Question

A 28-year-old pregnant woman at 34 weeks gestation is diagnosed with severe preeclampsia. The decision is made to start magnesium sulfate using the Pritchard regimen for seizure prophylaxis. What is the correct loading dose of magnesium sulfate in this regimen?

• A. 4 gm IV
• B. 6 gm IV + 5 gm IM each buttock
• C. 14 gm total
• D. 20 gm total

Hint:

Pritchard regimen loading dose = 4 gm IV + 5 gm IM in each buttock = 14 gm total.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the specific components of the "Pritchard Regimen" for Magnesium Sulfate (MgSO\(_4\)) administration in Eclampsia/Severe Preeclampsia.
Step 2: Detailed Explanation:

Magnesium Sulfate: The drug of choice for the prevention and treatment of eclamptic seizures. It works by reducing neuromuscular irritability and causing some cerebral vasodilation.

Pritchard Regimen (The IM Regimen): This is the standard protocol used in many settings where continuous IV monitoring is difficult.

Loading Dose Components:
- IV component: 4 gm of MgSO\(_4\) (as a 20% solution) is given slowly intravenously over 5-10 minutes.
- IM component: 10 gm of MgSO\(_4\) is given as a deep intramuscular injection (5 gm in each buttock as a 50% solution).
- Total Loading Dose: \(4 \text{ (IV)} + 10 \text{ (IM)} = 14 \text{ gm total}\).

Maintenance Dose: 5 gm IM (50% solution) is given every 4 hours in alternating buttocks, provided the patient has: 1. Patellar reflex present. 2. Respiratory rate \(> 12/\text{min}\). 3. Urine output \(> 30 \text{ ml/hr}\).

Comparison (Zuspan Regimen): This is a purely IV regimen involving a 4-6 gm IV load followed by a 1-2 gm/hr IV maintenance infusion.

Step 3: Final Answer:
The total loading dose of the Pritchard regimen is 14 gm (4 gm IV + 10 gm IM).