This document provides guidelines for using magnesium sulfate to treat pre-eclampsia and eclampsia. It defines pre-eclampsia and eclampsia and describes magnesium sulfate as an anticonvulsant rather than antihypertensive. It outlines the loading dose and maintenance dose regimens for magnesium sulfate, including administration routes and amounts. It also describes monitoring patients for magnesium toxicity and lists contraindications. The document aims to instruct medical professionals on safely and effectively using magnesium sulfate to prevent and control seizures in women experiencing pre-eclampsia or eclampsia during pregnancy.

1. MR. BASAVARAJ HUKKERI
BELAGAVI KARNATAKA

2.  Pre-eclampsia is a disorder of pregnancy, characterized
by hypertension (BP > 140/90 mmHg measured 2 times
with interval ≥ 4 hours) and proteinuria (urinary excretion
of ≥ 1+or more protein in dipstick) after the 20th weeks
of gestation in a previously normotensive and non-
proteinuric woman.
 Pre-eclampsia when complicated with generalized tonic
clonic convulsion and/or coma is called Eclampsia.

3.  Severe pre-eclampsia is defined by a systolic BP ≥ 160
mmHg or a diastolic BP ≥ 110 mmHg twice 4 hour
apart at bed rest with or without the following end-organ
findings: Proteinuria of ≥5 gm in a 24-hour urine
specimen (or 3+ on random urine dip on two occasions at
least 4 hours apart), Oliguria (<500 mL in 24
hours), Neurologic or visual disturbances (including
headache), Pulmonary edema, Elevation of
transaminases, Epigastric or right upper quadrant pain,
Thrombocytopenia, Fetal growth restriction or Eclampsia.

4.  Magnesium sulfate is an anticonvulsant rather than
an anti-hypertensive. It prevents seizures in pre-
eclampsia and doesn’t treat hypertension. In
eclampsia, it is given as soon as the convulsion has
ended. It causes vasodilation, increases cerebral,
uterine and renal blood flow. It decreased cerebral
edema.

5.  “x” % of Magnesium sulfate contains “x” gm in 100 ml
 1 ampoule contains 50% of 2 ml Magnesium sulfate
 1 ampoule contains 1 gm of Magnesium sulfate in 2 ml
 4 ampoule provides 4 gm of Magnesium sulfate in 8 ml
 To prepare 20% of 4 gm Magnesium sulfate, “y” ml of Normal
saline (NS) must be added:
◦ 20 gm/100 ml = 4 gm/(8 ml + “y” ml)
◦ 8 + “y” = 20
◦ “y” = 12

6. a. Loading dose:
 Initially: 4 gm of 20% MgSO4 IV over not less than 3
minutes
 Take one 20 ml syringe
 Draw 4 ampoules of Magnesium sulfate
 Add 12 ml Normal saline

7. Immediately followed by: 10 gm of 50% MgSO4 IM (5
gm in each buttock)
 Take two 10 ml syringes
 Draw 5 ampoules of MgSO4 in each syringe
 Add 1 ml of 2% Lignocaine in each syringe
 Give deep IM in each buttocks

9. If convuslion persists after 30 minutes: 2 gm of 50%
MgSO4 IV bolus over 5 minutes
 Take one 10 ml syringe
 Draw 2 ampoules of Magnesium sulfate
 To prepare 20% of 2 gm Magnesium sulfate, “y” ml
of Normal saline (NS) must be added:
◦ 20 gm/100 ml = 2 gm/(4 ml + “y” ml)
◦ 4 + “y” = 10
◦ “y” = 6

10. b. Maintenance dose:
 5 gm of 50% MgSO4 IM 4 hourly in alternate buttocks
 Take one 10 ml syringe
 Draw 5 ampoules of MgSO4
 Add 1 ml of 2% Lignocaine in each syringe
 Give deep IM 4 hourly in alternate buttocks
 Continue for 24 hours after the last convulsion or
delivery whichever is later.

11. Monitoring Hourly for Magnesium Sulfate toxicity:
 Suspend or postpone use of Magnesium sulfate, if any of
the following is present:
 Respiratory rate < 16/min (Respiratory depression)
 Absent patellar reflex (Muscle paresis)
 Urine output < 30 ml/hour in preceding 4 hours (Impaired
renal function)
 Note: Loss of patellar reflex is the 1st sign of Magnesium
toxicity: The therapeutic level of serum magnesium is 4-7
mEq/l. Serum levels of Magnesium toxicity

12.  8-12 mEq/l: Loss of patellar reflex, flushing, warmth,
somnolence, slurred speech
 15-17 mEq/l: Muscular paralysis, Respiratory difficulty
 30-35 mEq/l: Cardiac arrest

13. a. If urine output < 30 ml/hour:
 MgSO4 withheld
 IV ringer lactate infusion 1 liter over 8 hours
 Monitor for pulmonary edema
b. If respiratory arrest occurs:
 Perform assisted ventilation
 Antidote: Calcium gluconate 1 gm (10% of 10 ml) IV
slowly over 10 minutes

14. Contraindication of Magnesium Sulfate:
 Myasthenia gravis
 Impaired renal function
Note: Researches have found that the Zuspan regimen
is upto 8 times less effective than the Pritchard
regimen in preventing convulsions in severe pre-
eclampsia and eclampsia.

15. THANK U