Severe Preeclampsia at 36 Weeks: Magnesium Sulfate Safety
A 32-year-old woman, G2P1, at 36 weeks of gestation attends the antenatal clinic with a severe frontal headache and blurred vision for the past day. She also reports epigastric pain. Her blood pressure is 158/104 mmHg on two readings four hours apart; urine dipstick shows 3+ protein. She has hyperreflexia with two beats of clonus. Fetal heart rate is 142/min and the nonstress test is reactive. The obstetrician orders magnesium sulfate 4 g IV loading dose over 20 minutes followed by 1 g/hour infusion, plus labetalol 100 mg orally. The unit has calcium gluconate available. The patient asks whether she can go home after the injection because her first child is alone with a neighbour.
1. Classify her hypertensive disorder and identify the features that make it severe.
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She has severe preeclampsia. Hypertension of 158/104 mmHg after 20 weeks of gestation with 3+ proteinuria establishes preeclampsia. Severe features are present: severe headache, blurred vision, epigastric pain, and hyperreflexia with clonus. These indicate central nervous system irritability and a risk of eclamptic seizure, and epigastric pain may reflect hepatic capsule distension. She needs inpatient care, magnesium sulfate, blood pressure control, and planning for delivery at 36 weeks, because delivery is the definitive treatment. She should not be managed as an outpatient.
2. Outline the nursing assessments you would perform during and after the magnesium sulfate loading dose, including the specific parameters for withholding the infusion.
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Before and during the loading dose: record baseline pulse, respiratory rate, blood pressure, oxygen saturation, deep tendon reflexes, urine output, and level of consciousness. Give magnesium sulfate via an infusion pump and keep calcium gluconate 1 g (10% 10 mL) at the bedside. During the infusion, check respiratory rate every 15 minutes, deep tendon reflexes hourly, and urine output hourly. Withhold the infusion and notify the obstetrician if the respiratory rate falls below 16/min, the patellar reflex disappears, urine output falls below 30 mL/hr, or the patient becomes drowsy or confused. These are signs of magnesium toxicity. Also monitor the fetal heart rate continuously or by auscultation every 15 minutes, and watch for vaginal bleeding, contractions, or reduced fetal movement.
3. How would you respond to her request to go home, and what would you prioritise in her ongoing care?
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I would explain that she cannot go home: her blood pressure and symptoms mean she is at risk of a seizure, and magnesium sulfate requires continuous monitoring. I would acknowledge her childcare concern and ask the ASHA or a family member to arrange care for her first child, or involve the hospital social worker. I would keep her in a quiet, dim room, minimise stimulation, maintain seizure precautions with padded side rails and suction ready, continue labetalol as ordered, monitor blood pressure every 15–30 minutes initially, and prepare her for possible delivery. I would document the counselling and her concerns.