Asthma in pregnancy: Difference between revisions

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m (Text replacement - "Clinical Presentation" to "Clinical Manifestations")
 
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* Normal changes in pregnancy
* Normal changes in pregnancy


== Clinical Presentation ==
== Clinical Manifestations ==


* Chest tightness, shortness of breath
* Chest tightness, shortness of breath

Latest revision as of 23:13, 14 July 2020

Definition

  • Patients with asthma who become pregnant

Classification

  • Mild intermittent
    • Symptoms <2 times per week ... ...
  • Mild persistent
  • Moderate persistent
    • Daily symptoms
    • Affect usual activities ...
  • Severe
    • Continual symptoms
    • Nighttime symptoms
    • FEV1 <= 60% or predicted
    • Peak flow > 30% variability

Epidemiology

  • 4-8% of pregnancies
  • Most common chronic condition affecting pregnancy

Differential Diagnosis

  • Chronic obstructive lung disease
  • Pulmonary embolism
  • Normal changes in pregnancy

Clinical Manifestations

  • Chest tightness, shortness of breath
  • Triggers same as for asthma
    • Allergens
      • Pollen
      • Mold
      • Animals
      • Feathers
      • House dust mites
      • Cockroaches
    • Other environmental factors
    • Exercise
    • Infection
    • Stress

Investigations

  • Spirometry
    • Reversible airway obstruction with FEV1 improving by at least 12% after bronchodilator
    • See article on Asthma for further criteria

Prognosis

  • For the asthma, 1/3 of patients improve, 1/3 of patients worsen, and 1/3 of patients stay the same
    • Severe asthma is more likely to worsen
    • Changes in previous pregnancies is most predictive
    • Return to baseline within 3 months of delivery
    • Exacerbations more common during second half of pregnancy
  • For the pregnancy, mild and well-controlled asthma has excellent outcomes
  • For the pregnancy, severe or poorly-controlled can cause:
    • Hypertension
    • C section
    • Preeclapmsia
    • Stillbirth
    • Fetal growth restriction

Management

  • Treatment is safer than untreated asthma
  • Antenatal
    • Severe asthma
      • Respiratory exam
      • Peak flow measurement and spirometry
      • Review symptoms at every visit
    • All asthma
      • Influenza vaccination
      • Smoking cessation
  • General asthma control with step therapy
    • Patient education, including trigger control or avoidance
    • SABA prn
      • Albuterol preferred
    • Low-dose inhaled corticosteroids
      • Budesonide preferred in pregnancy
    • Add LABA or medium-dose corticosteroids
    • Systemic corticosteroids for exacerbations
  • Acute exacerbations
    • Humidified O2
    • Beta agonists
    • Corticosteroids
    • CXR
    • Pulse oximetry
    • Intubation
  • During labour
    • Continue medication
    • Hydration and analgesia to reduce chance of bronchospasm
    • Hydrocortisone if needed
  • Breastfeeding
    • Asthma medications not contraindicated