Cerebrovascular autoregulation in pediatric moyamoya disease

Authors: Lee JK, Williams M, Jennings JM, Jamrogowicz JL, Larson AC, Jordan LC, Heitmiller ES, Hogue CW, Ahn ES.

BACKGROUND: Moyamoya syndrome carries a high risk of cerebral ischemia, and impaired cerebrovascular autoregulation may play a critical role. Autoregulation indices derived from near-infrared spectroscopy (NIRS) may clarify hemodynamic goals that conform to the limits of autoregulation.
OBJECTIVES: The aims of this pilot study were to determine whether the NIRS-derived indices could identify blood pressure ranges that optimize autoregulation and whether autoregulatory function differs between anatomic sides in patients with unilateral vasculopathy.
METHODS: Pediatric patients undergoing indirect surgical revascularization for moyamoya were enrolled sequentially. NIRS-derived autoregulation indices, the cerebral oximetry index (COx) and the hemoglobin volume index (HVx), were calculated intraoperatively and postoperatively to measure autoregulatory function. The 5-mmHg ranges of optimal mean arterial blood pressure (MAPOPT ) with best autoregulation and the lower limit of autoregulation (LLA) were identified.
RESULTS: Of seven enrolled patients (aged 2-16 years), six had intraoperative and postoperative autoregulation monitoring and one had only intraoperative monitoring. Intraoperative MAPOPT was identified in six (86%) of seven patients with median values of 60-80 mmHg. Intraoperative LLA was identified in three (43%) patients with median values of 55-65 mmHg. Postoperative MAPOPT was identified in six (100%) of six patients with median values of 70-90 mmHg. Patients with unilateral disease had higher intraoperative HVx (P = 0.012) on side vasculopathy.
CONCLUSIONS: NIRS-derived indices may identify hemodynamic goals that optimize autoregulation in pediatric moyamoya.
© 2013 Blackwell Publishing Ltd.

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Paediatr Anaesth. 2013 Mar 18. doi: 10.1111/pan.12140.