HYPERVENTILATION AND THE CRISIS OF TETANY
Hyperventilation occurs when the organism stores more oxygen than it spends. At that moment, the ratio between oxygen and carbon dioxide is not what the organism expects. At a weak level, this imbalance can activate an agreeable euphoric state. When it becomes stronger, it leads to a crisis of hyperventilation. During such a crisis, people complain of rapid and superficial respiration, an oppressive thoracic sensation, and suffocation.33 Some people experience a muscular tetany, with a sharp flexion of the wrist and ankle joints. Such a crisis accelerates the pulse and abruptly lowers arterial pressure. It can provoke buzzing and hissing in the ears and cramps (typically in the hands).
Tetany is probably due to some modifications in the dynamics of the acids in the blood and the muscles.
One reason some therapists propose exercises that lead to hyperventilation is that it can sometimes provoke states of regression during which a person’s psychological defenses are weakened and unconscious content activated. When this happens, the patient becomes aware of past experiences that were repressed. Those regressions can be powerful and lead to an intense experience. In reliving such experiences, a person sometimes learns to no longer fear profound emotional experiences.
When an individual voluntarily hyperventilates for two to three minutes, we observe an automatic sequence (that cannot be controlled voluntarily) that William Francis Ganong calls periodic respiration.4 While holding her breath, the person experiences prolonged apnea. This moment can be experienced as an ecstasy by some, as panic by others, and as a mixture of both by the majority of people. When the person breathes spontaneously again, it is at first in a rapid and superficial fashion. One can then observe an oscillation between a phase of rapid breathing and apnea repeating itself several times, for not more than ten minutes: