Abstract
In an attempt to elucidate the true etiology of an abnormal increase in ventilation per minute (V_E) occurring in association with hyperventilation syndrome induced by psychological factors, a study was made of ventilatory response to carbon dioxide and airway occlusion pressure (P_<0.1>; a parameter reflecting respiratory center output) in 12 patients with hyperventilation syndrome. The second series of studies were made of the changes in the same values after adiministration of β-blocking agent, and after fasting therapy. Increments in V_E produced by a rise in end-tidal CO_2 pressure (P_<ETCO2>), i.e. ΔV_<E/BSA/ΔPETCO2> were larger in patients with hyperventilation syndrome than in 7 normal subjects. On the other hand, increments in P_<0.1> produced by an elevation of P_<ETCO2> (i.e. ΔP_<0.1>/ΔP_<ETCO2>) were significantly larger in patients with hyperventilation syndrome than in normal subjects. The response of V_E and P<0.1> to rising P<ETCO2> in hyperventilation syndrome was suppressed by the administration of a β-blocking agent. Similar response pattern of these parameters were observed after fasting therapy, a finding that is consistent with its clinical therapeutic effect.
