title: Body Weight-Related ionized hypomagnesemia in pediatric patients undergoing cardiopulmonary bypass for surgical repair of congenital cardiac defects.
abstract: OBJECTIVE
  To examine the serial time course of perioperative plasma ionized magnesium (iMg(2+)) concentrations and to analyze the plasma iMg(2+) concentrations in children with different body mass who were undergoing open-heart surgery.
  
  
  METHODS
  Randomized, single-blinded study.
  
  
  METHODS
  University-affiliated hospital of an academic medical institution.
  
  
  METHODS
  38 children undergoing open-heart surgery.
  
  
  METHODS
  Patients were divided into three groups according to their body mass: Group 1 (n = 12) <10 kg, Group 2 (n = 13) 10 kg to 20 kg, and Group 3 (n = 13) >20 kg.
  
  
  METHODS
  The relationship of iMg(2+) among the three groups of different body mass were analyzed at five different time intervals during the operation: induction of anesthesia, 5 minutes and 30 minutes after the onset of cardiopulmonary bypass (CPB), the beginning of rewarming, and the end of surgery.
  
  
  RESULTS
  iMg(2+) levels at 5 minutes after onset of CPB in patients weighing less than 20 kg (Groups 1 and 2) differed with those weighing more than 20 kg (Group 3) (p = 0.007 and 0.013). However, there was no difference in the iMg(2+) levels between Groups 1 and 2 (p = 0.993). In addition, iMg(2+) levels at 5 minutes after onset of bypass correlated well (r(2) = 0.66) in children with body mass less than 20 kg.
  
  
  CONCLUSIONS
  Low levels of ionized magnesium is an important finding in patients at the onset of CPB, which correlates well with the body mass of patients weighing less than 20 kg, and could be predicted by the regression curve. Based on these findings, hypomagnesemia can be prevented during CPB.
authors.affiliation: Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung Hsien, Taiwan.
authors.forename: Cheng-Yuan
authors.initials: CY
authors.lastname: Lu
authors.forename: Ping-Heng
authors.initials: PH
authors.lastname: Tan
authors.forename: Sheng-Han
authors.initials: SH
authors.lastname: Lin
authors.forename: Shen-Kou
authors.initials: SK
authors.lastname: Tsai
authors.forename: Su-Man
authors.initials: SM
authors.lastname: Lin
authors.forename: Chih-Cheh
authors.initials: CC
authors.lastname: Mao
authors.forename: Lin-Cheng
authors.initials: LC
authors.lastname: Yang
mesh_terms: D001835:Body Weight; D002315:Cardiopulmonary Bypass; D002675:Child, Preschool; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery*; D006801:Humans; D008274:Magnesium / Q000097:blood* / Q000627:therapeutic use; D008275:Magnesium Deficiency / Q000097:blood* / Q000628:therapy; D008297:Male; D016037:Single-Blind Method; D013997:Time Factors
chemical_list: D008274:Magnesium