title: Brain alkaline intracellular pH after neonatal encephalopathy.
abstract: Experimental studies demonstrate an alkaline shift in brain intracellular pH (pH(i)) after hypoxia-ischemia (HI). In infants with neonatal encephalopathy after HI, our aims were to assess (1) brain pH(i) during the first 2 weeks after birth in infants categorized according to magnetic resonance imaging (MRI) during the first 2 weeks after birth and at more than 3 months of age, and neurodevelopmental outcome at 1 year; (2) the relationship between brain pH(i) and lactate/creatine; and (3) duration of alkaline brain pH(i). Seventy-eight term infants with neonatal encephalopathy were studied using MR techniques. One hundred and fifty-one studies were performed throughout the first year including 56 studies of 50 infants during the first 2 weeks after birth. pH(i) was calculated using phosphorus-31 MR spectroscopy and lactate/creatine was measured using proton MRS. The mean (standard deviation [SD]) brain pH(i) during the first 2 weeks after birth in infants with severely abnormal versus normal MRI was 7.24 (SD, 0.17) versus 7.04 (SD, 0.05; p < 0.001); in infants who subsequently developed cerebral atrophy versus those who did not: 7.23 (SD, 0.17) versus 7.06 (SD, 0.06; p < 0.05); in infants who died or had a severe neurodevelopmental impairment versus normal outcome: 7.28 (SD, 0.15) versus 7.11 (SD, 0.09; p < 0.05). Brain alkalosis was associated with increased brain lactate/creatine (p < 0.001). pH(i) remained more alkaline in the severe outcome group up to 20 weeks after birth (p < 0.05).
authors.affiliation: Department of Paediatrics, Division of Paediatrics, Obstetrics and Gynaecology, Imperial College School of Science, Technology and Medicine, Hammersmith Hospital Campus, DuCane Road, LondonW12 0NN, UK. n.robertson@ic.ac.uk
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Robertson
authors.forename: Frances M
authors.initials: FM
authors.lastname: Cowan
authors.forename: I Jane
authors.initials: IJ
authors.lastname: Cox
authors.forename: A David
authors.initials: AD
authors.lastname: Edwards
mesh_terms: D000471:Alkalosis / Q000378:metabolism*; D000704:Analysis of Variance; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001930:Brain Injuries / Q000378:metabolism* / Q000473:pathology; D003401:Creatine / Q000032:analysis / Q000378:metabolism*; D005500:Follow-Up Studies; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007231:Infant, Newborn; D007424:Intracellular Fluid / Q000378:metabolism*; D019344:Lactic Acid / Q000032:analysis / Q000378:metabolism*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D011446:Prospective Studies
chemical_list: D019344:Lactic Acid; D003401:Creatine