[Post-monitoring changes in zero drift of "Codman" intracranial pressure sensors]

The purpose of the study was to estimate the drift of the zero value of "Codman" intracranial pressure sensors, compared with the duration of monitoring, location of intracranial pressure sensors, and also to assess the relationship of drift to the gauge number. 60 "Codman" intracranial pressure sensors were investigated. The analysis of zero drift were made depending on the length of monitoring and location of the intracranial pressure sensor, as well as on description of the gauge number. Data are presented as median, quartiles, minimum and maximum values. The gauge numbers of 499, 491 and 501, (475 and 513). The drift was 0 mm Hg. -1 And 0 (-2 to 3). In 43% of the ICP measurements of the drift of the zero value was absent. In 40% o the drift was within +/ - 1 mm Hg. The analysis showed no dependence of the drift of the zero value of the duration of monitoring, location of the sensor and gauge numbers. On two patients simultaneous recording of intracranial pressure in the ventricles and brain parenchyma was carried out. The high correlation between the measured values r = 0.94, p < 0.01. In one "in vivo" case the zero drift was detected, which amounted to 2 mm Hg and grew by 5th day of monitoring. The maximum value of the drift of the zero value was 3 mm Hg. The dependence of drift on the duration of monitoring, reference values of the calibration and sensor implant site was absent. This shows the accuracy and reliability of parenchymal ICP measurement.