A low dose ("Dhaka") magnesium sulphate regime for eclampsia

Eclampsia remains a common cause of maternal death in Bangladesh. Early experience of magnesium sulphate use for eclampsia in Bangladesh was based on a lower dose regime, tailored for use in the smaller woman.

a) To determine the recurrent convulsion rate with the low dose "Dhaka" magnesium sulphate regime (recognizing the limitations of sample size). b) To identify whether toxicity occurs with this regime. c) To measure serum level of magnesium with this regime.

This prospective study included 65 eclamptic patients receiving lower dose magnesium sulphate therapy at Dhaka Medical College Hospital from 25 March 1998-15 June 1998. The loading dose of magnesium sulphate was 10 gm. Following this 2.5 gm was given intramuscularly 4 hourly, for 24 hours after administration of the first dose. Four blood samples were collected for serum magnesium levels. Patients were monitored hourly by observing their respiratory rate, knee jerks and urinary output. Findings were matched with serum magnesium levels.

The range of serum magnesium levels was 1.74 to 6 mg/dl with mean (s.d.) values of 3.87 (0.78). Only five (9%) patients had diminished knee jerks 6, 10, 12, 12 and 15 hours after administration of the loading dose. But at those times the serum magnesium levels were 3.2 mg/dl, 3.8/dl, 3.4 mg/dl and 3.3 mg/dl respectively. Of the 65 patients, only one developed recurrent convulsions. This was 3 hours after the loading dose and was controlled by diazepam treatment and maintenance magnesium sulphate.

Half of the standard dose of magnesium sulphate appeared to be sufficient to control convulsions effectively and serum levels of magnesium remained lower than levels which produce toxicity.