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Updated: Sep 27, 2026
Non-invasive Optical Measurement of Cerebral Metabolism and Hemodynamics in Infants
Published on: March 14, 2013
Reproducibility of the blood flow index as noninvasive, bedside estimation of cerebral blood flow
Bendicht P Wagner1, Susanne Gertsch, Roland A Ammann
1Pediatric Intensive Care, Department of Pediatrics, Inselspital, University of Berne, 3010, Berne, Switzerland. wagner@insel.ch
Insights
The blood flow index (BFI) method offers a feasible and reproducible way to measure cerebral blood flow (CBF) in critically ill children. This noninvasive technique is suitable for monitoring changes in CBF during clinical interventions.
Area of Science:
- Pediatric intensive care
- Neuroscience
- Medical technology
Background:
- Cerebral blood flow (CBF) monitoring is crucial in pediatric intensive care.
- Noninvasive methods for assessing CBF are needed for clinical application.
Purpose of the Study:
- To evaluate the feasibility and reproducibility of the blood flow index (BFI) method for measuring CBF.
- To assess the BFI method's utility in a pediatric intensive care setting.
Main Methods:
- A prospective functional study was conducted on 14 mechanically ventilated pediatric patients.
- Cerebral blood flow was assessed using indocyanine green (ICG) and near-infrared spectroscopy to calculate BFI.
- Reproducibility was determined through repeated ICG injections at 5-minute intervals.
Main Results:
- The BFI method demonstrated good feasibility, with a low cancellation rate (6%) and injection failure rate (4%).
- Reproducibility was good, with a median coefficient of variation (CV) of 10% for BFI.
- Patient parameters remained stable during measurements, showing CV below 2%.
Conclusions:
- The BFI method provides rapid, repeatable, and reproducible measurements of relative CBF.
- BFI is a promising tool for clinical evaluation of intraindividual CBF changes and cerebrovascular reactivity in pediatric patients.
Objective:
To investigate the feasibility and reproducibility of the blood flow index (BFI) method for measuring cerebral blood flow.
Design And Setting:
Prospective functional study in pediatric intensive care.
Patients And Participants:
14 consecutive patients with median age of 2 months (range 1 days-11 years) requiring artificial ventilation, invasive arterial blood pressure monitoring, and central venous access.
Interventions:
The first passage of an intravenous indocyanine green (ICG) bolus through the cerebral vasculature was monitored by noninvasive near-infrared spectroscopy. BFI was calculated by dividing maximal ICG absorption change by rise time. Reproducibility was evaluated by six ICG injections at 5-min intervals.
Results:
Of all ICG injections 6% were canceled, and 4% were eliminated due to injection failures. Median BFI of 17 reproducibility determinations was 71 (range 12-213) and median coefficient of variation (CV) of BFI was 10% (4.9-18.5). The quantity of ICG bolus did not affect the CV (0.1 vs. 0.3 mg ICG/kg). Eight reproducibility tests in patients after cardiac surgery had smaller CV than the others, and the eight in newborns had higher CV than in older children. Patient parameters such as arterial blood pressure, endtidal CO(2), and percutaneous oxygen saturation were stable and showed CV below 2% during reproducibility determination.
Conclusions:
The BFI method allows rapid and repeated measurements of CBF with good feasibility and reproducibility. As a relative but not absolute measure of CBF, BFI seems to be suited for clinical evaluation of intraindividual CBF changes during determination of cerebrovascular reactivities or during therapeutic interventions.
