Hyperventilation syndrome is dyspnea and tachypnea often accompanied by systemic symptoms without an organic cause but may often be related to anxiety. It can be acute or chronic. There are no widely accepted diagnostic criteria, and other disorders must be excluded. Treatment is supportive.
Hyperventilation syndrome is a functional breathing disorder, often associated with anxiety, characterized by alveolar ventilation in excess of metabolic needs, leading to episodic or sustained hypocapnia and respiratory alkalosis in the absence of an alternative organic cause. It most commonly occurs among young women but can affect either sex at any age (1). It is sometimes precipitated by emotionally stressful events. Hyperventilation syndrome is separate from panic disorder, although the conditions overlap; approximately 50% of patients with each disorder have evidence of the other disorder (2). Asthma also coexists in a large proportion of patients and may be misdiagnosed or atypical (3).
General references
1. Pfortmueller CA, Pauchard-Neuwerth SE, Leichtle AB, Fiedler GM, Exadaktylos AK, Lindner G: Primary Hyperventilation in the Emergency Department: A First Overview. PLoS One 10(6):e0129562, 2015. doi:10.1371/journal.pone.0129562
2. Cowley DS, Roy-Byrne PP: Hyperventilation and panic disorder. Am J Med 83(5):929-937, 1987. doi:10.1016/0002-9343(87)90654-1
3. Tiotiu A, Ioan I, Poussel M, Schweitzer C, Kafi SA: Comparative analysis between available challenge tests in the hyperventilation syndrome. Respir Med 179:106329, 2021. doi:10.1016/j.rmed.2021.106329
Symptoms and Signs of Hyperventilation Syndrome
Patients with hyperventilation syndrome present with dyspnea sometimes so severe that they may liken it to suffocation. It can be accompanied by agitation and a sense of terror or fear, chest pain, tremors, paresthesias (peripheral and perioral), peripheral tetany (eg, stiffness of fingers or arms), and presyncope (with dizziness) or syncope or sometimes by a combination of all of these findings. Tetany can occur because respiratory alkalosis can lead to 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 radiograph, 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 radiograph
ECG
Pulse oximetry in hyperventilation syndrome shows oxygen saturation at or close to 100%. Chest radiography is typically normal. ECG should be performed to detect cardiac ischemia, although hyperventilation syndrome itself can cause ST-segment depressions, T-wave inversions, and prolonged QT intervals. In outpatient settings, cardiopulmonary exercise testing may be performed (1). Hyperventilation provocation testing (wherein the patient is asked to voluntarily hyperventilate for a set period to induce hypocapnia and thereafter symptoms and physiologic responses are observed) may be superior to exercise testing (2). The Nijmegen Questionnaire is a tool that quantifies and assesses subjective symptoms consistent with hyperventilation, although an elevated score may not be diagnostic of a particular syndrome (3).
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.
Diagnosis references
1. Brat K, Stastna N, Merta Z, Olson LJ, Johnson BD, Cundrle I Jr: Cardiopulmonary exercise testing for identification of patients with hyperventilation syndrome. PLoS One 14(4):e0215997, 2019. doi:10.1371/journal.pone.0215997
2. Tiotiu A, Ioan I, Poussel M, Schweitzer C, Kafi SA: Comparative analysis between available challenge tests in the hyperventilation syndrome. Respir Med 179:106329, 2021. doi:10.1016/j.rmed.2021.106329
3. van Dixhoorn J, Folgering H. The Nijmegen Questionnaire and dysfunctional breathing. ERJ Open Res 1(1):00001-2015, 2015. doi:10.1183/23120541.00001-2015
Treatment of Hyperventilation Syndrome
Supportive counseling
Sometimes psychiatric or psychologic treatment
Treatment of acute hyperventilation is primarily education and reassurance (1). Due to the scarcity of robust clinical evidence, treatments in the acute setting are frequently empirical.
Some physicians advocate teaching the patient structured breathing techniques (embedded in cognitive behavioral therapy).to include maximal and slowed exhalation and diaphragmatic breathing.
Cognitive behavioral therapy may be needed because most patients with hyperventilation syndrome require treatment for underlying mood or anxiety disorders; appropriate treatment also includes stress reduction techniques, psychotherapy (eg, anxiolytics, antidepressants, lithium), or a combination of these modalities.Cognitive behavioral therapy may be needed because most patients with hyperventilation syndrome require treatment for underlying mood or anxiety disorders; appropriate treatment also includes stress reduction techniques, psychotherapy (eg, anxiolytics, antidepressants, lithium), or a combination of these modalities.
Treatment reference
1. Wheatley CE: Hyperventilation syndrome: a frequent cause of chest pain. Chest 68(2):195–199, 1975. doi:10.1378/chest.68.2.195
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