title: Changes in cerebral oxygen saturation and haemoglobin concentration during paediatric cardiac surgery.
abstract: Although near-infrared spectroscopy (NIRS) enables bedside assessment of cerebral oxygenation, it provides little information on the cause of deoxygenation. The authors aimed to investigate the changes in cerebral oxygenation and haemoglobin concentration and their associations during paediatric cardiac surgery in order to elucidate the physiology underlying cerebral deoxygenation. An observational retrospective study on 399 patients who underwent paediatric cardiac surgery was conducted. With use of NIRS, cerebral oxygen saturation as expressed by tissue oxygen index (TOI) before and after surgery, concentration changes in oxygenated haemoglobin (Δ[HbO2]) and deoxygenated haemoglobin (Δ[HHb]) after surgery were studied as were the associations between these values and clinical variables. TOI decreased after surgery (preoperative versus postoperative value, 66.0% [56.9, 71.3] versus 63.2% [54.3, 69.4], median [25th, 75th percentile],P<0.001) and the decrease was greater in higher category groups in the Risk Adjusted Classification for Congenital Heart Surgery (RACHS-1). [HHb] increased from its baseline (+1.74 μmol/l [-1.57, +5.84],P<0.001) and the increase was greater in higher risk category groups. On the contrary, there was no evidence for a change in [HbO2] (+0.45 μmol/l [-4.76, +5.30],P=0.42). Cerebral oxygen saturation decreased after paediatric cardiac surgery and the decrease was greater in patients of higher risk groups. The increase in [HHb] was considered to play a predominant role in the cerebral deoxygenation noted, in particular in higher RACHS-1 category groups.
authors.affiliation: Visiting Researcher, Anaesthesia and Pain Management Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Suemori
authors.affiliation: Senior Perfusionist, Department of Cardiac Surgery, The Royal Children's Hospital Melbourne, Heart Research, Murdoch Childrens Research Institute, Melbourne, Victoria.
authors.forename: S B
authors.initials: SB
authors.lastname: Horton
authors.affiliation: Perfusionist, Department of Cardiac Surgery, The Royal Children's Hospital, Melbourne, Victoria.
authors.forename: S
authors.initials: S
authors.lastname: Bottrell
authors.affiliation: Senior Staff Anaesthetist, Discipline of Paediatrics and Child Health, University of Sydney, Department of Anaesthesia, The Children's Hospital at Westmead, Sydney Children's Hospital Network, Sydney, New South Wales.
authors.forename: J J
authors.initials: JJ
authors.lastname: Skowno
authors.affiliation: Senior Staff Anaesthetist, Anaesthesia and Pain Management Research Group, Murdoch Childrens Research Institute, Department of Paediatrics, University of Melbourne, Melbourne, Victoria.
authors.forename: A
authors.initials: A
authors.lastname: Davidson
mesh_terms: D001921:Brain / Q000378:metabolism*; D006348:Cardiac Surgical Procedures; D002560:Cerebrovascular Circulation; D002648:Child; D002675:Child, Preschool; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007223:Infant; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D012189:Retrospective Studies; D019265:Spectroscopy, Near-Infrared
chemical_list: D006454:Hemoglobins; D010100:Oxygen
keywords: congenital heart defects, perioperative care, cerebral ischaemia, near-infrared spectroscopy, oxyhaemoglobin, deoxyhaemoglobin