Total cerebrovascular blood flow and whole brain perfusion in children sedated using propofol with or without ketamine at induction: An investigation with 2D‐Cine PC and ASL

Abstract

Background Multiple sedation regimes may be used to facilitate pediatric MRI scans. These regimes might affect cerebral blood flow and hemodynamics to varying degrees, particularly in children who may be vulnerable to anesthetic side effects. Purpose To compare the effects of propofol monosedation solely (Pm group) vs. a combination of propofol and ketamine (KP group) on brain hemodynamics and perfusion. Study Type Prospective double‐blind randomized trial. Field Strength/Sequences 1.5T and 3T. 2D‐Cine phase contrast (2D‐Cine PC) and pseudocontinuous arterial spin labeling (ASL). Population Children aged from 3 months to 10 years referred for MRI with deep sedation were randomized into either the KP or the Pm group. Perfusion images were acquired with ASL followed by single‐slice 2D‐Cine PC acquired between the cervical vertebra C2 and C3. Assessment Average whole‐brain perfusion (WBP ml.min‐1.100 ml‐1) was extracted from the ASL perfusion maps and total cerebrovascular blood flow (CVF) was quantified by bilaterally summing the flow in the vertebral and the internal carotid arteries. The CVF values were converted to units of ml.min‐1.100 g‐1 to calculate the tissue CVF100g (ml.min‐1.100 g‐1). Images were assessed by a neuroradiologist and data from n = 81 (ASL) and n = 55 (PC) cases with no apparent pathology were entered into the analysis. Statistical Tests Multivariate analysis of covariance was performed to compare drug sedation effects on WBP, CVF, and CVF100g. Results No significant difference in arterial flow was observed (P = 0.57), but the KP group showed significantly higher WBP than the Pm group, covarying for scanner and age (P = 0.003). A correlation analysis showed a significant positive correlation between mean WBP (ml.min‐1.100 g‐1) and mean CVF100g. Data Conclusion The KP group showed higher perfusion but no significant difference in vascular flow compared with the Pm group. WBP and CVF100g correlated significantly, but ASL appeared to have more susceptibility to perfusion differences arising from the different sedation regimes. Level of Evidence: 1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2019;50:1433–1440.

Comparison of remifentanil and esketamine in combination with propofol for patient sedation during fiberoptic bronchoscopy: a randomized trial

“…At the insertion point of bronchoscopy, the elevated level of MAP and HR in remifentanil were signi cantly higher than that in esketamine group, indicating that esketamine provided better circulative stability. Similar to this study, Hegazy MA reported that the combination of fentanyl and propofol inhibited hemodynamics [21], but the combination of ketamine and propofol led to stable hemodynamics [22]. However, neither remifentanil combination nor esketamine combination completely prevented the increase in blood pressure and heart rate caused by endotracheal intubation, but such increase in blood pressure and heart rate was well tolerated and did not require any intervention.…”

Current state and guidance on arterial spin labeling perfusion MRI in clinical neuroimaging

“…It is important to consider that between birth and adulthood, many physiological parameters that may affect CBF measurements will evolve and can also be influenced by disease or sedation 129 (Table S2). Additionally, some sedatives and anesthetics can reduce CBF (e.g., propofol), whereas others increase CBF (ketamine without benzodiazepine) or have a variable influence on CBF depending on concentration (many narcotic gases) 130 . Consideration of all of these factors must be used when interpreting pediatric ASL imaging.…”

“…Additionally, some sedatives and anesthetics can reduce CBF (e.g., propofol), whereas others increase CBF (ketamine without benzodiazepine) or have a variable influence on CBF depending on concentration (many narcotic gases). 130 Consideration of all of these factors must be used when interpreting pediatric ASL imaging.…”

Effect of vitamin D supplementation on cerebral blood flow in male patients with adrenoleukodystrophy

“…This may be explained by two reasons: (1) The accuracy of the selected ASL technique (PCASL) is sensitive to the flow velocity of the arterial blood, and the scanning parameters were not optimized for the current cohort. Several studies have reported that the flow velocity of the arterial blood of participants was higher than those in healthy adults, and the resulting CBF can be underestimated by 8% without a correct measurement of the flow velocity (Gevers et al, 2012; Makki et al, 2019). A possible solution to improve the accuracy of CBF quantification would be to use a pulsed ASL labeling technique, which is insensitive to flow velocity variations, though this would also reduce the signal‐to‐noise ratio of the ASL data.…”