Intracranial pressure and clinical status: assessment of two intracranial pressure transducers.

The aim of this study was to determine the in vivo accuracy and reliability of intracranial pressure (ICP) measurement using the Codman MicroSensor by comparison with the Camino ICP transducer and associated clinical and radiological information. Paired ICP readings were recorded every minute in 17 patients. A total of 56,790 validated paired measurements were obtained over a wide range of ICP values (- 16 mm Hg to 114 mm Hg). Recording periods ranged from 3 hours to 6 days (median 41 hours). In 11 patients the MicroSensor and Camino readings were in good agreement. Paired readings were within 10 mmHg for 99% of the recording time and both readings were compatible with clinical intracranial events at all times (in one case it was not possible to verify the clinical information). In six patients large differences occurred between transducer readings (> 10 mm Hg apart for 41% of the recording period). In one case, either reading could have been compatible with intracranial clinical events. In two cases, although both readings were comparable, Camino readings were more consistent with clinical and radiological findings. In three cases, the MicroSensor readings were inconsistent with the clinical condition of the patients whereas the Camino readings were compatible. These results suggest that, during routine clinical use in our department, the MicroSensor provided misleading information in 18% of our patients and thus is not sufficiently reliable for routine use in the detection of adverse clinical events.