Intracranial Pressure, Cerebral Perfusion Pressure, and SPECT in the Management of Patients with SAH Hunt and Hess Grades I-II

Abstract

The objective of our study was to examine the course of intracranial pressure (ICP) in patients with SAH Hunt and Hess grades I-II and to analyze the relationship between ICP, cerebral perfusion pressure (CPP) and cerebral blood flow (CBF). Twenty-three patients were studied. ICP, arterial blood pressure (ABP) and CPP were continuously recorded. The measurements of CBF with single-photon emission computed tomography (SPECT) were performed in fifteen patients, who showed TCD flow velocities exceeding 120 cnlJsec. In the first two days after SAH four patients (15%) showed a normal ICP, six (25%) patients had a moderate increase of ICP ranged from 15 to 25mmHg and thirteen (60%) patients had ICP values higher than 25mmHg. Seven of these patients, with ICP values higher than 40mmHg, showed clinical signs of delayed ischaemia. After the treatment with osmotic diuretic, ICP decreased and a clinical improvement was observed with the exception of one patient. In this patient, the SPECT study showed middle cerebral hypoperfusion concordant with the clinically ischaemic hemisphere. Our study showed the utility of the monitoring of these parameters in patients with lower grade SAH, because it allows the modulation of the therapeutic approach and defines the onset of neurological deficits secondary to cerebral ischaemia in all grades of SAH.