THE BREATHING PATTERN AFTER BREATH‐HOLDING: THE INFLUENCE OF CHEST POSITION AND THE DRIVE TO BREATHE

Abstract

The pattern of breathing following the breaking‐point of sixty breath‐holds has been studied in five healthy adults and compared with the pattern during recovery from CO2‐rebreathing. The volume and direction of the first respiratory movement, and the VT, V relation for the first four complete breaths was measured. Only when breath‐holds were terminated with an inspiration was the accumulated drive to breathe reflected in an increased volume of the first respiratory movement: terminating expirations simply returned the chest to the resting respiratory level. The volume of the first inspiration was not influenced by the intervention of a terminating expiration, suggesting that expiratory movements do not dissipate the non‐chemical component of the drive to breathe. In three of the five subjects the tidal volumes for given levels of ventilation were greater following breath‐holding than following rebreathing. This altered pattern of breathing has been interpreted in terms of an insiratory‐augmenting reflex. © 1978 The Physiological Society