurred during day 1-4 after insertion. After 1 week of monitoring sometimes a positive drift occurred (being far less than the negative drift during the first 4 days). Compared to the old catheters (-10.3 +/- 17.3%) (on the first half of the patients) the new ones showed a lower sensitivity-drift (-6.8 +/- 13.4%). The zero-drift of 56 catheters was low with mean drift after 7.5 +/- 4.0 days of 1.5 +/- 1.5 mmHg. Here also the highest drift occurred on day 1-4 after insertion. No infection was seen and 2 times (2.7%) a small hematoma, not needing evacuation occurred. As the ti-pO2-catheter (having a smaller diameter) and the ICP-catheter were inserted at the same time, one cannot distinguish which catheter caused the hematoma. A possible explanation for the occurrence of the two hematomas is the insertion of the catheters too close to the midline. The authors conclude that LICOX ti-pO2-monitoring is a safe and reliable method. Further decrease of the complication rate and increase of the catheter-stability may be expected.
authors.affiliation: Neurosurgical Department, University of Würzburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Dings
authors.forename: J
authors.initials: J
authors.lastname: Meixensberger
authors.forename: K
authors.initials: K
authors.lastname: Roosen
mesh_terms: D001923:Brain Chemistry; D002404:Catheterization / Q000009:adverse effects* / Q000379:methods; D006259:Craniocerebral Trauma / Q000150:complications* / Q000000981:diagnostic imaging; D006406:Hematoma / Q000000981:diagnostic imaging / Q000209:etiology; D006801:Humans; D002534:Hypoxia, Brain / Q000000981:diagnostic imaging / Q000209:etiology*; D008839:Microelectrodes; D008991:Monitoring, Physiologic / Q000009:adverse effects / Q000379:methods; D010100:Oxygen / Q000032:analysis*; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000209:etiology*; D014057:Tomography, X-Ray Computed
chemical_list: D010100:Oxygen