Abstract T P355: Dobutamine versus Mirlinone for Intensive Hemodynamic Augmentation to Relieve Clinical Delayed Cerebral Ischemia after Subarachnoid Hemorrhage

Intensive hemodynamic augmentation by increasing cardiac output (CO) is a valuable method of elevating cerebral blood flow and oxygenation in the dysautoregulated vascular territories after subarachnoid hemorrhage (SAH). We prospectively assessed the effect of hyperdynamic therapy with dobutamine (DOB) or milrinone (MIL) on regional cerebral oxygenation (rSO 2 ) for reversing clinical deterioration induced by delayed cerebral ischemia, using an integrative monitoring with uncalibrated pulse contour CO analysis and multi-channel near-infrared spectroscopy. One-hundred ten SAH patients diagnosed to have clinical deterioration due to delayed cerebral ischemia were assigned to receive hemodynamic augmentation with DOB or MIL (n=56 per each group). For hyperdynamic therapy, each inotrope was initiated at low dose (DOB: 3μg/kg/min; MIL 0.15μg/kg/min) and then increased in each dose increment until resolution of the symptoms unless any adverse effects occur during the therapy, based on our predefined hemodynamic regimen to induce similar dose-related increase in CO. Real-time CO and rSO 2 changes in conjunction with the assessment of neurological improvements were compared. A total of 425 dose increment challenges (DOB, n=197; MIL, n=228) were performed. In spasm-affected territories, decreased and/or fluctuating rSO 2 was detected compared with recordings in other brain region. Patients who exhibited rapid elevation of CO by each challenge had subsequent uptake and stabilization of rSO 2 . The responses (total number and degree of neurological improvements) were more significant in patients treated with DOB than those treated with MIL ( P < 0.05), although tachycardia that may affect stroke volume depression during the DOB therapy was more evident (DOB 28% vs. MIL 9%). Area under the ROC curve to predict rSO 2 elevation or neurological improvement for both drug groups were significant ( P < 0.0001) and the values were significantly greater in DOB than in MIL ( P < 0.05). In conclusion, DOB can provide more effective hemodynamic augmentation in relieving focal cerebral ischemia in patients after SAH. MIL is also effective in the hyperdynamic therapy but may be used as a second line in a patient subgroup when DOB was contraindicated.