Changes on Dynamic Cerebral Autoregulation Are Associated with Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Early identification of vasospasm prior to symptom onset would allow prevention of delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH). Dynamic cerebral autoregulation (DCA) is a noninvasive means of assessing cerebral blood flow regulation by determining independence of low-frequency temporal oscillations of systemic blood pressure (BP) and cerebral blood flow velocities (CBFV). METHODS: Eight SAH patients underwent prospectively a median of 7 DCA assessments consisting of continuous measurements of BCFV and BP. Transfer function analysis was applied to calculate average phase shift (PS) in low (0.07-0.2 Hz) frequency range for each hemisphere as continuous measure of DCA. Lower PS indicated poorer regulatory response. DCI was defined as a 2-point decrease in Glasgow Coma Score and/or infarction on CT. RESULTS: Three subjects developed symptomatic vasospasm with median time-to-DCI of 9 days. DCI was significantly associated with lower PS over the entire recording period (Wald = 4.28; p = 0.039). Additionally, there was a significant change in PS over different recording periods after adjusting for DCI (Wald = 15.66; p = 0.001); particularly, a significantly lower mean PS day 3-5 after bleed (14.22 vs 27.51; p = 0.05). CONCLUSIONS: DCA might be useful for early detection of symptomatic vasospasm. A larger cohort study of SAH patients is currently underway.

Milrinone as a rescue therapy for symptomatic refractory cerebral vasospasm in aneurysmal subarachnoid hemorrhage.

INTRODUCTION: Delayed ischemic neurological deficit associated to cerebral vasospasm is the most common cause of sequelae and death that follows the rupture of an aneurysm. The objective of this study was to evaluate the safety and efficacy of intra-arterial Milrinone in patients with symptomatic refractory cerebral vasospasm. PATIENTS AND METHOD: Eight patients diagnosed with aneurysmal subarachnoid hemorrhage who developed symptomatic cerebral vasospasm refractory to conventional medical therapy were enrolled. They received an intra-arterial infusion of Milrinone at a rate of 0.25 mg/min, with a total dose of 10-15 mg. Qualitative evaluation of angiographic response, neurological and systemic complications as well as functional outcome at 3 months were documented. RESULTS: All patients had a significant angiographic response. This was evidenced by a pre-treatment vessel stenosis greater than 70%, that improved to less than 50% after the intra-arterial Milrinone infusion. Three patients developed recurrent vasospasm that improved after a second intra-arterial Milrinone infusion. None of the patients developed neurologic or systemic complications attributed to the intervention. At 3 months follow-up all patients were alive and had a mean modified Rankin scale of 2 +/- 1 and a Barthel index of 83 +/- 10. CONCLUSION: Intra-arterial Milrinone infusion seems to be a safe and effective treatment for patients who develop refractory symptomatic cerebral vasospasm following aneurysmal subarachnoid hemorrhage.