Prehospital Management of Preeclampsia with Magnesium Sulphate: Report

This report provides a comprehensive overview of magnesium sulphate and its application in managing preeclampsia and eclampsia within the prehospital setting, referencing Queensland Health guidelines. It defines preeclampsia, its diagnostic criteria, and the pharmacological actions of magnesium sulphate, including administration routes, dosages, and treatment criteria. The report details the drug's effects on the nervous and cardio-respiratory systems, as well as its impact on the fetus and interactions with other drugs, such as nifedipine. It also outlines the implications of introducing new pharmacology into paramedic practice, emphasizing the importance of monitoring blood pressure, considering drug interactions, and recognizing the signs and symptoms of preeclampsia. The report includes references to relevant literature and guidelines, offering a detailed analysis of prehospital management strategies for this critical condition.

MAGNESIUM SULPHATE AND THE MANAGEMENT OF PREECLAMPSIA/ECLA
PREHOSPITAL SETTING
Definition
Preeclampsia is a hypertensive disorder that occurs in pregnant women between 20 weeks of gestation and thirty days postpartum. The diagnosis is determined by a syst
140mmHg and a diastolic pressure above 90mmHG (Gordon et al., 2014).
Pharmacological Actions of Magnesium Sulphate
Administration
Most preferred routes are an intramuscular injection(IM) and intravenous infusion (IV).
Start dose- 4g in 20% of Normal saline solution followed by 5g in 50% solution intramuscular injection on each
buttock.
In IM injection, a maintenance dose of 5g in 50% solution is usually prescribed four hourly.
For IV injection, after a loading dose of 4g, a maintenance dose of 1g is administered hourly after the last episode of
seizure(Duhig and Shennan, 2015).
The dose can be altered 2-4g depending on the mother’s weight or status change of the condition
Dissemination and plasma amounts
A loading dose of 4g immediately rises in plasma levels for about 3.0mmol/l and then reduces to up to 1.5mmol/l in
an hour (Peres et al., 2018)
A dosage of 1g/h reaches 1.7mmol/l after a day, at 2g/h go up to 2.2mmol/l in six hours.
Excretion
Half of the magnesium sulfate is excreted in four hours after administration.
Magnesium sulfate Considered as among the first cleaning drug
Take caution in cardiac and respiratory failure(Duhig et al., 2018).
Toxicity
Toxicity is experienced when plasma levels are over 5mmol/l
Signs and symptoms of toxicity include respiratory distress, nausea, tendon flexes, malaise, and blurred vision.
If the plasma levels of magnesium sulfate exceed up to 6.3 -7.1, there is possible muscle paralysis and cardiac arrest.
A dose of 1g magnesium gluconate is used to correct toxicity(Jana et al., 2018).
Effect on the nervous system
Can work at the peripheral neuromuscular junction with less significant effects or at central nervous system blocking
the neural junctions(Duhig and Shennan, 2015)
In preeclampsia, Magnesium sulfate acts directly on CNS causing the release of excitatory transmitter(acetylcholine)
leading to reductions of convulsions(Duhig and Shennan, 2015).
Effect on the cardio-respiratory system
Leads to a drop in blood pressure which may lead to hypotension in high dosages
Due to its fast clearing, the above effect is rare to manifest clinically(Peres et al., 2018).
Weakens the heart and lower heart rate since it has inotropic effects.
Respiratory rates gradually drop with the use of magnesium sulfate(Peres et al., 2018)
Effect on fetus
Really crosses the placenta creating an equilibrium
Long periods of administration can raise the levels of magnesium in amniotic fluid.
After birth, magnesium in breast milk gradually drops in 24 hours (Duhig and Shennan, 2015
No risk is usually associated as healthy babies can easily create magnesium
Effects on Contractions
Magnesium sulfate neither long labor or increase risks for undergoing a cesarean section. (Peres et al., 2018)
Interaction with other drugs(nifedipine)
Nifedipine is normally used along magnesium sulfate to control hypertension.
Major side effects of their interaction are hypotension thus increasing magnesium sulfate toxicity
Use both drugs in caution and when necessary (Jana et al., 2018).
Current guideline and comparison to contemporary evidence
The basic objective in preeclampsia is to control blood pressure and prevent the develop
eclampsia (Queensland Ambulance Service, 2019).
If eclampsia occurs, the goals change to seizures management and hypoxia prevention i
and child (Queensland Ambulance Service, 2019).
Treatment
Criteria
Infuse IV fluids and magnesium sulfate in patients
with eclampsia (Queensland Ambulance Service,
2019).
Magnesium sulfate is the first line of treatment
where there are high risks for eclampsia followed by
midazolam as a second-line treatment.
With the presence of symptoms, take the patient to
the hospital as soon as possible
Make a proper diagnosis of eclampsia as some
conditions like epilepsy may present with similar
symptoms (Queensland Ambulance Service, 2019).
A 20mmol dose should be infused in a 30ml syringe
to attain the required concentration and then
administered over 20 minutes
Only a loading dose should be given, then the
patient should be taken to the hospital for
maintenance doses and further review.
Implications of introducing new
pharmacology into paramedic
practice
Always check the blood pressure before treatment,
treat only when it above 140/90 mmHg
It is important to initiate midazolam in refractive
seizure thus care should be taken during the
assessment
Consider drug interaction and adverse effects
while using other blood pressure drugs
Drugs interaction may be different in each
individual thus its better to check for any toxicity or
hypersensitivity symptom
References
DUHIG, K., VANDERMOLEN, B. & SHENNAN
A. 2018. Recent advances in the diagnosi
management of pre-eclampsia.F1000Res,7,
242.
DUHIG, K. E. & SHENNAN, A. H. 2015. Rec
advances in the diagnosis and manageme
pre-eclampsia.F1000Prime Rep,7, 24.
GORDON, R., MAGEE, L. A., PAYNE, B., FIR
T., SAWCHUCK, D., TU, D., VIDLER, M., DE
SILVA, D. & VON DADELSZEN, P. 2014.
Magnesium sulphate for the management
preeclampsia and eclampsia in low and
middle income countries: a systematic rev
of tested dosing regimens.J Obstet Gynaecol
Can,36, 154-163.
JANA, N., BARIK, S. & ARORA, N. 2018. Re
Clinical practice patterns on the use of
magnesium sulphate for treatment of pre
eclampsia and eclampsia: a multi-country
survey: Magnesium sulphate regimens for
eclampsia: should we adopt same 'gold
standard' for all women?BJOG,125, 909.
PERES, G. M., MARIANA, M. & CAIRRAO, E.
2018. Pre-Eclampsia and Eclampsia: An
Update on the Pharmacological Treatmen
Applied in Portugal.J Cardiovasc Dev Dis,5.
QUEENSLAND AMBULANCE SERVICE. (201
Drug Therapy Protocols: Magnesium
Sulphate. Queensland: Queensland
Signs and Symptoms
Headache
Visual problems
Vomiting or nausea
High blood pressure, acute
pulmonary edema
Jaundice