Clinical Use of a Portable Bedside Cerebral Blood Flow Machine in the Management of Aneurysmal Subarachnoid Hemorrhage

Recent advances in electronics and microprocessors have enabled the development of a compact portable cerebral blood flow (CBF) machine capable of being transported to the patient's bedside. We have used such a device, the Novo Cerebrograph 2a, during the past 7 months on a regular basis in the day to day management of our patients with intracranial aneurysms. One hundred three studies were performed in 23 cases of suspected intracranial aneurysm. Twenty-two cases presented with acute subarachnoid hemorrhage. Patients were studied on admission, preoperatively, in the recovery room, on postoperative Days 1, 5, and 14, and whenever the clinical condition of the patient warranted. The preoperative admission grade was found to correlate well with the mean CBFisi (ISI: initial slope index). Grade III and IV patients had flows significantly lower than those of Grade I and II patients. Serial CBF measurements proved useful in the management of 18 of 22 cases admitted with acute subarachnoid hemorrhage. Delayed ischemic deficits secondary to vasospasm occurred in 6 cases, with a concomitant average fail in mean flow in the symptomatic hemispheres of 27.9%. After volume expansion, an average increase in flow of 29.7% was noted. Low preoperative flows influenced management decision-making in 8 cases. In a further 4 cases, serial CBF measurements were helpful in the differential diagnosis of new neurological signs.