Tocolytic-Induced Pulmonary Edema

Epidemiology

  • Beta agonists (ritodrine, terbutaline, albuterol) are used to inhibit uterine contractions and preterm labor
  • Incidence: 0.5-5% of treated cases
  • Risk Factors
    • Use of Cortisosteroids
    • Twin Gestation
    • Fluid Overload (particularly with saline)
    • Anemia

Physiology

  • Possible Mechanisms
    • Prolonged exposure to catecholamines: increase maternal heart rate and cardiac output, as wella s cause peripheral vasodilation
    • Increased capillary permeability
    • Large volume of IVF administered in response to maternal tachycardia
    • Glucocorticoids administered in preterm labor can also contribute to fluid retention
    • Autotransfusion: due to uterine contraction during labor

Diagnosis

  • CBC: anemia
  • Albumin: decreased
  • Swan: PCWP may be normal-elevated
  • Echo: normal LV function (has been reported in cases with elevated PCWP)

Clinical Presentations

  • Hypotension (see [[Hypotension]]): may occur
  • Acute Lung Injury-ARDS (see [[Acute Lung Injury-ARDS]]): may occur in the post-partum period

Treatment

  • Oxygen
  • Supportive care
  • Discontinue beta agonists -> pulmonary edema usually resolves rapidly
  • Restart of beta agonists has been considered -> this may resume the peripheral vasodilation
  • Avoidance of corticosteroids

References

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