Magnesium sulphate in the Management of Eclampsia in Malawi Dr. Chisale Mhango FRCOG 1 NPC Training in MNH

Objectives of Use of MgSO4 in the Eclampsia Management 1.To prevent severe pre-eclampsia progressing to eclampsia (life- threatening convulsions). 2.To stop the convulsions of eclampsia. 2 NPC Training in MNH

Evidence of Effectiveness of Magnesium sulphate 1.In a series of 300 consecutive cases, of eclampsia, Pritchard in Texas USA achieved 100% survival 2.A 1998 review concluded that it is effective in preventing convulsions in women who have severe pre-eclampsia and in stopping convulsions in eclamptic women. (Obstetrics and Gynaecology, Vol. 92, pp ). 3 NPC Training in MNH

Local guidelines on use of magnesium sulphate Health Centre – All pre-eclampsia and eclampsia patients shall be referred to the hospital immediately after admission. – Give first dose (correct loading dose) to prevent progression of severe pre-eclampsia to eclampsia or stop fits and then refer to hospital. – On the way to hospital patient must be accompanied by an experienced clinician to stabilise patient during transit. Hospital – Give MgSO4 to prevent progression of severe pre-eclampsia to eclampsia as per national guidelines depending on whether or not the patient already has a loading dose at source. – Follow national protocol for the management of the eclamptic patient 4 NPC Training in MNH

Use of Valium NB MgSO4 is the drug of choice in all circumstances – it should always be available at both health centre and hospital levels Give diazepam 10 mg (2 ml) over 2 minutes if – Convulsions recur after giving MgSO4 – Convulsions occur early in pregnancy – There is MgSO4 toxicity – MgSO4 is not available 5 NPC Training in MNH

Administration of magnesium sulphate Health Centre Loading dose: 4 grams IV (over 5-15 min) plus 10 grams IM, – 5 grams IM in each buttock: deep intramuscular injection with 1ml 2% lignocaine or 2ml 1% lignocaine Rationale: – Pre-eclampsia can quickly develop into eclampsia – Shaking during transport is a convulsion stimulus – There is no risk of overdose after loading dose even in a woman with anuria. Hospital Loading dose: 4grams IV plus 10 grams IM (5 grams IM in each buttock) Maintenance dose: 5 grams IM every 4 hrs.. in alternate buttock NB a.Check for reflexes before giving the maintenance dose b. At least 100ml urine /4 hrs. c. At least 16 breaths/minute 6 NPC Training in MNH

Administration of MgSO4 20% MgSO4 Solution Recommended for IV injection 20% solution means 20g/100ml, i.e.. 4g/20ml. – i.e.. Give 20ml 20% solution IV over 5-15 minutes 50% MgSO4 Solution Recommended for IM injection 50% solution means 50g/100ml, i.e. 5g/10ml. – i.e.. Give 10ml solution IM 7

Administration in Hospitals with High Dependency Wards IV MgSO4 is the initial drug administered to terminate seizures and lower BP. Seizures usually terminate after the loading dose of magnesium. A loading dose of 6 g (15-20 min) and a maintenance dose of 2 g per hour as a continuous IV solution (preferably using a pump to administer). 8 NPC Training in MNH

1. Is Magnesium sulphate dangerous? After administration, about 40% of plasma magnesium is protein bound. The clinical effect and toxicity of MgSO4 can be linked to its concentration in plasma. – The unbound magnesium ion diffuses into the extravascular- extracellular space, into bone, and across the placenta and foetal membranes and into the foetus and amniotic fluid. Magnesium is almost exclusively excreted in the urine, with 90% of the dose excreted during the first 24 hours after an intravenous infusion of MgSO4. Hence the need to monitor urine output in patients receiving the drug. 9 NPC Training in MNH

2. Is Magnesium sulphate dangerous? MgSO4 toxicity is rare when it is carefully administered and monitored. Studies show that the benefits of MgSO4 may outweigh the risks to her and to her baby. The answer to this question is NO! 10 NPC Training in MNH

Do we need to control MgSO4 concentration in PIH management? In pregnant women, apparent volumes of distribution usually reach constant values between the third and fourth hours after administration, and range from to L/kg. A concentration of 1.8 to 3.0 mmol/L has been suggested for treatment of eclamptic convulsions. The answer to this question is NO! 11 NPC Training in MNH

Why is Eclampsia still a major cause of maternal deaths in Malawi? 1.Fear of use of MgSO4 by clinicians 1.Unjustified fear of fatal side-effects 2.Lack of training/confidence in use of drug 2.Late initiation of drug 1.Most patients develop eclampsia at home 2.Health centres not using MgSO4 3.Inappropriate use of drug 1.Lack of relating fluid balance to dosage of drug 12 NPC Training in MNH

Antidote for MgSO4 In the rare situations when the patient is found to have no reflexes and not breathing wells after MgSO4 the antidote is: Calcium gluconate(10%) 10 mls. IV over 10 minutes, especially if there is < 16 breaths/minute or no reflexes. 13 NPC Training in MNH

Can Magnesium be Administered in Combination with Other Drugs? Avoid the use of multiple agents to abate eclamptic seizures, unless necessary. Antihypertensive can be used together with MgSO4 Only where there is pulmonary oedema can a diuretic be used – otherwise diuretics are contraindicated in management of eclampsia Steroids may be administered in anticipation of delivery when gestational age is < 34 weeks. – Betamethasone (12 mg IM q24h × 2 doses) or dexamethasone (6 mg IM q12h × 4 doses) is recommended. 14 NPC Training in MNH

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