Apnea

APNEA (from Greek a- negative particle, and pnoe- breathing), absence of breathing, more precisely the absence of the need to perform breathing movements, i.e., to ventilate alveolar air (see), occurs in humans after forced breathing and is caused by a decrease in the tension of CO₂ in the alveolar air, and consequently in the blood, which weakens the stimulation of the respiratory center. A. is induced with varying ease in different subjects, and in some it cannot be induced at all. A. is interrupted due to the resulting lack of O. A. of newborns-physiological state of absence of breathing immediately after birth, resulting from some excess of O in the blood. It can last up to 10 minutes (in children delivered by cesarean section). A. of newborns should be distinguished from asphyxia in them, which is always a result of oxygen starvation and excess carbon dioxide. Lit.: Bayer C, Regulation d. Atmung (Bethe A. и. Bergmann в., Handb. d. norm. u. path. Physiol., B. II, p. 277, Berlin, 1925).