The Association between Hyperlactatemia and Adverse Long Term Outcome in Infants with Moderate to Severe Hypoxic Ischemic Encephalopathy 1Mohamed S. Elboraee, 1,2Ernest Phillipos, 4Leonora Hendson, 1,2,3,6Amber Reichert, 5Xiang Y. Ye, 1,3,6Mosarrat Qureshi 1University of Alberta, Edmonton AB; 2Stollery Children’s Hospital, Edmonton AB; 3Royal Alexandra Hospital, Edmonton AB; 4University of Calgary, Calgary AB; 5MiCare research Center, Toronto ON, 6Glenrose Rehabilitation Hospital, Edmonton AB Background Results Tables Of 167 infants, 106 had initial lactate >5.0mmol/L (63%) and 48 had initial lactate <5.0mmol/L (29%). Data was missing on 13 infants (8%) (Fig 1) . Thirty two out of the 167 infants (19%) died (Fig 2). After adjustment, initial Lactate was significantly associated with the primary outcome (OR: 1.06; 95%CI: 1.01- 1.13). In addition, the time required for lactate to normalize (≤2.0mmol/l) was associated with the primary outcome [table1]. The ROC curve (Fig 3) showed that initial Lactate>16mmol/L is significant (P0.0015) for detection of adverse outcome; sensitivity 29.3% and specificity 90.5% [table2]. Hypoxic ischemic encephalopathy (HIE) remains one of the most devastating events in the newborn period. Lactate is invariably produced with hypoxia and poor tissue perfusion. Initial highest lactate in the first hour of life and serial measurements of blood lactate have been found to be important predictors of moderate to severe neonatal encephalopathy in cases of intrapartum asphyxia. Table(1) Association between patient characteristics & outcome in infants with HIE II/III   No Death or Disability Death or any Disability p-value Gender (male), %(n/N) 65.35 (66/101) 44.62 (29/65) 0.008 Apgar score<5 at 5 min, %(n/N) 60.42 (58/96) 87.3 (55/63) 0.0003 Initial pH <7.0 %(n/N) 22.35 (19/85) 54.39 (31/57) <0.0001 Initial Lactate, mean(sd) 8.5 (5.6) 11.7 (7.2) 0.005 Highest Lactate, mean(sd) 9.5 (5.6) 14.2 (8.3) 0.0002 Normalization of Lactate, %(n/N) 0.001 <24hrs 29.27 (24/82) 6.98 (3/43) 24-48hrs 36.59 (30/82) 27.91 (12/43) >48hrs 34.15 (28/82) 65.12 (28/43) Objectives Figures To examine the association between initial lactate level and the long term adverse outcome in infants with moderate to severe HIE (HIE II/III). We hypothesized that the level of hyperlactatemia and time required for it to normalize in HIE infants can predict long term adverse neurodevelopmental outcome. Table(2) Association between Initial Lactate level and the adverse outcome in infants with moderate or severe HIE   No Death or Disability Death or any Disability p-value Infants number 101 65 Initial Lactate >16, %(n/N) 9.5 (9/95) 29.3 (17/58) 0.0015 Methods A retrospective chart and database review for all infants ≥ 35 weeks gestational age treated in the Northern Alberta Neonatal Program with HIE II/III from January 2006 to December 2012 (excluding infants who were growth restricted or with major congenital anomalies). The primary outcome was composite of death or any disability (cerebral palsy, cognitive delay <2SD below the mean, hearing loss and blindness) at 18 months or 3 years of age. Univariate and multivariable regression analyses were used to compare the outcome. Fig 1. Study Population Fig 2. The Outcome of HIE infants Conclusions Most term or near term infants with HIE II/III had initial lactate > 5 mmol/L Initial Lactate >16 mmol/L was associated with the adverse outcome The longer it takes for the lactate to normalize, the poorer the outcome (Fig 4) This research has been funded by the WCHRI through the generous support of the Stollery Children's Hospital Foundation Fig 4. ROC curve for the Initial Lactate