Examkin

Question

Difficulty: MediumObstetric Complications

A 34-year-old G1P0 woman at 35 weeks gestation is admitted to the labor and delivery unit for induction of labor due to preeclampsia with severe features. Upon admission, her blood pressure is 168/112 mm Hg, and laboratory studies reveal a serum creatinine of 1.1 mg/dL, platelet count of 110,000/mm³, and elevated liver transaminases. An intravenous infusion of magnesium sulfate is initiated for seizure prophylaxis, alongside continuous oxytocin for labor induction. A bolus of isotonic intravenous fluids is administered prior to initiating epidural anesthesia.

Fourteen hours later, the patient reports a sudden onset of severe shortness of breath and a cough productive of frothy pink sputum. Her temperature is 37.0°C (98.6°F), blood pressure is 160/105 mm Hg, heart rate is 112/min, and respiratory rate is 28/min. Arterial blood gas analysis on room air reveals a pH of 7.44, PaCO2 of 28 mm Hg, and PaO2 of 55 mm Hg. Physical examination reveals bilateral pitting edema of the lower extremities and diffuse crackles auscultated over the lower lung fields bilaterally. Deep tendon reflexes are 2+ and symmetric. The fetal heart rate tracing demonstrates a baseline of 145/min with moderate variability and no decelerations.

Which of the following is the most appropriate next step in the management of this patient's acute symptoms?

  1. Administer intravenous furosemideAnswer
  2. B
    Discontinue magnesium sulfate and administer calcium gluconate
  3. C
    Administer intravenous sodium bicarbonate
  4. D
    Proceed immediately to emergency cesarean delivery
  5. E
    Administer intravenous ceftriaxone and azithromycin

Answer

Administer intravenous furosemide
The correct answer is to administer intravenous furosemide. This patient has preeclampsia with severe features and has developed acute pulmonary edema. The pathophysiology of preeclampsia involves generalized endothelial dysfunction, increased capillary permeability, and increased systemic vascular resistance (elevated afterload). When this altered hemodynamic state is combined with iatrogenic fluid administration (such as the isotonic bolus routinely given before epidural placement) and the antidiuretic effects of oxytocin, patients are at a high risk for third-spacing fluid into the alveolar spaces. The clinical presentation is characterized by acute dyspnea, hypoxia, frothy pink sputum, and bilateral lung crackles. The immediate next best step is maternal stabilization with supplemental oxygen and diuresis using a loop diuretic (e.g., furosemide) to rapidly reduce pulmonary hydrostatic pressure and clear the alveolar fluid. Although delivery is the ultimate definitive treatment for preeclampsia, it must wait until the mother's respiratory status is medically stable.

Step-by-Step Solution

1
Evaluate maternal and fetal clinical stability.
The fetus is stable with a reassuring Category I tracing. However, the mother is exhibiting acute hypoxemic respiratory failure and signs of severe fluid overload.
Triage protocols in obstetrics require identifying and addressing the most critical, life-threatening derangements first.
2
Identify the etiology of the maternal respiratory distress.
The combination of severe preeclampsia, a recent intravenous fluid bolus, tachypnea, hypoxia, frothy sputum, and bilateral crackles points definitively to acute pulmonary edema.
Preeclampsia causes endothelial damage and increased systemic vascular resistance. Iatrogenic fluids (often given for epidural placement) combined with the antidiuretic effect of oxytocin easily precipitate alveolar flooding.
3
Select the most appropriate immediate intervention.
Intravenous furosemide must be administered.
Loop diuretics rapidly decrease intravascular volume and pulmonary capillary hydrostatic pressure, which clears the alveolar fluid and restores oxygenation. Maternal stabilization is mandatory before proceeding with any plans for delivery.

Key Concept

Acute pulmonary edema is a severe, life-threatening complication of preeclampsia that requires immediate maternal stabilization with loop diuretics (e.g., furosemide) and supplemental oxygen prior to definitive surgical or obstetric intervention.
Estimated Time:1m 30s
Rate this question

Topics

Obstetric Complications

More questions from this topic