title: Ionized and total magnesium concentration in patients with severe preeclampsia-eclampsia undergoing magnesium sulfate therapy.
abstract: OBJECTIVE
  As ionized magnesium is the active form of magnesium and exerts a therapeutic effect, the present study was performed to determine the levels and correlations between ionized and total magnesium under baseline and therapeutic conditions in patients with severe preeclampsia and eclampsia receiving magnesium sulfate.
  
  
  METHODS
  Fifty singleton patients with severe preeclampsia received a loading dose of 4 g of magnesium sulfate, followed by 2 g per hour as maintenance dose until 24 h after delivery, or 24 h after the last seizure in case of postpartum convulsions. Serial blood samples were taken before magnesium sulfate infusion, 30 min and 240 min after the initiation of the infusion and 4 h after the discontinuation of the drug. Data were analyzed by repeated measure ANOVA and paired t-test.
  
  
  RESULTS
  Baseline levels of total and ionized magnesium were 2.4+/-0.6 mEq/L and 1.3+/-0.5 mEq/L (mean+/-SD), respectively. Putative level of 4 mEq/L of total magnesium was not obtained in up to 42% of patients during the treatment. There was not any significant correlation between the two forms of magnesium under baseline and therapeutic conditions.
  
  
  CONCLUSIONS
  Despite the effectiveness of the standard regimen of magnesium sulfate in the treatment and prevention of eclamptic seizures, it can not provide the proposed therapeutic level of magnesium in all patients. With respect to the lack of correlation between ionized and total magnesium, further studies are necessary to investigate the superiority of measurement of ionized, rather than total magnesium, for titration of therapeutic magnesium sulfate infusion.
authors: Department of Obstetrics and Gynecology, Physiology Research Center, Kerman University of Medical Sciences, Kerman, Iran. shahnaz_aali@excite.com
authors: Bibi Shahnaz
authors: BS
authors: Aali
authors: Payam
authors: P
authors: Khazaeli
authors: Fatemeh
authors: F
authors: Ghasemi
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D003404:Creatinine / Q000097:blood; D004461:Eclampsia / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D013054:Spectrophotometry, Atomic
chemical_list: D000927:Anticonvulsants; D008278:Magnesium Sulfate; D003404:Creatinine