Assessment of magnesium sulphate usage in pre-eclamptic and eclamptic women in Omdurman Maternity Hospital, 2017: A cross-sectional study

Introduction

Preeclampsia/eclampsia is a pregnancy-specific disease with multisystem physiological disorder, which may lead to increased risk of maternal and perinatal mortality and morbidity¹. Regarding etiology, no clear cause has been defined, but some reports indicate that oxidative stress and placental defects during early pregnancy may represent the main causes². Preeclampsia is defined as pregnancy-related systemic disorder, which is associated with incidence new onset of hypertension as well as proteinuria³. Eclampsia is described as the beginning of grand mal seizure symptoms in preeclamptic women⁴. Epidemiologically, around 50,000–60,000 pregnant women die due to preeclampsia/eclampsia each year, which represents around one-quarter of maternal deaths in Latin America, and approximately one-tenth of maternal deaths in Africa and Asia^5,6.

Magnesium sulphate (MgSO₄) is one of the main interventions used to decrease the morbidity and mortality from preeclampsia/eclampsia. In 2011, MgSO₄ was been strongly suggested by the World Health Organization (WHO) to be the drug of choice for both treatment and prevention of eclampsia⁷. Currently, the WHO and other international organizations recommend two MgSO₄ prophylactic protocols for eclampsia. The first one is the Pritchard regimen, in which MgSO₄ is administered intramuscularly, while it is injected intravenously in the second protocol named as Zuspan regimen⁸. MgSO₄ might be toxic in some conditions, and the toxicity depends on the serum magnesium levels, for example: loss of the knee jerk may develop at 3.5–5 mmol/l; respiratory paralysis may occur at 5–6.5 mmol/l, cardiac conduction is altered at higher than 7.5 mmol/l⁹. Meanwhile, it can lead to death if the serum magnesium exceeds 12.5 mmol due to cardiac arrest⁹.

In Sudan, preeclampsia/eclampsia is considered as one of the main factors leading to an increase in morbidity and mortality among pregnant women². There is not enough assessment data reported about MgSO₄ efficacy, benefits and risks in pre-eclamptic and eclamptic women in this setting. Thus, the present study was carried out to assess MgSO₄ usage in preeclamptic and eclamptic women in Khartoum, Sudan.

Methods

Results

As shown in Figure 1A, 62 participants were 25–34 years (~48%). About 34% of participants were 15–24 years and only 18% were 35–45 years old. Regarding admitting diagnosis, the majority (78%) were diagnosed with preeclampsia, while 22% were diagnosed with eclampsia (Figure 1B).

Figure 1. Participant characteristics.

Graphs showing the distribution of the study population according to (A) age; (B) admitting diagnosis; (C) MgSO₄ indication; (D) administration of loading dose of MgSO₄; (E) administration of maintenance dose of MgSO₄

Every patient recruited to the study was followed up while they received MgSo4 therapy. During follow-up some of the preeclamptic women developed eclampsia; therefore, the ratio of preeclampsia:eclampsia became 88:42 instead of 101:29.

MgSO₄ was used as a prophylactic agent in 88 preeclamptic women and as treatment for 42 eclamptic women, as shown in Figure 1C. Moreover, magnesium sulphate was administered as a loading dose in 51 (39.2%) patients, while most treated patients (98.5%) were administered a maintenance dose of MgSO₄ (Figure 1D and E).

To avoid practitioner-related errors, patients’ vital signs and parameters must be monitored frequently during MgSO₄ administration¹¹. In this study, only vital signs (Pulse Rate, Blood Pressure, Respiratory Rate, and Pulse Oximeter) were checked ten minutes after starting loading dose (LD). At the end of LD, 4 hourly checks were performed during maintenance dose (Figure 2A). Other important parameters, such as urine output and deep tendon patellar reflexes, were checked in 42% and 25% of patients, respectively.

Figure 2. Outcomes of patients after magnesium sulphate administration for preeclampsia/eclampsia.

(A) Parameters monitored after MgSO₄ administration; (B) distribution of study population according to seizure outcome after administration of MgSO₄.

Regarding outcomes after administration of MgSO₄, the majority of patients (121; 93.1%) had controlled seizures (Figure 2B). Only one patient developed MgSO₄ toxicity (respiratory paralysis).

Discussion

Being pregnant at age 35 or more is one of the highest risks of developing preeclampsia/eclampsia¹², however, in the present study the 25–34 year age group was the largest age group of women with preeclampsia/eclampsia. MgSO₄ is considered as the golden choice for treatment and prevention of eclampsia, as endorsed by the WHO⁷. Therefore, it is no wonder that MgSO4 has been used to control every admitted eclamptic/preeclamptic case included in the present study.

Regarding the administration protocol, MgSO4 must be given by either Pritchard or Zuspan regimen. In Pritchard regimen, a loading dose of 4 g is injected intravenously, then a maintenance dose will be started immediately by intramuscular injections of 10 g followed by 5 g 6 times/day. In Zuspan regimen, 4 g dose is given a loading dose, then maintenance dose by using 1 to 2 g/h controlled infusion pump¹³. In present study, poor practice is observed as 61% of admitted patients didn’t receive loading doses and two patients didn’t receive maintenance dose.

Some reports indicate that the rate of eclamptic seizures was recorded as being lower than 35% of all recruited cases after using MgSO₄, while in present study the rate of uncontrolled-recurrent seizures was only 7% after using MgSO₄¹⁴. In this study, no patient died as a result of using MgSO₄ whereas some literature indicates that “if MgSO₄ was universally prescribed for all pre-eclamptic pregnant women, the death from magnesium toxicity may be more than that from seizures”¹⁴. On the other hand, the prevalence of MgSO₄ toxicity is very mild and only one toxicity case had been reported worldwide to date¹⁵.

Conclusion

Although practitioners in the present study did not properly adhere to MgSo4 protocol, the successful output of its usage as a treatment for eclampsia and prophylaxis for pre-eclampsia was shown by the majority of patients (93.1%) only having controlled seizures, with only one patient developing toxicity.

Practitioners’ adherence to MgSo4 protocol should be assured in the future to increase the percentage of the well-controlled patients.

Data availability