Respiratory and psychiatric abnormalities in chronic symptomatic hyperventilation.

Abstract

Many physicians believe that the hyperventilation syndrome is invariably associated with anxiety or undiagnosed organic disease such as asthma and pulmonary embolus, or both. Twenty one patients referred by specialist physicians with unexplained somatic symptoms and unequivocal chronic hypocapnia (resting end tidal Pco2. < 4 kPa (30 mm Hg) on repeated occasions during prolonged measurement) were investigated. All but one complained of inability to take a satisfying breath. Standard lung function test results and chest radiographs were normal in all patients, but histamine challenge showed bronchial hyper-reactivity in two of 20 patients tested, and skin tests to common allergens were positive in three of 18. Ventilation-perfusion scanning was abnormal in a further three of 15 patients studied, with unmatched perfusion defects in two and isolated ventilation defects in one. None of the 21 had thyrotoxicosis, severe coronary heart disease, or other relevant cardiovascular abnormalities. Ten of the 21 patients were neurotic and suffered from chronic psychiatric disturbance characterised by anxiety, panic, and phobic symptoms. The remainder had no detectable psychiatric disorders but reported proportionately more somatic than anxiety symptoms.Severe hyperventilation can occur in the absence of formal psychiatric or detectable respiratory or other organic abnormalities. Asthma and pulmonary embolus must be specifically excluded.

Voluntary Breath Holding in Panic and Generalized Anxiety Disorders

“…End-tidal pCO 2 was determined as the level at which pCO 2 stopped rising at the end of an expiration (final maximum). Expirations with a low percentage of alveolar air can be recognized by the CO 2 waveform not reaching a plateau [33], and these were excluded. We required plateaus to be present in 50% of breaths in a measuring epoch or it was discarded.…”

A Sense of Proportion: The Place of Psychiatry in Medicine

“…", chronic fatigueI 8 , hyperventilation 19 and facial pain?". Several intervention studies have demonstrated the value of pharmacolopical/"…”

Hyperventilation Disorders

“…In our laboratory, we use a value of 30 mmHg as the lower limit 9 • 1O , but this should ideally be standardized for each laboratory and can be profoundly affected by the total physiological inputs to respiration and the conscious state of the subject. In early papers in this field, measurement of Pc0 2 was tedious, difficult and rarely attempted.…”

“…Apart from renal compensation, there appear to be physiological mechanisms resetting the Pc0 2 to a lower level independent of chemoreceptor resetting 9 • 1O • Habit has been proposed as a perpetuating mechanism-", and undoubtedly some subjects deliberately take large breaths in an attempt to relieve chest discomfort. Misattribution of symptoms of hypocapnia or, for example, mild asthma to serious disease'P can also perpetuate hyperventilation.…”