T. Philip Ayre and the T Piece

There are some names that are well known in pediatric anesthesia but who were these people? For 60 years before work stations appeared, the Ayre’s T Piece was widely used. Appropriately initialed, T.P. Ayre (Philip) (Figure 1) was a Newcastle anesthetist who gave several hundred anesthetics as a student, so it was natural that he should become an anesthetist. Ayre’s T Piece was developed about 1937. It allowed fresh gas to be delivered to an endotracheal tube, allowing the anesthetist to be distanced from the operative field. The original T Piece was derived from part of a Phillips airway, which Ayre had been using. It had a bend in the side arm within the lumen of the connecting tube so that the gas could be delivered flowing toward or away from the patient. Ayre soon realized that patients did better when the flow was directed toward the patient. He thought that this aided inspiration. More importantly, although he may not have understood the reason, it kept the airways open preventing alveolar collapse and a reduction in functional residual capacity (FRC). This was unwittingly the first step in the development of the use of positive end expiratory pressure (PEEP). However, when it came to manufacturing the T piece, the makers preferred the simplicity of a tube attached at right angles to the airway (Figure 2), and hence, the advantage was lost until an angled side arm was developed. T. Philip Ayre.image The golden Ayre’s T Piece presented to him on retirement.image