Hyperventilation Syndrome

Basics

Description

  • Hyperventilation syndrome (HVS) is characterized by excessive ventilation beyond metabolic needs, leading to respiratory alkalosis and a constellation of symptoms:
    • Most commonly: Dyspnea, chest pain, lightheadedness, paresthesias, and a sense of doom
  • Often associated with anxiety disorders, but can also occur independently or in the presence of cardiopulmonary or neurologic conditions
  • Minute ventilation may be increased by increasing respiratory rate or tidal volume (sighs)
  • Symptoms result from inappropriate alveolar hyperventilation causing a decrease in PaCO2 and respiratory alkalosis
  • Hypocapnia leads to cerebral vasoconstriction, reducing oxygen delivery and causing dizziness, lightheadedness, and paresthesias
  • May involve increased sensitivity to CO2 or heightened fear network activation (amygdala, prefrontal cortex)
  • Pathologic or physiologic causes of hyperventilation must be excluded before the diagnosis of HVS can be assigned
  • Prevalence:
    • 10–15% in the general population
    • May be more common in women
    • High incidence after COVID-19 infection
    • 25–83% in patients with an anxiety disorder meet the criteria for HVS

Etiology

  • Usually a response to psychological stressors
  • Etiology of symptoms is unclear
  • Underlying disorders that may contribute to hyperventilation:
    • Hypocapnia
    • Hypophosphatemia
    • Hypocalcemia
    • Vestibular dysfunction
    • Vocal cord abnormalities
    • Post-COVID syndrome

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