Association of nadir oxygen delivery on cardiopulmonary bypass with serum glial fibrillary acid protein levels in paediatric heart surgery patients.
Protecting the brain during cardiac surgery is a major challenge. We evaluated associations between nadir oxygen delivery (DO2) during paediatric cardiac surgery and a biomarker of brain injury, glial fibrillary acidic protein (GFAP).



Blood samples were obtained during a prospective, single-centre observational study of children undergoing congenital heart surgery with cardiopulmonary bypass (CPB) (2010-2011). Remnant blood samples, collected serially prior to cannulation for bypass and until incision closure, were analysed for GFAP levels. Perfusion records were reviewed to calculate nadir DO2. Linear regression analysis was used to assess the association between nadir DO2 and GFAP levels.



A total of 116 consecutive children were included, with the median age of 0.75 years (interquartile range: 0.42-8.00) and the median weight of 8.3 kg (5.8-20.0). Single-ventricle anatomy was present in 19 patients (16.4%). Deep hypothermic circulatory arrest (DHCA) was used in 14 patients (12.1%). On univariable analysis, nadir DO2 was significantly associated with GFAP values measured during rewarming on CPB (P = 0.005) and after CPB decannulation (P = 0.02). On multivariable analysis controlling for CPB time, DHCA and procedure risk category, a significant negative relationship remained between nadir DO2 and post-CPB GFAP (P = 0.03).



Lower nadir DO2 is associated with increased GFAP levels, suggesting that diminished DO2 during paediatric heart surgery may be contributing to neurological injury. The DO2-GFAP relationship may provide a useful measure for the implementation of neuroprotective strategies in paediatric heart surgery, including goal-directed perfusion.
Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
J Trent
JT
Magruder
Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Narutoshi
N
Hibino
Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Sarah
S
Collica
Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Huaitao
H
Zhang
Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
H Lynn
HL
Harness
Division of Anesthesiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Eugenie S
ES
Heitmiller
Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Marshall L
ML
Jacobs
Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Duke E
DE
Cameron
Division of Cardiac Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Luca A
LA
Vricella
Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA aeveret3@jhmi.edu.
Allen D
AD
Everett
D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D002648:Child; D002675:Child, Preschool; D050792:Circulatory Arrest, Deep Hypothermia Induced; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000097:blood*; D006330:Heart Defects, Congenital / Q000097:blood* / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D010102:Oxygen Inhalation Therapy; D010477:Perfusion; D011446:Prospective Studies; D017694:Rewarming
D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein
Brain injury; Cardiopulmonary bypass; Congenital heart disease; Paediatric