Vasopressors and Inotropes

Vasopressors and inotropes are used in the neurosciences intensive care unit to treat hypotension and to augment blood pressure. Hypotension can be attributed to abnormal cardiac output, abnormal intravascular volume or abnormal systemic vascular resistance. Vasopressors are needed to manage hemodynamic augmentation in patients with severe cerebral vasospasm and aneurysmal subarachnoid hemorrhage, in patients with critical carotid or basilar artery stenosis producing marginal blood flow, or when patients are maintained in drug-induced comas. The main incentive is to maintain adequate perfusion pressure to the brain and vital organs, particularly the kidneys. This chapter provides the essentials of management of these complex drugs and how to avoid unintended side effects.

Extensive Mobile Thrombus of the Internal Carotid Discovered After Intravenous Thrombolysis

This case report describes a rare presentation of ischemic stroke secondary to an extensive internal carotid artery thrombus, subsequent therapeutic dilemma, and clinical management. A 58-year-old man was administered intravenous (IV) thrombolysis for right middle cerebral artery territory ischemic stroke symptoms. A computed tomography angiogram of the head and neck following thrombolysis showed a longitudinally extensive internal carotid artery thrombus originating at the region of high-grade calcific stenosis. Mechanical embolectomy was deferred because of risk of clot dislodgement and mild neurological symptoms. Recumbency and hemodynamic augmentation were used acutely to support cerebral perfusion. Anticoagulation was started 24 hours after thrombolysis. Carotid endarterectomy was completed successfully within 1 week of presentation. Clinical outcome was satisfactory with discharge modified Rankin Scale score 0. A longitudinally extensive carotid artery thrombus poses a risk of dislodgement and hemispheric stroke. Optimal management in these cases is not known with certainty. In our case, IV thrombolysis, hemodynamic augmentation, delayed anticoagulation, and carotid endarterectomy resulted in a favorable clinical outcome.

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.