Continuous cardiac output and near-infrared spectroscopy monitoring to assist in management of symptomatic cerebral vasospasm after subarachnoid hemorrhage

Background: Hemodynamic augmentation by increasing cardiac output with dobutamine (DOB) is believed to be a useful method of elevating decreased cerebral blood flow in the territory affected by vasospasm following aneurysmal subarachnoid hemorrhage (SAH). We described the clinical utility of uncalibrated radial artery-based pulse contour cardiac output (APCO) and near-infrared spectroscopy regional cerebral oxygen saturation (rSO₂) monitoring for reversing vasospasm symptoms with DOB-induced hyperdynamic therapy. Methods: Seven consecutive patients who underwent surgical clipping within 24 h of SAH onset and subsequently developed delayed ischemic neurological deficits attributable to vasospasm were investigated. They were treated with DOB administered at a dose of 3 μg/kg/min and then increased in 3 μg/kg/min increments until resolution of the symptoms. Continuous APCO and rSO₂ measurements in conjunction with the assessment of clinical courses and outcomes were performed. Results: In spasm-affected territories, decreased and/or fluctuating rSO₂ was detected at baseline compared with recordings in other brain regions. Patients who exhibited rapid elevation of APCO in response to an incremental dose of DOB had subsequent uptake and stabilization of rSO₂ followed by improvement of vasospasm-related clinical symptoms with a maximal dose of DOB, resulted in favorable functional outcomes thereafter. A fairly strong relationship was found between peak APCO slope and rSO₂ elevation, with a significantly high area under the receiver operating characteristic curve predicting neurological improvement with DOB treatment. Conclusions: Our clinical experience indicates that integrative monitoring with APCO and rSO₂ may provide continuous, real-time, and clinically relevant information on the effectiveness of medical treatment of distal vessel vasospasm.