AHA: Hemoglobin Index IDs Brain Ischemia During Bypass
HVx, glial fibrillary acidic protein detect impaired autoregulation during cardiopulmonary bypass
THURSDAY, April 26 (HealthDay News) -- Use of the hemoglobin volume index (HVx) allows for identification of autoregulation impairment during cardiopulmonary bypass (CPB), which corresponds to brain injury or ischemia that can be detected by elevations in serum glial fibrillary acidic protein (GFAP), according to a pilot study presented during the American Heart Association's Emerging Science Series Webinar, held on April 25.
Ronald B. Easley, M.D., from the Baylor College of Medicine in Houston, and colleagues conducted a multicenter observational study of 61 children undergoing CPB to investigate the feasibility of coupling real-time HVx monitoring with evidence of brain injury, measured using GFAP, during CPB. Intraoperative HVx was monitored and GFAP was measured, and data were analyzed according to CPB phase.
The researchers identified the lower limit of pressure autoregulation in 85 percent of participants. Significant perturbations were demonstrated by both HVx and GFAP during CPB, with peaks during rewarming. A trend was noted toward increased GFAP with increased time below the lower limit of pressure autoregulation (P = 0.06).
"Because the autoregulatory changes occurred almost concurrently with signs of brain injury, we may have a real-time measure where we can detect when injury is occurring and modify how we are managing the patients; for example, being more aggressive with controlling blood pressure," Easley said in a statement.
One of the authors disclosed a financial tie to Somanetics.