Alkaline Phosphatase in Infant Cardiopulmonary Bypass: Kinetics and Relationship to Organ Injury and Major Cardiovascular Events.


Journal Article

OBJECTIVES: To determine the kinetics of alkaline phosphatase (AP) activity and concentration after infant cardiopulmonary bypass, including isoform-specific changes, and to measure the association between postoperative AP activity and major postoperative cardiovascular events, organ injury/dysfunction, and postoperative support requirements STUDY DESIGN: Prospective cohort study of 120 infants ≤120 days of age undergoing cardiopulmonary bypass. AP total and isoform-specific activity was assessed at 6 time points (preoperation, rewarming, 6, 24, 48, and 72 hours postoperation). Low AP activity was defined as ≤80 U/L. AP concentrations and biomarkers of organ injury/dysfunction were collected through 24 hours postoperation. Major cardiovascular events were defined as cardiac arrest, mechanical circulatory support, or death. RESULTS: AP activity loss occurred primarily during the operation (median decrease 89 U/L; P < .0001) secondary to decreased bone and liver 2 isoforms. Activity declined through 24 hours in 27% of patients. AP activity strongly correlated with serum concentration (r = 0.87-0.91; P < .0001). Persistent low AP activity at 72 hours was associated independently with occurrence of a major cardiac event (OR 5.6; P < .05). Early AP activity was associated independently with subsequent vasoactive-inotropic score (P < .001), peak lactate (P < .0001), peak creatinine (P < .0005), N-terminal pro-brain natriuretic peptide (P < .05), and intestinal fatty acid binding protein (P < .005). CONCLUSIONS: AP activity decreases during infant cardiopulmonary bypass and may continue to decrease for 24 hours. Activity loss is secondary to decreased bone and liver 2 isoform concentrations. Early low AP activity is associated independently with subsequent postoperative support and organ injury/dysfunction, and persistence of AP activity ≤80 U/L at 72 hours is associated independently with increased odds of major cardiovascular events.

Full Text

Duke Authors

Cited Authors

  • Davidson, JA; Urban, TT; Baird, C; Tong, S; Woodruff, A; Twite, M; Jaggers, J; Simões, EAF; Wischmeyer, P

Published Date

  • November 2017

Published In

Volume / Issue

  • 190 /

Start / End Page

  • 49 - 55.e2

PubMed ID

  • 29144270

Pubmed Central ID

  • 29144270

Electronic International Standard Serial Number (EISSN)

  • 1097-6833

Digital Object Identifier (DOI)

  • 10.1016/j.jpeds.2017.07.035


  • eng

Conference Location

  • United States