Magnesium sulfate during pregnancy

Magnesium sulfate during pregnancy

1. Magnesium Sulfate In Pregnancy Nurses' Manual 1

2. Introduction Magnesium sulfate is the drug of choice for preventing and treating convulsion in severe pre-eclampsia and eclampsia . Nurses' Manual 2

3. Facts On Magnesium Sulfate AKA Epsom salt 1gm of salt= 98mg elements of magnesium Is an inorganic salt with formula MgSO4 Is in the WHO model list of Essential Medicine Highly water soluble Solubility inhibited by lipids Nurses' Manual 3

4. Physiological Roles Acts as mediator for Na ⁺/ K ⁺-ATPase system. Helps in oxidative phosphorylation, glucose utilization and protein synthesis Generation of cAMP via adenyl cyclase. Control release and action of parathyroid hormone thus regulates Ca 2+ metabolism Synthesis of DNA,RNA and protein Nurses' Manual 4

5. Cardiovascular Effects Direct depressant on myocardial and vascular smooth muscle. Reduce systolic BP but no changes in DBP. Inhibit release of catecholamines from adrenal medulla. Act as anti arrhythmic and slows HR. Reduce cardiac output and vascular tone causing hypotension Nurses' Manual 5

6. Nervous System Effects Reduce release of Ach at Neuromuscular junction by antagonizing Ca 2+ ions. Reduce excitability of nerves. Act as an anti convulsant by blocking Ca 2+ channel. Nurses' Manual 6

7. Routes Iv Im as anticonvulsants Orally -as laxative Nurses' Manual 7

8. Uses In Gynae/ Obs Severe pre-eclampsia Eclampsia Preterm labour (as tocolytic agent) Prevention of cerebral palsy in preterm babies (due to its neuroprotective action) Nurses' Manual 8

9. Other uses In hypomagnesia Treatment of severe asthma exacerbation Constipation Barium poisoning Nurses' Manual 9

10. Mode Of Action Decrease acetylcholine(Ach) release from nerve endings and reduce motor end plate sensitivity to Ach. Blocks calcium channel Cause vasodilation, increase cerebral, uterine and renal blood flow Nurses' Manual 10

11. Pharmacology For anticonvulsant action Onset: IV immediate/ IM 1 hour Protein bound 30% Excretion: via urine Nurses' Manual 11

12. Advantages of MgSO4 Relatively safe drug and DOC Can be given IV/IM In appropriate dose, it doesn’t affect fetus In appropriate dose, it doesn’t sedate patient Inexpensive and is on essential drug list It is metabolized by kidney, hence doesn’t cause hepatic problems that are often associated with severe pre-eclampsia Nurses' Manual 12

13. Disadvantages Respiratory depression Respiratory arrest Nurses' Manual 13

14. Administration 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 There is MgSO4 toxicity MgSO4 is not available Nurses' Manual 14

15. In Health Centre Loading dose: Wash hand properly and dry well Tell women that she may feel warmth while the medicine is given. Nurses' Manual 15

16. Give 4 g of 20% MgSO4 solution IV slowly over 5-15 min. Take one 20ml sterile syringe Draw 8ml(4g) of MgSO4 50% into syringe. Add/dissolve with 12ml of sterile water for injection to make a solution of 20%. Observe for any complications while giving. Nurses' Manual 16

17. Follow promptly with 10g of 50% mgso4 Give 5 g in each buttock as deep IM with 1ml of 2% lignocaine. Take two 10 ml syringe D raw 5g of MgSO4 (50%) i.e. 10ml in each syringe with 1ml of 2% lignocaine. Inject 1 st syringe by deep IM injection into 1 buttock(5g of mgso4) . Inject second syringe by deep IM into another buttock(5g mgso4) Nurses' Manual 17

18. Place needle and syringe in puncture proof container Remove gloves and discard properly Wash hand thoroughly with soap and water If convulsant reoccur after 15minutes, give 2g of mgso4(4ml) IV over five minutes. Rationale: Pre-eclampsia can quickly develop into eclampsia Shaking during transport is a convulsion stimulus Nurses' Manual 18

19. In Hospitals Loading dose -same as above Maintenance dose: 5 g of Mgso4 with 1ml of 2% lidocaine in the same syringe by deep IM every 4 hrs. in alternate buttock If no signs of toxicity , give next IM dose after 4 hours. Nurses' Manual 19

20. Maintaining IV dose: Continue treatment for 24 hours after childbirth or the last convulsion, whichever occur last. Nurses' Manual 20

21. TIPS 20% MgSO4 Solution Recommended for IV injection 50% MgSO4 Solution Recommended for IM injection 21 Nurses' Manual

22. Monitoring Signs Of Toxicity Count Respiration rate for 1 minute every hour, should be ≥ 16 Check Patellar reflex q. 4 hours , should be present Measure Urine output , should be ≥30ml/hr. Measure BP Measure serum magnesium level ( 1.7 to 2.2  mg /dL) Nurses' Manual 22

23. MgSO4 toxicity Nurses' Manual 23 BURP B P U rine output R espiration rate P atellar reflex absent

24. NOTE Repeat dose of MgSO4 should be withheld or delayed if Signs of toxicity are seen. Nurses' Manual 24

25. Antidote Keep antidote ready. In case of respiratory arrest: Assist ventilation(bag & mask ,anesthesia , intubation) Give Calcium Gluconate 1g(10ml of 10% solution) IV slowly over 3 minutes , until respiration begins to counteract effects of MgSO4 Nurses' Manual 25

26. Side Effects It is relatively safe drug Diminished knee jerk Respiratory failure Flushing Sweating Hypotension GI disturbances Hypothermia Circulatory collapse, cardiac and CNS depression Nurses' Manual 26

27. Contraindications of MgSO4 Renal function impairment Heart block, myocardial damage Myasthenia gravis Drug interaction: with Nifedipine Nurses' Manual 27

28. Nursing Consideration Assess vital signs with in 15min after IV dose Monitor serum magnesium level if used during labor, contractions and intensity Assess urine output and notify physician if ≤30ml/hour Examine patellar reflex. Use seizure precautions Nurses' Manual 28

29. Attention !!! Administration can be very painful, so administer it deep IM in gluteal region using 3-inch-long 20G needle 1ml of 2% xylocaine is added to reduce pain Each injection should be preceded by aspiration to ensure tip is not in blood vessel. Massaging buttocks after injection will help disperse magnesium in tissue. Nurses' Manual 29

30. 1. Is Magnesium sulphate dangerous? After administration, about 30% of plasma magnesium is protein bound. 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. 30 Nurses' Manual

31. 2. Is Magnesium sulphate dangerous in pregnancy ? 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! 31 Nurses' Manual

32. Why is Eclampsia still a major cause of maternal deaths in Nepal? 32 Nurses' Manual

33. Nurses' Manual 33