Clinical comparison of the Spiegelberg parenchymal transducer and ventricular fluid pressure

The Spiegelberg brain pressure catheter is a low cost implantable intracran ial. pressure measuring system which has the unique ability to perform regu lar automatic zeroing. A new version of the catheter has become available w ith a subdural bolt fixation to allow insertion of the device into the brai n parenchyma. The accuracy of this system has been evaluated in comparison with a ventricular fluid pressure method in a series of patients to determi ne its accuracy and utility in the clinical environment. Hourly readings from the Spiegelberg system have been compared with those o btained using a standard pressure transducer connected to an external ventr icular drain. Measurements continued while there was a clinical need for CS F drainage. Eleven patients were recruited to the study and data were recorded for peri ods ranging from 40 to 111 hours. A good agreement between the two systems was obtained. In 10 cases the mean difference was less than +/- 1.5 mm Hg a nd the dynamic changes in value were contemporaneous. In one case an intrac erebral haemorrhage developed around the tips of the Spiegelberg catheter a nd significant differences occurred between the two methods of measurement. In conclusion, the Spiegelberg parenchymal transducer provides an accurate measurement of intracranial pressure when compared with ventricular pressur e. The transducer was found to be robust in the clinical environment and ve ry popular with the nursing staff. Further studies may determine whether th e complication rate of this system is comparable with other available devic es.