Ventilation Standards for Use in Artificial Respiration

Abstract

For adequate ventila-tion to be provided during prolonged artificial respiration (e.g. poliomyelitis, anesthesia), both hypo- and hyperventilation must be avoided if possible. This paper discusses the derivation of human ventilation standards which can be compared to the patient''s measured ventilation as a guide to the adequacy of the ventilation being given. The standards are presented in the form of a nomo-gram, and are based on estimates of CO2 production and respiratory dead space, both of which may be estimated from the body weight. The CO2 production is derived from basal metabolism standards; a survey of available data on the relationships of dead space to body weight indicates that the dead space (BTPS) is approximately equal to the body weight in pounds. Corrections to the tidal volume derived from the nomogram are included to take account of changes in metabolism, PACO2 and dead space with fever, altitude, tracheotomy, the daytime rise of CO2 production, and other conditions. The limitations and approximate accuracy of the standards are discussed.