Hyperventilation syndrome is anxiety-related dyspnea and tachypnea often accompanied by systemic symptoms. It can be acute or chronic. Diagnosis is by exclusion. Treatment is supportive.
Hyperventilation syndrome most commonly occurs among young women but can affect either sex at any age. It is sometimes precipitated by emotionally stressful events. Hyperventilation syndrome is separate from panic disorder, although the two conditions overlap; about half of patients with panic disorder have hyperventilation syndrome and one quarter to one half of patients with hyperventilation syndrome have panic disorder (1).
Reference
1. Cowley DS, Roy-Byrne PP. Hyperventilation and panic disorder. Am J Med 1987;83(5):929-937. doi:10.1016/0002-9343(87)90654-1
Symptoms and Signs of Hyperventilation Syndrome
Patients with hyperventilation syndrome present with dyspnea sometimes so severe that they liken it to suffocation. It can be accompanied by agitation and a sense of terror or by symptoms of chest pain, paresthesias (peripheral and perioral), peripheral tetany (eg, stiffness of fingers or arms), and presyncope or syncope or sometimes by a combination of all of these findings. Tetany occurs because respiratory alkalosis causes both hypophosphatemia and hypocalcemia. On examination, patients may appear anxious, tachypneic, or both; lung examination is unremarkable.
Diagnosis of Hyperventilation Syndrome
Testing to exclude other diagnoses (chest x-ray, ECG, pulse oximetry)
Hyperventilation syndrome is a diagnosis of exclusion; the challenge is to use tests and resources judiciously to distinguish this syndrome from more serious diagnoses.
Basic testing includes
Pulse oximetry
Chest x-ray
ECG
Pulse oximetry in hyperventilation syndrome shows oxygen saturation at or close to 100%. Chest x-ray is normal. ECG is done to detect cardiac ischemia, although hyperventilation syndrome itself can cause ST-segment depressions, T-wave inversions, and prolonged QT intervals.
Arterial blood gas (ABG) measurements are needed when other causes of hyperventilation are suspected, such as metabolic acidosis.
Occasionally, hyperventilation syndrome is indistinguishable from acute pulmonary embolism, and tests for pulmonary embolism (eg, D-dimer, ventilation/perfusion scanning, CT angiography) may be necessary.
Treatment of Hyperventilation Syndrome
Supportive counseling
Sometimes psychiatric or psychologic treatment
