title: Serum calcium concentrations and incidence of hypocalcemia in infants with moderate or severe hypoxic-ischemic encephalopathy: Effect of therapeutic hypothermia.
abstract: BACKGROUND
  Hypocalcemia is a common morbidity in asphyxiated infants. Therapeutic hypothermia (TH), the standard of care for infants with moderate and severe hypoxic-ischemic encephalopathy (HIE), promotes neuroprotection by several mechanisms including a decrease in intracellular calcium (Ca(2+)) influx which may improve serum Ca(2+) levels and homeostasis.
  
  
  OBJECTIVE
  To evaluate the impact of TH on Ca(2+) homeostasis.
  
  
  METHODS
  Historical, retrospective cohort analysis.
  
  
  METHODS
  Infants with moderate or severe HIE admitted to the hospital with≤24hours of age, gestational age≥36weeks, and birth weight ≥1800g, before (pre-TH) and after (post-TH) TH was implemented.
  
  
  METHODS
  Minimum and maximum serum levels of ionized Ca(2+) (iCa(2+)) and magnesium (Mg), Ca(2+) and Mg intakes, and incidence of hypo/hypercalcemia during the first week of life.
  
  
  RESULTS
  A total of 67 infants were included: 29 pre-TH and 38 post-TH. Minimum iCa(2+)levels were significantly lower in the pre-TH group; some infants required Ca(2+) boluses infusions. In the post-TH group, a significantly lower intake of Ca(2+) was necessary to maintain normal Ca(2+) levels and no infant required boluses. The incidence of hypocalcemia was higher in the pre-TH group with a statistically significant difference on day 2 of life (18 vs 0%; p=0.01).
  
  
  CONCLUSIONS
  After the implementation of TH, iCa(2+) levels were within normal ranges despite lower Ca(2+) intakes. A lower incidence of hypocalcemia was observed during cooling. Our findings support the hypothesis that TH improves Ca(2+) homeostasis in HIE infants.
authors.affiliation: Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Chatchay
authors.initials: C
authors.lastname: Prempunpong
authors.affiliation: McGill University Health Center, Montreal Children's Hospital, Montreal, Canada.
authors.forename: Ionut
authors.initials: I
authors.lastname: Efanov
authors.affiliation: McGill University Health Center, Montreal Children's Hospital, Montreal, Canada. Electronic address: guilherme.santanna@mcgill.ca.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Sant'Anna
mesh_terms: D002118:Calcium / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000097:blood / Q000150:complications / Q000628:therapy*; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies
chemical_list: D002118:Calcium
keywords: Calcium; Hypocalcemia; Hypoxic-ischemic encephalopathy; Therapeutic hypothermia