Abstract 8897: Valid Cardiac Strategy for Reversing Focal Cerebral Ischemia Caused by Vasospasm after Subarachnoid Hemorrhage
Delayed cerebral ischemia (DCI) attributable to vasospasm is currently the leading cause of death and disability after subarachnoid hemorrhage (SAH). Therapeutic hemodynamic augmentation by increasing cardiac output (CO) is a valuable method for elevating cerebral blood flow and oxygenation in dysautoregulated territories affected by DCI. Our previous results suggest that the key for successful reversal of focal ischemia is to accomplish hemodynamic acceleration enough to improve cerebral microcirculation. We prospectively assessed more effective strategy for hyperdynamic therapy with dobutamine (DOB) either by intermittent dose-repetition or by continuous step-wise dose increments in the treatment of post-SAH DCI. Real-time CO and regional cerebral oxygenation (rSO2) recordings during the therapy in conjunction with the assessment of neurological improvements were analyzed. Forty patients with SAH treated surgically within 24 hours of ictus and diagnosed to have DCI between postoperative days 4 and 14 were enrolled. DOB was administered at an initial dose of 3 µg/kg/min and then increased in 3 µg/kg/min increments until resolution of the neurologic symptoms. Once the DCI recurred, 1) the DOB dose was reduced to the level where CO and rSO2 became stable to apply the same dose-repetition (LD) or 2) simply increased the same increments until maximal dose (18 µg/kg/min) (HD). A total of 158 DOB challenges were performed with a maximum therapeutic dose of 9 ± 3 µg/kg/min (LD) and 13 ± 4 µg/kg/min (HD) (p=0.001), respectively. In response to DOB, uptake and stabilization of rSO2 accompanied by a rapid elevation of CO usually occur, followed by improvement of the symptoms. Calculated peak slope of the CO uptake were greater in LD than in HD (p<0.05). Area under the ROC curve of peak CO slope to discriminate neurological responders for each challenge was not significantly different between the strategies (p>0.05). Patients managed with LD experienced less numbers of tachycardia, arrhythmia and paralytic ileus than those with HD. In conclusion, repeat application strategy with low-dose DOB will play a key role of hyperdynamic therapy in effectively relieving focal ischemia with less drug-induced complications in patients suffering from DCI after SAH.
- © 2012 by American Heart Association, Inc.