Clinical investigation of lumbar epidural pressure.

To evaluate the usefulness of measuring lumbar intraspinal epidural pressure (ISEDP) measurements for the estimation of intracranial pressure, we studied the relationship between ISEDP and intracranial epidural pressure (ICEDP) in 12 patients with high intracranial pressure after neurosurgical procedures. ISEDP was measured with a Gaeltec catheter-tip pressure transducer placed percutaneously in the lumbar epidural space with a Touhy needle. ICEDP was determined by the conventional method. During the measurement, some manipulations were carried out. ISEDP and ICEDP measurements exhibited a linear correlation. In all but one patient with normal cerebrospinal fluid, ISEDP was 84 to 100% of ICEDP. In patients with mild subarachnoid hemorrhage, ISEDP was 82 to 86% of ICEDP. In patients with severe subarachnoid hemorrhage, ISEDP was 45 to 57% of ICEDP and always fluctuated in parallel with ICEDP. ISEDP accurately reflected ICEDP in response to manipulations such as breath holding, neck compression, compression at the cranial defect, mannitol administration, and coughing. These data suggest that ISEDP measurement is useful in monitoring intracranial pressure in patients with intracranial hypertension. In addition, the measurements can be obtained easily and safely.