Randomized trial to compare acceptability of magnesium sulphate administration for preeclampsia and eclampsia: Springfusor pump versus standard of care

Abstract

Introduction: In low-resource settings, magnesium sulphate (MgSO4) for preeclampsia is administered majorly through an injection into the gluteal muscles 4-hourly for 24 hours. The repeated injections are very painful and may lead to infection, abscess formation, and reduced compliance.

Objective: To determine the acceptability of Springfusor® pump for the administration of Magnesium Sulphate in preeclampsia and eclampsia.

Design: Randomized Open Label Clinical Trial.

Methods: The study was conducted at Kawempe National Referral Hospital. Eligible women had a systolic blood pressure of ≥140mmHg and or diastolic blood pressure >90mmHg, proteinuria ≥+1, and the physician's decision to start on MgSO4. Four-hundred-ninety-six participants were randomized to a Springfusor® pump group (n = 248) or control (standard of care) (n = 248) administration of MgSO4. Intervention group had a loading dose (4gm of 50% MgSO4 intravenously over 20 minutes) and maintenance therapy (1gm of 50% MgSO4 intravenously per hour for 24 hours) administered using the Springfusor®. The standard of care (SOC) group received a loading dose of 4gm of 20% MgSO4 IV over 15-20 minutes, followed by 10gm of 50% MgSO4 intramuscular (5gm in each buttock) and a maintenance dose of 5gm of 50% MgSO4 was administered IM every 4 hours for 24 hours. Both arms received the rest of the care for preeclampsia/eclampsia as per the hospital guidelines. Acceptability of the method of administration was assessed using a Likert scale (1-5; 1 and 2: acceptable and 3-5: unacceptable). Pain at the site of MgSO4 administration was assessed using a Visual Analogue Scale 1-7, (1 minimal pain and 7 worst pain). Comparisons were assessed with the Chi-square test, Mann Whitney-Wilcoxon test, and Students' t-test.

Results: Intervention arm; was more acceptable than the standard of care arm, (95.3% vs70.3%; p<0.001), had a lower median pain score, (2(CI: 2-2), vs 4(CI: 4-5) p<0.001), and fewer side effects. Maternal mortality was comparable between groups (0.8% in the intervention arm vs 1.2% in the IM arm).

Trial registration: Trial No PACTR201712002887266 (https://pactr.samrc.ac.za/).

Fig 1. Consort diagram showing participants flow.

Fig 2. The Springfusor pump with a 10 ml syringe, and flow control tubing (FCT).

The Springfusor pump applies constant pressure to a syringe using a simple spring mechanism. The infusion rate is determined by a specific FCT, which provides consistent resistance to produce a steady flow. The FCT for the loading dose delivers 4 grams of 50% MgSO4 over 20 minutes, while the one for maintenance dose administration delivers 4 grams of 50% MgSO4 over 4 hours.

Fig 3. Showing participant with Springfusor pump with magnesium sulphate administered through a cannula.

The neck suspension string on the patient’s neck enables participants mobility without fear of dislodging the cannula.