Body Weight-Related ionized hypomagnesemia in pediatric patients undergoing cardiopulmonary bypass for surgical repair of congenital cardiac defects.
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.
Lu
Cheng-Yuan
CY
Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung Hsien, Taiwan.
Tan
Ping-Heng
PH
Lin
Sheng-Han
SH
Tsai
Shen-Kou
SK
Lin
Su-Man
SM
Mao
Chih-Cheh
CC
Yang
Lin-Cheng
LC
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
D008274:Magnesium