Intraoperative trans-fontanellar cerebral ultrasonography in infants during cardiac surgery under cardiopulmonary bypass: an observational study

Abstract

This study was performed to evaluate the feasibility of intraoperative point-of-care trans-fontanellar cerebral ultrasonography (TFCU) to obtain blood flow velocity (BFV) reference values at the internal carotid arteries (ICAs) and peri-callosal part of the anterior cerebral artery (pACA) during pediatric cardiac surgery under cardiopulmonary bypass (CPB). TFCU was performed at three time points (after induction of anesthesia, during CPB, after CPB) in 35 infants. BFV was measured at both ICAs and pACA through the anterior fontanelle with an ultrasound sector probe. We divided patients into Group S (< 5 kg, n = 16) and Group L (5 kg, n = 19) for comparisons according to weight. We also analyzed BFV in low cerebral regional oxygen saturation (rSO(2)) data. All measurements of the BFV at both the ICAs and the pACA were possible. BFVs at the ICAs were lower in Group S than in Group L at all three time points. BFVs at the pACA were similar in both groups except higher value in Group L after CPB. When the rSO(2) was < 50, most BFVs (14 of 15 measurements) were lower than the median BFV value during CPB. However, a low rSO(2) did not always reflect low BFV before and after CPB. Point-of-care TFCU can determine BFV at the ICAs and pACA during pediatric cardiac surgery. BFV differs according to the patient's size and CPB application. TFCU can be a practical cerebral blood flow monitoring method when rSO(2) changes without any specific reason in infants. ClinicalTrials.gov NCT01996020.