Body Position and Mode of Ventilation Influences Arterial pH, Oxygen, and Carbon Dioxide Tensions in Halothane-Anesthetized Horses

Abstract

SUMMARY Effects of body position and type of ventilation were determined on arterial blood gases (Pa O 2 , Pa CO 2 ) and pH during and immediately following clinical halo-thane anesthesia in 36 young, physically conditioned horses. Horses in dorsal recumbency had a lower Pa O 2 than did similarly breathing horses in a lateral position. Predictably controlled positive-pressure ventilation improved arterial oxygenation and permitted maintenance of a normal Pa CO 2 . Most horses, regardless of type of ventilation and operative body positioning, were hypoxemic in the immediate postanesthetic period.