Respiratory Complications and Management in Pregnancy: Insights from Asthma, Influenza, ARDS, and COVID-19

• Respiratory Changes During Pregnancy:
  • Pregnancy leads to numerous physiologic changes in the respiratory system.
  • These changes can affect oxygen consumption, metabolic rate, minute ventilation, tidal volume, and arterial blood gas measurements.
• Asthma in Pregnancy:
  • Asthma is a common pulmonary problem in pregnant women, affecting approximately 8% of pregnancies.
  • Untreated asthma can lead to adverse pregnancy outcomes such as low birth weight, preeclampsia, preterm birth, and stillbirth.
• Effects of Asthma on Pregnancy:
  • Asthma exacerbations before 24 weeks' gestation are more frequent, and fetal sex may influence asthma symptoms in pregnant women.
  • Maternal asthma is associated with an increase in low-birth-weight infants, intrauterine growth restriction, preterm delivery, and preeclampsia.
• Management of Asthma in Pregnancy:
  • Monitoring pulmonary function using FEV1 is important, and inhaled beta-agonists are commonly used in asthma treatment.
  • Inhaled corticosteroid therapy is recommended as first-line antiinflammatory treatment, and systemic corticosteroids should be reserved for acute exacerbations.
• Effects of Pregnancy on Asthma:
  • The course of asthma may be affected by pregnancy, with some women experiencing improvement, while others see no change or worsening of symptoms.
  • Various medications are used for asthma treatment during pregnancy, and monitoring pulmonary function is crucial.
• Physiologic Changes and Management Guidelines:
  • Guidance is provided to critical care specialists encountering pregnancies complicated by acute pulmonary complications.
  • National Asthma Education and Prevention Program issued specific guidelines for diagnosis and treatment of asthma among the gravid population.
• Treatment of Asthma in Pregnancy:
  • Mild asthma is characterized by FEV or PEFR ≥80% with brief exacerbations lasting less than 1 hour. Treatment includes inhaled beta-2-agonist.
  • Moderate asthma is characterized by FEV or PEFR ranging from 60% to 80% with exacerbations more than twice per week, often lasting several days. Treatment includes inhaled corticosteroids and inhaled beta-2-agonist.
• Pulmonary Edema in Pregnancy:
  • Pulmonary edema can be cardiogenic or noncardiogenic and is associated with hypertensive disease, tocolytic therapy, multiple gestations, subclinical infection, and underlying cardiovascular disease.
  • Treatment depends on the etiology and may include diuretic therapy, vasodilators, and hemodynamic monitoring for unclear cases.
• Acute Respiratory Distress Syndrome (ARDS) in Pregnancy:
  • Causes of ARDS in pregnancy include preeclampsia, sepsis, aspiration, pyelonephritis, and intrauterine infections.
  • Management includes maternal stabilization, fetal monitoring, investigation of underlying causes, evaluation for delivery, and a lung-protective ventilator strategy to improve outcomes.
• Management of ARDS in Pregnancy:
  • Prone positioning is indicated, fetal surveillance may be more difficult, and tocolytic therapy should be carefully considered.
• Timing of Delivery:
  • Authors recommend delivery after stabilization, while others have failed to demonstrate significant benefit to delivery. Delivery should be considered on a case-by-case basis.
• Use of ECMO:
  • ECMO support has been used successfully with high maternal and fetal survival rates, especially if the fetus is viable.
• Embolism Risk:
  • Increased risk of venous thromboembolism in pregnancy, and cesarean section confers a higher risk than vaginal delivery.
• Treatment of Pulmonary Embolism in Pregnancy:
  • Immediate therapy based on suspicion, use of appropriate diagnostic imaging tests, and maintenance of maternal and fetal oxygenation.
• Anticoagulation Therapy:
  • Low-molecular-weight heparin is the anticoagulant of choice in antepartum patients, and warfarin should be avoided if possible during pregnancy.
• Amniotic Fluid Embolism:
  • Rare phenomenon with severe respiratory distress, risk factors include rapid labor and uterine rupture, and supportive treatment with high maternal mortality.
• Pneumonia in Pregnancy:
  • Seriousness of influenza infection in pregnant patients, increased risk of hospitalization in the third trimester, and contemporary management includes the use of antiviral medications.
• Influenza and COVID-19 in Pregnancy:
  • Amivir and Relenza are recommended for preventing influenza infection in pregnant women.
  • Pregnant women with influenza symptoms in the first 48 hours should start medication immediately as it significantly reduces morbidity and mortality.
• Physiological Changes and Risk Factors:
  • Pregnancy causes physiological changes increasing susceptibility to respiratory compromise.
  • Chronic lung disease, diabetes, and cardiovascular conditions are more common in pregnant women with COVID-19.
  • Pregnant women with COVID-19 have a higher risk of hospitalization, ICU admission, mechanical ventilation, and death.